The two thought this might be a way to reverse the effects of aging on mitochondria, and in various trials found it to work to some degree. Free radicals were still damaging the cell, however, so they decided to pair it with one of the few antioxidants that gets into mitochondria, alpha-lipoic acid. Lipoic acid is produced by mitochondria and boosts levels of other antioxidants.
In the second of the PNAS studies, Hagen, Ames and colleagues compared 2- to 4-month-old rats to 24- to 28-month-old rats, all fed acetyl-L-carnitine in their water and alpha-lipoic acid in their chow.
After as much as a month on the supplements, the old and lethargic rats became more peppy, Ames said.
"We significantly reversed the decline in overall activity typical of aged rats to what you see in a middle-aged to young adult rat 7 to 10 months of age," Hagen said. "This is equivalent to making a 75- to 80-year-old person act middle-aged. We've only shown short-term effects, but the results give us the rationale for looking at these things long term."
They found also that the combination of lipoic acid and acetyl-carnitine improved mitochondrial activity and thus cellular metabolism, and increased levels of various chemicals known to decline with age, including ascorbic acid, an antioxidant.
In a third study, Liu, Hagen, Ames and colleagues fed old rats a similar diet of the two supplements and looked at memory function as measured by the Morris water maze test and a peak procedure for assessing temporal or time-based memory developed by Seth Roberts, professor of psychology at UC Berkeley. They found that supplementation improved both spatial and temporal memory, and reduced the amount of oxidative damage to RNA in the brain's hippocampus, an area important in memory. In electron microscope pictures of cells from the hipp
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Contact: Robert Sanders
rls@pa.urel.berkeley.edu
510-643-6998
University of California - Berkeley
18-Feb-2002