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There are a number of drugs intended to slow the aging process currently being researched. One type of research is related to the observed effects a calorie restriction diet, which has been shown to extend lifespan in some animals[42] Based on that research, there have been attempts to develop drugs that will have the same effect on the aging process as a caloric restriction diet, which are known as Caloric restriction mimetic drugs. Drugs that have been studied for possible longevity effects on laboratory animals because of a possible CR-mimic effect include Rapamycin,[43] Metformin,[44] and Resveratrol.[45] Two drugs that may have potential benefits of combating age-related maladies are Resveratrol and Rapamycin. These drugs are considered to be the forefront drugs in anti-aging research.[46] Before these drugs had been tested, the best-characterized anti-aging therapy was,and still is, calorie restriction or CR. Calorie restriction has been proven to extend the life of mice,yeast, and rhesus monkeys significantly.[47][48] Long-term human trials of CR are now being done.It is the hope of the anti-aging researchers that Resveratrol and Rapamycin may act as CR mimetics to increase the life span of humans.[46] Resveratrol was first thought to be an activator of sirtuins, a family of deacetylases, that would promote anti aging effects without having to restrict caloric intake.[49] However, recent replication studies have failed to show that Resveratrol increases the life span in yeast or mice and that Resveratrol may not activate sirtuins that are biologically beneficial to age reduction.[50][51][52][53] Another study was done showing that Resveratrol activates or inhibits fifteen or more different enzymes.[54] Of those enzymes, one stands out with potential for reducing age-related disease. AMP-activated protein kinase (AMPK) has shown to increase life span of nematodes and prevent obesity in mice.[55] Although Resveratrol has not been proven to extend the life-span of mammals at the current doses tested, Resveratrol could be used to access some of the same molecular pathways that CR does. Several examples would include diet induced obesity, some cancers, cardiovascular disease, and neurodegenerative diseases.[56] While Resveratrol has not been proven to increase life span, Rapamycin has shown much more promise.[46] Rapamycin is shown to increase longevity by inhibiting the target of rapamycin kinase (TOR) the same way CR does.[57] Study systems including yeast, nematodes, flies, and mammals, have shown that reduction of TOR signaling will result in an increased life span.[58][59] Additionally, Rapamycin has similar effects of Resveratrol in protecting against several cancers, cardiovascular, and neurodegenerative diseases.[46][58] Rapamycin also has been shown to act as an immunosuppressant, however more testing is needed to show if the life extending dose comes at the cost of an impaired immune system.[58] Resveratrol and Rapamycin have both shown protection against cancers, cardiovascular disease, and neurodegenerative diseases in multiple study systems.[56][58] Rapamycin looks to have more potential in life span extension than Resveratrol, but may come at a price of immune system impairment.[46][58] Clinical trails are now being performed to see if Rapamycin or Resveratrol will have anti-aging effects in humans. Other attempts to create anti-aging drugs have taken different research paths. One notable direction of research has been research into the possibility of using the enzyme telomerase in order to counter the process of telomere shortening.[60] However, there are potential dangers in this, since some research has also linked telomerase to cancer and to tumor growth and formation.[61] |
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