A wonder pill that prolongs life and cuts the risks of developing deadly diseases. Scientists have been looking for such a drug for a long time. Research in this direction shows that enhancing the expression of a certain gene called SIRT1 (sirtuin 1) may fare good results in this respect. Recently, researchers at the National Institute on Aging at the National Institutes of Health report that after feeding mice with sirtuin supplements their lives were significantly prolonged and showed better health than the control group of mice.
Sirtuin 1, or SIRT1, is known to play an important role in maintaining metabolic balance in multiple tissues, and studies in various organisms have shown that activating the protein can lead to many health benefits. Additionally, the NIANIH scientists report in the Cell Press journal that expression of SIRT1 is also associated with the delay of age-associated diseases in several animal models.
Representative photographs from blinded histopathological analysis of kidney, liver, and lung panels for mice on standard diet (SD) and SRT1720 supplementation (credit: Sarah J. Mitchell et al./Cell Reports)
Dr. Rafael de Cabo along with colleagues fed mice beginning at 6 months of age with a diet containing a small molecule that activates SIRT1, called SIRT1720, for the remainder of their lives. It was found that SIRT1720 significantly extended the average lifespan of mice by 8.8%. In addition, the 100 mg/kg SRT1720 diet also reduced body weight and body fat percentage, and it improved muscle function and motor coordination throughout the animals’ lives.
Besides the beneficial metabolic effects, SRT1720 supplementation led to decreases in total cholesterol and LDL-cholesterol levels, which might help protect against heart disease, and improvements in insulin sensitivity, which could help prevent diabetes. The supplement was also found to be effective against tissue inflammation, yet again backing it longevity properties since low-grade chronic inflammation is thought to contribute to aging and age-related diseases.
“Here, we show for the first time that a synthetic SIRT1 activator extends lifespan and improves healthspan of mice fed a standard diet,” says Dr. de Cabo. “It illustrates that we can develop molecules that ameliorate the burden of metabolic and chronic diseases associated with aging.”
Like I said before, though, sirtuin is no new player in the longevity game. Two years ago, I wrote about the developments at the time concerning sirtuin research. No particular connection to enhanced lifespan from SIRT1 in fruit flies or nematodes was discovered, but tests on mammals hadn’t been made yet.
What’s more interesting maybe is that researchers at Bar-Ilan University in Ramat-Gan, Israel chose to take an alternate route, yet still in the sirtuin family – SIRT6. Instead of feeding them supplements, the Israeli researchers engineered mice that overexpressed SIRT6 and found male mice median lifespan rose by 14.5% in one line of their transgenic mice and 9.9% in another. When maximum life span is concerned, the metric rose by 15.8% in the first line of mice, and 13.1% in the second. Curiously enough, there weren’t any signaled differences in lifespan for female mice.
