(-)-Epigallocatechin gallate attenuates NADPH-dNOS expression in motor neurons of rats following peripheral nerve injury

摘要

BackgroundOxidative stress and large amounts of nitric oxide (NO) have been implicated in the pathophysiology of neuronal injury and neurodegenerative disease. Recent studies have shown that (-)-epigallocatechin gallate (EGCG), one of the green tea polyphenols, has potent antioxidant effects against free radical-mediated lipid peroxidation in ischemia-induced neuronal damage. The purpose of this study was to examine whether EGCG would attenuate neuronal expression of NADPH-dNOS in the motor neurons of the lower brainstem following peripheral nerve crush. Thus, young adult rats were treated with EGCG (10, 25, or 50 mg/kg, i.p.) 30 min prior to crushing their hypoglossal and vagus nerves for 30 seconds (left side, at the cervical level). The treatment (pre-crush doses of EGCG) was continued from day 1 to day 6, and the animals were sacrificed on days 3, 7, 14 and 28. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry were used to assess neuronal NADPH-dNOS expression in the hypoglossal nucleus and dorsal motor nucleus of the vagus.