Lettuce glycoside B ameliorates cerebral ischemia reperfusion injury by increasing nerve growth factor and neurotrophin-3 expression of cerebral cortex in rats

AIMS: The aim of the study was to investigate the effects of LGB on cerebral ischemia-reperfusion (I/R) injury in rats and the mechanisms of action of LGB. MATERIALS AND METHODS: The study involved extracting LGB from P. laciniata, exploring affects of LGB on brain ischemia and action mechanism at the molecular level. The cerebral ischemia reperfusion injury of middle cerebral artery occlusion was established. We measured brain histopathology and brain infarct rate to evaluate the effects of LGB on brain ischemia injury. The expressions of nerve growth factor (NGF) and neurotrophin-3 (NT-3) were also measured to investigate the mechanisms of action by the real-time polymerase chain reaction and immunohistochemistry. STATISTICAL ANALYSIS: All results were mentioned as mean ± standard deviation. One-way analysis of variance was used to determine statistically significant differences among the groups. Values of P < 0.05 were considered to be statistically significant. RESULTS: Intraperitoneal injection of LGB at the dose of 12, 24, and 48 mg/kg after brain ischemia injury remarkably ameliorated the morphology of neurons and brain infarct rate (P < 0.05, P < 0.01). LGB significantly increased NGF and NT-3 mRNA (messenger RNA) and both protein expression in cerebral cortex at the 24 and 72 h after drug administration (P < 0.05, P < 0.01). CONCLUSIONS: LGB has a neuroprotective effect in cerebral I/R injury and this effect might be attributed to its upregulation of NGF and NT-3 expression ability in the brain cortex during the latter phase of brain ischemia.