Regulation of iNOS -NF-kappa B- COX-2 inflammatory pathway by alpha-pinene neuroprotective effects in brain ischemia model

Abstract Inflammatory stimulus during cerebral ischemia are the central component in the progression of cell damage and pathological events in the brain. α-Pinene is an organic compound of many aromatic plants and is known as a potent agent to possess antimicrobial, antioxidant, and anti-inflammatory properties. Here, we sought to identify the anti-inflammatory mechanism by which α-Pinene improves brain ischemia injury. Male Wistar rats underwent a MCAO surgery for 1 hour and different doses of alpha-pinene (25, 50, and 100 mg/kg) were intraperitoneally injected immediately after reperfusion to test this hypothesis. Gene and protein expression of inflammatory mediators inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB) p65 were determined by RT-PCR and Enzyme-linked immunosorbent assay (ELISA). Results demonstrated that alpha-pinene regulates complex post-ischemic inflammatory responses. NF-κB p65 gene and protein expression increased in the hippocampus, cortex, and striatum after 24 h of reperfusion, and alpha-pinene significantly inhibited NF-kB p65 expression. In addition, the gene and protein expression of iNOS and COX-2 in the hippocampus, cortex, and striatum was suppressed by alpha-pinene treatment after 1 h of MCAO and 24 h of reperfusion. Results showed that alpha-pinene protects the cerebral against ischemic damage caused by MCAO, and this effect may be through the regulating iNOS -NF-kappa B- COX-2 inflammatory pathway.