sábado, 18 de fevereiro de 2017

Árvores medicinais em São Paulo - guaçatonga

Texto:
Jessica Tiyoko Yamashita - acadêmica de agronomia - Faculdade Cantareira
Marcos Roberto Furlan - Engenheiro Agrônomo - Professor UNITAU e Faculdade Cantareira

Planta nativa de ocorrência em todo o território nacional, a guaçatonga (ou guaçatunga) é referenciada como uma planta importante na medicina tradicional, principalmente pelo uso como cicatrizante. Diz a lenda que lagartos com ferimentos ficam sob a copa da planta para tentar usar as suas folhas como medicamento, daí um outro nome popular, erva-de-lagarto. Algumas tribos indígenas possuem um nome específico, como a tribo Xucuru, de Pernambuco, que utilizam o nome caiubim.

Pertence à família Salicaceae. Seu nome científico é Casearia sylvestris. A denominação guaçatunga, em Tupi guarani, significa “madeira ou cerne com riscos pretos”. Há ainda outros nomes populares, como, por exemplo, cafezeiro-do-mato, cavalinha e varre-forno.

Apesar de também ser denominada de chá-de-bugre, uma outra espécie, a Casearia decandra é mais associada à essa denominação.

Uma de suas características para garantir sua identificação é presença de glândulas nas olhas que brilham quando colocamos a folha entre nossos olhos e o sol.

Quanto aos usos medicinais, a guaçatonga, que apresenta ações farmacológicas, como, por exemplo, antidiarreica, antirreumática, diurética, anti-inflamatória, antipirética e antiofídica (IMATOMI et al., 2009). Também é uma espécie de interesse do Sistema Único de Saúde (SUS) em função do uso contra gastrite e como cicatrizante.

Algumas pesquisas que foram publicadas nos últimos anos:

2015
Eficaz na prevenção da úlcera gástrica
Estudo do extrato fluido de Casearia sylvestris: constituintes químicos, potencial terapêutico e interações medicamentosas

2016
Atividade antimicrobiana contra microorganismos orais.
Antimicrobial potential of Casearia sylvestris against oral bacteria. http://www.scielo.br/pdf/rounesp/v45n4/1807-2577-rounesp-1807-257711015.pdf

Demonstra potencial contra câncer
Preclinical anticancer effectiveness of a fraction from Casearia sylvestris and its component Casearin X : in vivo and ex vivo methods and microscopy examinations

Referência

IMATOMI M., PEREZ, S. C. J. G. A., FERREIRA, A. G. Caracterização e comportamento germinativo de sementes de Casearia sylvestris Swartz (SALICACEAE). Rev. Bras. Sementes v. 31, n.2, 2009. Disponível em: http://www.scielo.br/pdf/rbs/v31n2/v31n2a04.pdf. Acesso em: 14 de fev 2017.
Fotos
Autoria: Jessica Tiyoko Yamashita

Oferecido pela Capes, portal reúne publicações internacionais dos últimos 400 anos

Plataforma digital reúne publicações internacionais dos últimos 400 anos

Oferecido pela Capes, portal tem arquivos com mais de 10 milhões de páginas digitalizadas de publicações periódicas, como The Economist e Financial Times

Por Portal Brasil
A Gale NewsVault, plataforma oferecida pelo Portal de Periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes), reúne dados históricos que contemplam os últimos 400 anos de informações publicadas em grandes veículos de comunicação internacionais. O acesso é gratuito.

A plataforma reúne arquivos com mais de 10 milhões de páginas digitalizadas de publicações periódicas, como The Economist, Financial Times, Liberty Magazine, Listener, Picture Post, Sunday Times e Times.

Na base da dados é possível fazer pesquisa cruzada de dados, procurar jornais publicados em determinada data, visualizar publicações em tela cheia, salvar, marcar e imprimir resultados, entre outras funcionalidades.

Mais informações sobre as coleções da Gale NewsVault na página da Capes na internet. Os arquivos da da editora Gale Cengage Learning estão acessíveis on-line no Portal de Periódicos.


in EcoDebate, 27/01/2017

Agricultores familiares produzem mais de 70% dos alimentos, diz estudo

IHU

Pesquisadores da UFPB e da USP revisam dados do Censo Agropecuário 2006 e dizem que estimativa do IBGE subestimou papel dos pequenos.

Os camponeses têm pouca terra, mas colocam bem mais que 70% dos alimentos na nossa mesa, defendem os autores do artigo “Quem produz comida para os brasileiros? 10 anos do Censo Agropecuário 2006”

A reportagem é de Inês Castilho, publicada por De Olho nos Ruralistas, 05-02-2017.

O Censo Agropecuário 2006 dizia que os agricultores familiares eram responsáveis pelo cultivo de 70% dos alimentos que chegam à nossa mesa. Foi o último censo realizado no país, e uma das principais referências sobre o campo. Dez anos depois, pesquisadores relançam a pergunta: “Quem produz os alimentos que compõem a cesta básica nacional?”

Para Marco Antonio Mitidiero Junior, Humberto Junior Neves Barbosa (ambos da Universidade Federal da Paraíba) e Thiago Hérick de Sá (da Universidade de São Paulo), a participação do campesinato é bem maior do que isso.

Para ver onde se concentram o volume e o valor dessa produção, eles trabalharam os dados do Censo 2006 a partir de outra metodologia. Eles dizem que as que foram usadas pelo IBGE para analisar os dados apurados pelo Censo “visaram esconder e deturpar o papel preponderante da pequena produção”.
Arroz, feijão e mistura

Os dados revelam que alimentos presentes no dia a dia à mesa dos brasileiros, em todo o país, são produzidos nos pequenos estabelecimentos rurais (área de 0 a 200 hectares). Várias espécies de feijão são cultivadas principalmente pelos pequenos: 88,1% do feijão-preto e 88,9% do feijão-fradinho, por exemplo.

O arroz em casca tem grande participação dos grandes – aqueles com propriedades acima de 1.000 hectares -, com 30% do total. Mas ainda assim a superioridade é dos pequenos: 42,3%. Os médios (200 a 1000 ha) produzem 27%.

Mais marcante é a supremacia da pequena produção na horticultura. Para citar os que mais frequentam nossa mesa: 98,2% do alface, 98,4% do repolho, 96% da berinjela, 95% da abobrinha, 86,8% da cenoura, 81,7% do tomate (estaqueado), 96,4% da pimenta, 90,8% da mandioca, 57% do milho, 94,1% da cebola, 73,3% do tomate (rasteiro) e 55,4% da batata inglesa são cultivados nos pequenos estabelecimentos rurais.

Quanto à carne, os pequenos são responsáveis por 88,7% da produção de aves, 84,3% da produção de suínos e 39,0% da de bovinos. “Até na criação bovina, palco das megafazendas e dos famosos fazendeiros pecuaristas que marcam o imaginário social, os pequenos produtores, com área até 200 ha, superam produtivamente as grandes áreas”, ressaltam os pesquisadores.
Menos terra, menos recursos, mais emprego

“Os sujeitos que produzem mais alimentos são os que possuem menos terra (geralmente terras menos favorecidas do ponto de vista da fertilidade, acesso à água, localização geográfica, etc.) e são menos assistidos pelo Estado”, sustentam os autores.

“Aqueles que detêm a maior parte das terras não são os maiores produtores de comida, porém são os que recebem a maior fatia dos recursos para financiamento. Ao contrário, os que possuem a menor porção das terras são os que mais produzem, contudo recebem bem menos financiamentos para produção”.

Os dados do IBGE mostram o peso da concentração agrária do país: pequenos produtores, 90,2% do total das unidades de produção, ocupam 29,9% da área total da agricultura do país. Já os grandes, 0,9% das propriedades rurais, dominam 45% da área. Os médios são 4% dos estabelecimentos, em 25,1% da área.

“Apesar disso, a agricultura familiar é responsável por 74,4% (12,3 milhões de pessoas) da ocupação laboral no campo, dominando a geração de trabalho/emprego”, apontam os pesquisadores.
Financiamento para os grandes

Os pesquisadores informam que os pequenos correspondem a 92,5% (849.754) dos estabelecimentos que receberam financiamento, embora tenham recebido apenas 36,7% do valor disponibilizado.

Os médios correspondem a 3,7% (34.443) dos estabelecimentos que receberam financiamento. Mas receberam 18,9% dos recursos.

Os grandes abocanharam 44,1% dos recursos oferecidos, embora representem apenas 0,9% (8.444) dos estabelecimentos que receberam financiamento.

Cada estabelecimento pequeno que recebeu financiamento teve, em média, R$ 9.252 reais. Essa média aumenta mais de dez vezes no caso dos médios, que receberam R$ 117.138, e mais de cem vezes no caso dos grandes: R$ 1.117.433.

(EcoDebate, 08/02/2017) publicado pela IHU On-line, parceira editorial da revista eletrônica EcoDebate na socialização da informação.

Quais são os itens do dia a dia que, silenciosamente, provocam distúrbios hormonais

BBC Brasil

Eles provocam distúrbios hormonais, mas estão escondidos em cosméticos, embalagens de alimentos e até em brinquedos. Por isso é quase impossível escapar deles no dia a dia.

Existem cerca de 800 compostos químicos suspeitos de interferir no sistema hormonal, segundo a Organização Mundial de Saúde (OMS).

A maioria ainda está sendo submetida a mais estudos, mas a Comissão Europeia garante que pelo menos 66 destes compostos, como bisfenol A (BPA), dioxina, atrazina e vários ftalatos (BBP, DEHP, DOP e DBP), têm “clara evidência de perturbação da atividade endócrina”.

Esse alerta fez parte de uma proposta divulgada ano passado pela OMS com o objetivo de regular seu uso.

** Acesse a matéria na íntegra, no site da BBC Brasil, clicando aqui **

in EcoDebate, ISSN 2446-9394, 10/02/2017

Pesquisadores da UFSCar criam método simples para diagnosticar Alzheimer

ABr
Biomarcador para detecção de Alzheimer criado por cientistas da Universidade de São Carlos. Foto: Divulgacão Ufscar

Pesquisadores da Universidade Federal de São Carlos (UFSCar) desenvolveram um método simples, rápido e de baixo custo para detectar a doença de Alzheimer. Atualmente, os médicos contam apenas com técnicas pouco precisas para o diagnóstico, como tomografia, ressonância magnética e análise clínica dos sintomas.

O Alzheimer é a forma mais comum de demência em pessoas idosas, uma doença progressiva que não tem cura, que destrói a memória e outras funções mentais..A causa ainda é desconhecida, mas pode ter relação com a genética. “É muito difícil diferenciar o Alzheimer de outras demências. Normalmente, pessoas idosas tendem a ter mais demências e 60% delas são relacionadas ao Alzheimer”, disse o professor do Departamento de Química da UFSCar Ronaldo Censi Faria, um dos responsáveis pelo estudo.

Na pesquisa, os cientistas notaram que pacientes com Alzheimer apresentam alteração na proteína ADAM10, presente no sangue. Para comprovar a alteração, foram selecionados 24 voluntários com mais de 60 anos, divididos entre saudáveis, portadores de Alzheimer e de transtorno neurocognitivo leve (considerado o pré-Alzheimer). A etapa foi coordenada pela professora Márcia Regina Cominetti, do Departamento de Gerontologia.

A conclusão foi que a proteína apresentava alterações tanto nos pacientes portadores de Alzheimer, como nos de pré-Alzheimer. “Nesse universo pequeno de 24 indivíduos ficou bem notória a diferença nos valores da ADAM10. Isso mostra que [o método] tem uma boa precisão”, afirmou o professor.

O exame foi feito com o uso de biomarcadores, cujo custo material não passa de R$ 3, tornando possível identificar diferentes estágios da doença e até mesmo predisposição ao Alzheimer, segundo a pesquisa. Uma pequena quantidade de sangue é tratada com partículas magnéticas que são capturadas por um imã. A concentração é determinada com um dispositivo sensor descartável. O nível do biomarcador tende a aumentar dependendo do grau da doença.

Em termos de custo, essa tecnologia é vantajosa por ser mais acessível à população, uma vez que o valor cobrado pela tomografia computadorizada gira em torno de 400 a 800 reais. Outra vantagem do biomarcador é que, se descoberto de forma precoce, o tratamento do Alzheimer pode até retardar o avanço da doença. Os métodos atuais só detectam a doença em estágios mais avançados.

Segundo os pesquisadores, a patente do biomarcador já foi registrada, mas a previsão é que o produto leve de cinco a 10 anos para chegar ao mercado. A próxima etapa do estudo será a ampliação do número de voluntários para 200 a 300.

Por Fernanda Cruz, da Agência Brasil, in EcoDebate, ISSN 2446-9394, 15/02/2017

Gluten-free diet may increase risk of arsenic, mercury exposure

Date: February 13, 2017

Source: University of Illinois at Chicago

Summary:
People who eat a gluten-free diet may be at risk for increased exposure to arsenic and mercury -- toxic metals that can lead to cardiovascular disease, cancer and neurological effects, according to a report in the journal Epidemiology.
Gluten-free products often contain rice flour as a substitute for wheat. Rice is known to bioaccumulate certain toxic metals, including arsenic and mercury from fertilizers, soil, or water, but little is known about the health effects of diets high in rice content.
Credit: © Marek / Fotolia

People who eat a gluten-free diet may be at risk for increased exposure to arsenic and mercury -- toxic metals that can lead to cardiovascular disease, cancer and neurological effects, according to a report in the journal Epidemiology.

Gluten-free diets have become popular in the U.S., although less than 1 percent of Americans have been diagnosed with celiac disease -- an out-of-control immune response to gluten, a protein found in wheat, rye and barley.

A gluten-free diet is recommended for people with celiac disease, but others often say they prefer eating gluten-free because it reduces inflammation -- a claim that has not been scientifically proven. In 2015, one-quarter of Americans reported eating gluten-free, a 67 percent increase from 2013.

Gluten-free products often contain rice flour as a substitute for wheat. Rice is known to bioaccumulate certain toxic metals, including arsenic and mercury from fertilizers, soil, or water, but little is known about the health effects of diets high in rice content.

Maria Argos, assistant professor of epidemiology in the UIC School of Public Health, and her colleagues looked at data from the National Health and Nutrition Examination Survey searching for a link between gluten-free diet and biomarkers of toxic metals in blood and urine.

They found 73 participants who reported eating a gluten-free diet among the 7,471 who completed the survey, between 2009 and 2014. Participants ranged in age from 6 to 80 years old.

People who reported eating gluten-free had higher concentrations of arsenic in their urine, and mercury in their blood, than those who did not. The arsenic levels were almost twice as high for people eating a gluten-free diet, and mercury levels were 70 percent higher.

"These results indicate that there could be unintended consequences of eating a gluten-free diet," Argos said. "But until we perform the studies to determine if there are corresponding health consequences that could be related to higher levels of exposure to arsenic and mercury by eating gluten-free, more research is needed before we can determine whether this diet poses a significant health risk."

"In Europe, there are regulations for food-based arsenic exposure, and perhaps that is something we here in the United States need to consider," Argos said. "We regulate levels of arsenic in water, but if rice flour consumption increases the risk for exposure to arsenic, it would make sense to regulate the metal in foods as well."

Story Source:

Materials provided by University of Illinois at Chicago. Original written by Sharon Parmet. Note: Content may be edited for style and length.

Journal Reference:
Catherine M. Bulka, Matthew A. Davis, Margaret R. Karagas, Habibul Ahsan, Maria Argos. The Unintended Consequences of a Gluten-Free Diet. Epidemiology, 2017; 1 DOI: 10.1097/EDE.0000000000000640

Cite This Page:
University of Illinois at Chicago. "Gluten-free diet may increase risk of arsenic, mercury exposure." ScienceDaily. ScienceDaily, 13 February 2017. <www.sciencedaily.com/releases/2017/02/170213131150.htm>.

Plant-made hemophilia therapy shows promise

Date: February 13, 2017

Source: University of Pennsylvania

Summary:
Researchers have developed a therapy to prevent a significant complication of hemophilia treatment. Results in dogs show promise.
Henry Daniell.
Credit: Image courtesy of University of Pennsylvania

People with hemophilia require regular infusions of clotting factor to prevent them from experiencing uncontrolled bleeding. But a significant fraction develop antibodies against the clotting factor, essentially experiencing an allergic reaction to the very treatment that can prolong their lives.

Researchers from the University of Pennsylvania School of Dental Medicine and University of Florida have worked to develop a therapy to prevent these antibodies from developing, using a protein drug produced in plant cells to teach the body to tolerate rather than block the clotting factor.

Successful results from a new study of the treatment in dogs give hope for an eventual human treatment.

Henry Daniell a professor in Penn Dental Medicine's Department of Biochemistry and director of translational research, was the senior author on the study, collaborating on the work with his former advisee, Roland W. Herzog, a professor at the University of Florida and lead author on the paper. The work was published in the journal Molecular Therapy.

"The results were quite dramatic," Daniell said. "We corrected blood clotting time in each of the dogs and were able to suppress antibody formation as well. All signs point to this material being ready for the clinic."

The study made use of Daniell's patented plant-based drug-production platform, in which genetic modifications enable the growth of plants that have specified human proteins in their leaves. In the case of hemophilia, the researchers' aim was to prevent individuals with hemophilia from developing antibodies that would cause a rejection of life-saving clotting-factor infusions.

The researchers had the idea that ingesting a material containing the clotting factor, such as the transformed plant leaves, could promote oral tolerance to the factor protein, just as children fed peanuts early in life are less likely to develop an allergic reaction.

This technique had shown promise in previous experiments, in which the researchers demonstrated that feeding hemophilia A plant material containing the clotting factor VIII to mice greatly reduced the formation of inhibitors against that factor.

In the new work, the team focused on hemophilia B, a rarer form of disease in which patients have deficiencies in clotting factor IX. The researchers produced lettuce that had been modified to produce a fusion protein containing human clotting factor IX and the cholera non-toxin B subunit. The latter component helps the fused protein cross the intestinal lining as the lettuce cells are digested by gut microbes while the plant cell walls protect the clotting factor from digestion in the stomach. The lettuce plants were grown in a hydroponic facility.

Because the researchers also wanted to ensure that the therapy would work in an animal model closer to humans, they pursued their trials in dogs with hemophilia B.

The researchers began with a pilot study of two dogs, headed by co-author Timothy Nichols of the University of North Carolina. Twice a week for 10 months, the dogs consumed the freeze-dried lettuce material, which was spiked with bacon flavor and sprinkled on their food.

Observing no negative effects of the treatment, the team went on to a more robust study, including four dogs that were fed the lettuce material and four others that served as controls. The four dogs in the experimental group were fed the lettuce material for four weeks. At that point, they also began receiving weekly injections of factor IX, which continued for eight weeks. The control dogs only received the injections.

All four of the dogs in the control group developed significant levels of antibodies aginst factor IX, and two had visible anaphylactic reactions that required the administration of antihistamine. In contrast, three of the four dogs in the experimental group had only minimal levels of one type of antibody, IgG2, and no detectable levels of IgG1 or IgE. The fourth dog in the experimental group had only a partial response to the treatment, which the researchers believe to be due to a pre-existing antibody to human factor IX.

Overall, levels of IgG2 were 32 times lower in the treated dogs than in the controls.

In addition, the dogs showed no negative side effects from the treatment, and blood samples taken throughout the experiment revealed no signs of toxicity from the treatment.

Daniell said the results are encouraging.

"Looking at the dogs that were fed the lettuce materials, you can see it's quite effective," he said. "They either developed no antibodies to factor IX, or their antibodies went up just a little bit and then came down."

Though rarer than hemophilia A, more patients with hemophilia B develop antibodies against their treatment, thus making the need for a tolerance treatment all the more urgent.

The next steps for the research team include additional toxicology and pharmacokinetics studies before applying for an Investigational New Drug application with the FDA, a step they hope to take before the end of the year. A National Institutes of Health grant called Science Moving Towards Research Translation and Therapy and which uses the acronym SMARTT, is supporting IND-enabling studies. SMARTT's mission is to accelerate the progress of therapies that have shown promise in animal models to the stage of pursuing clinical trials in humans.

Story Source:

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

Journal Reference:
Roland W. Herzog, Timothy C. Nichols, Jin Su, Bei Zhang, Alexandra Sherman, Elizabeth P. Merricks, Robin Raymer, George Q. Perrin, Mattias Häger, Bo Wiinberg, Henry Daniell. Oral Tolerance Induction in Hemophilia B Dogs Fed with Transplastomic Lettuce. Molecular Therapy, 2016; 24 (8): 1342 DOI: 10.1016/j.ymthe.2016.11.009

Cite This Page:
University of Pennsylvania. "Plant-made hemophilia therapy shows promise." ScienceDaily. ScienceDaily, 13 February 2017. <www.sciencedaily.com/releases/2017/02/170213131206.htm>.

How eating less can slow the aging process

Date: February 13, 2017

Source: Brigham Young University

Summary:
New research shows why calorie restriction made mice live longer and healthier lives.
"When you restrict calorie consumption, there's almost a linear increase in lifespan," Price said.
Credit: © Steven R Breininger / Fotolia

There's a multi-billion-dollar industry devoted to products that fight signs of aging, but moisturizers only go skin deep. Aging occurs deeper -- at a cellular level -- and scientists have found that eating less can slow this cellular process.

Recent research published in Molecular & Cellular Proteomics offers one glimpse into how cutting calories impacts aging inside a cell. The researchers found that when ribosomes -- the cell's protein makers -- slow down, the aging process slows too. The decreased speed lowers production but gives ribosomes extra time to repair themselves.

"The ribosome is a very complex machine, sort of like your car, and it periodically needs maintenance to replace the parts that wear out the fastest," said Brigham Young University biochemistry professor and senior author John Price. "When tires wear out, you don't throw the whole car away and buy new ones. It's cheaper to replace the tires."

So what causes ribosome production to slow down in the first place? At least for mice: reduced calorie consumption.

Price and his fellow researchers observed two groups of mice. One group had unlimited access to food while the other was restricted to consume 35 percent fewer calories, though still receiving all the necessary nutrients for survival.

"When you restrict calorie consumption, there's almost a linear increase in lifespan," Price said. "We inferred that the restriction caused real biochemical changes that slowed down the rate of aging."

Price's team isn't the first to make the connection between cut calories and lifespan, but they were the first to show that general protein synthesis slows down and to recognize the ribosome's role in facilitating those youth-extending biochemical changes.

"The calorie-restricted mice are more energetic and suffered fewer diseases," Price said. "And it's not just that they're living longer, but because they're better at maintaining their bodies, they're younger for longer as well."

Ribosomes, like cars, are expensive and important -- they use 10-20 percent of the cell's total energy to build all the proteins necessary for the cell to operate. Because of this, it's impractical to destroy an entire ribosome when it starts to malfunction. But repairing individual parts of the ribosome on a regular basis enables ribosomes to continue producing high-quality proteins for longer than they would otherwise. This top-quality production in turn keeps cells and the entire body functioning well.

Despite this study's observed connection between consuming fewer calories and improved lifespan, Price assured that people shouldn't start counting calories and expect to stay forever young. Calorie restriction has not been tested in humans as an anti-aging strategy, and the essential message is understanding the importance of taking care of our bodies.

"Food isn't just material to be burned -- it's a signal that tells our body and cells how to respond," Price said. "We're getting down to the mechanisms of aging, which may help us make more educated decisions about what we eat."

Story Source:

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

Journal Reference:
Andrew D. Mathis, Bradley C. Naylor, Richard H. Carson, Eric Evans, Justin Harwell, Jared Knecht, Eric Hexem, Fredrick F. Peelor, Benjamin F. Miller, Karyn L. Hamilton, Mark K. Transtrum, Benjamin T. Bikman, John C. Price. Mechanisms of In Vivo Ribosome Maintenance Change in Response to Nutrient Signals. Molecular & Cellular Proteomics, 2017; 16 (2): 243 DOI: 10.1074/mcp.M116.063255

Cite This Page:
Brigham Young University. "How eating less can slow the aging process." ScienceDaily. ScienceDaily, 13 February 2017. <www.sciencedaily.com/releases/2017/02/170213151306.htm>.

Mediterranean diet with virgin olive oil may boost 'good' cholesterol

Date: February 13, 2017

Source: American Heart Association

Summary:
A Mediterranean diet, particularly when enriched with virgin olive oil, appears to improve the function of high-density lipoprotein, the so-called good cholesterol, in patients at high risk for heart disease. A Mediterranean diet rich in virgin olive oil may help the body remove excess cholesterol from arteries, serve as an antioxidant and keep blood vessels open -- all of which are known to reduce cardiovascular risk.

A Mediterranean diet rich in virgin olive oil may enhance the cardioprotective benefits of high-density lipoproteins (HDL -- the "good" cholesterol) compared to other diets, according to new research in the American Heart Association's journal Circulation.

High levels of low-density lipoproteins (LDL -- the "bad cholesterol") and triglycerides, a type of blood fat, are associated with an increased risk of heart and blood vessel diseases. HDL cholesterol is associated with a lower risk because these lipoproteins help eliminate the excess cholesterol from the bloodstream.

"However, studies have shown that HDL doesn't work as well in people at high risk for heart attacks, strokes and other cardiovascular diseases, and that the functional ability of HDL matters as much as its quantity," said senior study author Montserrat Fitó, M.D., Ph.D., and coordinator of the Cardiovascular Risk and Nutrition Research Group at the Hospital del Mar Medical Research Institute in Barcelona and at the Ciber of Physipathology of Obesity and Nutrition (CIBEROBN), Spain. "At the same time, small-scale trials have shown that consuming antioxidant-rich foods like virgin olive oil, tomatoes and berries improved HDL function in humans. We wanted to test those findings in a larger, controlled study."

Researchers randomly selected 296 people at high risk of cardiovascular disease participating in the PREDIMED (PREvención con DIeta MEDiterránea) study. Blood samples were taken from the participants at the beginning of the study and again at the end. Participants, average age 66, were randomly assigned to one of three diets for a year: a traditional Mediterranean diet enriched with virgin olive oil (about 4 tablespoons) each day, a traditional Mediterranean diet enriched with extra nuts (about a fistful) each day, or a healthy "control" diet that reduced consumption of red meat, processed food, high-fat dairy products and sweets. In addition to emphasizing fruit, vegetables, legumes, such as beans, chickpeas and lentils, and whole grains, both Mediterranean diets included moderate amounts of fish and poultry.

The study found that only the control diet reduced total and LDL cholesterol levels. None of the diets increased HDL levels significantly, but the Mediterranean diets did improve HDL function. The improvement in HDL function was much larger among those consuming an extra quantity of virgin olive oil.

Fitó and her team found that the Mediterranean diet enriched with virgin olive oil improved key HDL functions, including:
Reverse cholesterol transport, the process by which HDL removes cholesterol from plaque in the arteries and transports it to the liver where it is used to produce hormonal compounds or eliminated from the body.
Antioxidant protection, the ability of HDL to counteract the oxidation of LDL, which has been found to trigger the development of plaque in the arteries.
Vasodilator capacity, which relaxes blood vessels, keeping them open and blood flowing.

Researchers said they were surprised to find that the control diet, which like the Mediterranean diets was rich in fruits and vegetables, had a negative impact on HDL's anti-inflammatory properties. A decrease in HDL's anti-inflammatory capability is associated with cardiovascular disease. Participants on the Mediterranean diets did not experience a decline in this important HDL function, the authors wrote.

Researchers said the differences in results between the diets were relatively small because the modifications of the Mediterranean diets were modest and the control diet was a healthy one. They added that study results are mainly focused on a high cardiovascular risk population that includes people who can obtain the most benefits from this diet intervention.

Still, Fitó said, "following a Mediterranean diet rich in virgin olive oil could protect our cardiovascular health in several ways, including making our 'good cholesterol' work in a more complete way."

Story Source:

Materials provided by American Heart Association. Note: Content may be edited for style and length.

Journal Reference:
Álvaro Hernáez, Olga Castañer, Roberto Elosua, Xavier Pintó, Ramón Estruch, Jordi Salas-Salvadó, Dolores Corella, Fernando Arós, Lluis Serra-Majem, Miquel Fiol, Manuel Ortega-Calvo, Emilio Ros, Miguel Ángel Martínez-González, Rafael de la Torre, M. Carmen López-Sabater, Montserrat Fitó. Mediterranean Diet Improves High-Density Lipoprotein Function in High-Cardiovascular-Risk IndividualsClinical Perspective. Circulation, 2017; 135 (7): 633 DOI: 10.1161/CIRCULATIONAHA.116.023712

Cite This Page:
American Heart Association. "Mediterranean diet with virgin olive oil may boost 'good' cholesterol." ScienceDaily. ScienceDaily, 13 February 2017. <www.sciencedaily.com/releases/2017/02/170213171419.htm>.

Fructose consumption linked to the increase of liver disease among adolescents and children

New study indicates that sugar intake and uric acid concentration independently contribute to incidence and progression of liver disease

Date: February 14, 2017

Source: Elsevier Health Sciences

Summary:
Recent research suggests that dietary fructose intake may increase serum uric acid concentrations and that both uric acid concentration and fructose consumption may be increased in individuals with non-alcoholic fatty liver disease (NAFLD). Investigators have now established that both dietary fructose consumption and serum uric acid concentrations are independently associated with non-alcoholic steatohepatitis (NASH).

Link:

Setting the record straight on some common beliefs about food and health

Date: February 14, 2017

Source: Wake Forest Baptist Medical Center

Summary:
When it comes to what certain foods can do to or for you, it’s probably best to take motherly advice, familiar sayings and other bits of conventional wisdom with a grain of salt.
Wake Forest Baptist Medical Center dietitian Annette Frain displays a plate with three varieties of fish rich in omega-3 fatty acids – salmon, sardines and herring – that have been shown to improve cognitive function.
Credit: Wake Forest Baptist Medical Center

"Everything our parents said was good is bad," complains Alvy Singer, the character played by Woody Allen in "Annie Hall," his 1977 Oscar-winning romantic comedy.

That's a bit of an exaggeration, but when it comes to what certain foods can do to or for you, it's probably best to take motherly advice, familiar sayings and other bits of conventional wisdom with a grain of salt.

"There's some validity to some of them, but many of them are just old wives' tales or myths that have trickled down over the years," said Annette Frain, a registered dietitian at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina.

To help draw the line between what is and isn't baloney, so to speak, here's the medical lowdown on a couple of widely held notions about food and health.

Fish is brain food

Score one for Mom.

"Many long-term studies have found a correlation between improved cognition and the consumption of fish that are high in omega-3 fatty acids such as DHA," said Frain, the medical program coordinator at Wake Forest Baptist's Weight Management Center. "This isn't a speedy fix -- you're not going to get a higher score on your test or do a better job on your project at work because you ate fish last night. It's rather the build-up over time. So the sooner you start, the better off you'll be in the long run."

The best seafood sources of these omega-3s that promote optimal brain function are fatty and oil-rich fish such as salmon, albacore tuna, mackerel, sardines and herring.

These obviously aren't among America's most popular types of seafood. The "lighter" fish like flounder and tilapia that more frequently appear on our plates are good for you, too. Just not as good.

"They aren't as potent in terms of omega-3s, and they're often breaded and fried, which only adds calories," said Frain, who recommends grilling as the best way to prepare fish.

Eating chocolate causes acne

Nope.

"I remember hearing that when I was growing up and I still hear it when I see patients, especially teenagers," said Sarah Taylor, M.D., a dermatologist at Wake Forest Baptist. "But it's not true. Chocolate has been studied, and there's no hard evidence it has anything to do with acne."

Acne occurs when the skin's pores become clogged with excess oil produced by hair follicles. This allows dirt, bacteria and dead skin cells to build up in the pores and form the lesions and blemishes of acne.

What triggers this isn't clear. Hormonal changes can prompt the overproduction of oil, and heredity can be a factor. But eating chocolate is not. That goes for pizza, potato chips, french fries and cheeseburgers, too.

Research, however, has identified one acne-food connection.

"Non-organic dairy products can make acne worse, because the cows are treated with growth hormones," Taylor said. "So we'll tell patients that when they're having yogurt, cheese, milk or ice cream to make sure it's organic if they want to help their acne out."

Eating carrots improves vision

Not exactly.

"Carrots are a good source of vitamin A, which is one of the nutrients necessary for good ocular health," said Craig Greven, M.D., chair of ophthalmology at Wake Forest Baptist. "But they won't improve your eyesight."

Their vision-friendly reputation notwithstanding, carrots are far from the only way to get vitamin A. Dairy products, eggs, fish and liver are prime sources, as are a number of fruits (peaches, mangoes, tomatoes) and vegetables (spinach, kale, broccoli, peas, red bell peppers) that also provide other nutrients and antioxidants that contribute to good vision.

"In general, a balanced diet, and really anything that leads to a healthy lifestyle, is good for your eyes," Greven said. "But there's not one specific perfect eye food."

Spicy foods cause ulcers

No. Jalapenos and habaneros aren't to blame.

Ulcers are sores on the inside lining of the stomach, esophagus or small intestine that develop when acid is able to penetrate the layer of mucus that normally protects the digestive tract. But spicy foods have nothing to do with that.

"About 75 percent of all ulcers are caused by bacteria called Helicobacter pylori," said Joel Bruggen, M.D., a gastroenterologist at Wake Forest Baptist. "Most of the others are caused by the use of aspirin and other non-steroidal anti-inflammatory medications."

So how did chili, curry and kung-pao chicken get such a bad rap?

"Stomach ulcers can produce a burning pain in your stomach," Bruggen said, "and if you have a pain in your stomach after eating spicy food you might think you have an ulcer, or a doctor might even tell you you have an ulcer, but you probably don't."

Stress and alcohol also can be added to the list of things that don't cause ulcers. In fact, the research pointing to bacteria as the primary culprit has been around since the mid-1980s.

But, as Bruggen put it, "Some legends just live on."

Story Source:

Materials provided by Wake Forest Baptist Medical Center. Note: Content may be edited for style and length.

Cite This Page:
Wake Forest Baptist Medical Center. "Setting the record straight on some common beliefs about food and health." ScienceDaily. ScienceDaily, 14 February 2017. <www.sciencedaily.com/releases/2017/02/170214095827.htm>.

Imbalance of calcium in a cell's energy factory may drive Alzheimer's disease

Date: February 14, 2017

Source: Biophysical Society

Summary:
Calcium in the mitochondria -- the energy factory of cells -- may be one of the keys to understanding and treating Alzheimer's disease and dementia. Researchers have now identified how an imbalance of calcium ions in the mitochondria may contribute to cell death and, specifically, neurodegeneration in brain cells during Alzheimer's and dementia. The findings could eventually point to new therapies for preventing or delaying these diseases.

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Doctors prescribe more antibiotics when expectations are high, study says

New experimental evidence finds link between expectations, prescribing

Date: February 16, 2017

Source:
American Psychological AssociationSummary:Experimental evidence confirms what surveys have long suggested: Physicians are more likely to prescribe antibiotics when they believe there is a high expectation of it from their patients, even if they think the probability of bacterial infection is low and antibiotics would not be effective, according to a study.

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B vitamins reduce schizophrenia symptoms, study finds

Date: February 16, 2017

Source: University of Manchester

Summary:
A review of worldwide studies has found that add-on treatment with high-dose B vitamins -- including B6, B8 and B12 -- can significantly reduce symptoms of schizophrenia more than standard treatments alone.

A review of worldwide studies has found that add-on treatment with high-dose b-vitamins -- including B6, B8 and B12 -- can significantly reduce symptoms of schizophrenia more than standard treatments alone.

The research -- on the effect of vitamin and mineral supplements on symptoms of schizophrenia -- is funded by The Medical Research Council and University of Manchester, and is published in Psychological Medicine, one of the world's leading psychology journals

Lead author Joseph Firth, based at the University's Division of Psychology and Mental Health, said: "Looking at all of the data from clinical trials of vitamin and mineral supplements for schizophrenia to date, we can see that B vitamins effectively improve outcomes for some patients.

"This could be an important advance, given that new treatments for this condition are so desperately needed."

Schizophrenia affects around 1% of the population and is among the most disabling and costly long term conditions worldwide.

Currently, treatment is based around the administration of antipsychotic drugs.

Although patients typically experience remission of symptoms such as hallucinations and delusions within the first few months of treatment, long-term outcomes are poor; 80% of patients relapse within five years.

The researchers reviewed all randomized clinical trials reporting effects of vitamin or mineral supplements on psychiatric symptoms in people with schizophrenia.

In what is the first meta-analysis carried out on this topic, they identified 18 clinical trials with a combined total of 832 patients receiving antipsychotic treatment for schizophrenia.

B-vitamin interventions which used higher dosages or combined several vitamins were consistently effective for reducing psychiatric symptoms, whereas those which used lower doses were ineffective.

Also, the available evidence also suggests that B-vitamin supplements may be most beneficial when implemented early on, as b-vitamins were most likely to reduce symptoms when used in studies of patients with shorter illness durations.

Firth added: "High-dose B-vitamins may be useful for reducing residual symptoms in people with schizophrenia, although there were significant differences among the findings of the studies we looked at."

"There is also some indication that these overall effects may be driven by larger benefits among subgroups of patients who have relevant genetic or dietary nutritional deficiencies."

Co-author Jerome Sarris, Professor of Integrative Mental Health at Western Sydney University, added: "This builds on existing evidence of other food-derived supplements, such as certain amino-acids, been beneficial for people with schizophrenia.

"These new findings also fit with our latest research examining how multi-nutrient treatments can reduce depression and other disorders."

The research team say more studies are now needed to discover how nutrients act on the brain to improve mental health, and to measure effects of nutrient-based treatments on other outcomes such as brain functioning and metabolic health.

Story Source:

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

Journal Reference:
J. Firth, B. Stubbs, J. Sarris, S. Rosenbaum, S. Teasdale, M. Berk, A. R. Yung. The effects of vitamin and mineral supplementation on symptoms of schizophrenia: a systematic review and meta-analysis. Psychological Medicine, 2017; 1 DOI: 10.1017/S0033291717000022

Cite This Page:
University of Manchester. "B vitamins reduce schizophrenia symptoms, study finds." ScienceDaily. ScienceDaily, 16 February 2017. <www.sciencedaily.com/releases/2017/02/170216103913.htm>.

Pizza, burgers and the like: A single high-fat meal can damage the metabolism

Date: February 16, 2017

Source: Deutsches Zentrum fuer Diabetesforschung DZD

Summary:
The global proliferation of overweight and obese people and people with type 2 diabetes is often associated with the consumption of saturated fats. Scientists have found that even the one-off consumption of a greater amount of palm oil reduces the body's sensitivity to insulin and causes increased fat deposits as well as changes in the energy metabolism of the liver.
This image shows the impact of saturated fatty acids on the liver, muscles and fatty tissue.
Credit: © DDZ

The global proliferation of overweight and obese people and people with type 2 diabetes is often associated with the consumption of saturated fats. Scientists at the German Diabetes Center (Deutsches Diabetes-Zentrum, DDZ) and the Helmholtz Center in Munich (HMGU) have found that even the one-off consumption of a greater amount of palm oil reduces the body's sensitivity to insulin and causes increased fat deposits as well as changes in the energy metabolism of the liver. The results of the study provide information on the earliest changes in the metabolism of the liver that in the long term lead to fatty liver disease in overweight persons as well as in those with type 2 diabetes.

In the current issue of the Journal of Clinical Investigation, DZD researchers working at the German Diabetes Center, in conjunction with the Helmholtz Center in Munich and colleagues from Portugal, published a scientific investigation conducted on healthy, slim men, who were given at random a flavored palm oil drink or a glass of clear water in a control experiment. The palm oil drink contained a similar amount of saturated fat as two cheeseburgers with bacon and a large portion of French fries or two salami pizzas. The scientists showed that this single high-fat meal sufficed to reduce the insulin action, e.g. cause insulin resistance and increase the fat content of the liver. In addition, changes in the energy balance of the liver were proven. The observed metabolic changes were similar to changes observed in persons with type 2 diabetes or non-alcoholic fatty liver disease (NAFLD). NAFLD is the most common liver disease in the industrial nations and associated with obesity, the so-called "metabolic syndrome," and is associated with an increased risk in developing type 2 diabetes. Furthermore, NAFLD in advanced stages can result in severe liver damage.

"The surprise was that a single dosage of palm oil has such a rapid and direct impact on the liver of a healthy person and that the amount of fat administered already triggered insulin resistance," explained Prof. Dr. Michael Roden, scientist, Managing Director and Chairman at the DDZ and the German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung, DZD). "A special feature of our study is that we monitored the liver metabolism of people with a predominantly non-invasive technology, e.g. by magnetic resonance spectroscopy. This allows us to track the storage of sugar and fat as well as the energy metabolism of the mitochondria (power plants of the cell)." Thanks to the new methods of investigation, the scientists were able to verify that the intake of palm oil affects the metabolic activity of muscles, liver and fatty tissue. The induced insulin resistance leads to an increased new formation of sugar in the liver with a concomitant decreased sugar absorption in the skeletal muscles -- a mechanism that makes the glucose level rise in persons afflicted with type 2 diabetes and its pre-stages. In addition, the insulin resistance of the fatty tissue causes an increased release of fats into the blood stream, which in turn continues to foster the insulin resistance. The increased availability of fat leads to an increased workload for the mitochondria, which can in the long term overtax these cellular power plants and contribute to the emergence of a liver disease.

The team of Prof. Roden suspects that healthy people, depending on genetic predisposition, can easily manage this direct impact of fatty food on the metabolism. The long-term consequences for regular eaters of such high-fat meals can be far more problematic, however.

Story Source:

Materials provided by Deutsches Zentrum fuer Diabetesforschung DZD. Note: Content may be edited for style and length.

Journal Reference:
Elisa Álvarez Hernández, Sabine Kahl, Anett Seelig, Paul Begovatz, Martin Irmler, Yuliya Kupriyanova, Bettina Nowotny, Peter Nowotny, Christian Herder, Cristina Barosa, Filipa Carvalho, Jan Rozman, Susanne Neschen, John G. Jones, Johannes Beckers, Martin Hrabě de Angelis, Michael Roden. Acute dietary fat intake initiates alterations in energy metabolism and insulin resistance. Journal of Clinical Investigation, 2017; 127 (2): 695 DOI: 10.1172/JCI89444

Cite This Page:
Deutsches Zentrum fuer Diabetesforschung DZD. "Pizza, burgers and the like: A single high-fat meal can damage the metabolism." ScienceDaily. ScienceDaily, 16 February 2017. <www.sciencedaily.com/releases/2017/02/170216143956.htm>.

Panc em São Paulo - carurus

Texto:
Leila de Araújo Borges Proença - acadêmica de agronomia - Faculdade Cantareia
Marcos Roberto Furlan - engenheiro agrônomo - Prof. UNITAU e Faculdade Cantareira

Dependendo da região, são denominados de carurus ou bredos. Os nomes no plural é porque existem mais de uma espécie com esses nomes, a maioria pertencente ao gênero Amaranthus, sendo as mais comuns: Amaranthus hybridus, A. retroflexus, A. viridis e A. spinosus.

Os carurus são utilizados tanto na alimentação de animais quanto na de seres humanos. São considerados ricos em ferro, daí a justificativa de combaterem a anemia.

Alguns carurus eram mais conhecidos pela população, principalmente para consumo em sopa de fubá. Com a ênfase atual sobre as plantas alimentícias não convencionais (PANCS), informações sobre o uso dos carurus na alimentação estão sendo resgatadas.

Ainda com relação à culinária, há espécies de Amaranthus que produzem grãos comercializados como amarantos (Amaranthus caudatus e A. cruentus). Outra espécie comestível e que produz até “pipoca” é o Amaranthus hypochondriachus. As sementes são utilizadas na confecção de farinhas e leites vegetais. Importante ressaltar que não contém glúten.

Como algumas espécies podem ter alto teor de oxalato de cálcio, se recomenda sempre o cozimento.

Nos arredores da horta é interessante manter os carurus, pois servem de alimento para besouros. Quando os carurus são arrancados, esses besouros atacam em maior intensidade as plantas cultivadas. Outra informação relacionada aos aspectos agronômicos, é que os carurus indicam solos ricos em matéria orgânica. No entanto, quando ocorre apenas caruru, o solo é rico em matéria orgânica mas está faltando alguns micronutrientes.

Do ponto de vista medicinal, são poucas as pesquisas sobre a aplicação dos carurus no tratamento de doenças, necessitando ainda de maior segurança para afirmar suas ações terapêuticas, tais como diuréticas e laxativas.
Foto: Amaranthus sp
Autoria: Leila de Araújo Borges Proença

quarta-feira, 15 de fevereiro de 2017

Árvores em São Paulo - Muntingia calabura

Texto:
Jessica Tiyoko Yamashita - acadêmica de agronomia - Faculdade Cantareira
Marcos Roberto Furlan - Engenheiro Agrônomo - Professor UNITAU e Faculdade Cantareira

Algumas referências mencionam que é exótica, nativa na América Central, Bolívia e Peru, outros referências indicam que é nativa. O fato que ela é encontrada em quase todo o Brasil, inclusive na cidade de São Paulo, onde se destaca como ornamental e na arborização urbana.

Seu nome científico é Muntingia calabura L.. Pertence à família Muntingiaceae. Outras denominações populares da espécie são cereja-das-antilhas e cereja-da-jamaica. É uma árvore considerada de pequeno porte, pois atinge cerca de sete metros de altura. 

Seus frutos, de coloração rosa-avermelhados, surgem logo após um ano a partir do plantio. São apreciados por abelhas, aves, morcegos, dentre outros. Os frutos da calabura são usados para atrair peixes. A madeira também pode ser aproveitada, e por ser de baixa densidade é mais recomendada para caixotes e caixas, por exemplo. 

Também pode ser considerada uma planta alimentícia não convencional, pois seus frutos doces e suculentos, são comestíveis, sendo consumidos in natura, nas formas de geleia e compota. 

Com relação aos usos medicinais tradicionais, a infusão de suas flores é usada como antiespasmódica e tratamentos de gripes e resfriados. As folhas podem ser consumidas na forma de chá.
Fotos: calabura
Autoria: Jessica Tiyoko Yamashita

Referências 

LORENZI, H.; BACHER, L,; LACERDA, M,; SARTORI, S. Brazilian Fruits & Cultivated Exotics. 1ª ed. São Paulo: Instituto Plantarum de Estudos da Flora Ltda; 2006.

domingo, 12 de fevereiro de 2017

Pancs em Cotia, SP - begônia - Begonia cucullata

Texto:
Leila de Araújo Borges Proença - acadêmica de agronomia - Faculdade Cantareia
Marcos Roberto Furlan - engenheiro agrônomo - Prof. UNITAU e Faculdade Cantareira

Atualmente, a alimentação do ser humano é restrita a poucas espécies de vegetais e de animais, apesar da imensa biodiversidade existente em todo o mundo. Esta reduzida variedade na alimentação também possui relação com uma menor diversidade na oferta de nutrientes.Outro aspecto nutricional importante, é que o melhoramento vegetal gera variedades ou cultivares também com menor variação de nutrientes, além das exigências do uso de produtos químicos para alcançar boas produtividades.

Para melhorar a oferta, se encontra na natureza uma grande quantidade de espécies vegetais, das quais muitas eram consumidas antigamente e outras que podem se transformar em alimentos. No entanto, estas plantas por não serem consumidas pela maioria da população, são denominadas plantas alimentícias não convencionais (PANCs).

Dentre as PANCs, há espécies do gênero Begonia, o qual, além de fornecer ornamentais e medicinais, também oferece espécies que podem ser utilizadas na alimentação, como a Begonia cucullata (fotos).

A B. cucullata recebe denominações populares tais como: azedinha, azedinha-do-brejo, begônia-cerosa e begoninha. Encontrada em terrenos úmidos, mas raras vezes em grandes quantidades.

Dessa espécie, de sabor levemente azedo, são consumidas suas flores, folhas, ramos e frutos em saladas. As flores podem gerar geleia e as folhas adicionadas em sucos verdes. 

Referências

KINUPP, Valdely Ferreira; LORENZI, Harri. Plantas Alimentícias não Convencionais (PANC) no Brasil. Nova Odessa: Instituto Plantarum de Estudos da Flora, 2014. p. 228.

LORENZI, Harri. Plantas Daninhas do Brasil. Nova Odessa: Instituto Plantarum de Estudos da Flora, 2000. p. 71.
Fotos: Begonia cucullata
Autoria: Leila de Araújo Borges Proença

Mudança na coloração de flores do manacá-da-serra

Texto e fotos: Jessica Tiyoko Yamashita - acadêmica de Agronomia - Faculdade Cantareira

O manacá-da-serra é uma árvore nativa, pioneira, pertencente à família Melastomataceae. É muito utilizada na arborização urbana devido a sua beleza ornamental durante a floração, a qual ocorre, principalmente, nos meses de novembro a fevereiro.


As espécies do gênero Tibouchina, durante a fase fenológica chamada de antese (maturação floral), apresentam mudança na coloração de suas flores.

Assim que os botões florais se abrem, surgem as flores brancas que posteriormente irão mudar para a coloração lilás e finalmente rosa. Esse mecanismo de mudança de cores das flores é interpretado como um alerta aos seus polinizadores, avisando-os que a flor está velha.

Segundo estudos com T. pulchra, com flores parecidas com as da T. mutabilis, as flores brancas são consideradas como novas e mais atraentes aos polinizadores. No entanto, as suas flores se mantém receptivas à polinização durante todo o tempo da antese, e ocorre diminuição na quantidade de pólen (PEREIRA-ROCHA, 2008). Silva (2006) descreve que as flores brancas mudam rapidamente de cor após a polinização.

Referências

PEREIRA-ROCHA, A. C., 2008. Variações de cores e perfumes alteram a visitação por himenópteros nas quaresmeiras? 31p. Dissertação (Mestrado em ecologia e Conservação). Universidade Federal do Paraná.


SILVA, J. B. 2006. Biologia das interações entre os visitantes florais (Hymenoptera, Apidae) em Tibouchina pulchra Cogn. (Melastomateceae). Dissertação de Mestrado. Universidade Federal do Paraná, Curitiba.

Fotos: variações de cores no manacá-da-serra