The experimental treatment developed by researchers at Harvard Medical School turned weak and feeble old mice into healthy rodents by regenerating their aged bodies.
"These mice were equivalent to 80-year-old humans and were about to pass away," said Ronald DePinho, co-author of the paper and a scientist at the Dana-Farber Cancer Institute in Boston. After the experiment, "they were the physiological equivalent of young adults," The Wall Street Journal reported.
The experiment involved telomerase, an enzyme that makes small units of DNA that seal the tips of chromosomes. They act like the plastic caps at the ends of a shoelace, preventing chromosomes from fraying and genes from unraveling. When scientists increased levels of telomerase in the mice, their organs began to rejuvenate.
Shriveled testes grew back to normal and the animals regained their fertility. Other organs, such as the spleen, liver and intestines, recuperated from their degenerated state, the Harvard study said.
Anti-aging therapies could dramatically affect the rapidly increasing elderly population by treating devastating afflictions including dementia, stroke and cardiac failure.
"What we saw in these animals was not a slowing down or stabilization of the aging process. We saw a dramatic reversal -- and that was unexpected," DePinho said.
But replicating that reversal in humans will likely be more difficult. Mice produce telomerase throughout their lives, but the enzyme is switched off in adult humans, an evolutionary trait that prevents cells from dividing out of control. So the risk of cancer cells prospering would substantially increase, Britain's The Guardian reported.