sábado, 16 de novembro de 2019
Native California medicinal plant may hold promise for treating Alzheimer's
Salk scientists identify possible healing compound in Yerba santa
Date: February 20, 2019 Source: Salk Institute Summary: The medicinal powers of aspirin, digitalis, and the anti-malarial artemisinin all come from plants. A discovery of a potent neuroprotective and anti-inflammatory chemical in a native California shrub may lead to a treatment for Alzheimer's disease based on a compound found in nature.
The medicinal powers of aspirin, digitalis, and the anti-malarial artemisinin all come from plants. A Salk Institute discovery of a potent neuroprotective and anti-inflammatory chemical in a native California shrub may lead to a treatment for Alzheimer's disease based on a compound found in nature. The research appears in the February 2019 issue of the journal Redox Biology.
"Alzheimer's disease is a leading cause of death in the United States," says Senior Staff Scientist Pamela Maher, a member of Salk's Cellular Neurobiology Laboratory, run by Professor David Schubert. "And because age is a major risk factor, researchers are looking at ways to counter aging's effects on the brain. Our identification of sterubin as a potent neuroprotective component of a native California plant called Yerba santa (Eriodictyon californicum) is a promising step in that direction."
Native California tribes, which dubbed the plant "holy herb" in Spanish, have long used Yerba santa for its medicinal properties. Devotees brew its leaves to treat respiratory ailments, fever and headaches; and mash it into a poultice for wounds, sore muscles and rheumatism.
To identify natural compounds that might reverse neurological disease symptoms, Maher applied a screening technique used in drug discovery to a commercial library of 400 plant extracts with known pharmacological properties. The lab had previously used this approach to identify other chemicals (called flavonoids) from plants that have anti-inflammatory and neuroprotective properties.
Through the screen, the lab identified a molecule called sterubin as Yerba santa's most active component. The researchers tested sterubin and other plant extracts for their impact on energy depletion in mouse nerve cells, as well as other age-associated neurotoxicity and survival pathways directly related to the reduced energy metabolism, accumulation of misfolded, aggregated proteins and inflammation seen in Alzheimer's. Sterubin had a potent anti-inflammatory impact on brain cells known as microglia. It was also an effective iron remover -- potentially beneficial because iron can contribute to nerve cell damage in aging and neurodegenerative diseases. Overall, the compound was effective against multiple inducers of cell death in the nerve cells, according to Maher.
"This is a compound that was known but ignored," Maher says. "Not only did sterubin turn out to be much more active than the other flavonoids in Yerba santa in our assays, it appears as good as, if not better than, other flavonoids we have studied."
Next, the lab plans to test sterubin in an animal model of Alzheimer's, then determine its drug-like characteristics and toxicity levels in animals. With that data, Maher says, it might be possible to test the compound in humans, although it would be critical to use sterubin derived from plants grown under standardized, controlled conditions. She says the team will likely generate synthetic derivatives of sterubin.
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Journal Reference:
Wolfgang Fischer, Antonio Currais, Zhibin Liang, Antonio Pinto, Pamela Maher. Old age-associated phenotypic screening for Alzheimer's disease drug candidates identifies sterubin as a potent neuroprotective compound from Yerba santa. Redox Biology, 2019; 21: 101089 DOI: 10.1016/j.redox.2018.101089
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Salk Institute. "Native California medicinal plant may hold promise for treating Alzheimer's: Salk scientists identify possible healing compound in Yerba santa." ScienceDaily. ScienceDaily, 20 February 2019. <www.sciencedaily.com/releases/2019/02/190220174105.htm>.
sexta-feira, 15 de novembro de 2019
Root extract of Chinese medicinal plant makes worms live longer
Date: October 9, 2018 Source: Martin-Luther-Universität Halle-Wittenberg Summary: A root extract of the Fallopia multiflora, or Chinese knotweed, has special properties: it enables the nematode C. elegans to live longer and protects it from oxidative stress, according to a new study.
A root extract of the Fallopia multiflora, or Chinese knotweed, has special properties: it enables the nematode C. elegans to live longer and protects it from oxidative stress. This has been demonstrated in a new study by nutritional scientists at Martin Luther University Halle-Wittenberg (MLU). The researchers provide scientifically substantiated evidence for the effectiveness of this extract, which is primarily used in traditional Chinese medicine and as a dietary supplement. At the same time, they have identified molecular signalling pathways that could be responsible for the extract's effect.
Their study was recently published in the international scientific journal Plants.
The Chinese knotweed is very popular. Many suppliers sell extracts and powders of this plant as dietary supplements and advertise the rejuvenating and particularly health-promoting effect that the products supposedly possess. However only a handful of scientifically based studies have examined its effects. "Most studies have only focused on the primary active ingredient of the plant extract. But it actually contains many different substances whose combined efficacy has not yet been thoroughly researched," says nutritional scientist Professor Wim Wätjen from MLU. His research group has been studying the plant, its ingredients, and their possible effects for several years.
In the current study, the researchers from Halle examined whether the much-praised anti-ageing effects can actually be proven. They administered a high amount of the extract to the nematode C. elegans, a model organism frequently used in the bio- and life sciences. "Most earlier studies investigated the effects of the plant on isolated cells or in a test tube; we wanted to study it in a living organism," explains Wätjen. When the highest concentration was administered to the worms, 1,000 micrograms per millilitre, various effects were observed: The lifetime of the worms was extended by almost 19 per cent. For C. elegans this corresponds to an increase of about three days. In two further tests, the scientists investigated the extent to which the drug also protects the worms from oxidative stress or heat stress. Even though the extract did not improve the survival rate of worms in hot conditions, it was found to reduce the formation of harmful oxygen radicals and protect the animals significantly better against elevated oxidative stress.
In the next step the researchers repeated the tests with worms whose genetic material had been specifically altered at certain sites. This switched off special proteins that are critical for ageing. "If the genes responsible for producing the proteins DAF-16 or Sir-2.1 were defective, the positive effects of the root extract were also significantly lower," says Wätjen. A longer lifespan could only be observed if all proteins functioned properly. "This confirms that ageing is a complex process that depends on many factors," says Wätjen.
The results of the new study fit in well with previous studies: The primary component of the root extract is a substance that has a similar structure to resveratrol. "This substance is found in grapes, for example, and is known to activate a special class of enzymes called sirtuins. These have long been considered the most important substances for controlling the body's ageing process," says Wätjen.
The new study provides clues on how plant-based ingredients intervene in basic mechanisms and signalling pathways of ageing which can serve as a basis for further research. However, the findings cannot be transferred directly to humans. Although the basic principles and signalling pathways in other organisms may be similar, says Wätjen, subsequent studies are needed to clarify whether the effects observed in C. elegans can also be demonstrated in other organisms. In the future researchers in Halle will investigate the protective effect the extract has on the development of plaques in Alzheimer's disease.
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Journal Reference:
Christina Saier, Christian Büchter, Karoline Koch, Wim Wätjen. Polygonum multiflorum Extract Exerts Antioxidative Effects and Increases Life Span and Stress Resistance in the Model Organism Caenorhabditis elegans via DAF-16 and SIR-2.1. Plants, 2018; 7 (3): 60 DOI: 10.3390/plants7030060
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Martin-Luther-Universität Halle-Wittenberg. "Root extract of Chinese medicinal plant makes worms live longer." ScienceDaily. ScienceDaily, 9 October 2018. <www.sciencedaily.com/releases/2018/10/181009102529.htm>.
Health benefits of the Mediterranean diet are confirmed, but just for the upper class
Only the most advantaged people actually benefit from the Mediterranean diet, Italian study says
Date: August 1, 2017 Source: Istituto Neurologico Mediterraneo Neuromed I.R.C.C.S. Summary: The Mediterranean diet reduces the risk of cardiovascular disease but only if you are rich or highly educated. This is the surprising finding by researchers who performed a study on over 18,000 subjects.
The Mediterranean diet reduces the risk of cardiovascular disease but only if you are rich or highly educated. This is the surprising finding by researchers from the Italian I.R.C.C.S. Neuromed, who performed a study on over 18,000 subjects recruited within the Moli-sani study and published in the International Journal of Epidemiology.
Cardiovascular advantages associated with the Mediterranean diet are well-known but now the Italian study, conducted by a team of researchers at the Department of Epidemiology and Prevention led by Giovanni de Gaetano, reveals that such benefits are strongly influenced by the socioeconomic position of people. Basically, given a comparable adherence to this eating pattern, the study has shown that the reduction in cardiovascular risk is observed only in people with higher educational level and/or greater household income. No actual benefits were observed for the less advantaged groups.
"The cardiovascular benefits associated with the Mediterranean diet in a general population are well known -- says Marialaura Bonaccio, researcher at the Department of Epidemiology and Prevention and first author of the study -- Yet for the first time our study has revealed that the socioeconomic position is able to modulate the health advantages linked to Mediterranean diet. In other words, a person from low socioeconomic status who struggles to follow a Mediterranean model, is unlikely to get the same advantages of a person with higher income, despite the fact that they both similarly adhere to the same healthy diet."
Neuromed researchers went further and tried to unravel the possible mechanisms underlying such disparities.
"Given a comparable adherence to the Mediterranean diet, the most advantaged groups were more likely to report a larger number of indices of high quality diet as opposed to people with low socioeconomic status -- explains Licia Iacoviello, head of the Laboratory of nutritional and molecular Epidemiology at the Department -- For example, within those reporting an optimal adherence to the Mediterranean diet (as measured by a score comprising fruits and nuts, vegetables, legumes, cereals, fish, fats, meat, dairy products and alcohol intake) people with high income or higher educational level consumed products richer in antioxidants and polyphenols, and had a greater diversity in fruit and vegetables choice. We have also found a socioeconomic gradient in the consumption of whole-grain products and in the preferred cooking methods. These substantial differences in consuming products belonging to Mediterranean diet lead us to think that quality of foods may be as important for health as quantity and frequency of intake."
"Our results should promote a serious consideration of socioeconomic scenario of health -- comments Giovanni de Gaetano, director of the Department -- Socioeconomic disparities in health are growing also in access to healthy diets. During the very last years, we documented a rapid shifting from the Mediterranean diet in the whole population, but it might also be that the weakest citizens tend to buy 'Mediterranean' food with lower nutritional value. We cannot be keeping on say that the Mediterranean diet is good for health -- de Gaetano concludes -- if we are not able to guarantee an equal access to it."
The Moli-sani Project
Started in March 2005, it involves about 25,000 citizens living in the Molise region. The aim is to learn about environmental and genetic factors underlying cardiovascular disease, cancer and degenerative pathologies. Moli-sani study, now based in I.R.C.C.S. Neuromed, has transformed an entire Italian region in a large research lab.
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Journal Reference:
Marialaura Bonaccio, Augusto Di Castelnuovo, George Pounis, Simona Costanzo, Mariarosaria Persichillo, Chiara Cerletti, Maria Benedetta Donati, Giovanni de Gaetano, Licia Iacoviello on behalf of the Moli-sani Study Investigators. High adherence to the Mediterranean diet is associated with cardiovascular protection in higher but not in lower socioeconomic groups: prospective findings from the Moli-sani study. International Journal of Epidemiology, 2017 DOI: 10.1093/ije/dyx145
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Istituto Neurologico Mediterraneo Neuromed I.R.C.C.S.. "Health benefits of the Mediterranean diet are confirmed, but just for the upper class: Only the most advantaged people actually benefit from the Mediterranean diet, Italian study says." ScienceDaily. ScienceDaily, 1 August 2017. <www.sciencedaily.com/releases/2017/08/170801171047.htm>.
On the path to vitamin A in rice
Date: July 21, 2017 Source: Albert-Ludwigs-Universität Freiburg Summary: Biochemists have elucidated the structure of an enzyme that supplies carotenoid, investigators report. The lack of vitamin A in food is a major cause of health problems worldwide and can lead to blindness and even death. This is especially a problem in threshold or third-world countries, where children are likely to suffer from a lack of vitamin A or its precursor beta-carotene due to malnourishment.
The lack of vitamin A in food is a major cause of health problems worldwide and can lead to blindness and even death. This is especially a problem in threshold or third-world countries, where children are likely to suffer from a lack of vitamin A or its precursor beta-carotene due to malnourishment. Among their many functions, carotenoids are responsible for the bright orange color of sweet potatoes as well as their namesake, the carrot. Thanks to its intense color, beta-carotene is used in the food industry in soft drinks, yoghurts, and other food and is known as food coloring E160. Rice, which is the most important basic nutrient in Asia, has no beta-carotene in its kernel, but there are carotenoids in the leaves of the rice plant. These long, fat-soluble pigments are used by the plant not only in photosynthesis, during which the plant generates energy and oxygen, but in other processes as well.
One of the first precursors to beta-carotene is phytoene, which is colorless and not water-soluble and can be found in the lipid bilayer of plastid organelles -- in other words, in the outer layer of these closed cellular compartments, which is involved in many processes including photosynthesis. Here, the enzyme phytoene desaturase (PDS) transforms the phytoene into the next intermediate of synthesis, which already has a yellowish color. Researchers in the labs of Prof. Dr. Peter Beyer at the Faculty of Biology and Prof. Dr. Oliver Einsle at the Faculty of Chemistry and Pharmacy of the University of Freiburg have successfully elucidated the three-dimensional structure of phytoene desaturase in rice, along with the mechanism of phytoene transformation. In order to achieve this, Dr. Sandra Gemmecker and Anton Brausemann had to isolate the highly pure enzyme and crystalize it, so they could obtain a three-dimensional structural image through diffraction experiments with X-rays. They then discovered that the PDS becomes partially immersed in the lipid bilayer of the plastid organelles and contains a hydrophobic tunnel that leads into its interior. Catalysis begins when the phytoene molecule enters this tunnel and reaches the reaction center of the enzyme, where one half of the phytoene molecule is transformed into the next intermediary carotenoid stage. After this intermediary product leaves the tunnel the same way it came, it enters another PDS enzyme right next to the first, where it is completely transformed. A helper molecule known as a quinone then regenerates the enzyme. The quinone accesses the enzyme through the same tunnel and takes up excess electrons, thereby preparing the enzyme for the next reaction cycle.
If the PDS enzyme in a plant does not function properly, for example due to a reaction to a herbicide, then the plant's seedlings become pale and whitish instead of green and the plant dies within a few days. Since the early twentieth century, scientists worldwide have been working to reveal the exact mechanisms of carotene synthesis. This has proven difficult, however, due to the complicated composition of various enzyme complexes and because of their relatively low numbers in plant cells. The researchers from the University of Freiburg were able to elucidate the structure of the PDS enzyme using a specialty: They added a molecule of norflurazon, an herbicide developed in the 1970s, during the isolation of PDS. Due to the presence of norflurazon, PDS is deactivated and thus no longer available to the growing plant, causing it to bleach and die. Knowledge about the position and orientation of this bleaching herbicide within the enzyme can therefore be useful to researchers when developing new agents in the future. It is now also possible to induce specific changes in the sequence of the enzyme and use biotechnological procedures to give crops an advantage over weeds.
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Journal Reference:
Anton Brausemann, Sandra Gemmecker, Julian Koschmieder, Sandro Ghisla, Peter Beyer, Oliver Einsle. Structure of Phytoene Desaturase Provides Insights into Herbicide Binding and Reaction Mechanisms Involved in Carotene Desaturation. Structure, 2017; DOI: 10.1016/j.str.2017.06.002
Cite This Page:
Albert-Ludwigs-Universität Freiburg. "On the path to vitamin A in rice." ScienceDaily. ScienceDaily, 21 July 2017. <www.sciencedaily.com/releases/2017/07/170721090111.htm>.
quinta-feira, 14 de novembro de 2019
Too much vitamin A may increase risk of bone fractures
Date: October 9, 2018 Source: Society for Endocrinology Summary: Consuming too much vitamin A may decrease bone thickness, leading to weak and fracture prone bones, according to a new study in mice.
Consuming too much vitamin A may decrease bone thickness, leading to weak and fracture prone bones, according to a study published in the Journal of Endocrinology. The study, undertaken in mice, found that sustained intake of vitamin A, at levels equivalent to 4.5-13 times the human recommended daily allowance (RDA), caused significant weakening of the bones, and suggests that people should be cautious of over-supplementing vitamin A in their diets.
Vitamin A is an essential vitamin that is important for numerous biological processes including growth, vision, immunity and organ function. Our bodies are unable to make vitamin A but a healthy diet including meat, dairy products and vegetables should be sufficient to maintain the body's nutritional needs. Some evidence has suggested that people who take vitamin A supplements may be increasing their risk of bone damage. Previous studies in mice have shown that short-term overdosing of vitamin A, at the equivalent of 13-142 times the recommended daily allowance in people, results in decreased bone thickness and an increased fracture risk after just 1-2 weeks. This study is the first to examine the effects of lower vitamin A doses that are more equivalent to those consumed by people taking supplements, over longer time-periods.
In this study, Dr Ulf Lerner and colleagues from Sahlgrenska Academy at the University of Gothenburg, report that mice given lower doses of vitamin A, equivalent to 4.5-13 times the RDA in humans, over a longer time period, also showed thinning of their bones after just 8 days, which progressed over the ten week study period.
Dr Ulf Lerner commented, "Previous studies in rodents have shown that vitamin A decreases bone thickness but these studies were performed with very high doses of vitamin A, over a short period of time. In our study we have shown that much lower concentrations of vitamin A, a range more relevant for humans, still decreases rodent bone thickness and strength."
Next, Dr Ulf Lerner intends to investigate if human-relevant doses of vitamin A affect bone growth induced by exercise, which was not addressed in this study. Additionally, his team will study the effects of vitamin A supplementation in older mice, where growth of the skeleton has ceased, as is seen in the elderly.
Dr Ulf Lerner cautions: "Overconsumption of vitamin A may be an increasing problem as many more people now take vitamin supplements. Overdose of vitamin A could be increasing the risk of bone weakening disorders in humans but more studies are needed to investigate this. In the majority of cases, a balanced diet is perfectly sufficient to maintain the body's nutritional needs for vitamin A."
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Journal Reference:
Vikte Lionikaite, Karin L Gustafsson, Anna Westerlund, Sara H Windahl, Antti Koskela, Juha Tuukkanen, Helena Johansson, Claes Ohlsson, Herschel H Conaway, Petra Henning, Ulf H Lerner. Clinically relevant doses of vitamin A decrease cortical bone mass in mice. Journal of Endocrinology, 2018; DOI: 10.1530/JOE-18-0316
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Society for Endocrinology. "Too much vitamin A may increase risk of bone fractures." ScienceDaily. ScienceDaily, 9 October 2018. <www.sciencedaily.com/releases/2018/10/181009102538.htm>.
What flowers looked like 100 million years ago
Date: August 2, 2017 Source: University of Vienna Summary: Flowering plants with at least 300,000 species are by far the most diverse group of plants on Earth. They include almost all the species used by people for food, medicine, and many other purposes. However, flowering plants arose only about 140 million years ago, quite late in the evolution of plants, toward the end of the age of the dinosaurs, but since then have diversified spectacularly. No one knows exactly how this happened, and the origin and early evolution of flowering plants and especially their flowers still remains one of the biggest enigmas in biology, almost 140 years after Charles Darwin called their rapid rise in the Cretaceous "an abominable mystery".
Flowering plants with at least 300,000 species are by far the most diverse group of plants on Earth. They include almost all the species used by people for food, medicine, and many other purposes. However, flowering plants arose only about 140 million years ago, quite late in the evolution of plants, toward the end of the age of the dinosaurs, but since then have diversified spectacularly. No one knows exactly how this happened, and the origin and early evolution of flowering plants and especially their flowers still remains one of the biggest enigmas in biology, almost 140 years after Charles Darwin called their rapid rise in the Cretaceous "an abominable mystery."
This new study, the "eFLOWER project," is an unprecedented international effort to combine information on the structure of flowers with the latest information on the evolutionary tree of flowering plants based on DNA. The results shed new light on the early evolution of flowers as well as major patterns in floral evolution across all living flowering plants.
Among the most surprising results is a new model of the original ancestral flower that does not match any of the ideas proposed previously. "When we finally got the full results, I was quite startled until I realized that they actually made good sense," said Hervé Sauquet, the leader of the study and an Associate Professor at Université Paris-Sud in France. "No one has really been thinking about the early evolution of flowers in this way, yet so much is easily explained by the new scenario that emerges from our models."
According to the new study, the ancestral flower was bisexual, with both female (carpels) and male (stamens) parts, and with multiple whorls (concentric cycles) of petal-like organs, in sets of threes. About 20% of flowers today have such "trimerous" whorls, but typically fewer: lilies have two, magnolias have three. "These results call into question much of what has been thought and taught previously about floral evolution!," said Juerg Schoenenberger, a Professor at the University of Vienna, who coordinated the study together with Hervé Sauquet. It has long been assumed that the ancestral flower had all organs arranged in a spiral.
The researchers also reconstructed what flowers looked like at all the key divergences in the flowering plant evolutionary tree, including the early evolution of monocots (e.g., orchids, lilies, and grasses) and eudicots (e.g., poppies, roses, and sunflowers), the two largest groups of flowering plants. "The results are really exciting!" said Maria von Balthazar, a Senior Scientist and specialist of floral morphology and development at the University of Vienna. "This is the first time that we have a clear vision for the early evolution of flowers across all angiosperms."
The new study sheds new light on the earliest phases in the evolution of flowers and offers for the first time a simple, plausible scenario to explain the spectacular diversity of floral forms. Nevertheless, many questions remain. The fossil record of flowering plants is still very incomplete, and scientists have not yet found fossil flowers as old as the group itself. "This study is a very important step toward developing a new and increasingly sophisticated understanding of the major patterns in the evolution of flowers," said Peter Crane, President of the Oak Spring Garden Foundation and a colleague familiar with the results of the study. "It reflects great progress and the results on the earliest flowers are especially intriguing."
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Journal Reference:
Hervé Sauquet, Maria von Balthazar, Susana Magallón, James A. Doyle, Peter K. Endress, Emily J. Bailes, Erica Barroso de Morais, Kester Bull-Hereñu, Laetitia Carrive, Marion Chartier, Guillaume Chomicki, Mario Coiro, Raphaël Cornette, Juliana H. L. El Ottra, Cyril Epicoco, Charles S. P. Foster, Florian Jabbour, Agathe Haevermans, Thomas Haevermans, Rebeca Hernández, Stefan A. Little, Stefan Löfstrand, Javier A. Luna, Julien Massoni, Sophie Nadot, Susanne Pamperl, Charlotte Prieu, Elisabeth Reyes, Patrícia dos Santos, Kristel M. Schoonderwoerd, Susanne Sontag, Anaëlle Soulebeau, Yannick Staedler, Georg F. Tschan, Amy Wing-Sze Leung, Jürg Schönenberger. The ancestral flower of angiosperms and its early diversification. Nature Communications, 2017; 8: 16047 DOI: 10.1038/NCOMMS16047
Cite This Page:
University of Vienna. "What flowers looked like 100 million years ago." ScienceDaily. ScienceDaily, 2 August 2017. <www.sciencedaily.com/releases/2017/08/170802092836.htm>.
quarta-feira, 13 de novembro de 2019
terça-feira, 12 de novembro de 2019
Reações adversas - 2
Fonte: BALBINO, Evelin E. and DIAS, Murilo F.. Farmacovigilância: um passo em direção ao uso racional de plantas medicinais e fitoterápicos. Rev. bras. farmacogn. [online]. 2010, vol.20, n.6 [cited 2020-01-03], pp.992-1000. Available from: . Epub Oct 29, 2010. ISSN 0102-695X. http://dx.doi.org/10.1590/S0102-695X2010005000031.
Plastic teabags release microscopic particles into tea
Date: September 25, 2019 Source: American Chemical Society Summary: Many people are trying to reduce their plastic use, but some tea manufacturers are moving in the opposite direction: replacing traditional paper teabags with plastic ones. Now, researchers have discovered that a soothing cup of the brewed beverage may come with a dose of micro- and nano-sized plastics shed from the bags. Possible health effects of ingesting these particles are currently unknown, the researchers say.
Many people are trying to reduce their plastic use, but some tea manufacturers are moving in the opposite direction: replacing traditional paper teabags with plastic ones. Now, researchers reporting in ACS' Environmental Science & Technology have discovered that a soothing cup of the brewed beverage may come with a dose of micro- and nano-sized plastics shed from the bags. Possible health effects of ingesting these particles are currently unknown, the researchers say.
Over time, plastic breaks down into tiny microplastics and even smaller nanoplastics, the latter being less than 100 nanometers (nm) in size. (For comparison, a human hair has a diameter of about 75,000 nm.) Scientists have detected the microscopic particles in the environment, aquatic organisms and the food supply, but they don't know yet whether they are harmful to humans. Nathalie Tufenkji and colleagues wondered whether recently introduced plastic teabags could be releasing micro- and nanoplastics into the beverage during brewing. They also wanted to explore effects of the released particles on small aquatic organisms called Daphnia magna, or water fleas, which are model organisms often used in environmental studies.
To conduct their analysis, the researchers purchased four different commercial teas packaged in plastic teabags. The researchers cut open the bags, removed the tea leaves and washed the empty bags. Then, they heated the teabags in containers of water to simulate brewing conditions. Using electron microscopy, the team found that a single plastic teabag at brewing temperature released about 11.6 billion microplastic and 3.1 billion nanoplastic particles into the water. These levels were thousands of times higher than those reported previously in other foods. In another experiment, the researchers treated water fleas with various doses of the micro- and nanoplastics from teabags. Although the animals survived, they did show some anatomical and behavioral abnormalities. More research is needed to determine if the plastics could have more subtle or chronic effects on humans, the researchers say.
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American Chemical Society. "Plastic teabags release microscopic particles into tea." ScienceDaily. ScienceDaily, 25 September 2019. <www.sciencedaily.com/releases/2019/09/190925083805.htm>.
A grape constituent protects against cancer
Date: October 3, 2018 Source: Université de Genève Summary: Lung cancer is the deadliest form of cancer in the world, and 80% of death are related to smoking. In addition to tobacco control, effective chemoprevention strategies are therefore needed. A team of scientists studied a well-known natural product, resveratrol, which is found in grapes and in red wine. While its chemopreventive properties against cancers affecting the digestive tract have been documented by previous studies, resveratrol has so far shown no effect on lung cancers. Thanks to nasal administration, the UNIGE team obtained very promising results in a study conducted in mice.
Lung cancer is the deadliest form of cancer in the world, and 80% of death are related to smoking. In addition to tobacco control, effective chemoprevention strategies are therefore needed. A team of scientists from the University of Geneva (UNIGE), Switzerland, studied a well-known natural product, resveratrol, which is found in grapes and in red wine. While its chemopreventive properties against cancers affecting the digestive tract have been documented by previous studies, resveratrol has so far shown no effect on lung cancers. Thanks to nasal administration, the UNIGE team obtained very promising results in a study conducted in mice and described in the journal Scientific Reports.
"We tried to prevent lung cancer induced by a carcinogen found in cigarette smoke by using resveratrol, an already well-documented molecule, in a mouse model," explains Muriel Cuendet, Associate Professor in the School of pharmaceutical sciences of the UNIGE Faculty of Science. This 26 week long study contained four groups of mice. The first one, the control, received neither carcinogen nor resveratrol treatment. The second received only the carcinogen, the third received both the carcinogen and the treatment, and the fourth received only the treatment. "We observed a 45% decrease in tumor load per mouse in the treated mice. They developed fewer tumors and of smaller size than untreated mice," says Muriel Cuendet. When comparing the two groups that were not exposed to carcinogen, 63% of the mice treated did not develop cancer, compared to only 12.5% of the untreated mice. "Resveratrol could therefore play a preventive role against lung cancer," she continues.
This formulation is applicable to humans
However, resveratrol does not seem suitable for preventing lung cancer: when ingested, it is metabolized and eliminated within minutes, and therefore does not have time to reach the lungs. "This is why our challenge was to find a formulation in which resveratrol could be solubilized in large quantities, even though it is poorly soluble in water, in order to allow nasal administration. This formulation, applicable to humans, allows the compound to reach the lungs," explains Aymeric Monteillier, a scientist in the School of pharmaceutical sciences of the UNIGE Faculty of Science, and the first author of the study. The resveratrol concentration obtained in the lungs after nasal administration of the formulation was 22 times higher than when taken orally. The chemoprevention mechanism is probably related to apoptosis, a process by which cells program their own death and from which cancer cells escape. The UNIGE research team will now focus on finding a biomarker that could contribute to the selection of people eligible for preventive treatment with resveratrol.
Towards a preventive treatment?
Resveratrol is an already well-known molecule, which is found in food supplements, meaning that no further toxicological study would be needed prior to commercialisation as a preventive treatment. "This discovery is unfortunately of little economic interest to pharmaceutical groups. The molecule is indeed simple and non-patentable and cancer prevention studies require a follow-up over many years," regrets Muriel Cuendet, without excluding the development of preventive treatment in humans.
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Journal Reference:
Aymeric Monteillier, Aymone Voisin, Pascal Furrer, Eric Allémann, Muriel Cuendet. Intranasal administration of resveratrol successfully prevents lung cancer in A/J mice. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-32423-0
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Université de Genève. "A grape constituent protects against cancer." ScienceDaily. ScienceDaily, 3 October 2018. <www.sciencedaily.com/releases/2018/10/181003102423.htm>.
Eelgrass acid and resveratrol produced by cell factories for the first time
Date: November 4, 2019 Source: Technical University of Denmark Summary: Scientists are now able to produce a wide range of sulfated aromatic compounds such as antifouling eelgrass acid, resveratrol and vanillic acid derivatives using microbial production hosts. This pioneering work could lead to new environmentally friendly anti-fouling paint for ships, as well as improved and sustainable nutraceuticals and medicine.
Leveraging on nature's ways of adding sulfate groups by enzymes, scientists at The Novo Nordisk Foundation Center for Biosustainability at Technical University of Denmark (DTU) have for the first time demonstrated how to produce a wide range of sulfated phenolic compounds in microbial hosts -- cell factories. This pioneering research, published in Nature Communications, enables large scale production of sulfated phenolic compounds by fermentation.
"The perspectives are far-reaching since sulfation can be used for a wide range of products such as antifouling agents and pharmaceuticals. This work could mean cheaper and better drugs in the future as well as bio-chemicals and polymers with new properties," says corresponding author Professor Alex Toftgaard Nielsen from The Novo Nordisk Foundation Center for Biosustainability. He is also CSO at Cysbio -- a company that works to commercialize products from, amongst other things, sulfated molecules.
Phenolic compounds are aromatic molecules with uses in areas such as medicine, nutraceuticals and other antioxidants, the cosmetic industry as well as in the polymer industry. Adding sulfate residues to phenolic compounds can increase the acidity and solubility of the molecule as well as decreasing the toxicity.
As a proof of concept for the sulfation process in cell factories, the researchers wanted to produce zosteric acid. This acid is found in the marina plant eelgrass and is a powerful antifouling agent. Used in ship paint, it could potentially inhibit the growth of algae on the hull. Furthermore, it has applications in disinfectants, where it can prevent the attachment of bacteria on surfaces (biofilms) e.g. in hospitals.
Today, zosteric acid can be extracted from plant material, but titers are low, and the cost is high. Zosteric acid may also be synthesized chemically, but this requires harsh chemical conditions and generates a lot of chemical waste. Thus, a biological process is preferable.
The researchers had to re-engineer and rewire several genes within the cell factory to optimize the sulfation process. This was both done by improving sulfate uptake and by optimizing the availability of the sulfate donor enzyme in the cell.
The result was production of up to five grams per liter of zosteric acid in a so-called fed-batch fermentation. This yield is impressive, since nature normally only produces zosteric acid in very low quantities, and because chemical synthesis is extremely difficult and expensive.
Biologically, zosteric acid is created by an enzyme (sulfotransferase) that transfers a sulfate side-group to a specific building block molecule. Therefore, the researchers isolated sulfotransferases from humans, fruit flies, eelgrass, rats, chickens, rabbits, dogs, worms, zebrafish and pigs to find the most efficient one. The winner enzyme was actually isolated from rat liver and worked superbly in the microbial production host.
Using this method, the researchers also found sulfotransferases that could sulfate the powerful antioxidant resveratrol that is found in red wine. Today, due to its very low content in grapes, tedious purification processes, and a need for use of harsh chemicals in doing so, resveratrol extraction from plants is difficult, time consuming and unsustainable.
In grapes, resveratrol is found in an inactive un-sulfated form. Entering the human body, resveratrol is sulfated by the liver to become active, which gives the molecule its antioxidant properties. Thus, being able to produce large amounts of sulfated resveratrol in cell factories opens to production of a more active and bioavailable antioxidant, a process that may be used to modify the properties of pharmaceuticals as well.
Furthermore, the researchers showed that some of the sulfotransferases were also able to sulfate vanillic acid. This, too, is a product that can be made in a microbial cell factory and has market potential.
"From a scientific perspective, being able to produce sulfated phenolic compounds in microbial cell factories is fantastic, but it might also have societal impacts as these molecules have applications both as bio-chemicals, as nutraceuticals and even as drugs," says first author of the study, Christian Bille Jendresen, R&D Director of Sulfation Technologies at the start-up company Cysbio, which has spun out of The Novo Nordisk Foundation Center for Biosustainability, DTU.
"We can create a wide range of interesting chemicals that will find different ways into market," he says.
This pioneering work has thus enabled the production of a novel class of sulfated biochemicals that will likely find many biotechnological applications.
Story Source:
Materials provided by Technical University of Denmark. Note: Content may be edited for style and length.
Journal Reference:
Christian Bille Jendresen, Alex Toftgaard Nielsen. Production of zosteric acid and other sulfated phenolic biochemicals in microbial cell factories. Nature Communications, 2019; 10 (1) DOI: 10.1038/s41467-019-12022-x
Cite This Page:
Technical University of Denmark. "Eelgrass acid and resveratrol produced by cell factories for the first time." ScienceDaily. ScienceDaily, 4 November 2019. <www.sciencedaily.com/releases/2019/11/191104112840.htm>.
segunda-feira, 11 de novembro de 2019
Red wine's resveratrol could help Mars explorers stay strong
Nutraceuticals that preserve muscle in reduced gravity will support long-term space missions
Date: July 18, 2019 Source: Frontiers Summary: Mars is about 9 months from Earth with today's tech, NASA reckons. As the new space race hurtles forward, researchers are asking: how do we make sure the winners can still stand when they reach the finish line? A new study shows that resveratrol substantially preserves muscle mass and strength in rats exposed to the wasting effects of simulated Mars gravity.
Mars is about 9 months from Earth with today's tech, NASA reckons. As the new space race hurtles forward, Harvard researchers are asking: how do we make sure the winners can still stand when they reach the finish line?
Published in Frontiers in Physiology, their study shows that resveratrol substantially preserves muscle mass and strength in rats exposed to the wasting effects of simulated Mars gravity.
Space supplements
Out in space, unchallenged by gravity, muscles and bones weaken. Weight-bearing muscles are hit first and worst, like the soleus muscle in the calf.
"After just 3 weeks in space, the human soleus muscle shrinks by a third," says Dr. Marie Mortreux, lead author of the NASA-funded study at the laboratory of Dr. Seward Rutkove, Beth Israel Deaconess Medical Center, Harvard Medical School. "This is accompanied by a loss of slow-twitch muscle fibers, which are needed for endurance."
To allow astronauts to operate safely on long missions to Mars -- whose gravitational pull is just 40% of Earth's -- mitigating strategies will be needed to prevent muscle deconditioning.
"Dietary strategies could be key," says Dr. Mortreux, "especially since astronauts travelling to Mars won't have access to the type of exercise machines deployed on the ISS."
A strong candidate is resveratrol: a compound commonly found in grape skin and blueberries that has been widely investigated for its anti-inflammatory, anti-oxidative, and anti-diabetic effects.
"Resveratrol has been shown to preserve bone and muscle mass in rats during complete unloading, analogous to microgravity during spaceflight. So, we hypothesized that a moderate daily dose would help mitigate muscle deconditioning in a Mars gravity analogue, too."
Mars rats
To mimic Mars gravity, the researchers used an approach first developed in mice by Mary Bouxsein, PhD, also at Beth Israel Deaconess, in which rats were fitted with a full-body harness and suspended by a chain from their cage ceiling.
Thus, 24 male rats were exposed to normal loading (Earth) or 40% loading (Mars) for 14 days. In each group, half received resveratrol (150 mg/kg/day) in water; the others got just the water. Otherwise, they fed freely from the same chow.
Calf circumference and front and rear paw grip force were measured weekly, and at 14 days the calf muscles were analyzed.
Resveratrol to the rescue
The results were impressive.
As expected, the 'Mars' condition weakened the rats' grip and shrank their calf circumference, muscle weight and slow-twitch fiber content.
But incredibly, resveratrol supplementation almost entirely rescued front and rear paw grip in the Mars rats, to the level of the non-supplemented Earth rats.
What's more, resveratrol completely protected muscle mass (soleus and gastrocnemius) in the Mars rats, and in particular reduced the loss of slow-twitch muscle fibers. The protection was not complete, though: the supplement did not entirely rescue average soleus and gastrocnemius fibers cross-sectional area, or calf circumference.
As reported previously, resveratrol did not affect food intake or total body weight.
Perfecting the dose
Previous resveratrol research can explain these findings, says Dr. Mortreux.
"A likely factor here is insulin sensitivity.
"Resveratrol treatment promotes muscle growth in diabetic or unloaded animals, by increasing insulin sensitivity and glucose uptake in the muscle fibers. This is relevant for astronauts, who are known to develop reduced insulin sensitivity during spaceflight."
The anti-inflammatory effects of resveratrol could also help to conserve muscle and bone, and other anti-oxidant sources such as dried plums are being used to test this, adds Dr. Mortreux.
"Further studies are needed to explore the mechanisms involved, as well as the effects of different doses of resveratrol (up to 700 mg/kg/day) in both males and females. In addition, it will be important to confirm the lack of any potentially harmful interactions of resveratrol with other drugs administered to astronauts during space missions."
Story Source:
Materials provided by Frontiers. Note: Content may be edited for style and length.
Journal Reference:
Marie Mortreux, Daniela Riveros, Mary L. Bouxsein, Seward B. Rutkove. A Moderate Daily Dose of Resveratrol Mitigates Muscle Deconditioning in a Martian Gravity Analog. Frontiers in Physiology, 2019; 10 DOI: 10.3389/fphys.2019.00899
Cite This Page:
Frontiers. "Red wine's resveratrol could help Mars explorers stay strong: Nutraceuticals that preserve muscle in reduced gravity will support long-term space missions." ScienceDaily. ScienceDaily, 18 July 2019. <www.sciencedaily.com/releases/2019/07/190718085319.htm>.
domingo, 10 de novembro de 2019
Wheat that pumps iron, naturally
Research shows possibility of increasing nutrition without sacrificing yield
Date: October 3, 2018 Source: American Society of Agronomy Summary: Crop breeders are developing a biofortified wheat that could make proper nutrition
Is biofortification the best thing since sliced bread? Well, biofortified wheat could certainly make it easier to help some humans get proper nutrition.
Biofortification is the process of naturally increasing the nutritional value of a crop. Unlike fortification, which might add a mineral like iron directly to something like bread dough, the goal of biofortification is to have the wheat in the dough naturally contain more iron in the first place.
Robert Graybosch of the USDA Agricultural Research Service explains that about 60% of the world's population doesn't get enough iron. This happens because the food people eat doesn't contain enough minerals or contains what are called 'antinutrients.' These are molecules that prevent the body from absorbing good nutrients.
"Fortification is potentially useful as people in many parts of the world do not consume a balanced diet and their main foods lack minerals," he says. "This can be addressed by fortification, the process of adding minerals back to food products. This is done with flours used for bread baking."
However, some people are hesitant to eat products with what they think might be weird ingredients, he adds. Graybosch is trying to naturally enhance the minerals of wheat flours to help people around the world get more iron.
"Biofortification can be done via traditional plant breeding using natural genetic variation or natural mutations, or via genetic engineering," he says. "If one found a mutation that resulted in more grain iron, and then bred this trait into wheat that was produced and consumed, then we could say the crop has been biofortified."
Graybosch and his team developed experimental breeding lines of winter wheat. Breeding lines are the first step in the long process of creating a new type of wheat that farmers can grow. The team tried to combine two properties -- low phytate and high grain protein -- without lowering grain yield. Phytate is an antinutrient that prevents the body from taking in some minerals.
Biofortification is a delicate balance. Often, increasing the nutrition causes the overall grain yield to drop. This can lead to the wheat being overall less nutritious and can also hurt farmers' profits.
Their results show that combining the two traits without any bad effects on grain yield is possible. It increased the amount of zinc, calcium, and manganese humans could get from it. Although more work needs to be done to get it in wheat that can be planted by farmers, the genes can be used to develop more nutritious wheat without sacrificing yield.
The next steps in their research, some of which they have already undertaken, are to then breed these beneficial genes into plants adapted for areas where wheat is grown, such as the Great Plains of the U.S.
"It is important to note that all wheat grown in a specific area is adapted to that area," Graybosch explains. "Great Plains wheats do well in the Great Plains, but not elsewhere. If the trait is of interest in other locations, additional breeders need to start introducing it to their own backgrounds. And they are interested in doing so."
Graybosch says his journey to this research began as he walked home from work one day. He wanted to devise a project to investigate "the most important nutritional problem facing mankind," which he learned was likely that people weren't getting enough iron. He and then-graduate student Jorge Venegas started to look for genes that would improve the nutrition of wheat.
"I think anything that can improve food mineral nutrition at low or no cost to the consumer is of value," Graybosch says. "Anything we can do to improve nutrition worldwide will go a long way toward improving the lives of our fellow earthlings."
Story Source:
Materials provided by American Society of Agronomy. Original written by Kaine Korzekwa. Note: Content may be edited for style and length.
Journal Reference:
Jorge P. Venegas, Robert A. Graybosch, Brian Wienhold, Devin J. Rose, Brian M. Waters, P. Stephen Baenziger, Kent Eskridge, Guihua Bai, Paul St. Amand. Biofortification of Hard Red Winter Wheat by Genes Conditioning Low Phytate and High Grain Protein Concentration. Crop Science, 2018; 58 (5): 1942 DOI: 10.2135/cropsci2018.03.0175
Cite This Page:
American Society of Agronomy. "Wheat that pumps iron, naturally: Research shows possibility of increasing nutrition without sacrificing yield." ScienceDaily. ScienceDaily, 3 October 2018. <www.sciencedaily.com/releases/2018/10/181003090336.htm>.
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