Joy Ochai - Neuroscience Unit, Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Medical Sciences, Ahmadu Bello University, Zaria, Nigeria
Samuel Adebisi - Neuroscience Unit, Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Medical Sciences, Ahmadu Bello University, Zaria, Nigeria
Augustine Ibegbu - Department of Human Anatomy, Faculty of Basic Medical Sciences, Alex Ekwueme Federal University, Ndufu-Alike, Ebonyi state, Nigeria

Background: The protective activity exerted by Psidium guajava on the nervous system has been suggested to be via its antioxidant composition; however, its role in mercury-induced neurotoxicity remains elusive. This study investigated the ameliorative activity of ethanolic extract of P. guajava leaves on mercuric chloride-induced toxicity in the cerebral cortex of male Wistar rats.Methods: Thirty-five (۳۵) male Wistar rats were separated into seven groups with five rats each. Group, I served as control, Group II received ۴۱.۵ mg/kg of mercuric chloride (HgCl۲), Group III received ۱۰۰۰ mg/kg bwt of EEPGL, Group IV received ۴۱.۵ mg/kg of HgCl۲ and distilled water, Group V received ۴۱.۵ mg/kg of HgCl۲ and ۵۰۰ mg/kg bwt of EEPGL, Group VI received ۴۱.۵ mg/kg of HgCl۲ and ۱۰۰۰ mg/kg bwt of EEPGL, while Group VII received ۴۱.۵ mg/kg HgCl۲ and ۱۱۹۰ mg/kg bwt of Vitamin C. At the end of the administration, the brains of the Wistar rats were excised, oxidative stress markers quantified and brain tissues were fixed in Bouin’s fluid, processed, and stained for histological studies.Results: The results revealed a significant decrease in body weight gain and oxidative stress markers, weak staining of Nissl substance and cytoarchitectural distortion of the cerebral cortices of Wistar rats in mercuric chloride only treated groups when contrasted to the Control and the Groups co-administered mercuric chloride and increasing doses of EEPGL.Conclusion: Ethanolic extract of P. guajava leaves was able to ameliorate neurotoxicity induced by mercuric chloride exposure by mitigating against oxidative stress, preventing weight loss and distortion in the cytoarchitecture of the cerebral cortex.

Mercuric chloride, Psidium guajava, Cerebral cortex, Neurodegeneration, antioxidants