Buyang Huanwu decoction alleviates oxidative injury of cerebral ischemia-reperfusion through PKCε/Nrf2 signaling pathway

Ischemic stroke is a significant risk factor for human health, and Buyang Huanwu Decoction is a classical and famous Chinese formula for treating it, but without clear pharmacological mechanism.The aim of this study was to investigate that the molecular mechanism of BYHWD activation of the PKCε/Nrf2 signaling pathway to attenuate cerebral ischemia-reperfusion (I/R) oxidative damage.The MCAO method was used to establish a brain I/R injury model in SD rats, and neurological deficits were evaluated by neurological function score. Neuronal damage was observed by Nissl staining and immunofluorescence detection of MAP2 expression. Oxidative damage was observed by ROS, SOD, GSH-PX, MDA, and 8-OHdG. Changes in mitochondrial membrane potential were detected by using the fluorescent probe JC-1. The Western blot analysis detected protein expression of PKCε, P-PKCε, total Nrf2, nuclear Nrf2, HO-1, and NQO1.BYHWD significantly enhanced neural function, reduced neuronal damage, inhibited the production of ROS, decreased MDA and 8-OHdG levels, increased SOD and GSH-PX activity to reduce oxidative damage, and restored mitochondrial membrane potential. BYHWD and Nrf2 activator TBHQ increased total Nrf2, nucleus Nrf2 protein expression, and its downstream HO-1 and NQO1 proteins, and the administration of the Nrf2 inhibitor brusatol reduced the enhancing effect of BYHWD. Meanwhile, BYHWD increased the expression of PKCε and P-PKCε and the administration of the PKCε inhibitor εV1-2 reduced the effect of BYHWD in increasing the expression of PKCε, P-PKCε, nuclear Nrf2, and HO-1, as well as promoting the effect of Nrf2 translocation to the nucleus.This study marks the first to demonstrate that BYHWD ameliorates oxidative damage and attenuates brain I/R injury by activating the PKCε/Nrf2/HO-1 pathway.