Baicalin attenuates global cerebral ischemia/reperfusion injury in gerbils via anti-oxidative and anti-apoptotic pathways.

Baicalin is an important medicinal herb purified from the dry roots of Scutellaria baicalensis Georgi. The present study was undertaken to evaluate the neuroprotective effects of baicalin in gerbils subjected to transient global cerebral ischemic-reperfusion injury. Baicalin at doses of 50, 100 and 200mg/kg was intraperitoneally injected into the gerbils immediately after cerebral ischemia. Seven days after reperfusion, hematoxylin and eosin (HE) staining was performed to analyze hippocampal CA1 pyramidal damage histopathologically. In addition, in order to understand the potential protective mechanism of baicalin, we examined anti-oxidative enzymes, such superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), non-enzymatic scavenger glutathione (GSH) and measured the content of malondialdehyde (MDA) in hippocampus. The mRNA and protein expressions of BDNF were determined in ischemic hippocampus by real-time RT-PCR and Western blot, respectively. Evidence for neuronal apoptosis was detected by real-time RT-PCR, Western blot and caspase-3 activity measurement. Histopathological examination showed that the administration of baicalin by the dose of 100 and 200mg/kg significantly attenuated ischemia-induced neuronal cell damage. Reduced level of MDA, obviously elevated activities of SOD and GSH as well as GSH-PX were also found in baicalin-treated groups. Further investigation demonstrated that treatment with baicalin remarkably promoted the expression of BDNF and inhibited the expression of caspase-3 at mRNA and protein levels by real-time RT-PCR and Western blot, respectively. Besides, caspase-3 activity assay also elucidated that the administration of baicalin could significantly suppress caspase-3 in ischemic gerbils hippocampus. Theses findings suggest that baicalin's neuroprotection appears to be associated with its anti-oxidative and anti-apoptotic properties in global cerebral ischemia in the gerbils.