Endocrine Abstracts

Background: Alzheimer’s disease (AD) is the most common form of dementia in the elderly. AD is characterized by the presence of amyloid plaques which are formed from deposits of b-amyloid protein (Ab). These changes increase during menopausal condition in females when the level of estradiol is decreased.

Objective: The objective of this study was to investigate neuroprotective potential of 17β estradiol (E2) treatment on the activities of acetylcholinesterase and monoamine oxidase, membrane fluidity, neurolipofuscin, genomic DNA degradation, protein oxidation levels and testing learning memory, 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.

Methods: The aged rats (12 and 24 months old) (n=8 for each group) were given subcutaneous injection of 17β -estradiol (0.1 μg/g body weight) daily for 1 month. After 30 days of hormone treatment, experimental animals of all the groups were sacrificed and brains were isolated for further study. Learning was tested in a Morris water maze and ultrastructural studies of brain region by MRI.

Results: The results obtained in the present work revealed that normal aging was associated with significant increases in the activity of monoamine oxidase, genomic DNA degradation and protein oxidation levels in the brains of aging female rats, and a decrease in acetylcholinesterase activity and membrane polarization. Ultrastructural studies of the frontal cortex of exposed rats revealed that the changes were more pronounced in the aged treated rats in terms of presence of lipofuscin, vacuolization and lysosomal degradation. Our data showed that exogenous administration of E2 brought these changes to near normalcy in aging female rats.

Conclusions: 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 for the AD.