Exogenous administration of dehydroepiendrosterone attenuates loss of superoxide dismuatse activity in the brain of old rats

Abstract

The influence of exogenously administered dehyroepiendrosterone (DHEA) on the activity of superoxide dismutase (SOD) was investigated in the mitochondrial and cytosolic fractions from cerebral cortex, cerebellum, hippocampus and medulla regions of the brains of 12- and 22-months old rats. DHEA was administered daily at the dose of 30 mg/kg/body wt, intraperitonially (i.p) in both age groups of rats for 1 month. Results showed that SOD activity was significantly higher in the mitochondrial fraction than in the cytosolic fraction, in DHEA-treated animals in both age groups. This indicated that exogenous DHEA affected mitochondrial SOD more than the cytosolic SOD. In terms of percent increase, 22 months-old animals showed significant increase in the SOD activity in both the fractions of all the four brain regions than in the 12 months old DHEA-treated animals. This showed that exogenous DHEA provided more protection to the SOD in ageing brain of older rats (22 months) than the younger (12 month) ones. The study suggests that exogenous DHEA is more beneficial at old age in terms of neuroprotection against oxidative stress-mediated brain dysfunctions and may protect age-related alterations in cognitive functions like learning and memory.