Grape seed extract elevates antioxidant enzymes, lowers lipid peroxidation in rat CNS

The August 5 2005 issue of Neuroscience Letters published the findings of researchers at the University of Madras in Chennai, India that administering grape seed extract to older rats had a rejuvenating effect on their central nervous system antioxidant system. Reactive oxygen species and reactive nitrogen species oxidize proteins, DNA and lipids in the brain, leading to cell death and such neurodegenerative disorders as Alzheimer's disease or Parkinson's disease. Higher levels of antioxidants in the brain help prevent some of this damage from occurring.

Chinakannu Panneerselvam and colleagues gave young and old male rats 100 milligrams per kilogram body weight grape seed extract per day . Young and old rats who did not receive the extract served as controls.

Upon examination of the spinal cord, cerebral cortex, striatum and hippocampus of the rats after 30 days, lipid peroxidation (a marker of oxidative stress) was found to be increased in the older rats compared to both younger groups. Among rats who received grape seed extract, lipid peroxidation was lower in every area than levels measured in their same-aged nonsupplemented counterparts, but this difference was only significant among the aged group. The antioxidants vitamin C, vitamin E and reduced glutathione, and antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase were lower all areas examined in the older groups than in the younger animals, and similarly, both young and old rats who received grape seed extract had higher levels of antioxidants in nearly every area examined than rats of the same age who did not receive the supplement, yet the difference was significant only in the older group.

The authors suggest that the ability of grape seed extract to reduce lipid peroxidation is due to the free radical scavenging property of flavonoids contained in the extract.

—D Dye