Researchers leading the National Institute on Aging’s Intervention Testing Program (ITP) at the University of Michigan in Ann Arbor, the Jackson Laboratory in Bar Harbor, Maine, and the University of Texas Health Sciences Center at San Antonio have found that acarbose, a drug commonly used to treat type 2 diabetes, increases median lifespan of male mice by 22 percent. The drug’s effects were smaller in female mice, producing only a 5-percent increase in lifespan. The effect on maximum lifespan was similar in male and female mice, increasing longevity by 11 percent and 9 percent, respectively.
In the same paper, published online October 26, 2013, in Aging Cell, researchers report the effects of three other agents on mice lifespan: sex hormone 17-α-estradiol (EST); antioxidant nordihydroguaiaretic acid (NDGA); and dye and antioxidant methylene blue (MB). None had as large an impact on lifespan as acarbose. EST increased male median lifespan by 12 percent, but did not affect maximum lifespan; it had no effect on female lifespan. NDGA increased male median lifespan by 8 to 10 percent at three different doses; but, like EST, had no significant effect on female lifespan. Maximum lifespan data are not yet available. MB had no effect on male lifespan and only a 6–percent increase on female maximum lifespan.
The researchers say that these findings reinforce the importance of evaluating both males and females in aging studies, since it appears that some interventions have gender-specific effects.
Acarbose, EST, NDGA, and MB are four of several treatments that have been investigated through the ITP, which studies compounds in mice for their potential to extend lifespan and delay disease and dysfunction. So far, 6 of 18 compounds tested have shown a significant increase in lifespan of at least one sex of mice; other studies are still in progress. A noteworthy discovery from the ITP was that rapamycin, an immunosuppressant, significantly increases lifespan of both male and female mice, mimicking many of the health benefits of calorie restriction. Learn more about the ITP.
Reference: Harrison D, et al. Acarbose, 17-α-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males. Aging Cell, Epub 26 Oct 2013, DOI: 10.1111/acel.12170.