Background: Methyl mercury (MeHg) is one form of organic Hg. Brain tissue is the most susceptible for its toxicity. Both berberine (BBR) and green tea extracts (GTex) exhibit antioxidant capabilities.
Aim: The current study assessed biochemical and histological changes to compare between impact of BBR and GTex on MeHg-induced cerebellar toxicity in rats.
Methods: forty eight male albino rats were used. Control group; Subgroup Ia: received no treatment. Subgroup Ib: received 1 mg of L-cysteine powder dissolved in 1 ml distilled water. Subgroup Ic: recieved 1 ml of distilled water. Group II(BBR) group: received 100 mg/kg of BBR orally daily for 30 days. Group III (GTex) group: received GTex solution as their only source of drinking water for 30 days. Group IV(MeHg) group: Rats received MeHg orally once daily for 30 days at a dose of 10 mg/kg. Group V(MeHg + BBR) group: received 100 mg/kg of BBR by orally daily along with MeHg for 30 days. Group VI(MeHg+ GTex) group: received GTex solution as their only source of drinking water, combined with MeHg. The cerebellum was taken out of animals under anaesthesia after 30 days. Biochemical analysis and light microscopic inspection of cerebellar tissues were conducted.
Results: MeHg significantly raised MDA and NO levels, while significantly lowering GSH levels in comparison to control subgroup Ia. Histologically, Purkinje cells in MeHg group were destroyed, others had pyknotic nuclei. Mean area% of positive cells for bax immunostain significantly increased, the optical density of calbindin immunopositive cells dramatically reduced . When compared to the MeHg group, both BBR and GTex treatments significantly reduced MDA and NO levels and significantly improved GSH levels , improved histological cerebellar architecture, and reversed calbindin and bax immunoexpressions.
Conclusions: Following MeHg poisoning, BBR had more beneficial effect on the rat cerebellum than GTex but without significant difference.