Neuroprotective and anti-inflammatory effects of myricetin 3-glucoside in a rat model of cerebral ischemia

Purpose: To investigate the effect of myricetin 3-glucoside (M3GLS) on middle cerebral artery occlusion (MCAO)-induced cerebral ischemia in a rat model, and the mechanism of action involved. Methods: A cerebral ischemia rat model was established using MCAO under 10 % chloral hydrate anesthesia. Neurological severity score was determined by analyzing reflex, motor and sensory functions, as well as balancing potential. Infarction volume was determined using triphenyl tetrazolium chloride dye, while counting of Nissl bodies was done after toluidine blue staining. The protein expression levels of Bax and Bcl-2 were assayed using western blotting, while cytokine levels were determined by enzyme-linked immunosorbent assay (ELISA). Results: Treatment of cerebral ischemia rats with M3GLS effectively reduced infarct volume, when compared to vehicle-treated group (p < 0.05). Moreover, M3GLS treatment significantly increased the population of Nissl bodies and effectively improved neurologic scores (p < 0.05). In M3GLS-pretreated rats, cerebral ischemia-induced elevation of protein expressions of TNF-alpha, IL-6 and IL-1 beta were significantly suppressed. M3GL treatment significantly reversed cerebral ischemia-mediated downregulation of Bcl-2 protein level, but markedly reduced cerebral ischemia-induced upregulation of Bax protein level (p < 0.05). Conclusion: M3GLS exerts protective effect against cerebral ischemia-induced brain injury in rats via downregulation of inflammatory cytokines. It reduces infarction volume in the brain of cerebral ischemia rats, and regulates Bcl-2/Bax protein ratio. Thus, M3GLS has a potential for use in the clinical management of cerebral ischemia.