terça-feira, 27 de novembro de 2018

Cafeína reduz sensação de fadiga e melhora desempenho de ciclistas

25/10/2018

Substância age na fadiga mental, que é responsável pelo aumento da percepção de esforço e pela queda de rendimento
A cafeína foi administrada em cápsulas e os ciclistas ingeriram uma dosagem referente à massa corporal de cada um, sendo que foi administrado individualmente 5 mg/kg – Foto: Cecília Bastos/USP Imagens

Estudo realizado na Escola de Artes, Ciências e Humanidades (EACH) da USP indica que a cafeína é capaz de atenuar e reverter a sensação de fadiga mental e ainda melhorar o desempenho de atletas de ciclismo. Atualmente o cansaço mental não está presente apenas na vida de pessoas com rotina agitada por diversas atividades, mas também faz parte do dia a dia de atletas.

Segundo a pesquisa de Paulo Estevão Franco Alvarenga, os atletas com fadiga mental acabam perdendo desempenho e possuem aumento na percepção de esforço para a mesma intensidade de exercício, sem nenhuma alteração fisiológica na musculatura. Dessa forma, surgiu o interesse de estudar possíveis manipulações que revertam os efeitos da fadiga mental sobre o desempenho de ciclistas.

Iniciado em 2016, o projeto de mestrado Efeitos da ingestão de cafeína sobre o desempenho de ciclistas mentalmente fadigados durante um teste de ciclismo contrarrelógio de 20 km mostrou que “a cafeína é um recurso ergogênico com efeito potencial para reverter os efeitos da fadiga mental sobre o desempenho”, afirma Paulo Estevão, que teve orientação do professor Flávio Pires, coordenador do Grupo de Estudos em Psicofisiologia do Exercício (GEPsE) da EACH.

Previamente selecionados, os ciclistas foram ao Laboratório de Ciências da Atividade Física por quatros vezes e se submeteram ao teste de contrarrelógio de 20 km, análise cortical e muscular. Havia uma amostra de ciclistas livres de qualquer manipulação, outra amostra sob o efeito de fadiga mental e nas seguintes os indivíduos mentalmente fadigados faziam a ingestão de cafeína ou placebo.
De acordo com o estudo, os ciclistas mentalmente fadigados apresentaram uma redução de 4,8% na ativação do córtex pré-frontal e consequentemente aumentaram o tempo para concluir o contrarrelógio em aproximadamente 1%. No entanto, ao ingerir cafeína, mesmo após a indução da fadiga mental, houve um aumento na ativação do córtex pré-frontal em aproximadamente 8% e redução no tempo de conclusão do teste em 1,8%. “Portanto, os sujeitos ao ingerir cafeína perceberam menos esforço comparados com as demais condições. Além disso, com a ingestão de cafeína, eles apresentaram uma maior eficiência neuromuscular”, destaca Paulo.

O estudante ressalta que, mesmo já sendo consumida em nosso cotidiano quando nos sentimos mentalmente cansados, por meio de ingestão de café, por exemplo, a cafeína deve ser utilizada para atletas sob orientação de um nutricionista, respeitando as características de dosagem e tempo de efeito da substância.

O projeto de mestrado contou também com a colaboração da professora Florentina Hettinga, da University of Essex, Inglaterra; de pesquisadores pós-doc e alunos de mestrado da EACH e de alunos de graduação da Faculdade de Ensino Superior de Bragança, em Bragança Paulista (SP).

Natália Dourado/Assessoria de Comunicação da EACH

Mais informações: (11) 3091-8161; e-mail piresfo@usp.br, com Flávio Pires

Link:

Cientista de alimentos produz cookies altamente nutritivos com sobras de frutas

29/10/2018

Para produção dos biscoitos, foram aproveitados talo de abacaxi, miolo de maçã e casca de melão
Os biscoitos vitaminados seriam uma alternativa para o aproveitamento de sobras e aparas de frutas que possuem compostos nutricionais para a saúde humana – fibras, vitaminas, minerais e antioxidantes – Foto: Nataly Maria Viva de Toledo

Estudo desenvolvido na Escola Superior de Agricultura Luiz de Queiroz (Esalq) USP produziu biscoitos do tipo cookies aproveitando subprodutos de frutas. Com alto teor nutricional, foram acrescentados aos biscoitos o talo do abacaxi, o miolo da maçã e as cascas de melão. A pesquisa é de autoria de Nataly Maria Viva de Toledo e teve a orientação da professora Solange Guidolin Canniatti Brazaca, do Departamento de Agroindústria, Alimentos e Nutrição.

Segundo a autora da pesquisa, é importante se pensar em alternativas e aplicações para o grande volume de resíduos alimentares (cascas, sementes, bagaço e talos) descartados pelas indústrias alimentícias. Para a cientista de alimentos, tais materiais, quando não recebem tratamento adequado, podem representar fontes de contaminação ambiental e custos operacionais. A produção dos biscoitos seria uma alternativa para o aproveitamento de sobras e aparas de frutas que possuem compostos nutricionais importantes, como fibras, vitaminas, minerais e antioxidantes, relata.
Nataly Maria Viva de Toledo – Foto: Arquivo pessoal

A opção pelos biscoitos foi baseada no fato deste produto ser considerado um alimento versátil, de baixo custo e ter boa aceitação por pessoas de diversas idades e classes sociais. Os resíduos foram provenientes de uma indústria de alimentos minimamente processados localizada no município de Engenheiro Coelho, no interior de São Paulo. A partir dos resultados obtidos, verificou-se que, quanto aos benefícios nutricionais, a adição de subprodutos de frutas contribuiu para elevar o teor de fibras e minerais dos biscoitos, com destaque para os cookies elaborados com cascas de melão. Já quanto às propriedades antioxidantes, as formulações de biscoitos acrescidas de miolo de maçã e cascas de melão foram as que apresentaram resultados mais relevantes.

“O uso de subprodutos de frutas contribuiu ainda para características tecnológicas como formação da cor dourada e textura crocante nos cookies após forneamento. A partir de testes sensoriais, constatou-se que todas as formulações demonstraram aceitação satisfatória pelos consumidores, sendo que o biscoito formulado com talo de abacaxi apresentou 97% de aceitação”, revela a autora do estudo.

A investigação ainda avaliou também a presença de fatores antinutricionais (fitato e oxalato) nos cookies, substâncias capazes de interferir na absorção e utilização de nutrientes pelo organismo.Os “cookies acrescidos de subprodutos de frutas demonstraram menores teores de fatores antinutricionais, o que promoveu mudanças na biodisponibilidade de alguns minerais como cálcio, ferro e zinco”, detalha.

De acordo com a pesquisadora, vale destacar que, antes de serem utilizados para consumo humano, os subprodutos de frutas passaram por análises microbiológicas e de resíduos de defensivos agrícolas. “Além disso, evidências sobre a não toxicidade desses subprodutos foram averiguadas na literatura disponível. Todas essas precauções são importantes para garantir que os alimentos disponibilizados à população estavam aptos para consumo humano.”

Em síntese, a pesquisa conseguiu constatar que os subprodutos de frutas estudados se apresentaram como potenciais ingredientes para formulações de cookies, atribuindo-lhes propriedades físico-químicas, tecnológicas, nutricionais e sensoriais específicas de acordo com o subproduto utilizado. “Espera-se que esta nova abordagem incentive uso de partes não convencionais de alimentos, evitando seu desperdício, além de agregar valor aos subprodutos e funcionalidade a produtos alimentícios desenvolvidos”, finaliza Nataly Toledo.

Caio Albuquerque/Divisão de Comunicação Esalq

Mais informações: (19) 3447-8813 ou 3429-4109

Vitamin D levels in the blood linked to cardiorespiratory fitness

Date: October 30, 2018 Source: European Society of Cardiology Summary: New research finds that higher levels of vitamin D are associated with better exercise capacity.

Vitamin D levels in the blood are linked to cardiorespiratory fitness, according to a study published today in the European Journal of Preventive Cardiology, a publication of the European Society of Cardiology (ESC).

"Our study shows that higher levels of vitamin D are associated with better exercise capacity," said Dr Amr Marawan, assistant professor of internal medicine, Virginia Commonwealth University, Virginia, US. "We also know from previous research that vitamin D has positive effects on the heart and bones. Make sure your vitamin D levels are normal to high. You can do this with diet, supplements, and a sensible amount of sun exposure."

It is well established that vitamin D is important for healthy bones, but there is increasing evidence that it plays a role in other areas of the body including the heart and muscles.

Cardiorespiratory fitness, a reliable surrogate for physical fitness, is the ability of the heart and lungs to supply oxygen to the muscles during exercise. It is best measured as the maximal oxygen consumption during exercise, referred to as VO2 max. People with higher cardiorespiratory fitness are healthier and live longer.

This study investigated whether people with higher levels of vitamin D in the blood have improved cardiorespiratory fitness. The study was conducted in a representative sample of the US population aged 20-49 years using the National Health and Nutrition Survey (NHANES) in 2001-2004. Data was collected on serum vitamin D and VO2 max. Participants were divided into quartiles of vitamin D levels.

Of 1,995 participants, 45% were women, 49% were white, 13% had hypertension, and 4% had diabetes. Participants in the top quartile of vitamin D had a 4.3-fold higher cardiorespiratory fitness than those in the bottom quartile. The link remained significant, with a 2.9-fold strength, after adjusting for factors that could influence the association such as age, sex, race, body mass index, smoking, hypertension, and diabetes.

Dr Marawan said: "The relationship between higher vitamin D levels and better exercise capacity holds in men and women, across the young and middle age groups, across ethnicities, regardless of body mass index or smoking status, and whether or not participants have hypertension or diabetes."

Each 10 nmol/L increase in vitamin D was associated with a statistically significant 0.78 mL/kg/min increase in VO2 max. "This suggests that there is a dose response relationship, with each rise in vitamin D associated with a rise in exercise capacity," said Dr Marawan.

Dr Marawan noted that this was an observational study and it cannot be concluded that vitamin D improves exercise capacity. But he added: "The association was strong, incremental, and consistent across groups. This suggests that there is a robust connection and provides further impetus for having adequate vitamin D levels, which is particularly challenging in cold, cloudy places where people are less exposed to the sun."

On the other hand, Vitamin D toxicity can lead to excess calcium in the blood, which can cause nausea, vomiting, and weakness. "It is not the case that the more vitamin D, the better," said Dr Marawan. "Toxicity is caused by megadoses of supplements rather than diet or sun exposure, so caution is needed when taking tablets."

Regarding further research, Dr Marawan said: "We know the optimum vitamin D levels for healthy bones but studies are required to determine how much the heart needs to function at its best. Randomised controlled trials should be conducted to examine the impact of differing amounts of vitamin D supplements on cardiorespiratory fitness. From a public health perspective, research should look into whether supplementing food products with vitamin D provides additional benefits beyond bone health."

Story Source:

Materials provided by European Society of Cardiology. Note: Content may be edited for style and length.

Journal Reference:
Amr Marawan, Nargiza Kurbanova, Rehan Qayyum. Association between serum vitamin D levels and cardiorespiratory fitness in the adult population of the USA. European Journal of Preventive Cardiology, 2018; 204748731880727 DOI: 10.1177/2047487318807279

Cite This Page:
European Society of Cardiology. "Vitamin D levels in the blood linked to cardiorespiratory fitness." ScienceDaily. ScienceDaily, 30 October 2018. <www.sciencedaily.com/releases/2018/10/181030091449.htm>.

How plants cope with stress

Date: October 30, 2018 Source: University of Pennsylvania Summary: With climate change comes drought, and with drought comes higher salt concentrations in the soil. Scientists have identified a mechanism by which plants respond to salt stress, a pathway that could be targeted to engineer more adaptable crops.

The future looks challenging for plants. Climate change is forecast to bring widespread drought to parts of the planet already struggling with dry conditions. To mitigate the potentially devastating effects to agriculture, researchers are seeking strategies to help plants withstand extreme environmental hazards including drought and salt stress, a problem exacerbated when irrigated water passes through the soil, depositing salts which can then absorbed by plant roots, lowering their overall productivity.

One tack is to look at ways that plants have naturally evolved to cope with stresses such as too much salt. In a new study out in Cell Reports, researchers led by University of Pennsylvania biologist Brian D. Gregory and graduate student Stephen J. Anderson have identified a mechanism that could potentially be manipulated to develop more salt-tolerant crops.

Their work shows that a tiny tag on RNA molecules -- the transcripts that are translated to produce proteins -- serves to stabilize and protect these strands of genetic material. When plants are exposed to high-salt conditions, the RNA mark, known as N6-methyladenosine, or m6A, prevents the breakdown of transcripts encoding proteins that help plants more effectively deal with the challenging conditions.

"This is how we're going to help farmers," says Gregory, an associate professor in Penn's Department of Biology in the School of Arts and Sciences and the senior author on the paper. "We need to identify ways that we can make more salt-resistant and drought-resistant plants, and manipulating this pathway might be one way to do it."

For an organism to produce any protein, it must first possess the corresponding strand of messenger RNA (mRNA). But not all mRNAs are turned into proteins; some are degraded before they reach that stage. In recent years, both mammalian and plant biologists have been paying attention to the m6A mark as a player in the process by which mRNAs are targeted to either keep around or destroy.

"There's been an explosion of interest in this mark," Gregory says. "It's been found to be the most abundant internal modification in mRNA."

In mammals, the bulk of research points to the mark labeling mRNA for destruction. And, while some studies have suggested it may function the same way in plants, Gregory, Anderson, and colleagues wanted to get a more global view.

Analyzing leaves from mature Arabidopsis, the researchers globally identified m6A in normal plants as well as in those in which the enzyme that adds m6A had been eliminated, thus experimentally depleting them of the mark.

They found that transcripts that were abundant when marked by m6A in the normal plants were much lower in the m6A-depleted mutant plants, a sign that the mark was acting in a protective capacity to stabilize the transcripts.

Closely comparing the normal and the mutant plants, the team found that m6A, when present, protected the transcripts by preventing an enzyme from degrading them. When this mark was missing, the transcripts were cleaved and subsequently degraded.

"It was kind of serendipitous," says Anderson, "but it turned out that this destabilization was occurring right next to where these marks should have been but weren't in the experimental group of plants."

The next step was to ask why the plants might have evolved this mechanism in the first place. The researchers had hints that m6A labeling might be involved in stress response, judging from the affected genes between the normal and mutant plants. But, to put it to the test, they grew plants in a high-salt soil and repeated their experiments.

The salt treatment, they discovered, caused plants to affix more m6A marks on mRNA transcripts associated with responding to salt stress, as well as drought stress. In other words, the plants were girding themselves to deal with an environmental challenge.

"This gives plants a dynamic and really powerful mechanism to regulate stress response," Gregory says. "You can move this mark onto transcripts you want to keep around."

"There's also evidence," Anderson says, "that plants may be able to actively remove the mark from transcripts they don't need. We're still investigating that mechanism."

"This work," says Karen Cone at the National Science Foundation, which funded the research, "provides exciting new understanding of how genomic information interacts with signals from the environment to produce beneficial outcomes for the organism. The results promise to open the door to future discoveries of how organisms use RNA-based mechanisms to maintain the robustness and adaptability they need to survive in the face of changing environments, a finding that is directly relevant to one of NSF's 10 Big Ideas, Understanding the Rules of Life: Predicting Phenotype."

In additional follow-up experiments, Gregory's lab will examine this mark's involvement in other stressful situations for plants, like when they are subject to damage from organisms like bacteria or fungi. Gregory and colleagues also plan to pursue experiments in plant species important to agriculture, such as soy beans.

Further study may also help them zero in on the mechanism by which plants attach this mark to transcripts, helping in the development of strategies for engineering plants that may better resist the challenging conditions posed by drought.

Story Source:

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

Journal Reference:
Stephen J. Anderson, Marianne C. Kramer, Sager J. Gosai, Xiang Yu, Lee E. Vandivier, Andrew D.L. Nelson, Zachary D. Anderson, Mark A. Beilstein, Rupert G. Fray, Eric Lyons, Brian D. Gregory. N6-Methyladenosine Inhibits Local Ribonucleolytic Cleavage to Stabilize mRNAs in Arabidopsis. Cell Reports, 2018; 25 (5): 1146 DOI: 10.1016/j.celrep.2018.10.020

Cite This Page:
University of Pennsylvania. "How plants cope with stress." ScienceDaily. ScienceDaily, 30 October 2018. <www.sciencedaily.com/releases/2018/10/181030150659.htm>.

Hot brew coffee has higher levels of antioxidants than cold brew

Date: November 1, 2018 Source: Thomas Jefferson University Summary: Comparing the properties of cold- and hot-brew coffee, researchers found similar acidity in both, but higher antioxidant levels in hot coffee.
Study authors Megan Fuller (left) and Niny Rao (right), faculty at Jefferson (Philadelphia University + Thomas Jefferson University)
Credit: Jefferson (Philadelphia University + Thomas Jefferson University)

In a new study, Jefferson (Philadelphia University + Thomas Jefferson University) researchers found chemical differences between hot and cold brew coffee that may have health impacts. In particular, the researchers found that hot-brewed coffee has higher levels of antioxidants, which are believed to be responsible for some of the health benefits of coffee.

The study, published Oct. 30 in Scientific Reports, also found that the pH levels of both hot and cold coffee were similar, ranging from 4.85 to 5.13 for all coffee samples tested. Coffee companies and lifestyle blogs have tended to tout cold brew coffee as being less acidic than hot coffee and thus less likely to cause heartburn or gastrointestinal problems.

The study was done by Niny Rao, PhD, associate professor of chemistry, and Megan Fuller, PhD, assistant professor of chemistry, both of them coffee drinkers who wondered whether the chemical make-up of cold brew differed from that of hot coffee.

While the popularity of cold brew coffee has soared in recent years -- the U.S. market grew 580 percent from 2011 to 2016 -- they found almost no studies on cold brew, which is a no-heat, long-steeping method of preparation. At the same time, there is well-documented research that hot-brewed coffee has some measurable health benefits, including lower risk of some cancers, diabetes and depression.

While the overall pH levels were similar, Fuller and Rao found that the hot-brewed coffee method had more total titratable acids, which may be responsible for the hot cup's higher antioxidant levels.

"Coffee has a lot of antioxidants, if you drink it in moderation, research shows it can be pretty good for you," Fuller said. "We found the hot brew has more antioxidant capacity."

And considering hot and cold brews have comparable pH levels, Rao said, coffee drinkers should not consider cold brew a "silver bullet" for avoiding gastrointestinal distress.

Story Source:

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

Journal Reference:
Niny Z. Rao, Megan Fuller. Acidity and Antioxidant Activity of Cold Brew Coffee. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-34392-w

Cite This Page:
Thomas Jefferson University. "Hot brew coffee has higher levels of antioxidants than cold brew." ScienceDaily. ScienceDaily, 1 November 2018. <www.sciencedaily.com/releases/2018/11/181101085137.htm>.

Can chocolate, tea, coffee and zinc help make you more healthy?

Scientists discover new protection against oxidative stress

Date: November 2, 2018 Source: University of Erlangen-Nuremberg Summary: Ageing and a low life expectancy are caused, at least partly, by oxidative stress. Scientists have discovered that zinc can activate an organic molecule, helping to protect against oxidative stress.

Ageing and a low life expectancy are caused, at least partly, by oxidative stress. A team of researchers led by Prof. Dr. Ivana Ivanovi-Burmazovi from the Chair of Bioinorganic Chemistry at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), together with researchers from the USA, have discovered that zinc can activate an organic molecule, helping to protect against oxidative stress.

Zinc is a trace mineral we need in order to remain healthy. FAU researchers working together with Prof. Dr. Christian Goldsmith from Auburn University, Alabama, USA, have discovered that zinc can protect against the superoxide responsible for oxidative stress when taken together with a component found in foodstuffs such as wine, coffee, tea and chocolate. This component is a hydroquinone group found in polyphenols, in other words the plant substances responsible for smell and taste. Zinc activates the hydroquinone groups, producing natural protection against superoxide, a by-product of human cell respiration which damages the body's own biomolecules, for example proteins or lipids, as well as the human genome. Superoxide is thought to have a role to play in the ageing process and a number of illnesses such as inflammation, cancer or neurodegenerative diseases.

New metal complex against superoxide

Hydroquinone alone is not capable of breaking down superoxide. If zinc and hydroquinone combine, however, a metal complex is created which imitates a superoxide dismutase enzyme (SOD). These enzymes protect the body from the degradation processes caused by oxidation and have an antioxidative effect. In this way, the superoxide can be metabolised and damage to the organism prevented; oxidative stress is avoided.

Chocolate, coffee etc. with added zinc

For the first time, the function of this enzyme has been copied without reverting to redox-active transition metals such as manganese, iron, copper or nickel. Whilst the metals could also have an antioxidative effect, any positive effects are quickly outweighed by the fact that if too much is taken they can even cause oxidative stress to increase. Zinc is much less toxic than the transition metals mentioned above, making it possible for new medication or supplements to be created with considerably fewer side-effects. It would also be plausible to add zinc to food which contains hydroquinone naturally to boost the consumer's health. 'It is certainly possible that wine, coffee, tea or chocolate may well become be available in future with added zinc. However, any alcohol content whatsoever would destroy the positive effects of this combination,' emphasises Ivana Ivanovi-Burmazovi.

Story Source:

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

Journal Reference:
Meghan B. Ward, Andreas Scheitler, Meng Yu, Laura Senft, Annika S. Zillmann, John D. Gorden, Dean D. Schwartz, Ivana Ivanović-Burmazović, Christian R. Goldsmith. Superoxide dismutase activity enabled by a redox-active ligand rather than metal. Nature Chemistry, 2018; DOI: 10.1038/s41557-018-0137-1

Cite This Page:
University of Erlangen-Nuremberg. "Can chocolate, tea, coffee and zinc help make you more healthy? Scientists discover new protection against oxidative stress." ScienceDaily. ScienceDaily, 2 November 2018. <www.sciencedaily.com/releases/2018/11/181102083430.htm>.

Extrato da casca de jabuticaba promove efeitos benéficos à saúde

06 de novembro de 2018
Em pesquisa feita na Unicamp, composto diminuiu o ganho de peso e preveniu o aumento do acúmulo de gordura no fígado de camundongos (fotomicrografias do fígado de camundongos demonstrando redução do acúmulo de lipídeos e preservação da morfologia hepática após o tratamento com extrato de casca de jaboticaba em animais com sobrepeso induzido pelo consumo de dieta hiperlipídica / imagem: divulgação)Elton Alisson | Agência FAPESP – Um grupo de pesquisadores do Instituto de Biologia da Universidade Estadual de Campinas (IB-Unicamp) constatou que o extrato da casca da jabuticaba foi capaz de prevenir o pré-diabetes e o aumento do acúmulo de gordura no fígado (esteatose hepática) em camundongos.

Os resultados do estudo, apoiado pela FAPESP, foram publicados no Journal of Functional Foods.

“Observamos que a ingestão do extrato da casca da jabuticaba por camundongos envelhecidos, submetidos a uma dieta com alto teor de gordura, também causou a diminuição no ganho de peso e da dislipidemia [aumento de gordura no sangue] e da hiperglicemia [excesso de glicose no sangue] e melhorou o HDL [colesterol bom] dos animais, entre outros benefícios”, disse Valéria Helena Alves Cagnon Quitete, professora do IB-Unicamp e coordenadora do projeto, à Agência FAPESP.

O extrato da casca da fruta nativa da Mata Atlântica foi desenvolvido em uma parceria entre pesquisadores do IB e da Faculdade de Engenharia de Alimentos (FEA) da Unicamp. Um grupo de pesquisadores da FEA, coordenado pelo professor Mário Roberto Maróstica Junior, vinha estudando o efeito da adição da casca de jabuticaba na ração de camundongos.

Por meio da parceria, os pesquisadores conseguiram produzir um extrato da casca da fruta que pode ser administrado de forma controlada e com grande concentração de compostos bioativos – substâncias que ocorrem naturalmente em alimentos e que interferem positivamente no metabolismo, mas que não são nutricionalmente necessárias. O extrato resultou no depósito de uma patente, que está em processo de licenciamento por uma empresa brasileira.

“Conseguimos desenvolver um método que permite obter uma grande quantidade de compostos bioativos da casca de jabuticaba em um baixo volume de extrato”, disse Celina de Almeida Lamas, doutoranda no IB-Unicamp e uma das autoras do estudo.

As análises químicas do extrato de casca de jabuticaba demostraram que o composto possui um alto teor de compostos fenólicos, como as antocianinas, presentes também no vinho tinto, com efeitos positivos no metabolismo orgânico.

Os pesquisadores fizeram um experimento com camundongos em processo de envelhecimento a fim de avaliar o limite da dose de extrato da casca de jabuticaba que pode ser consumida para promover os efeitos benéficos desejados e se uma dose alta do composto amplificaria os efeitos.

O envelhecimento está diretamente associado à redução da capacidade metabólica e alterações do metabolismo hepático, glicídico e lipídico. Durante o envelhecimento há uma deficiência de controle do nível de glicose no sangue, um aumento da deposição de triglicerídeos no fígado e desequilíbrio hormonal. Além disso, é comum os idosos apresentarem dislipidemia, hiperinsulinemia, diabetes e doenças cardiovasculares.

A fim de potencializar esses efeitos danosos do processo de envelhecimento, os pesquisadores ofereceram aos camundongos uma dieta rica em gordura (lipídeos), capaz de promover ganho de peso, aumentar a gordura no fígado, estimular a dislipidemia e aumentar os níveis de glicose. A dieta possuía cinco vezes mais lipídeos do que uma dieta normal.

“Estudos apontavam que se os animais consumissem essa dieta hiperlipídica por 60 dias seria suficiente para desenvolverem pré-diabetes e alterações hepáticas. Pensamos em fornecer o extrato por esse tempo para verificar se, no final, eles não teriam esses problemas”, disse Lamas.

Melhoria no fígado

Os camundongos foram divididos aleatoriamente em grupos, dos quais um foi composto por animais jovens, com três meses de idade, que recebeu dieta padrão. Outro foi formado por camundongos com 11 meses de idade, também com dieta padrão. O terceiro grupo foi integrado por camundongos com 11 meses de idade, submetidos a uma dieta rica em gordura.

Um quarto e quinto grupos, compostos por animais envelhecidos, receberam, respectivamente, por gavagem (introduzida por tubo de PVC) uma dose de 2,9 ou 5,8 gramas de extrato por quilo de peso e uma dieta padrão durante 60 dias.

Um sexto e um sétimo grupo, compostos por animais envelhecidos, receberam, respectivamente, por gavagem uma dose de 2,9 ou 5,8 gramas de extrato por quilo de peso e uma dieta rica em gordura durante 60 dias.

As análises revelaram que ambas as doses do extrato da casca de jabuticaba aplicadas nos camundongos envelhecidos impediram o ganho de peso, diminuíram o processo inflamatório e causaram uma redução da hiperglicemia e da dislipidemia – o que preveniu o pré-diabetes.

Além disso, aumentaram os níveis de HDL e a atividade de receptores relacionados à insulina e de algumas moléculas relacionadas à proliferação de peroxissomos – bolsas membranosas que possuem alguns tipos de enzimas digestivas.

“Também percebemos que o extrato da casca de jabuticaba promoveu uma melhoria na morfologia do fígado dos animais”, disse Quitete.

Os pesquisadores também observaram que a dose maior de extrato da casca de jabuticaba, com 5,8 gramas de extrato por quilo do peso do animal, foi mais eficiente na promoção desses efeitos benéficos em comparação com a dosagem menor.

“A dose duplicada apresentou melhores efeitos em vias metabólicas importantes ligadas à obesidade, ao pré-diabetes e à restauração da estrutura do fígado dos camundongos envelhecidos”, disse Quitete.

Os pesquisadores também estão realizando um estudo em que avaliam o uso do extrato da casca de jabuticaba no atraso da progressão do câncer de próstata em camundongos transgênicos, também com apoio da FAPESP.

Os resultados preliminares indicaram que o composto foi capaz de diminuir as lesões na próstata dos animais. “Percebemos uma melhora substancial na morfologia da próstata dos camundongos, além da diminuição do estresse oxidativo e da inflamação”, disse Quitete.

“A diminuição da inflamação e o equilíbrio do estresse oxidativo levaram a uma melhora tecidual e molecular da próstata dos animais”, disse.

O artigo Jaboticaba Extract prevents prediabetes and liver steatosis in high-fat-fed aging mice, de Celina de Almeida Lamas, Valéria Helena Alves Cagnon Quitete e outros, pode ser lido no Journal of Functional Foods em www.sciencedirect.com/science/article/pii/S1756464618303013.

Link:

Olive oil and fungus protect wood from wood rot

Date: November 5, 2018

Source: Eindhoven University of Technology

Summary:
A fungus that does not attack wood, but preserves it. It sounds strange, but it is possible. A new study shows that black fungi on oiled wood can behave like a 'biofinish'. This layer colors the wood and protects it from wood rot and degradation by sunlight. An additional advantage: the fungus automatically repairs damage in the protective layer.

See more at: 
www.sciencedaily.com/releases/2018/11/181105122508.htm

Drinking coffee may reduce your chances of developing Alzheimer's, Parkinson's

Date: November 5, 2018 Source: University Health Network Summary: A new study suggests drinking coffee may protect you against developing both Alzheimer's and Parkinson's disease.

Approximately 500 billion cups of coffee are consumed worldwide each year.

A new study out of the Krembil Brain Institute, part of the Krembil Research Institute, suggests there could be more to that morning jolt of goodness than a boost in energy and attention. Drinking coffee may also protect you against developing both Alzheimer's and Parkinson's disease.

"Coffee consumption does seem to have some correlation to a decreased risk of developing Alzheimer's disease and Parkinson's disease," says Dr. Donald Weaver, Co-director of the Krembil Brain Institute. "But we wanted to investigate why that is -- which compounds are involved and how they may impact age-related cognitive decline."

Dr. Weaver enlisted Dr. Ross Mancini, a research fellow in medicinal chemistry and Yanfei Wang, a biologist, to help. The team chose to investigate three different types of coffee -- light roast, dark roast, and decaffeinated dark roast.

"The caffeinated and de-caffeinated dark roast both had identical potencies in our initial experimental tests," says Dr. Mancini. "So we observed early on that its protective effect could not be due to caffeine."

Dr. Mancini then identified a group of compounds known as phenylindanes, which emerge as a result of the roasting process for coffee beans. Phenylindanes are unique in that they are the only compound investigated in the study that prevent -- or rather, inhibit -- both beta amyloid and tau, two protein fragments common in Alzheimer's and Parkinson's, from clumping. "So phenylindanes are a dual-inhibitor. Very interesting, we were not expecting that." says Dr. Weaver.

As roasting leads to higher quantities of phenylindanes, dark roasted coffee appears to be more protective than light roasted coffee.

"It's the first time anybody's investigated how phenylindanes interact with the proteins that are responsible for Alzheimer's and Parkinson's," says Dr. Mancini. "The next step would be to investigate how beneficial these compounds are, and whether they have the ability to enter the bloodstream, or cross the blood-brain barrier."

The fact that it's a natural compound vs. synthetic is also a major advantage, says Dr. Weaver.

"Mother Nature is a much better chemist than we are and Mother Nature is able to make these compounds. If you have a complicated compound, it's nicer to grow it in a crop, harvest the crop, grind the crop out and extract it than try to make it."

But, he admits, there is much more research needed before it can translate into potential therapeutic options.

"What this study does is take the epidemiological evidence and try to refine it and to demonstrate that there are indeed components within coffee that are beneficial to warding off cognitive decline. It's interesting but are we suggesting that coffee is a cure? Absolutely not."

Story Source:

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

Journal Reference:
Ross S. Mancini, Yanfei Wang, Donald F. Weaver. Phenylindanes in Brewed Coffee Inhibit Amyloid-Beta and Tau Aggregation. Frontiers in Neuroscience, 2018; 12 DOI: 10.3389/fnins.2018.00735

Cite This Page:
University Health Network. "Drinking coffee may reduce your chances of developing Alzheimer's, Parkinson's." ScienceDaily. ScienceDaily, 5 November 2018. <www.sciencedaily.com/releases/2018/11/181105160825.htm>.

If your diet fails, try again; your heart will thank you

Diet fluctuations lead to a rollercoaster of risk for heart disease and diabetes

Date: November 13, 2018 Source: Purdue University Summary: Risk factors for cardiovascular disease closely track with changes in eating patterns, even only after a month or so.

During the holiday season, it can be difficult for even the most determined of us to stick to a healthy diet. A piece of Halloween candy here, a pumpkin spice latte there, and suddenly we're left feeling like we forgot what vegetables taste like.

Our weight isn't the only aspect of our health that can fluctuate during times like these. According to a new article in the journal Nutrients, risk factors for cardiovascular disease closely track with changes in eating patterns, even only after a month or so.

"If you're inconsistent about what kinds of foods you eat, your risk factors for developing these diseases are going to fluctuate," said Wayne Campbell, a professor of nutrition science at Purdue University. "Even in the short term, your food choices influence whether you're going to have a successful or unsuccessful visit with your doctor."

Diet failure isn't an anomaly, it's the norm, and there are a variety of reasons for that. This can lead to repetitive attempts of adopting, but not maintaining, healthy eating patterns.

To assess how these diet fluctuations affect risk factors for diabetes and cardiovascular disease, such as blood pressure and cholesterol, Campbell's team looked to two previous studies (also led by Campbell at Purdue). The research study participants adopted either a DASH-style eating pattern (Dietary Approaches to Stop Hypertension) or a Mediterranean-style eating pattern.

"Our DASH-style eating pattern focused on controlling sodium intake, while our Mediterranean-style focused on increasing healthy fats," said Lauren O'Connor, the lead author of the paper. "Both eating patterns were rich in fruits, vegetables and whole grains."

Participants adopted a healthy eating pattern for five or six weeks and then had their risk factors measured. The study participants then returned to their normal eating patterns for four weeks and came back for a checkup. After adopting a healthy eating pattern again for another five or six weeks, participants had their risk factors assessed one last time.

The results look almost exactly as you'd expect: like a cardiovascular rollercoaster. How fast the participants' health started to improve after adopting a healthier diet is impressive, though. It only takes a few weeks of healthy eating to generate lower blood pressure and cholesterol.

"These findings should encourage people to try again if they fail at their first attempt to adopt a healthy eating pattern," Campbell said. "It seems that your body isn't going to become resistant to the health-promoting effects of this diet pattern just because you tried it and weren't successful the first time. The best option is to keep the healthy pattern going, but if you slip up, try again."

The long-term effects of adopting and abandoning healthy eating patterns on cardiovascular disease are unknown. Research on weight cycling suggests that when people who are overweight repeatedly attempt to lose weight, quit, and try again, that may be more damaging to their long-term health than if they maintained a steady weight. To know if long-term health effects of cycling between eating patterns raise similar concerns, further studies are needed.

Story Source:

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

Journal Reference:
Lauren O'Connor, Jia Li, R. Drew Sayer, Jane E. Hennessy and Wayne Campbell. Short-Term Effects of Healthy Eating Pattern Cycling on Cardiovascular Disease Risk Factors: Pooled Results from Two Randomized Controlled Trials. Nutrients, 2018 DOI: 10.3390/nu10111725

Cite This Page:
Purdue University. "If your diet fails, try again; your heart will thank you: Diet fluctuations lead to a rollercoaster of risk for heart disease and diabetes." ScienceDaily. ScienceDaily, 13 November 2018. <www.sciencedaily.com/releases/2018/11/181113171335.htm>.

Recommending plants to benefit and attract pollinators

Date: November 14, 2018 Source: American Society for Horticultural Science Summary: Pollinating insects are integral to the health of all terrestrial ecosystems and agriculture worldwide. As homeowners attempt to conserve pollinators through horticulture practices, they often seek the advice and guidance of horticulture retail employees regarding what plants they can successfully include on their properties to maximize their intended benefit to pollinators as well as to their home ecosystems.

A survey was conducted by the University of Nebraska to unveil the extent to which horticultural employees are knowledgeable about pollinators. Carter Westerhold, Samuel Wortman, Kim Todd, and Douglas Golick sought to determine what plant and management recommendations these employees were passing along to customers regarding pollinator conservation and to assess what other advice could be added to their repertoire of recommendations to augment their general benefit.

Their findings were published in the article "Knowledge of Pollinator Conservation and Associated Plant Recommendations in the Horticultural Retail Industry" in HortTechnology.

As detailed in the article, pollinating insects are integral to the health of all terrestrial ecosystems and agriculture worldwide. Urbanization can greatly reduce nutritional resources and habitat for pollinators. However, these losses can be mitigated through targeted landscape practices, such as planting nectar- and pollen-rich plants and managing pollinator habitats in urban areas, especially in home landscapes.

As homeowners attempt to conserve pollinators through horticulture practices, they often seek the advice and guidance of horticulture retail employees regarding what plants they can successfully include on their properties to maximize their intended benefit to pollinators as well as to their home ecosystems.

The researchers discovered at the outset that overall employee knowledge was adequate. However, among uncertified and part-time employees, knowledge and awareness was significantly lower, especially related to the breadth of possible plant selection. Due to that evident information gap, the researchers identified several opportunities for educational outreach aimed at improving both employee and customer understanding on this important subject.

Results and determinations of this survey were extrapolated and generalized from its 224 respondents used as a cross-section of horticulture employees nationally. Initial advice from these employees lacked uniformity, although the glaring variables there were often due to an understanding of the needs of localized ecosystems and were based on personal observations from each individual.

However, accurate knowledge of beneficial plants for pollinators proved to be the weakest topic for horticulture employees, signaling a need for specialized education and training to strengthen a verifiable transference of information.

The researchers also determined that more-detailed labeling of pollinator food plants would benefit this endeavor, as customers may purchase more pollinator-friendly plants when correctly labeled as "pollinator friendly." Also, they surmise that businesses could distribute information to customers on pollinator conservation in the form of pamphlets or booklets that focused on plant selection and landscape management.

Public interest in pollinator conservation has increased markedly in the past decade. The number of homeowners seeking pollinator conservation advice from horticulture retail businesses should rise as well. Knowledgeability of horticulture retail staff in plant selection is an important quality for a garden center to have. The results of this survey might help to determine how to better ensure that accurate information is being passed on to customers.

Westerhold adds "The home landscape could be an invaluable asset to pollinator conservation efforts. Our study highlights opportunities for extension and industry to ensure home pollinator conservation efforts are successful by equipping retailers with scientifically accurate information for homeowners."

Story Source:

Materials provided by American Society for Horticultural Science. Note: Content may be edited for style and length.

Journal Reference:
Carter M. Westerhold, Samuel Wortman, Kim Todd, Douglas Golick. Knowledge of Pollinator Conservation and Associated Plant Recommendations in the Horticultural Retail Industry. HortTechnology, 2018; 28 (4): 529 DOI: 10.21273/HORTTECH03973-18

Cite This Page:
American Society for Horticultural Science. "Recommending plants to benefit and attract pollinators." ScienceDaily. ScienceDaily, 14 November 2018. <www.sciencedaily.com/releases/2018/11/181114132011.htm>.

Large areas of the Brazilian rainforest at risk of losing protection

Date: November 14, 2018 Source: Chalmers University of Technology Summary: Up to 15 million hectares of the Brazilian Amazon is at risk of losing its legal protection, according to a new study.

Up to 15 million hectares of the Brazilian Amazon is at risk of losing its legal protection, according to a new study from researchers at Chalmers University of Technology and KTH Royal Institute of Technology, Sweden, and the University of Sao Paulo, Brazil. This is equivalent to more than 4 times the entire forest area of the UK.

"Brazil has favourable conditions for increasing production on land which is already used for agriculture, in particular lands where low-intensity animal grazing is practised. But if the legal protections for nature are weakened, it could lead to agricultural growth being based more on increasing the amount of agricultural land, rather than increasing the production on lands already in use. This would be at the expense of valuable natural ecosystems, with negative impacts on biodiversity. It would also lead to extensive greenhouse gas emissions, since much of the Amazon is covered by forests," says Flavio Freitas at the Department for Sustainable Development, Environmental Science and Technology at KTH, and leader of the study.

In Brazil, there is a legislative requirement that private landowners designate a certain part of their land for the protection of native vegetation. Private landowners in states that lie in the Amazon region may use up to 20 percent of their land for agriculture, with the rest reserved for nature. But the law contains a paragraph which makes it possible for states to reduce this land use restriction, if more than 65 percent the state's territory is protected public land.

"Earlier studies concluded that this paragraph probably would never be invoked. But we have now shown that the ongoing land tenure regularisation process of undesignated land in the Amazon could lead to the paragraph being invoked in several states in the Amazon region. If this happens, it would become legal to use a further 30 percent of the privately-owned land for agriculture," says Göran Berndes, Professor at Chalmers, and one of the authors behind the study.

This means that between 6.5 and 15.4 million hectares could lose the protections they enjoy today. By way of comparison, the total forest area of the UK is about 3.17 million hectares. The areas that might become legally available for agriculture consist primarily of tropical rainforest, which hold high biodiversity values. Additionally, tropical deforestation causes large carbon dioxide emissions, which contributes to global warming.

"Brazil has pledged that by 2025, its greenhouse gas emissions will be at a level 37 percent lower than in 2025," says Göran Berndes. "That will be a struggle if deforestation is not kept down."

"If this protection disappears, it doesn't automatically mean that these rainforests would be lost. But it is important to acknowledge the situation, and to consider possible mitigation actions before such development take place. We hope that our study can make an impact in Brazil as well as internationally," says Flavio Freitas.

"One possibility is that the law could be revised, with the paragraph adjusted or removed entirely. In addition to legal measures, businesses could help to reduce the risk through non-deforestation commitments. Such measures could be motivated by simple economic reasons -- there is a strong international awareness of the downsides of deforestation, and Brazilian agricultural exports will likely be negatively influenced through their association," he continues.

Story Source:

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

Journal Reference:
Flavio L. M. Freitas, Gerd Sparovek, Göran Berndes, U. Martin Persson, Oskar Englund, Alberto Barretto, Ulla Mörtberg. Potential increase of legal deforestation in Brazilian Amazon after Forest Act revision. Nature Sustainability, 2018; 1 (11): 665 DOI: 10.1038/s41893-018-0171-4

Cite This Page:
Chalmers University of Technology. "Large areas of the Brazilian rainforest at risk of losing protection." ScienceDaily. ScienceDaily, 14 November 2018. <www.sciencedaily.com/releases/2018/11/181114132017.htm>.

Rainforest vine compound starves pancreatic cancer cells

Date: November 14, 2018 Source: American Chemical Society Summary: Pancreatic cancer cells are known for their ability to thrive under extreme conditions of low nutrients and oxygen, a trait known in the cancer field as 'austerity.' The cells' remarkable resistance to starvation is one reason why pancreatic cancer is so deadly. Now researchers have identified a compound from a Congolese plant that has strong ''antiausterity'' potential, making pancreatic cancer cells susceptible to nutrient starvation.

Pancreatic cancer cells are known for their ability to thrive under extreme conditions of low nutrients and oxygen, a trait known in the cancer field as "austerity." The cells' remarkable resistance to starvation is one reason why pancreatic cancer is so deadly. Now researchers have identified a compound from a Congolese plant that has strong "antiausterity" potential, making pancreatic cancer cells susceptible to nutrient starvation. They report their results in ACS' Journal of Natural Products.

Pancreatic cancer is one of the deadliest forms of cancer, with a 5-year survival rate of less than 5 percent. Because these cancer cells proliferate so aggressively, they deplete nutrients and oxygen in the region of the tumor. Whereas most cells would die under these extreme conditions, pancreatic cancer cells survive by activating a cell signaling pathway called Akt/mTOR. Some researchers are testing plants for antiausterity compounds that disrupt this pathway. Suresh Awale, Gerhard Bringmann and colleagues previously identified some unusual alkaloid compounds with antiausterity potential from vines found in the Congolese rainforest. Now they wanted to look for additional new compounds from twigs of the vine Ancistrocladus likoko.

The team extracted compounds from ground twigs and separated them by high-performance liquid chromatography. They then characterized the 3D structure of a new alkaloid compound, which they named ancistrolikokine E3. The researchers found that this new compound killed pancreatic cancer cells under conditions of nutrient starvation but not when nutrients were plentiful. Ancistrolikokine E3 also inhibited cancer cell migration and colonization in lab tests, which suggests that the compound could help prevent metastasis in patients. The researchers showed that the compound worked by inhibiting the Akt/mTOR pathway. The new alkaloid is a promising compound for anticancer drug development based on the antiausterity strategy, the researchers say.

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Materials provided by American Chemical Society. Note: Content may be edited for style and length.

Journal Reference:
Suresh Awale, Dya Fita Dibwe, Chandrasekar Balachandran, Shaimaa Fayez, Doris Feineis, Blaise Kimbadi Lombe, Gerhard Bringmann. Ancistrolikokine E3, a 5,8′-Coupled Naphthylisoquinoline Alkaloid, Eliminates the Tolerance of Cancer Cells to Nutrition Starvation by Inhibition of the Akt/mTOR/Autophagy Signaling Pathway. Journal of Natural Products, 2018; 81 (10): 2282 DOI: 10.1021/acs.jnatprod.8b00733

Cite This Page:
American Chemical Society. "Rainforest vine compound starves pancreatic cancer cells." ScienceDaily. ScienceDaily, 14 November 2018. <www.sciencedaily.com/releases/2018/11/181114120314.htm>.