Research progress on aging mechanism and drugs and the role of stem cells in anti-aging process

There have been many discussions on longevity from ancient times to the present day. In the Laozi, it is said, “Heaven and earth are long and enduring because they do not arise from themselves, so they can live forever.” In Zhuangzi - Zai You, it is also said, “Keep your mental peace, and your body will be healthy. Don't strain your body and don't consume your spirit to live a long life.” It is clear that people attach importance to anti-aging and the desire for longevity. Throughout human history, we have treated aging as an inevitable process, but with the development of medical science, we have become more aware of the various molecular changes in the human body. In an aging society, more people are suffering from age-related diseases such as osteoporosis, Alzheimer's disease, and cardiovascular disease, which has led to a search for anti-aging. However, by ‘living longer’ we mean not only living but also living longer in good health. The mechanisms of aging are still unclear and there is a great deal of interest and curiosity in how to combat aging effectively. Some potential criteria exist for the determination of anti-aging drugs: the first criterion is the ability to exert life-extending effects in model organisms, preferably in mammals; the second criterion is the ability to prevent or delay several age-related diseases in mammals; and the third criterion is the ability to inhibit the transition of cells from a quiescent to a senescent state. Based on these criteria, the current anti-aging drugs often involved are rapamycin, metformin, curcumin and other polyphenols, polysaccharides, resveratrol, etc. The most studied and relatively well-understood pathways and factors of aging are currently known to include seven enzymes, six biological factors, and one chemical, which mainly involve more than ten pathways such as Nrf2/SKN-1; NFκB; AMPK; P13K/AKT; IGF; and NAD.