The objective of this study was to investigate protective potential of 17β estradiol (E2) treatment on the activity of monoamine oxidase, calcium homeostasis, membrane polarization, genomic DNA degradation, 4- hydroxynonenal and protein oxidation levels occurring in brains of female rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of estradiol.

The aged rats (12 and 24 months old) (n= 8 for each group) were given subcutaneous injection of 17b-estradiol (0.1 μg/g body weight) daily for one month. After 30 days of hormone treatment, experimental animals of all the groups were sacrificed and brains were isolated for further study.

The results obtained in the present work revealed that normal aging was associated with significant increases in the activity of monoamine oxidase, calcium homeostasis, genomic DNA degradation, 4- hydroxynonenal and protein oxidation levels in the brains of aging female rats, and a decrease in membrane polarization. Our data showed that exogenous administration of E2 brought these changes to near normalcy in aging female rats.

It can therefore be concluded that E2's beneficial effects seemed to arise from its, antioxidant and antilipidperoxidative effects, implying a therapeutic potential drug for age related changes. Based on our studies and others, we conclude that E2 have therapeutic potential for adjunctive therapy along with dopamine replacement in Parkinson's disease.