Rapamycin prolongs life and helps with Alzheimer's disease, but...
Longevity substance relieved mice of Alzheimer's diseaseAlexey Tymoshenko, GZT.RU
Rapamycin, previously described by scientists as a way to prolong the life of experimental animals, also turned out to be a remedy for Alzheimer's disease.
This is evidenced by experiments on mice.
Rapamycin attracted the attention of biologists almost immediately after its discovery, in 1975. Then scientists isolated a new substance, unknown to them before, from soil samples from Easter Island. Initially, it was planned to use it as an antifungal drug. However, this idea was quickly recognized as unsuccessful, since rapamycin suppressed immunity (was an immunosuppressant) and prevented cell growth (pharmacologists call this effect an antiproliferative effect).
The name "rapamycin", registered by Wyeth, was taken from the language of the locals (the aborigines designate Easter Island "Rapa Nui"). Along with it, there is also an international non–commercial designation - "sirolimus".
It would seem that if a substance has an immunosuppressive and antiproliferative effect, then who needs it? However, the answer to this question was not long in coming: the activity of the immune system must be suppressed after transplants of a donor organ, and the suppression of tissue growth allows you to fight cancerous tumors. Rapamycin began to be produced on an industrial scale first by Wyeth, and after the patent expired, other pharmaceutical companies.
Life extension
In 2009, there was evidence that rapamycin prolongs the life of mice, and quite significantly. In terms of human standards, they lived up to hundreds of years, and the processes of development of cancerous tumors in the body of animals slowed down significantly. It would seem that here it is, a wonderful remedy for a long life!
The cost of rapamycin is estimated at $37 per day of therapy when using the original drug and $20 in case of replacement with generic drugs produced by other companies. Theoretically, with mass production, the price may fall, but so far there is simply no need for the release of rapamycin for all inhabitants of the planet. However, scientists and doctors were in no hurry to rejoice precisely because of the immunosuppressive properties of rapamycin. Yes, mice lived longer when taking it, but a sterile vivarium is one thing and the real world is quite another. The constant risk of developing infectious diseases can negate the increase in life expectancy, so you should not even think about any preventive use of this drug. Another thing is laboratory studies in which biologists are trying to determine the mechanism of action of a substance from Easter Island.
This mechanism, according to preliminary data, is reduced to the effect of rapamycin on a protein codenamed TOR, which, in turn, regulates the rate of protein synthesis and cell division. It is obvious that these processes affect both the growth of cancerous tumors and life expectancy. The question is, what else can rapamycin affect?
Alzheimer's Like many other substances with a wide spectrum of action, rapamycin was tested in a series of experiments designed to find a cure for a variety of diseases.
In 2008, during experiments on mice, researchers from the United States showed the potential effectiveness of rapamycin in the so-called tuberous sclerosis and suggested that the same substance could be useful in the treatment of autism. (Tuberous sclerosis is a rare disease in which several body systems are affected at once, the brain, kidneys, lungs and the cardiovascular system suffer. In all these organs, multiple tumors begin to grow, however non-malignant. With adequate treatment, the patient can live as long as a healthy person.)
And since rapamycin is able to help with diseases of the nervous system and slow down aging, then why not check its effect on animals that develop Alzheimer's disease? Alzheimer's disease, due to its prevalence among the elderly and the severity of symptoms in the late stages, forces developed countries to spend billions of dollars a year searching for potential drugs. Therefore, scientists even have mice at their disposal, in which this disease develops with almost 100 percent probability at a young age.
It was such mice that became the object of research by a group of scientists from the University of Texas. At the age of six months (approximately this corresponds to 20 years, if by human standards), rodents have already had memory problems in special tests. Starting from the age of six months, the experimental group began to add rapamycin to the feed. After 10 weeks, the experimental group, together with the control group, was run through a series of tests and sent to a histological laboratory to study the structure of the brain. (Histological, from the Greek. ίστίομ – "tissue", studies, alas, are carried out posthumously. The brain for them needs to be cut into thin layers, which, after special coloring, are studied under a microscope).
On drugs obtained from the brains of mice who underwent a rapamycin course, scientists found a smaller number of protein plaques formed in Alzheimer's disease and disabling neurons. In addition, such animals showed better results in experiments compared to those who did not receive rapamycin and at the same time were initially similarly predisposed to the development of Alzheimer's disease.
What's next?
Due to the side effects of rapamycin already mentioned above, it is not necessary to talk about its use for the prevention or treatment of Alzheimer's disease yet. However, the new property of rapamycin found by scientists means the discovery of a new direction of research, which may lead to the creation of drugs that can help cope with the disease without significant side effects.
Portal "Eternal youth" http://vechnayamolodost.ru04.03.2010