QUINTAIS IMORTAIS

https://www.unicamp.br/unicamp/index.php/ju/noticias/2018/05/02/pesquisadora-obtem-extrato-do-fruto-verde-do-cafe

Oregon State University. "Oilseed crop's waste product yields compounds that protect skin from the sun." ScienceDaily. ScienceDaily, 8 May 2018. <www.sciencedaily.com/releases/2018/05/180508102203.htm>.

Mistura de óleos essenciais revela ação anti-salmonela e antioxidante

https://www.unicamp.br/unicamp/index.php/ju/noticias/2018/04/18/mistura-de-oleos-essenciais-revela-acao-anti-salmonela-e-antioxidante

18.04.2018

Mix de plantas aromáticas é alternativa tanto nas dietas de animais como na elaboração de produtos à base de carne de frango

TEXTO CARMO GALLO NETTO FOTOS ANTONIO SCARPINETTI EDIÇÃO DE IMAGEM LUIS PAULO SILVA

Por ser um alimento altamente perecível, a carne de frango e os produtos dela derivados são comumente passíveis de contaminação por salmonela (cujo nome científico é Salmonella), além de facilmente suscetíveis à perda de qualidade devido ao processo de oxidação lipídica.

A utilização de antibióticos e antioxidantes sintéticos no enfrentamento desses problemas tem sido a prática comum na indústria de alimentação animal e humana. Entretanto, os rigores cada vez maiores das regulamentações internacionais e mesmo nacionais, que proíbem ou restringem a utilização de aditivos sintéticos na produção alimentícia, e a conscientização crescente dos consumidores, em decorrência das mudanças nos contextos socioeconômicos e culturais, têm aumentado progressivamente a demanda por produtos mais naturais e que tendem a oferecer menores riscos à saúde.

Estes fatos têm levado a indústria alimentícia à utilização de componentes alternativos aos sintéticos. Ressalte-se que, no Brasil, que se tornou há mais de dez anos o maior exportador de carne de frango e seu segundo produtor mundial, apenas superado pelos EUA, essa preocupação assume particular importância, principalmente depois de a Operação Carne Fraca ter colocado em questão a seriedade e a competência das grandes empresas exportadoras brasileiras.

Nesse contexto, as plantas aromáticas e seus óleos essenciais, que possuem pluralidades de atividades, constituem uma possibilidade de uso na ação antimicrobiana e antioxidante tanto nas dietas dos animais como na elaboração de produtos cárneos.

Adriana Nogueira Figueiredo (à esq.), autora do estudo, e Marta Cristina Teixeira Duarte, coordenadora da linha de pesquisa: encapsulamento de óleos essenciais em produtos cárneos rendeu patente

Em trabalho desenvolvido junto à linha de pesquisa mantida pela bióloga Marta Cristina Teixeira Duarte - pesquisadora do CPQBA-Unicamp e professora credenciada junto ao Programa de Pós-Graduação em Ciências de Alimentos da Faculdade de Ciências de Alimentos (FEA) da Universidade - que tem como foco a busca de novos antimicrobianos naturais a partir de plantas medicinais aromáticas, a zootecnista Adriana Nogueira Figueiredo utilizou uma mistura de dois óleos essenciais com o objetivo de obter um produto alternativo aos antibióticos e, portanto, com efeito anti-salmonela, e que também atuasse como antioxidante, propiciando ampliação do tempo de vida útil da carne, quando adicionado à alimentação de frangos.

Em vista das reconhecidas múltiplas funções dos óleos essenciais, a pesquisadora partiu da hipótese de que uma mistura de óleos essenciais provenientes das espécies aromáticas tomilho (Thymus vulgaris) e alfavacão (Ocimum gratissimum) poderiam exercer ação em frangos de corte tanto para o controle da salmonela (atividade antibacteriana) como da oxidação lipídica da carne (atividade antioxidante).

Diante dos bons resultados, a mesma composição de óleos essenciais foi também adicionada na elaboração de almôndegas, em substituição aos antioxidantes sintéticos, produzidas segundo processos industriais a partir das carnes moídas de peito e de sobrecoxa dos animais, cortes selecionados por se distinguirem na quantidade de gordura. A mistura dos óleos essenciais encapsulados nesses produtos cárneos revelou-se verdadeiramente eficaz e esse novo processamento foi patenteado mesmo antes da conclusão do doutorado da pesquisadora.

A professora Marta ressalta a importância do trabalho quando se sabe da tendência cada vez maior da substituição de produtos sintéticos antimicrobianos e antioxidantes por produtos naturais na indústria alimentícia. No caso dos antimicrobianos ela lembra o perigo crescente de resistência aos antibióticos pelo seu uso indiscriminado em vários segmentos, o que aponta na necessidade de desenvolvimento de antibióticos cada vez mais potentes.

Ação anti-salmonela

Para verificar a ação anti-salmonela da mistura dos óleos essenciais utilizados, Adriana inoculou em pintinhos, com três dias de vida, salmonelas resistentes coletadas de aves contaminadas. Esses animais foram então divididos em grupos e alimentados durante 21 dias com ração em que foi adicionada a mistura encapsulada dos óleos para facilitar a homogeneização e evitar perdas por volatilização. Cada um dos grupos recebeu ração com uma determinada concentração da blenda para comparação dos resultados inclusive com o grupo de controle, alimentado com ração padrão. Periodicamente animais desses grupos eram abatidos para que pudessem ser obtidas as respectivas curvas de variação das salmonelas através da coleta das excretas e do conteúdo do ceco das aves, parte final do intestino em que estas proliferam. Verificou-se que os óleos essenciais efetivamente diminuíram o crescimento das salmonelas durante o período experimental bem mais do que ocorria na situação de controle, chegando essa diminuição a ser mil vezes menor.

Ação antioxidante

Em vista de a literatura indicar que esses mesmos óleos essenciais também exercem efeito antioxidantes, as pesquisadoras resolveram testá-los no frango durante o seu crescimento e depois do abate até chegar ao consumidor, de modo a abranger toda a cadeia produtiva. Para tanto, à ração das aves foi adicionada a mesma mistura de óleos essenciais encapsulados, fornecida durante 35 dias até o abate. Nesse período mediu-se o efeito antioxidante em dois cortes de frangos: o peito e a sobrecoxa, ou seja, partes com menor e maior quantidade de gordura. Os resultados mostraram que os óleos essenciais retardaram a oxidação lipídica da carne e que seus efeitos foram mais efetivos na sobrecoxa, porção mais rica em lipídios. Os ensaios se estenderam até sete dias depois do abate, período em que a carne comercializada permanece na geladeira. Os resultados foram melhores quando comparados com a adição do antioxidante sintético à ração.

Patenteada ação no prato pronto

Restava testar ainda qual o efeito antioxidante da mesma mistura de óleos essenciais encapsulados, quando utilizada em substituição aos antioxidantes sintéticos, em almôndegas feitas com peito e sobrecoxa de frangos do grupo de controle, ou seja, de aves criadas com ração padrão, sem antioxidantes.

As almôndegas foram preparadas com carne moída de peito e sobrecoxa e temperadas, segundo processos industriais convencionais, e receberam a adição dos óleos encapsulados e foram então avaliados os efeitos protetores nessas almôndegas antes e depois do cozimento. A professora Marta considera os resultados de extrema importância: “A substituição do antioxidante sintético pelo natural é totalmente viável. A mistura encapsulada utilizada tem ação efetiva quando adicionada na alimentação do frango de corte, mas, principalmente na fabricação de produtos cárneos, o que nos levou a patentear o processo”. Embora tenham sido também produzidas almôndegas a partir dos mesmos cortes oriundos de frangos que já tinham recebido a blenda na ração, os efeitos mostraram-se muito superiores quando a mistura é adicionada diretamente à carne processada.

Apesar das ervas utilizadas para a extração dos óleos essenciais serem muito baratas, os processos de extração e encapsulamento os encarecem, e os custos ainda não os fazem competitivos com os antioxidantes sintéticos. “Mas o apelo de produto natural, uma exigência cada vez maior em decorrência do aumento da consciência do consumidor, obriga a indústria alimentícia à oferta de produtos livres de aditivos sintéticos, pressionada inclusive por regulamentações legais progressivamente mais rigorosas e lideradas por países centrais”, afirma Adriana.

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Pesquisadora obtém extrato do fruto verde do café

02.05.2018

Compostos têm potencial para aplicação pelas indústrias alimentícia, farmacêutica e de cosméticos

TEXTO MANUEL ALVES FILHO FOTOS ANTONIO SCARPINETTI EDIÇÃO DE IMAGEM LUIS PAULO SILVA

Quando utilizado para a produção de bebida, o desejável é que o grão do café esteja maduro, no estágio denominado pelo mercado de “cereja”. É quando o produto reúne os melhores atributos para ser secado, torrado e transformado num líquido saboroso, aromático e revigorante. Ocorre que o grão verde também apresenta propriedades muito interessantes, como acaba de constatar tese de doutorado desenvolvida pela cientista de alimentos Wanessa Costa Silva Faria, defendida na Faculdade de Engenharia de Alimentos (FEA) da Unicamp, sob a orientação da professora Neura Bragagnolo e coorientação de Edemilson Cardoso da Conceição, docente da Universidade Federal de Goiás (UFG). A pesquisa desenvolveu processos para a obtenção e microencapsulação do extrato do fruto verde, com potencial para aplicação pelas indústrias alimentícia, farmacêutica e de cosméticos. O trabalho gerou pedido de registro de patente que engloba as duas metodologias.

De acordo com Wanessa, comparado ao grão maduro, o fruto verde do café apresenta maiores teores de ácidos clorogênicos e cafeína, dois compostos bioativos que proporcionam variados benefícios à saúde humana. A literatura científica aponta que essas substâncias apresentam propriedades antioxidantes, anti-inflamatórias, antibacterianas, anticarcinogênicas e neuroprotetivas. No estudo, Wanessa utilizou duas variedades de café (arábica e canéfora), ambas cedidas pela Empresa de Pesquisa Agropecuária de Minas Gerais (Epamig), unidade de Viçosa.

Wanessa Faria, autora da tese: fruto verde do café apresenta maiores teores de ácidos clorogênicos e cafeína, compostos bioativos com propriedades antioxidantes, anti-inflamatórias, antibacterianas, anticarcinogênicas e neuroprotetivas

No laboratório da FEA, foram realizados estudos de extração, otimização do processo extrativo e caracterização dos frutos. Já o processo de microencapsulação foi feito na UFG. As análises sobre a eficácia antioxidante do extrato e o seu grau de segurança (toxicidade) foram executadas, respectivamente, no Instituto Federal de Mato Grosso (IFMT) e Universidade Federal de Mato Grosso (UFMT). “Foram parcerias importantes, uma vez que a pesquisa teve um forte caráter multidisciplinar. Aqui na FEA, por exemplo, nós não teríamos condições de fazer os estudos in vivo”, justifica a professora Neura.

A autora da tese explica que a investigação em torno da atividade antioxidante envolveu o uso do extrato livre e também microencapsulado das duas variedades de cafés em óleo de girassol. Essa matriz alimentícia foi escolhida porque é rica em ácidos graxos insaturados. “Fizemos um estudo de estabilidade acelerada por 45 dias. Durante esse período, analisamos a formação de compostos primários e secundários da oxidação lipídica. Nós constatamos que tanto o extrato livre quanto o microencapsulado foram tão eficientes quanto o antioxidante sintético utilizado hoje em dia. Ou seja, ambos poderiam ser utilizados como aditivos em alimentos que contêm gordura, de modo a inibir a oxidação lipídica”, atesta Wanessa.

A professora Neura acrescenta que, nesse caso, o extrato microencapsulado demonstrou um desempenho superior ao livre. A explicação provavelmente está no fato de as microcápsulas liberarem gradualmente os compostos, ampliando assim o tempo de preservação da matriz alimentícia contra o processo de oxidação. “Isso abre perspectiva não apenas de usar o extrato de café verde com esse objetivo, mas também em alimentos que, após ingeridos, vão combater o envelhecimento das células do organismo humano”, assinala a docente.

O estudo que avaliou a segurança dos biocompostos foram precedidos de uma simulação computacional, que orientou posteriormente os ensaios em modelo animal. O ensaio de toxicidade aguda, esclarece Wanessa, foi feito com camundongos. Foram administradas seis dosagens – de 100 a 5 mil miligramas por quilo – nos animais. “Somente na dosagem de 5 mil miligramas de extrato livre foram registradas mortes (50%) dos animais, tanto machos quanto fêmeas. Vale ressaltar que, de acordo com o guia em que nos baseamos, seria impossível ao ser humano consumir essa quantidade”, explica.

A professora Neura Bragagnolo, orientadora do trabalho: “Nosso objetivo é licenciar essas metodologias, de modo a oferecer novas alternativas ao setor produtivo, que, a partir delas, poderia desenvolver produtos que agregariam valor ao café e trariam benefícios à sociedade”

Entretanto, a mesma dose de 5 mil mg/kg do extrato microencapsulado não causou morte em nenhum dos animais, mostrando que o processo de microencapsulação retardou a absorção das substâncias responsáveis pela morte dos camundongos que receberam o extrato livre. A autora da tese também testou a toxicidade subaguda, mas somente com os compostos microencapsulados, também em modelo animal, durante 30 dias. Ratos receberam dosagem diária diretamente no estômago, sendo que nenhum deles apresentou qualquer alteração dos fatores hematológicos ou bioquímicos, nem em relação ao ganho de peso. “O comportamento foi igual ao do grupo controle, que recebeu apenas água”, relata a cientista de alimentos.

Tanto na visão da autora da tese quanto na da orientadora, os dois processos desenvolvidos ao longo da pesquisa poderiam ser transferidos sem grandes dificuldades para a indústria, caso alguma demonstre interesse. “Nosso objetivo é conseguir licenciar essas metodologias, de modo a oferecer novas alternativas ao setor produtivo, que, a partir delas, poderia desenvolver produtos que agregariam valor ao café e trariam benefícios à sociedade”, entende a professora Neura.

De acordo com Wanessa, uma das vantagens do método de extração desenvolvido por ela foi a dispensa de solventes tóxicos. “Eu utilizei somente água e etanol. O processo se mostrou econômico e proporcionou um bom rendimento em comparação com os métodos convencionais”, afirma a pesquisadora, que contou com bolsa de estudo concedida pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes).

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Agroecology: A better alternative in Sub-Saharan Africa

Date: May 4, 2018 Source: Lund University Summary: Agroecology is a better alternative than large-scale agriculture, both for the climate and for small farmers in Sub-Saharan Africa, according to researcher. This agricultural model preserves biodiversity and safeguards food supply while avoiding soil depletion.

Agroecology is a better alternative than large-scale agriculture, both for the climate and for small farmers in Sub-Saharan Africa, according to researcher Ellinor Isgren from Lund University in Sweden. This agricultural model preserves biodiversity and safeguards food supply while avoiding soil depletion.

"We must consider other, alternative models for developing agriculture, particularly in countries that have not already transitioned to large-scale rationalisation. Large parts of the world's soil have already been degraded by depletion and excessively resource-intensive agriculture", says Ellinor Isgren, a researcher at the Lund University Centre for Sustainability Studies.

She maintains that today's intensive, large-scale agriculture brings a major environmental impact in the form of soil depletion, high use of pesticides, high energy and water consumption and reduced biodiversity. Large areas are often cultivated with one or only a few different crops, making this type of agriculture vulnerable to pests, diseases and climate change.

Large-scale agriculture also requires major investments in the form of machinery, grains and seed, while utilising little labour. This means that poorer farmers in many African countries are excluded from the advantages of intensive agriculture: technological development, increased food production, access to the agricultural market and general economic growth.

"A development that excludes a large number of small-holders creates income differences and a divided society. From a social and fairness perspective, transition to large-scale agriculture is not a positive technological conversion for the whole of society", she says.

In her doctoral thesis, focusing on Uganda, Ellinor Isgren proposes agroecology as a possible alternative for small farmers in Sub-Saharan Africa. The model is based on each farm being an integrated ecosystem, in which crops, plants and animals interact to create favourable conditions for cultivation. This alternative is knowledge-intensive, requiring farmers to have a lot of knowledge about the functioning of various components in the ecological system, as well as an ability to create synergies between plants, insects, crops and soil fertility. The model also rests on traditional farming methods.

"If farmers use the model correctly, they can increase their yields and ensure their food supply while preserving biodiversity and reducing their impact on the climate and soil depletion. They also become less vulnerable to climate change as they grow many different crops and improve the soil structure", she says.

Further benefits are that the system does not require major resources in the form of machinery, pesticides and fertiliser, as the cultivation model is mainly organic, so even poor small-holders can farm in this way.

There are also good conditions for scaling up the model for sale to domestic and international markets. This would require more research and better collaboration between various agricultural institutions to develop knowledge of how different ecosystems function together and how local conditions affect the fertility of plants and crops. Initiatives are also needed to train farmers in how to apply an agroecological model.

"There is currently no political will in Uganda to push development of the agricultural sector. This has left the market open to private investors and strong financial interests in the form of seed and pesticide companies", she says.

At the same time, there is growing interest in alternative models of agriculture in the civil sector, and she believes that a change could occur through that channel.

"Agroecology is a real alternative to conventional agricultural production, and a model that safeguards both the climate and social development. However, it requires civil society to push for change from the bottom up in Uganda, and for markets worldwide to transition to supporting alternative ways of farming the land", she concludes.

Story Source:

Materials provided by Lund University. Note: Content may be edited for style and length.

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Lund University. "Agroecology: A better alternative in Sub-Saharan Africa." ScienceDaily. ScienceDaily, 4 May 2018. <www.sciencedaily.com/releases/2018/05/180504103753.htm>.

Walnuts impact gut microbiome and improve health

Date: May 3, 2018 Source: University of Illinois College of Agricultural, Consumer and Environmental Sciences Summary: Diets rich in nuts, such as walnuts, have been shown to play a role in heart health and in reducing colorectal cancer. According to a new study, the way walnuts impact the gut microbiome -- the collection of trillions of microbes or bacteria in the gastrointestinal tract -- may be behind some of those health benefits.

Diets rich in nuts, such as walnuts, have been shown to play a role in heart health and in reducing colorectal cancer. According to a new study from the University of Illinois, the way walnuts impact the gut microbiome -- the collection of trillions of microbes or bacteria in the gastrointestinal tract -- may be behind some of those health benefits.

Walnuts are just one in a line foods that contain dietary fiber and have interested scientists for their impact on the microbiome and health. Dietary fiber acts as a food source for gut microbiota, helping the bacteria to do their jobs -- breaking down complex foods, providing us nutrients, or helping us feel full, for example.

Fruits, vegetables, whole grains, nuts, and legumes are important plant sources of dietary fiber. Eating a variety of these foods helps promote a diverse gut microbiota, which in turn helps to support health.

Findings from the study, published in The Journal of Nutrition, show that consuming walnuts not only impacted the gut microbiota and microbial derived secondary bile acids, but also reduced LDL-cholesterol levels in the adults participating in the study; good news for cardio, metabolic, and gastrointestinal health.

"We found that when you consume walnuts it increases microbes that produce butyrate, a beneficial metabolite for colonic health. So the interaction of walnuts with the microbiome is helping to produce some of those health effects," says Hannah Holscher, assistant professor of food science and human nutrition at U of I, and lead author of the study. "It is about getting to the 'black box' that is all the microbes in our GI tract to see how they are interfacing with the food we eat and having downstream health effects.

"Some of those health effects are hypothesized to be related to the metabolites bacteria produce," she adds.

For the controlled-feeding study, 18 healthy male and female adults consumed diets that either included 0 grams of walnuts or 42 grams -- about a third cup or a palm-full of walnuts -- for two, three-week periods. Fecal and blood samples were collected at the beginning and end of each period to assess secondary outcomes of the study, including effects of walnut consumption on fecal microbiota and bile acids and metabolic markers of health.

Walnut consumption resulted in higher relative abundance of three bacteria of interest: Faecalibacterium, Roseburia, and Clostridium.

"The microbes that increased in relative abundance in this walnut study are from one of the Clostridium clusters of microbes, and there's increased interest in those because they have the ability to make butyrate," Holscher says. "Unfortunately in this study we didn't measure butyrate, so we can't say that just because these microbes increased that butyrate did increase. We still need to answer that question.

"There is a lot of interest in Faecalibacterium because it has also been shown in animals to reduce inflammation. Animals with higher amounts also have better insulin sensitivity. There is also growing interest in Faecalibacterium as a potential probiotic bacteria, and so we are trying to follow up on foods that help support Faecalibacterium."

The findings also show, with walnut consumption, a reduction in secondary bile acids compared to the control. "Secondary bile acids have been shown to be higher in individuals with higher rates of colorectal cancer," Holscher explains. "Secondary bile acids can be damaging to cells within the GI tract, and microbes make those secondary bile acids. If we can reduce secondary bile acids in the gut, it may also help with human health."

Previous research that prompted this microbial research showed that the amount of energy (calories) derived from walnuts after we eat them is less than previously thought.

"When you do calculations to determine how much energy we predicted we would get from eating walnuts, it didn't line up with the energy that was absorbed," Holscher says. "You're really only absorbing around 80 percent of the energy from walnuts that labels say. That means that the microbes get access to that extra 20 percent of calories and the fats and fiber left in them, and so what happens then? Does it produce a positive health outcome, or a negative health outcome? Our study provides initial findings that suggest that the interactions of microbes with the undigested walnut components are producing positive outcomes.

"We need more research to look at additional microbial metabolites and how those are influencing health outcomes, instead of just characterizing the changes in the microbiome," Holscher says.

Story Source:

Materials provided by University of Illinois College of Agricultural, Consumer and Environmental Sciences. Note: Content may be edited for style and length.

Journal Reference:

Hannah D Holscher, Heather M Guetterman, Kelly S Swanson, Ruopeng An, Nirupa R Matthan, Alice H Lichtenstein, Janet A Novotny, David J Baer. Walnut Consumption Alters the Gastrointestinal Microbiota, Microbially Derived Secondary Bile Acids, and Health Markers in Healthy Adults: A Randomized Controlled Trial. The Journal of Nutrition, 2018; DOI: 10.1093/jn/nxy004

Cite This Page:

University of Illinois College of Agricultural, Consumer and Environmental Sciences. "Walnuts impact gut microbiome and improve health." ScienceDaily. ScienceDaily, 3 May 2018. <www.sciencedaily.com/releases/2018/05/180503175033.htm>.

Gut microbiome plays an important role in atherosclerosis

Date: May 2, 2018 Source: University of Western Ontario Summary: Researchers have shown a novel relationship between the intestinal microbiome and atherosclerosis, one of the major causes of heart attack and stroke. This was measured as the burden of plaque in the carotid arteries.

Researchers at Western University and Lawson Health Research Institute have shown a novel relationship between the intestinal microbiome and atherosclerosis, one of the major causes of heart attack and stroke. This was measured as the burden of plaque in the carotid arteries.

In order to understand the role that bacteria in the gut may play in atherosclerosis, the researchers examined blood levels of metabolic products of the intestinal microbiome. They studied a total of 316 people from three distinct groups of patients -- those with about as much plaque as predicted by traditional risk factors, those who seem to be protected from atherosclerosis because they have high levels of traditional risk factors but normal arteries, and those with unexplained atherosclerosis who don't have any traditional risk factors but still have high levels of plaque burden.

"What we found was that patients with unexplained atherosclerosis had significantly higher blood levels of these toxic metabolites that are produced by the intestinal bacteria," said Dr. David Spence, professor at Western's Schulich School of Medicine & Dentistry and scientist at Robarts Research Institute. The researchers looked specifically at the metabolites TMAO, p-cresyl sulfate, p-cresyl glucuronide, and phenylacetylglutamine, and measured the build-up of plaque in the arteries using carotid ultrasound.

The study, published in the journal Atherosclerosis, noted that these differences could not be explained by diet or kidney function, pointing to a difference in the make-up of their intestinal bacteria.

"There is growing consensus in the microbiome field that function trumps taxonomy. In other words, bacterial communities are not defined so much by who is there, as by what they are doing and what products they are making," said Greg Gloor, PhD, professor at Schulich Medicine & Dentistry, scientist at Lawson and a co-author on the study.

The study indicates that the gut microbiome plays an important role in an individual's risk for atherosclerosis, opening the door for new treatment options for those patients with unexplained plaque build-up in the arteries.

"The finding, and studies we have performed since, present us with an opportunity to use probiotics to counter these compounds in the gut and reduce the risk of cardiovascular disease," said Gregor Reid, PhD, professor at Schulich Medicine & Dentistry, scientist at Lawson, and an expert in probiotics who contributed to the study. Spence adds that repopulation of the intestinal microbiome is another novel approach to treatment of atherosclerosis that arises from this study.

Story Source:

Materials provided by University of Western Ontario. Note: Content may be edited for style and length.

Journal Reference:

Chrysi Bogiatzi, Gregory Gloor, Emma Allen-Vercoe, Gregor Reid, Ruth G. Wong, Bradley L. Urquhart, Vincent Dinculescu, Kelsey N. Ruetz, Thomas J. Velenosi, Michael Pignanelli, J. David Spence. Metabolic products of the intestinal microbiome and extremes of atherosclerosis. Atherosclerosis, 2018; 273: 91 DOI: 10.1016/j.atherosclerosis.2018.04.015

Cite This Page:

University of Western Ontario. "Gut microbiome plays an important role in atherosclerosis." ScienceDaily. ScienceDaily, 2 May 2018. <www.sciencedaily.com/releases/2018/05/180502115949.htm>.

Substance in Chinese medicine can cause cardiac arrhythmia

Date: May 2, 2018 Source: University of Basel Summary: A medicinal plant frequently used in Traditional Chinese Medicine (TCM) -- Evodia rutaecarpa -- contains substances that can cause cardiac arrhythmia.

Medicinal plants are an essential part of Traditional Chinese Medicine. However, these plants have rarely been scientifically examined. They may contain highly active substances with side effects, such as Evodia.

Credit: University of Basel

A medicinal plant frequently used in Traditional Chinese Medicine (TCM) -- Evodia rutaecarpa -- contains substances that can cause cardiac arrhythmia. This is what researchers from the Universities of Basel, Vienna and Utrecht have recently found out.

Extracts of the plant Evodia rutaecarpa are used in Traditional Chinese Medicine for a variety of symptoms, such as headaches, nausea and vomiting as well as menstrual complaints and ulcers in the mouth area.

Researchers led by Professor Matthias Hamburger from the Department of Pharmaceutical Sciences at the University of Basel investigated the effect of Evodia extracts in collaboration with pharmacologists and toxicologists from the University of Vienna. The natural substances dehydroevodiamine (DHE) and hortiamine isolated from the plant in Basel proved to be very potent inhibitors of potassium channels in the heart muscle. If these channels are blocked, the excitation processes in the heart muscle change, which can trigger severe heart rhythm disturbances -- so-called Torsade de pointes (TdP) -- and ventricular fibrillation and lead to sudden cardiac death.

Effect confirmed in animal models

The development of severe TdP arrhythmias following the administration of DHE was confirmed by researchers at the University of Utrecht in ECG studies on dogs, a model that is also used to test drug safety in the industry.

Further investigations showed that the two natural substances cause oscillations in the heart muscle cells even in very low concentrations, which can cause cardiac arrhythmia. For instance, these substances can get into a tea made from Evodia fruits.

For drugs that may potentially trigger cardiac arrhythmias, it is typically required that a cardiac examination using ECG is carried out before medication. This is especially true for heart disease patients for their risk to be assessed. To date, no clinical studies have been conducted to investigate the incidence of cardiac arrhythmias after taking Evodia preparations.

Re-evaluate security

Studies at the University of Basel have also shown that the DHE content of Evodia fruits is considerable. Hamburger currently investigates the extent to which these substances find their way into tea preparations. "If DHE and hortiamine are detected, the safety of Evodia products has to be re-evaluated," says Hamburger. TCM medicinal plants and products reach the European market relatively uncontrolled, and they can also be purchased on the internet.

The authors of the study, therefore, call for increased vigilance regarding possible toxic effects of Evodia preparations. "The popularization of medicinal plants from other cultures entails risks. These plants can contain highly active substances with side effects, as in the case of Evodia. A closer examination of such risks is therefore indispensable to protect the population," says Hamburger.

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Materials provided by University of Basel. Note: Content may be edited for style and length.

Journal Reference:

Igor Baburin, Rosanne Varkevisser, Anja Schramm, Priyanka Saxena, Stanislav Beyl, Phillip Szkokan, Tobias Linder, Anna Stary-Weinzinger, Marcel A.G. van der Heyden, Marien Houtman, Hiroki Takanari, Malin Jonsson, Jet H.D. Beekman, Matthias Hamburger, Marc A. Vos, Steffen Hering. Dehydroevodiamine and hortiamine, alkaloids from the traditional Chinese herbal drug Evodia rutaecarpa , are I Kr blockers with proarrhythmic effects in vitro and in vivo. Pharmacological Research, 2018; 131: 150 DOI: 10.1016/j.phrs.2018.02.024

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University of Basel. "Substance in Chinese medicine can cause cardiac arrhythmia." ScienceDaily. ScienceDaily, 2 May 2018. <www.sciencedaily.com/releases/2018/05/180502104059.htm>.

Acupuncture possible treatment for dental anxiety

Date: May 1, 2018 Source: University of York Summary: Researchers have found evidence that acupuncture could help people who experience dental anxiety.

Researchers have found evidence that acupuncture could help people who experience dental anxiety.

Dental anxiety affects up to an estimated 30% of the adult population in countries world-wide. Patients can experience nausea, difficulty breathing and dizziness at the thought of going to the dentist, during an examination, and following treatment.

Reasons behind dental anxiety can be various, such as fear of pain, needles or anaesthetic side effects, as well as embarrassment or feeling a loss of control.

In a review of six trials with 800 patients, researchers used a points scale to measure anxiety and studies show that anxiety reduced by eight points when dental patients were given acupuncture as a treatment. This level of reduction is considered to be clinically relevant, which means that acupuncture could be a possibility for tackling dental anxiety.

Previous clinical trials have involved acupuncture for treatment on a range of conditions, including lower back pain, depression, and irritable bowel syndrome. There is, however, limited research detailing its impact on specific cases of anxiety.

More than 120 trials across England, China, Spain, Portugal and Germany were identified as having investigated the effects of acupuncture on patients with dental anxiety, and six trials were eligible for review, with two demonstrating high quality methods.

Professor of Acupuncture, Hugh MacPherson, at the University of York's Department of Health Sciences, said: "There is increasing scientific interest in the effectiveness of acupuncture either as a standalone treatment or as an accompanying treatment to more traditional medications.

"We have recently shown, for example, that acupuncture treatment can boost the effectiveness of standard medical care in chronic pain and depression.

"Chronic pain is often a symptom of a long-term condition, so to further our understanding of the various uses of acupuncture we wanted to see what it could achieve for conditions that occur suddenly, rapidly and as a reaction to particular experiences."

Studies that compared anxiety levels between patients that received acupuncture and those that did not, showed a significant difference in anxiety scores during dental treatment. A clinically relevant reduction in anxiety was found when acupuncture was compared with not receiving acupuncture.

No conclusions could be drawn, however, between patients that received acupuncture as an intervention and those that received placebo treatment, suggesting that larger scale controlled trials are needed to increase the robustness of the findings.

Professor MacPherson said: "These are interesting findings, but we need more trials that measure the impact of acupuncture on anxiety before going to the dentist, during treatment and after treatment.

"If acupuncture is to be integrated into dental practices, or for use in other cases of extreme anxiety, then there needs to be more high quality research that demonstrates that it can have a lasting impact on the patient. Early indications look positive, but there is still more work to be done."

The research is published in the European Journal of Integrative Medicine.

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Materials provided by University of York. Note: Content may be edited for style and length.

Journal Reference:

Fraser Kirkwood Allan, Emily Peckham, Jianping Liu, Kristina Charlotte Dietz, Tingting Zhang, Aline Arakaki, Hugh MacPherson. Acupuncture for anxiety in dental patients: Systematic review and meta-analysis. European Journal of Integrative Medicine, 2018; 20: 22 DOI: 10.1016/j.eujim.2018.03.008

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University of York. "Acupuncture possible treatment for dental anxiety." ScienceDaily. ScienceDaily, 1 May 2018. <www.sciencedaily.com/releases/2018/05/180501130805.htm>.

A rose is a rose is a rose: Mathematical model explains how two brains agree on smells

Researchers propose new and critical role for neurons in brain's smell center

Date: May 1, 2018 Source: The Zuckerman Institute at Columbia University Summary: Scientists have discovered why the brain's olfactory system is so remarkably consistent between individuals, even though the wiring of brain cells in this region differs greatly from person to person. To make sense of this apparent paradox, the researchers developed a computational model showing that two brains need not have previously sniffed the same exact set of odors in order to agree on a new set of scents.

In a new study, Columbia scientists have discovered why the brain's olfactory system is so remarkably consistent between individuals, even though the wiring of brain cells in this region differs greatly from person to person. To make sense of this apparent paradox, the researchers developed a computational model showing that two brains need not have previously sniffed the same exact set of odors in order to agree on a new set of scents. Instead, any two brains will know to associate new similar odors with each other (such as two different flowers) so long as both brains have experienced even the smallest overlap in odors during their lifetimes.

This work was published last week in Neuron.

"Many of the brain cells, or neurons, in our olfactory system are wired together seemingly at random, meaning that the neurons that activate when I smell a rose are different than yours. So why do we both agree with certainty what we're smelling?" said the paper's senior author Larry Abbott, PhD, a computational neuroscientist and principal investigator at Columbia's Mortimer B. Zuckerman Mind Brain Behavior Institute. "By creating this model, we could detect, for the first time, the patterns that underlie seemingly random activity, revealing a mathematical consistency to how our brains are identifying scents."

The journey an odor takes from the nose to the brain is labyrinthine. When an odor enters the nasal cavity, specialized proteins called olfactory receptors send information about that scent to a designated location in the brain called the olfactory bulb. In a series of pioneering studies in the 1990s, Richard Axel, MD, a codirector at Columbia's Zuckerman Institute and a co-author of the new Neuron paper, discovered the more than 1,000 genes that encode these olfactory receptors. This work, which was performed alongside his colleague Linda B. Buck, PhD, earned them both the 2004 Nobel Prize in Physiology or Medicine.

Today's paper focuses on how information leaves the olfactory bulb and is interpreted by a brain region called the piriform cortex. The piriform cortex is believed to be a crucial structure for processing odors. Because no two whiffs of an odor are identical, the brain must make associations between odors that are similar. This process, called generalization, is what helps the brain to interpret similar smells.

"Generalization is critical because it lets you take the memory of a previous scent -- such as coffee -- and connect it to the odor of coffee you're currently smelling, to guide you as you stumble to the kitchen in the morning," said Evan Schaffer, PhD, a postdoctoral researcher in the Axel lab and the paper's first author.

However, as scientists have investigated the concept of generalization, they have been puzzled by two paradoxes about the piriform cortex. First, the neural activity in the piriform cortex appeared random, with no apparent logic or organization, so researchers could not tie a particular pattern of neural activity to a class of scents.

And second, the piriform cortex itself seemed too big. "Scientists could deduce a need for only about 50,000 of the roughly one-million piriform cortex neurons in the human brain," said Dr. Schaffer. "Given how energetically expensive neurons are, this raised the question: Why are there so many neurons in this part of the brain?"

The researchers developed a mathematical model that offered a resolution to both paradoxes: Two brains could indeed agree on a class of scents (i.e. fragrant flowers versus smelly garbage) if the neural activity came from a large enough pool of neurons.

The idea is similar to crowdsourcing, whereby different people each analyze one part of a complex question. That analysis is then pooled together into a central hub.

"This is analogous to what is happening in the piriform cortex," said Dr. Schaffer. "The different patterns of neural activity generated by these one-million neurons, while incomplete on their own, when combined give a complete picture of what the brain is smelling."

By then testing this model on data gathered from the brains of fruit flies, the team further showed that this neural activity helps two brains to agree on common odors, even with limited common experience.

Scientists have long argued that two brains must share a common reference point, such as each having previously smelled a rose, in order to identify the same scent. But this model suggests that the reference point can be anything -- the memory of the scent of a rose can help two people agree on the smell of coffee.

"Even the tiniest bit of common experience seems to realign the brains, so that while my neural activity is different than yours, the association we each make between two related scents -- such as flowers -- is similar for both of us," said Dr. Schaffer.

This model, while lending insight into a long-held paradox of perception, highlights an underlying elegance to the olfactory system: despite containing different neurons, memories and experiences -- two brains can still come to an agreement.

"You and I don't need to have sniffed every type of odor in the world to come to an agreement about what we're smelling," said Dr. Schaffer. "As long we have a little bit of common experience, that's enough."

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Materials provided by The Zuckerman Institute at Columbia University. Note: Content may be edited for style and length.

Journal Reference:

Evan S. Schaffer, Dan D. Stettler, Daniel Kato, Gloria B. Choi, Richard Axel, L.F. Abbott. Odor Perception on the Two Sides of the Brain: Consistency Despite Randomness. Neuron, 2018; DOI: 10.1016/j.neuron.2018.04.004

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The Zuckerman Institute at Columbia University. "A rose is a rose is a rose: Mathematical model explains how two brains agree on smells: Researchers propose new and critical role for neurons in brain's smell center." ScienceDaily. ScienceDaily, 1 May 2018. <www.sciencedaily.com/releases/2018/05/180501130800.htm>.

Medical marijuana could reduce opioid use in older adults

Study shows up to 65 percent of older adults who use medical marijuana significantly reduced their chronic pain and dependence on opioid painkillers

Date: May 1, 2018 Source: Northwell Health Summary: A study shows up to 65 percent of older adults who use medical marijuana significantly reduced their chronic pain and dependence on opioid painkillers.

A questionnaire of older men and women suffering from chronic pain who were given medical marijuana found that the drug significantly reduced pain and their need for opioid painkillers, Northwell Health researchers report.

The results of the study, "Older Adults' Use of Medical Marijuana for Chronic Pain: A Multisite Community-Based Survey," are scheduled to be presented May 3, 2018 at the annual meeting of the American Geriatrics Society in Orlando, FL.

To gauge how effective medical marijuana was at managing chronic pain and reducing opioid use, researchers surveyed 138 medical marijuana users with an anonymous 20-question survey focusing on how often they used the marijuana, in what form they took it, how much it reduced pain and whether or not they were able to cut back their use of other painkillers.

When patients were asked if they were able to curb their use of other painkillers after starting medical marijuana, 18 percent reported decreasing their use "moderately," 20 percent "extremely" and 27 percent "completely." An overwhelming number of subjects (91 percent) would recommend medical marijuana to others.

Comments from patients tell the tale:

"My quality of life has increased considerably since starting medical marijuana," one patient said. "I was on opiates for 15 years, and 6 months on marijuana, and off both completely."

Another patient said: "It [medical marijuana] is extremely effective and has allowed me to function in my work and life again. It has not completely taken away the pain, but allows me to manage it."

"I was on Percocet and replaced it with medical marijuana. Thank you, thank you, thank you," said another.

These patients had been living with chronic pain from osteoarthritis, spinal stenosis, hips and knees that could not be replaced, and pain not relieved by steroid injections, said Diana Martins-Welch, MD, a co-author of the study and physician in the Division of Geriatric and Palliative Medicine, Department of Medicine at Northwell Health.

Based on these results, she believes that medical marijuana could be effective in curbing the opioid epidemic now ravaging the United States. "What I'm seeing in my practice, and what I'm hearing from other providers who are participating in medical marijuana programs, is that their patients are using less opioids," said Martins-Welch. "I've even gotten some patients completely off opioids."

As effective as medical marijuana can be, it's not widely available or prescribed, Martins-Welch said. Plus, people have to jump through many hoops just to get certified to receive it, she said.

Martins-Welch believes medical marijuana should be more widely available and easier to get. Medical marijuana is legal in only 30 states, she said. In addition, because marijuana is federally illegal, it's expensive and not covered by insurance, putting it beyond the reach of many patients who could benefit from it, she said.

Medical marijuana can cost on average $300 for a one-month supply, Martins-Welch said. "And it's a cash-only business."

"Even the process you have to go through to get certified is expensive," she said.

Martins-Welch and colleagues surveyed men and women between the ages 61 to 70 about their use of medical marijuana. Patients responded to 20 questions about their marijuana use. The researchers found that most patients, 45 percent, used vaporized oil, while 28 percent used pills and 17 percent used marijuana-laced oil. Twenty-one percent used marijuana once a day, 23 percent used it twice daily, and 39 percent used marijuana more than twice a day.

Using marijuana in these forms dramatically reduces its mind-altering effect, Martins-Welch said.

In most cases, a doctor recommended medical marijuana (46 percent) followed by a family member or friend (24 percent) or another health care provider (6 percent), while others did not specify who recommended it (24 percent).

When asked how pain levels changed before and one month after starting marijuana, most patients reported that average pain scores dropped from 9.0 on a scale of 0-10 to a more moderate pain threshold of 5.6.

However, older patients reported a reduction in the use of other painkillers less often than younger patients (64 percent versus 93 percent), the researchers found. Older patients also recommended medical marijuana less often than younger ones (86 percent versus 100 percent respectively).

When patients were quizzed about whether side effects of medications impacted their daily activities, the average score went from 6.9 before starting medical marijuana to 3.5 a month after using the drug.

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Materials provided by Northwell Health. Note: Content may be edited for style and length.

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Northwell Health. "Medical marijuana could reduce opioid use in older adults: Study shows up to 65 percent of older adults who use medical marijuana significantly reduced their chronic pain and dependence on opioid painkillers." ScienceDaily. ScienceDaily, 1 May 2018. <www.sciencedaily.com/releases/2018/05/180501085137.htm>.

Diet rich in fish and legumes may help delay natural menopause

But high dietary intake of refined carbs may help to hasten it, suggests research

Date: April 30, 2018 Source: BMJ Summary: A diet rich in fish and legumes may help to delay the natural menopause, while high dietary intake of refined carbs, such as pasta and rice, may instead help to hasten it, suggests the first UK study of its kind.

A diet rich in fish and legumes may help to delay the natural menopause, while high dietary intake of refined carbs, such as pasta and rice, may instead help to hasten it, suggests the first UK study of its kind, published online in the Journal of Epidemiology & Community Health.

Several genetic, behavioural, and environmental factors are thought to be involved in the timing of the menopause, and some studies have implicated diet.

To explore this further, the researchers drew on participants from the UK Women's Cohort Study, involving more than 35,000 women between the ages of 35 and 69 from England, Scotland, and Wales.

The women provided information on potentially influential factors such as weight history, physical activity levels, reproductive history, and use of hormone replacement therapy (HRT).

They also estimated the quantities of 217 foodstuffs they ate every day by completing a food frequency questionnaire. The food items were collated into groups according to their culinary uses.

Further information on when the women had gone through the menopause naturally was gathered 4 years later.

In all, some 14,000 women provided information at both time points, and the final analysis included the 914 who had gone through the menopause naturally after the age of 40 and before the age of 65.

The average age at menopause was 51, and certain foods seemed to be associated with its timing.

Each additional daily portion of refined carbs -- specifically pasta and rice -- was associated with reaching the menopause 1.5 years earlier, after taking account of potentially influential factors.

But each additional portion of oily fish and fresh legumes (eg peas, beans) was associated with a delay of more than 3 years. Higher intakes of vitamin B6 and zinc (per mg/day) were also associated with later menopause.

Similar results emerged when the analysis looked at particular groups. For example, eating meat was associated with menopause arriving almost a year later than a vegetarian diet.

Among those who weren't vegetarian, upping daily portions of savoury snacks was associated with the arrival of the menopause almost 2 years earlier, while higher intake of oily fish and fresh legumes was linked to later menopause of more than 3 and nearly 1.5 years, respectively.

Similarly, among mothers, higher intake of oily fish and fresh legumes was associated with later menopause, while additional daily portions of pasta, rice, and savoury snacks were associated with earlier menopause.

Among childless women, eating more grapes and poultry was significantly associated with later menopause.

Egg maturation and release are adversely affected by reactive oxygen species, so a high intake of legumes, which contain antioxidants, may counter this, preserving menstruation for longer, suggest the researchers, in a bid to explain the findings. And omega 3 fatty acids, which are abundant in oily fish, stimulate antioxidant capacity in the body.

On the other hand, refined carbs boost the risk of insulin resistance, which can interfere with sex hormone activity and boost oestrogen levels, both of which might increase the number of menstrual cycles and deplete egg supply faster, they say.

Vegetarians consume a lot of antioxidants too, but they are also likely to eat a lot more fibre and less animal fat than carnivores, both of which are associated with low oestrogen levels, which may also alter the timing of the menopause, suggest the researchers.

This is an observational study, and as such, can't prove causality. Food Frequency Questionnaires are subject to faulty recall, and the study sample was also more affluent and health conscious than average, all of which might have influenced the findings.

But women who go through the menopause early are at increased risk of osteoporosis and heart disease, while those who go through it late are at increased risk of breast, womb, and ovarian cancers, so timing matters, say the researchers.

And they conclude: "Our findings confirm that diet may be associated with the age at natural menopause. This may be relevant at a public health level since age at natural menopause may have implications on future health outcomes."

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Materials provided by BMJ. Note: Content may be edited for style and length.

Journal Reference:

Yashvee Dunneram, Darren Charles Greenwood, Victoria J Burley, Janet E Cade. Dietary intake and age at natural menopause: results from the UK Women’s Cohort Study. Journal of Epidemiology and Community Health, 2018; DOI: 10.1136/jech-2017-209887

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BMJ. "Diet rich in fish and legumes may help delay natural menopause: But high dietary intake of refined carbs may help to hasten it, suggests research." ScienceDaily. ScienceDaily, 30 April 2018. <www.sciencedaily.com/releases/2018/04/180430212400.htm>.

Vitamin B6 helps people recall their dreams

Date: April 27, 2018 Source: University of Adelaide Summary: New research has found that taking vitamin B6 could help people to recall their dreams.

New research from the University of Adelaide has found that taking vitamin B6 could help people to recall their dreams.

The study published online ahead of print in Perceptual and Motor Skills, included 100 participants from around Australia taking high-dose vitamin B6 supplements before going to bed for five consecutive days.

"Our results show that taking vitamin B6 improved people's ability to recall dreams compared to a placebo," says research author Dr Denholm Aspy, from the University's School of Psychology.

"Vitamin B6 did not affect the vividness, bizarreness or colour of their dreams, and did not affect other aspects of their sleep patterns.

"This is the first time that such a study into the effects of vitamin B6 and other B vitamins on dreams has been carried out on a large and diverse group of people," Dr Aspy says.

The randomised, double-blind, placebo-controlled study saw participants taking 240mg of vitamin B6 immediately before bed.

Prior to taking the supplements, many of the participants rarely remembered their dreams, but they reported improvements by the end of the study.

"It seems as time went on my dreams were clearer and clearer and easier to remember. I also did not lose fragments as the day went on," said one of the participants after completing the study.

According to another participant of the study, "My dreams were more real, I couldn't wait to go to bed and dream!"

Dr Aspy says: "The average person spends around six years of their lives dreaming. If we are able to become lucid and control our dreams, we can then use our dreaming time more productively.

"Lucid dreaming, where you know that you are dreaming while the dream is still happening, has many potential benefits. For example, it may be possible to use lucid dreaming for overcoming nightmares, treating phobias, creative problem solving, refining motor skills and even helping with rehabilitation from physical trauma.

"In order to have lucid dreams it is very important to first be able to recall dreams on a regular basis. This study suggests that vitamin B6 may be one way to help people have lucid dreams."

Vitamin B6 occurs naturally in various foods, including whole grain cereals, legumes, fruits (such as banana and avocado), vegetables (such as spinach and potato), milk, cheese, eggs, red meat, liver, and fish.

"Further research is needed to investigate whether the effects of vitamin B6 vary according to how much is obtained from the diet. If vitamin B6 is only effective for people with low dietary intake, its effects on dreaming may diminish with prolonged supplementation," says Dr Aspy.

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Materials provided by University of Adelaide. Note: Content may be edited for style and length.

Journal Reference:

Denholm J. Aspy, Natasha A. Madden, Paul Delfabbro. Effects of Vitamin B6 (Pyridoxine) and a B Complex Preparation on Dreaming and Sleep. Perceptual and Motor Skills, 2018; 003151251877032 DOI: 10.1177/0031512518770326

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University of Adelaide. "Vitamin B6 helps people recall their dreams." ScienceDaily. ScienceDaily, 27 April 2018. <www.sciencedaily.com/releases/2018/04/180427100258.htm>.

The complicated biology of garlic

Date: April 26, 2018 Source: Cell Press Summary: Researchers generally agree that garlic, used for thousands of years to treat human disease, can reduce the risk of developing certain kinds of cancers, cardiovascular disease, and type 2 diabetes. Nevertheless, researchers in the UK argue that explaining how garlic affects human health -- and getting consistent results during clinical trials -- is more complex, because of the vast array of compounds garlic produces.

Researchers today generally agree that eating garlic, used for thousands of years to treat human disease, can reduce the risk of developing certain kinds of cancers, cardiovascular disease, and type 2 diabetes. Nevertheless, in a review published April 26 in the journal Trends in Pharmacological Sciences, researchers in the UK argue that explaining exactly how garlic affects human health -- and getting consistent results during clinical trials -- is more complex, because of the vast array of compounds garlic produces.

Garlic's unique flavor comes from sulfur compounds. Like other members of the allium family, the plant absorbs sulfate from the soil and incorporates it into amino acids and sulfur storage molecules. These sulfur storage molecules can then be broken down into approximately 50 different sulfur-containing compounds when the garlic is prepared and eaten. "These molecules give the plants an ecological advantage when they're growing out in the wild. As it happens, they're also biologically active within mammalian cells and tissues," says senior author Peter Rose, a biochemist at the University of Nottingham.

These compounds are well studied in garlic, and there is research to suggest that they are important in producing the health effects for which garlic is renowned. Understanding how they produce those effects is less clear, however, in part because how we prepare garlic affects which sulfur compounds we end up consuming. Chopping fresh garlic, fermenting garlic in alcohol, and pressing garlic for oil, for example, all yield different sulfur compounds. "Each of these preparative forms could have a different effect within mammalian systems. And that's what makes this research so complex, because we don't really understand how these compounds are metabolized in humans and it's very difficult to identify common mechanisms of action for these molecules," he says.

While there's no right or wrong way to prepare your garlic, this quirk of garlic's biochemistry could explain why studies of the plant's effects on humans have had such mixed results. "When it comes to human intervention studies, there's been quite a lot of disparity. Sometimes the consumption of and exposure to these compounds has biological effects, and other times, it does nothing. I think it needs reinvestigating, just because of the sheer complexity of the diversity of these sorts of compounds and the different distribution of them between different garlic products," he says.

Rose and his colleagues are particularly interested in how these sulfur compounds might affect gaseous signaling molecules like nitric oxide and hydrogen sulfide, which are naturally produced by our bodies. Gaseous signaling molecules play an important role in cell communication and maintaining homeostasis, and altered levels of them are present in many diseases. Recent research in vitro has linked the kinds of sulfur compounds we get from garlic to increased production of these molecules, suggesting that this might be the common mechanism by which the different sulfur compounds affect the human body.

There's still a lot of research to be done, but Rose believes that someday we might be able to identify other plants that stimulate the production of these gases or modify garlic, onions, and other alliums to be more efficient at producing them once ingested. "There is a lot of possibility within this area for finding approaches that could reduce the risk of diseases and improve human health, but it all comes back to those fundamental questions of what actually happens to these compounds when we metabolize them. There's a whole spectrum of human work that still needs to be done to further explore some of these weird and wonderful sulfur compounds that we find within our diets," he says.

He also believes that it's important to remember that garlic isn't some kind of magic bullet. "I don't think there is one individual plant species that is a cure-all, but there are certainly plant species that are strongly associated with reducing disease risk within humans. Variety is the spice of life, but understanding the chemistry of some of your spices is probably a very advantageous thing to do."

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Materials provided by Cell Press. Note: Content may be edited for style and length.

Journal Reference:

Peter Rose, Philip Keith Moore, Yi-Zhun Zhu. Garlic and Gaseous Mediators. Trends in Pharmacological Sciences, 2018; DOI: 10.1016/j.tips.2018.03.009

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