Protective effects of methoxyflavone derivatives from black galingale against glutamate induced neurotoxicity in primary cultured rat cortical cells

Abstract

To examine the neuroprotective effects of black galingale, its protection was tested against glutamate-induced neurotoxicity in primary cortical cultured neurons. It was found that an aqueous extract of this medicinal plant exhibited significant protection against glutamate-induced toxicity in primary cultured rat cortical cells. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. By such fractionation, bioactive methoxyflavone derivatives were isolated from the methanol extracts from the air-dried rhizomes of black galingale. 5-Hydroxy-3,7,3',4'-tetramethoxyflavone exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 60-70%, at concentrations ranging from 0.1 μm to 10 μm. Therefore, the neuroprotective effect of black galingale might be due to the inhibition of glutamate-induced toxicity by the methoxyflavone derivatives it contains.