Based on previous findings that this plant extract could directly inhibit the superoxide anion formation (Russo and Borrelli, 2005) and could increase the hippocampal superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities, we suggested that the neuroprotective and cholinoprotective effects of the plant extract might be partly due to its antioxidant (Bhattacharya et al., 2000).