Protective Effects of Extract with Phenolics from Camellia (Camellia japonica) Leaf against Oxidative Stress-induced Neurotoxicity

摘要

Antioxidant and neuronal cell protective effects of aqueous extract from camellia {Camellia japonica) leaf (CJLE) were evaluated The 1,1-phenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferric reducing/antioxidant power (FRAP) assays of the CJLE were increased in a dose dependent manner. In neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide (MTT), the aqueous extract showed protective effect against H_2O_2-induced neurotoxicity and lactate dehydrogenase (LDH) release into medium was also inhibited by CJLE (7.13-43.89%). The cell viability of CJLE was higher than vitamin C (200 μM) by neutral red uptake (NRU) assay at a concentration of 250-1,000 μg/ mL. Phenolics of CJLE were 21.75 mg/g, and major phenolic compounds were quercetin (12020 mg/100 g) and kaempferol (88.13 mg/100 g). Therefore these data suggested that the CJLE including above phenolics may be useful in the natural antioxidant substance and reduce the risk of neurodegenerative disease such as Alzheimer's disease.