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

• Published in: Journal of ethnopharmacology 2023-03, Vol.303, p.115953-115953, Article 115953
• Main Authors: Yin, Meijuan, Liu, Zhenyi, Wang, Jing, Gao, Weijuan
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant; Brain Ischemia - drug therapy; Brain Ischemia - metabolism; BYHWD; Cerebral Infarction; Cerebral ischemia-reperfusion; NF-E2-Related Factor 2 - metabolism; Nrf2; Oxidative Stress; PKCε; Protein Kinase C-epsilon - metabolism; Protein Kinase C-epsilon - pharmacology; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion; Reperfusion Injury - drug therapy; Reperfusion Injury - metabolism; Signal Transduction; Superoxide Dismutase - metabolism
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2022.115953

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. The progressive increase of ROS is one of the critical pathogenesis of cerebral I/R injury. ROS are generated during cerebral ischemia and reperfusion. ROS can dramatically impact mitochondrial functional homeostasis and defense, while disruption of mitochondrial structure can continue to generate ROS, forming a vicious cycle. BYHWD can decrease oxidative damage, restore mitochondrial membrane potential and reduce brain I/R damage by triggering PKCε to promote the entry of Nrf2 into the nucleus and enhancing the expression of its downstream antioxidant proteins, like HO-1 and NQO1. [Display omitted]