Rapamycin is a drug that was originally developed to suppress the immune response to prevent organ rejection in kidney transplant patients. It is now being studied (and used) as a “geroprotective” drug to prolong longevity. It has a number of interesting effects on our physiology.
It also has a fascinating history.
Rapamycin was discovered by a Canadian expedition to Easter Island in 1964. The Polynesian name for Easter Island is “Rapa Nui,” hence the name “rapamycin.” It is an antibiotic produced by a bacterium in the soil called Streptomyces hydroscopicus. Studies over the next 2 decades demonstrated that rapamycin inhibits fungal growth and functions as an immunosuppressant. Subsequent studies showed that it inhibits a molecule now called mTOR (mammalian – or machanistic – Target Of Rapamycin). mTOR inhibition has favorable effects on many diseases, including cancer, diabetes, arthritis, osteoporosis, heart failure, and the disease known as aging. mTOR is ubiquitous in the body.
The sub-type mTOR1, among other molecules found in humans and other primates, is responsible for inflammation. Chronic inflammation has adverse effects on longevity.
Rapamycin mimics the effects of caloric restriction and intermittent fasting, both of which extend lifespan in laboratory animals (to be discussed further in upcoming articles).
One beneficial effect of caloric restriction and intermittent fasting is that they activate the process of “autophagy” in which deadcells in the body that promote inflammation are destroyed.
In mice, rapamycin prolongs healthy life even when started at the age of 20-months, equivalent to around 65 years in humans. There is a current, large study in domestic dogs that may provide confirmatory results. We need this information, since human studies would be very difficult to conduct at this stage.
Some clinicians are already prescribing rapamycin to their patients who are especially interested in longevity. There is no standard dosing, but 5-8 mg is commonly used taken once a week by mouth.
Stay tuned for more information on rapamycin as a longevity drug!
Note: Although I am a physician, the content in this article is not meant to diagnose, treat, cure or prevent illness or disease in the reader – it is for educational purposes only.
References
- Bitto A, Ito TK, Pineda VV, et al. Transient rapamycin treatment can increase lifespan and healthspan in middle-aged mice. eLife 2016;5:e15361.
- K Ganesh S, C SD. Formulation of cost-effective medium and optimization studies for enhanced production of rapamycin. Microb Cell Fact. 2023 Sep 20;22(1):189.
- Zhilin Z, Tao T, Hongmei L, Xiao Zhu. mTOR signaling pathway and mTOR inhibitors in cancer: progress and challenges. Cell Biosci 2020;10:31-42.
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