The antioxidant activities of the extracts of dangyuja (Citrus grandis Osbeck) leaves were evaluated. The highest phenolic content was obtained from the ethyl acetate fraction (EF) (202.1±0.8 mg GAE/g dried extract) and it exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The cytoprotective effects of EF on oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in a human hepatoma cell line, HepG2 cells, were investigated to understand the intracellular antioxidant mechanisms. Treatment of HepG2 cells with EF prior to oxidative stress was found to inhibit reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage in a dose-dependent manner. Gas chromatography-mass spectrometry (GC-MS) studies on EF resulted in tentative identification of 19 compounds representing 94.3% of the total content. Taken together, these results demonstrated that EF has excellent antioxidant activities and thus dangyuja leaves have great potential as a source for natural antioxidant which can be applied in food products.
목차
Abstract Introduction Materials and Methods Materials Preparation of extracts Determination of total phenolics and flavonoids Gas chromatography GC-MS Free radical scavenging activity Cell culture Determination of ROS generation Measurement of lipid peroxidation Determination of DNA damage (Comet assay) Cytotoxicity assay Statistical analysis Results and Discussion Total phenolic content and total flavonoid content DPPH free radical scavenging activity Effect of EF on t-BHP-induced intracellular ROSgeneration Compositional analysis of EF References
Yunjung Kim [ Faculty of Biotechnology, College of Applied Life Sciences, Cheju National University ]
Moonjae Cho [ Department of Medicine, Medical School, Cheju National University ]
Somi Kim Cho [ 1Faculty of Biotechnology, College of Applied Life Sciences, Cheju National University, The Research Institute for Subtropical Agriculture and Biotechnology, Cheju National University ]
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