Efficacy of Shouzhangshen(Rhizoma Gymnadeniae Crassinervidis)extract against acute high altitude hypoxia-induced brain injury in mice

OBJECTIVE:To evaluate the protective effect of Shouzhangshen(Rhizoma Gymnadeniae Crassinervidis)extract against acute high altitude hypoxia-induced brain injury in mice.METHODS:Sixty C57BL/6J mice were selected and assigned to six groups(n=10):normal control group,low-pressure hypoxia group,positive control group(dexamethasone 500 mg/kg),and three groups treated with Shouzhangshen extract(250,500,and 750 mg/kg,respectively).The Morris water maze test was performed to evaluate alterations in spatial learning and memory deficits.Nissl staining was performed to detect Nissl bodies and neuron damage.Hypoxia-inducible factor(HIF)-1α,interleukin(IL)-1β,tumor necrosis factor(TNF)-α,vascular endothelial growth factor(VEGF),and malondialdehyde(MDA)expression in brain tissue and serum,as well as superoxide dismutase(SOD)and glutathione(GSH)activity in brain tissues were measured by enzyme-linked immunosorbent assays,quantitative real-time-polymerase chain reaction and western blots.RESULTS:The Morris water maze test results showed that Shouzhangshen extract can significantly reduce the latency and swimming distance to escape onto a visible platform,increase neuron density and hierarchy and the number of pyramidal neurons,and decrease the expression of HIF-1α,IL-1β,TNF-α,and VEGF mRNAs and proteins in both brain tissue and serum(P<0.05).Furthermore,significantly lower MDA expression and higher GSH activity were detected in the three groups treated with Shouzhangshen compared with the low-pressure hypoxia group(P<0.05).However,no significant alteration was observed for SOD activity(P>0.05).CONCLUSION:Our findings suggest that Shouzhangshen extract may have a significant effect on acute high altitude hypoxia-induced brain injury in mice.