衰老 z-bo 2020-12-16 338

　　Aging is an irreversible natural law. This is a common belief. However, a team of scientists in the United States believes that aging is a disease and is looking for drugs that can cure aging. They also filed an application with the U.S. Food and Drug Administration, suggesting that anti-aging drugs should be listed as a new drug category, and this organization has also recently approved the world's first anti-aging drug metformin for clinical trials. If the trial is successful, It is expected to extend the life span of human beings and delay the onset of senile diseases. In other words, human beings have taken another step towards the goal of "immortality".

　　A, anti-aging drugs found in the soil

　　Aging is a mysterious process. There will be obvious changes such as hair turning white and wrinkles all over, but few people know the changes at the cellular level in their bodies. Scientists believe that aging is the accumulation of tissue damage inside cells. Cells constantly receive signals from people's body and the surrounding environment. These signals will accelerate cell aging, such as oxidative damage and inflammation. This process is an extremely complicated labyrinth that makes researchers quite puzzled. Aging is the biggest risk factor for diseases, and scientists hope to find a "master switch" to control aging. In theory, anti-aging drugs can control this "switch", which can not only slow down or stop aging, but also delay many aging-related Disease occurs. So far, they have used various means to try to find a way to extend human life.

　　 In August of this year, a research team composed of doctors and scientists in the United States filed an application with the US Food and Drug Administration, suggesting that anti-aging drugs be listed as a new drug category. This means that people have regarded aging as a disease rather than a natural law. In fact, many scientists believe that whether anti-aging drugs can be manufactured is no longer a problem, the question is when they will come out.

　　 Scientists have discovered anti-aging drugs more than thirty years ago. This is rapamycin. It was found in soil samples on the island of Rapa Nui in Polynesia and may be the most effective anti-aging drug found so far. Rapamycin is currently used as an immunosuppressant to reduce rejection during kidney transplantation. At the same time, it is also used to treat certain cancers due to its ability to inhibit cell growth. As early as 2009, researchers conducted observational studies on the drug: feeding rapamycin to mice equivalent to 60-year-old humans, as a result, the life span of female mice was extended by 38%, and the life span of male mice was extended. Up 28%. The test also proved that the drug can also extend the lifespan of yeast, worms and fruit flies. The secret of rapamycin to extend lifespan is that it can block the cell channel-mTOR channel. It controls many processes that affect cell growth and reproduction. It is one of the "master switches" researchers have been looking for. It is also all cells in our body. It can control the speed of aging, as well as one of the channels for diseases such as heart disease, cancer, and Alzheimer's disease. This channel gets signals from hormones and nutrients. When food is sufficient, it sends out a signal to make cells absorb nutrients and grow. In this process, the cell metabolism and growth process will produce by-products that stimulate cell aging. When the intake of food calories is restricted, this channel can send a signal to stop the growth of cells-thereby delaying aging. The advantage of rapamycin as an anti-aging drug is that it can block mTOR channels without restricting food calorie intake.

　　 B, try to manipulate genes to extend life

　　 In the 1930s, Clive McKay, a nutritionist at Cornell University, discovered that rats that restricted food calorie intake lived longer than other rats. Over the same period, restricting food calorie intake has been proven to extend the lifespan of yeast, worms, fruit flies, and non-human primates.

　　 However, so far, humans have little knowledge of the principle of restricting food calorie intake to extend life. It is likely to reduce the harmful by-products produced by the cells in the process of breaking down food-free radicals, thereby reducing the pressure on the cells.

　　 Rapamycin simulates the restriction of food calorie intake by blocking the mTOR signal channel. And Harvard University researcher David Sinclair is dedicated to studying another channel, which is the genome called sirtuin. Similar to mTOR, the SIRT1 gene in this genome may be the key to prolong life and prevent aging-related diseases.

　　SIRT1 gene is the switch that controls food calorie intake. In 2003, Sinclair and his colleagues discovered resveratrol, a natural compound in grapes, red wine, and certain nuts. This compound can turn on the SIRT1 gene and extend the lifespan of yeast by 70%.

　　 Then the researchers fed two groups of mice with high-fat food. One group of mice fed with resveratrol lived longer than mice fed with non-resveratrol. However, for mice that do not eat high-fat foods and are fed normally, resveratrol does not show a very significant effect of prolonging life. The results of this study and other studies have raised doubts about the anti-aging effects of resveratrol.

　　 There are more than 4000 studies on resveratrol, but very few studies have been conducted on humans. Therefore, it is too early to draw conclusions on whether resveratrol has the effects of delaying aging and preventing aging diseases.

　　 In addition, researchers are still looking for other ways to manipulate genes. The chromosome telomere is a cap-like structure at the end of a chromosome. It shortens every time a cell divides and is a potential target. When the chromosome telomeres become shorter, the cell will no longer divide and die.

　　 There is an enzyme in the cell responsible for the extension of telomeres, which is called telomerase. Telomerase can fill in defects in DNA replication, thereby prolonging telomere repair, so that telomeres will not be lost due to cell division and increase the number of cell divisions. Ronald and his team of the Dana Farber Cancer Institute in Boston have been working on how to manipulate telomerase, looking for a drug that can enhance telomerase, especially as a treatment for rare diseases such as premature aging in humans. Potential drugs. But it is worth noting that enhancing telomerase can promote cell division and may become tumor cells.

　　 Another Klotho gene related to longevity gene has also been discovered. Researchers have found that mice without the Klotho gene age faster and are more likely to suffer from senile diseases, but it is still too early to discuss whether this gene can be manipulated to delay aging.

　　C, anti-aging drugs enter clinical trials

　　 Although these studies have groundbreaking significance for extending human lifespan, compared with laboratory animals, the role of cell channels and genes in human aging is more complicated. Therefore, the leap from mice to humans still needs to overcome many obstacles. For example, the ability of rapamycin to prolong the lifespan of invertebrates and mice is exciting, but it remains to be seen and explored whether it has the same effect in humans, and rapamycin is not without side effects, it will Increases cholesterol and blood pressure. In 2012, a report on mice taking rapamycin for a long time showed that rapamycin would increase the probability of mice suffering from cataracts and testicular degeneration. Another unresolved problem is that rapamycin will delay aging while making people more susceptible to bacteria and viruses. In this way, it is not a perfect longevity medicine.

　　 Although the way of restricting food calorie intake is generally accepted, scientists do not know whether long-term food calorie restriction is harmful to human nutrition and health. Moreover, although food calorie restriction has achieved exciting results in the laboratory, this approach does not seem to have much effect on rats in the wild. Researchers are currently studying primates, but there is still a long way to go.

　　 So far, the idea of quickly stopping or reversing the ingenious human biological system is tantamount to daydreaming. We still need to conduct more in-depth research on the mechanism of human aging. Although some drugs have shown anti-aging properties in the laboratory, we do not know whether they can safely work in humans. This requires clinical trials to verify. This attempt has already begun. The US Food and Drug Administration recently approved the world’s first anti-aging drug metformin for clinical trials. This drug has been used to treat diabetes in the past and has now successfully extended the life of animals in the laboratory. . If the clinical trial is successful, it is expected to extend the life span of humans and delay the onset of senile diseases. In other words, humans have taken another step toward the goal of "immortality", and hope that it can seek "immortality" in humans. Add a strong stroke to it. At the same time, what we cannot ignore is that to effectively delay aging and prevent aging-related diseases requires a balanced diet and regular exercise. This is an eternal truth.