Protective effects of 3′‐deoxy‐4‐O‐methylepisappanol from <i>Caesalpinia sappan</i> against glutamate‐induced neurotoxicity in primary cultured rat cortical cells

Abstract

To examine the neuroprotective effects of Caesalpinia sappan L., we tested its protection against the glutamate-induced neurotoxicity in primary cortical cultured neurons. We 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, two known compounds - sappanchalcone and 3'-deoxy-4-O-methylepisappanol - were isolated from the methanol extracts from the air-dried and chipped C. sappan. Among these two compounds, 3'-deoxy-4-O-methylepisappanol exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 50%, at concentrations ranging from 0.1 microM to 10 microM. Therefore, the neuroprotective effect of C. sappan might be due to the inhibition of glutamate-induced toxicity by the protosappanin derivative it contains.