Neuroprotective Effects of Longan (Dimocarpus longan Lour.) Flower Water Extract on MPP+-Induced Neurotoxicity in Rat Brain

In this study, the neuroprotective effect of Dimocarpus longan Lour. flower water extract (LFWE) was investigated. First, an in vitro study showed that LFWE concentration-dependently inhibited lipid peroxidation of brain homogenates incubated at 37 degrees C. The antioxidative activity of LFWE was more potent than that of glutathione or Trolox. Furthermore, an ex vivo study found that the basal lipid peroxidation (0 degrees C) and lipid peroxidation incubated at 37 degrees C were lower in the brain homogenates of LFWE-treated (500 mg/day) rats, indicating that the brain of LFWE-treated rats was more resistant to oxidative stress. Moreover, a Parkinsonian animal model was employed to demonstrate that oral administration of LFWE (125-500 mg/kg/day) dose-dependently attenuated 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity in the nigrostriatal dopaminergic system of rat brain. In conclusion, this study suggests that LFWE is antioxidative, anti-inflammatory, and antiapoptotic. Furthermore, oral administration of LFWE appears to be useful in preventing and/or treating central nervous system neurodegenerative diseases, including Parkinsonism.