Endocrine Abstracts

Background: Parkinson’s disease (PD) is a neurodegenerative disease and a movement disorder characterized by loss of dopaminergic neurons in the substantia nigra causing dopamine depletion in the striatum. Neurodegeneration in PD occurs due to multiple pathways including oxidative stress, mitochondrial damage, protein aggregation. These changes increase during menopausal condition in females when the level of estradiol is decreased. Recently, there has been a growing interest in the action and functions of the ovarian steroid hormone estradiol, particularly on whether they are neuroprotective for such age related disease and neurodegenerative conditions like stroke, PD and Alzheimer’s disease.

Objective: 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.

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.

Results: 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.

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 along with dopamine replacement in PD.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.