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Xenohormesis
Xenohormesis is a hypothesis that posits that certain molecules such as plant polyphenols, which indicate stress in the plants, can have a longevity-conferring effect in consumers of plants (i.e. mammals) and studies that relationship. It was first used in the paper "Small molecules that regulate lifespan: evidence for xenohormesis" by David Sinclair and colleagues from the Harvard Medical School. If the plants an animal is eating are under stress, their increased polyphenol content may signal forthcoming famine conditions. It could be advantageous for the animal to begin to react—i.e. to hunker down to prepare for the lean times to come. The effects researchers have observed from resveratrol Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi. Sources ... may be just such a response. See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormesis
Hormesis is a characteristic of many biological processes, namely a biphasic or triphasic response to exposure to increasing amounts of a substance or condition. Within the hormetic zone, the biological response to low exposures to toxins and other stressors is generally favorable. The term "hormesis" comes from Greek ''hórmēsis'' "rapid motion, eagerness", itself from ancient Greek ''hormáein'' "to set in motion, impel, urge on", the same Greek root as the word ''hormone''. The term 'hormetics' has been proposed for the study and science of hormesis. In toxicology, hormesis is a dose response phenomenon to xenobiotics or other stressors characterized by a low-dose stimulation, with zero dose and high-dose inhibition, thus resulting in a J-shaped or an inverted U-shaped dose response (e.g. the arms of the "U" are inhibitory or toxic concentrations whereas the curve region stimulates a beneficial response.) Generally speaking, hormesis pertains to the study of benefits of exposu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress (biology)
Stress, either physiological, biological or psychological, is an organism's response to a stressor such as an environmental condition. Stress is the body's method of reacting to a condition such as a threat, challenge or physical and psychological barrier. There are two hormones that an individual produces during a stressful situation, these are well known as adrenaline and cortisol. There are two kinds of stress hormone levels. Resting (basal) cortisol levels are normal everyday quantities that are essential for standard functioning. Reactive cortisol levels are increases in cortisol in response to stressors. Stimuli that alter an organism's environment are responded to by multiple systems in the body. In humans and most mammals, the autonomic nervous system and hypothalamic-pituitary-adrenal (HPA) axis are the two major systems that respond to stress. The sympathoadrenal medullary (SAM) axis may activate the fight-or-flight response through the sympathetic nervous system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenol
Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments. Etymology The name derives from the Ancient Greek word (''polus'', meaning "many, much") and the word phenol which refers to a chemical structure formed by attaching to an aromatic benzenoid (phenyl) ring to a hydroxyl (-OH) group as is found in alcohols (hence the ''-ol'' suffix). The term polyphenol has been in use at least since 1894. Definition The term polyphenol is not well-defined, but is generally agreed that they are natural products "having a polyphenol structure (i.e., several hydroxyl groups on aromatic rings)" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans". *Flavonoids include flavones, flavonols, flavanols, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Sinclair (biologist)
David Andrew Sinclair (born June 26, 1969) is an Australian biologist and academic known for his research on aging and epigenetics. Sinclair is a professor of genetics at Harvard Medical School and is the co-director of its Paul F. Glenn Center for Biology of Aging Research. He is an officer of the Order of Australia (AO). Sinclair has appeared in '' Time'' magazine, '' The New York Times'', '' The Charlie Rose Show'', ''60 Minutes'', '' Boston'' magazine, '' The Washington Post'', '' The Economist'', TED and '' The Joe Rogan Experience''. Early life and education David Andrew Sinclair was born in Australia in 1969, and he grew up in St Ives, New South Wales. His paternal grandmother had emigrated to Australia following the suppression of the Hungarian Uprising of 1956, and his father changed the family name from Szigeti to Sinclair. Sinclair studied at the University of New South Wales, Sydney, obtaining a BSc in biochemistry with honours in 1991 and a Ph.D. in molecula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard Medical School
Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consistently ranked first for research among medical schools by '' U.S. News & World Report''. Unlike most other leading medical schools, HMS does not operate in conjunction with a single hospital but is directly affiliated with several teaching hospitals in the Boston area. Affiliated teaching hospitals and research institutes include Dana–Farber Cancer Institute, Massachusetts General Hospital, Brigham and Women's Hospital, Beth Israel Deaconess Medical Center, Boston Children's Hospital, McLean Hospital, Cambridge Health Alliance, The Baker Center for Children and Families, and Spaulding Rehabilitation Hospital. History Harvard Medical School was founded on September 19, 1782, after President Joseph Willard presented a report with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Famine
A famine is a widespread scarcity of food, caused by several factors including war, natural disasters, crop failure, Demographic trap, population imbalance, widespread poverty, an Financial crisis, economic catastrophe or government policies. This phenomenon is usually accompanied or followed by regional malnutrition, starvation, epidemic, and increased death, mortality. Every inhabited continent in the world has experienced a period of famine throughout history. In the 19th and 20th century, generally characterized Southeast and South Asia, as well as Eastern and Central Europe, in terms of having suffered most number of deaths from famine. The numbers dying from famine began to fall sharply from the 2000s. Since 2010, Africa has been the most affected continent of famine in the world. Definitions According to the United Nations World Food Programme, famine is declared when malnutrition is widespread, and when people have started dying of starvation through lack of access to suf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunker Down
Squatting is a versatile posture where the weight of the body is on the feet but the knees and hips are bent. In contrast, sitting involves taking the weight of the body, at least in part, on the buttocks against the ground or a horizontal object. The angle between the legs when squatting can vary from zero to widely splayed out, flexibility permitting. Another variable may be the degree of forward tilt of the upper body from the hips. Squatting may be either full or partial. Crouching is usually considered to be synonymous with squatting. It is common to squat with one leg and kneel with the other leg. One or both heels may be up when squatting. Young children often instinctively squat. Among Chinese, Southeast Asian and Eastern European adults, squatting often takes the place of sitting or standing. Etymology Squatting comes from the Old French ''esquatir/escatir'', meaning to "compress/press down". The weight-lifting sense of squatting is from 1954.Harper, D. (n.d.). Etymol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resveratrol
Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi. Sources of resveratrol in food include the skin of grapes, blueberries, raspberries, mulberries, and peanuts. Although commonly used as a dietary supplement and studied in laboratory models of human diseases, there is no high-quality evidence that resveratrol improves lifespan or has a substantial effect on any human disease. Research Resveratrol has been studied for its potential therapeutic use, with little evidence of anti-disease effects or health benefits in humans. Cardiovascular disease There is no evidence of benefit from resveratrol in people who already have heart disease. A 2018 meta-analysis found no effect on systolic or diastolic blood pressure; a sub-analysis revealed a 2 mmHg decrease in systolic pressure only from res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
