Arctigenin protects focal cerebral ischemia-reperfusion rats through inhibiting neuroinflammation

Stroke is the third leading cause of death in industrialized countries and the most important cause of acquired adult disability. Many evidences suggest that inflammation accounts for the progression of cerebral ischemic injury. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignin isolated from certain plants, has shown anti-inflammatory activity against diabetes and Alzheimer's disease. In this study, we tested whether arctigenin can protect middle cerebral artery occluded (MCAO) rats. Male Sprague-Dawley rats were pretreated with arctigenin or vehicle for 7 d before being subjected to transient occlusion of middle cerebral artery and reperfusion. Rats were evaluated at 24 h after MCAO for neurological deficit scoring. Furthermore, the mechanism of the anti-inflammatory effect of arctigenin was investigated with a focus on inflammatory cells, proinflammatory cytokines, and transcriptional factors. Arctigenin significantly reduced cerebral infarction and improved neurological outcome. Arctigenin suppressed the activation of microglia and decreased the expression of interleukin (IL)- 1β and tumor necrosis factor (TNF)-α. These results revealed that arctigenin has a promising therapeutic effect in ischemic stroke treatment through an anti-inflammatory mechanism.