Suppressive effects of Gua Lou Gui Zhi decoction on MCAO-induced NO and PGE(2) production are dependent on the MAPK and NF-κB signaling pathways

The present study aimed to investigate the inhibitory effects, and underlying mechanisms, of Gua Lou Gui Zhi decoction (GLGZD) in a rat model of neuroinflammation. Sprague-Dawley rats were treated with GLGZD following middle cerebral artery occlusion (MCAO). Neurological function and infarct volume were evaluated to confirm successful generation of the rat model. Subsequently, brain tissues and blood samples were collected for further analysis. Nitric oxide (NO) and prostaglandin E(2) (PGE(2)) were evaluated in peripheral blood samples using the Griess reagent assay and an ELISA, respectively. The relative expression levels of inducible nitric oxide synthase (iNOS) and cylooxygenase-2 (COX-2) were detected by quantitative polymerase chain reaction and immunohistochemistry. The associated pathways, including nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPK) signaling pathways, were detected by electrophoretic mobility shift assay and western blotting. The results demonstrated that treatment with GLGZD significantly inhibited MCAO-induced inflammation; GLGZD suppressed the production of NO and PGE(2), and the expression of iNOS and COX-2, by inhibiting NF-κB activation and MAPK phosphorylation. These findings suggest that GLGZD, a potential agent for post-stroke treatment, may exert anti-inflammatory effects, thus providing neuroprotection.