A study of the neuroprotective effect of the phenolic glucoside gastrodin during cerebral ischemia in vivo and in vitro

The phenolic glucoside gastrodin (Gas) is a main component extracted from the rhizome of Gastrodia elata, a Chinese herbal medicine, which has long been used for treating dizziness, epilepsy, stroke and dementia. In this study, we investigated the neuroprotective effects of Gas on cerebral ischemic injury in rats caused by transient middle cerebral arterial occlusion (MCAO), oxygen/glucose deprivation (OGD) and glutamate-induced injury in cultured rat hippocampal neurons. Additionally, the effects of Gas on the extracellular glutamate level and changes in intracellular Ca2+ and the generation of nitric oxide (NO) were examined in cultured hippocampal neurons subjected to OGD in vitro. The results showed that the high dose of Gas (100 mg/kg) markedly decreased the infarct volume and edema volume, and improved the neurological functions after MCAO. Gas treatment (15 mu g/mL, 30 mu g/mL) also significantly inhibited OGD- and glutamate-induced neuronal cell death and reduced the extracellular glutamate level following OGD. Moreover, Gas treatment significantly inhibited the OGD-induced Ca2+ and NO increases. In conclusion, the present study indicates that Gas has a neuroprotective action.