Antioxidant and Neuronal Cell Protective Effects of Aqueous Extracts from Lotus Leaf Tea

Abstract

Antioxidant and neuronal cell protective effects of aqueous extract from lotus (Nelumbo nucifera) leaf tea (LLTE) were investigated. The 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging effect, ferric reducing antioxidant power, and malondialdehyde inhibition of LLTE were increased in a dose dependent manner. Intracellular reactive oxygen species accumulation resulting from hydrogen peroxide (H2O2) treatment was significantly reduced when LLTE were present in the media compared to PC12 cells treated with H2O2 only. In neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl- tetrazoliumbromide (MTT), LLTE showed protective effect against H2O2-induced neurotoxicity. In addition, lactate dehydrogenase release into medium was also inhibited by LLTE (7.13-43.89%). Total phenolics of LLTE were 33.16 mg/g and a quercetin was identified as major phenolics (105.93 mg/100g). Therefore, above these data suggest that LLTE including quercetin may be useful in the natural antioxidant substance, and may reduce the risk of neurodegenerative disease.