| Summary: | 碩士 === 靜宜大學 === 食品營養研究所 === 98 === There is a close association between oxidative stress, chronic inflammation and carcinogenesis. Previously we reported that the extracts of red bean (Phaseolus radiatus L. var Aurea, RBE) had the antioxidative characteristics in vitro and in vivo. To get insight into the underlying the antioxidant mechanism and cancer chemopreventive activity of RBE, we investigated the protective effects of RBE on H2O2-induced cytotoxicity in RAW264.7 macrophages. Level of DNA damage, malondialdehyde (MDA) concentrations, and the antioxidant system; such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) , and glutathione (GSH) concentrations were measured. The results showed that co-treatment of the macrophages with RBE could significantly enhance H2O2-decreased cell survival, intracellular MDA, SOD and GPx activity, and also inhibited H2O2 increased DNA damage, intracellular GSH content and CAT activity. In addition, several researches indicate that antioxidants have potential as ant-inflammatory agents. In order to understand the anti-inflammatory effect of RBE, we further performed to investigate the effects of RBE on the lipopolysaccharide (LPS) activation of macrophages and resultant production of inflammatory mediators. In vitro, RBE concentration-dependently prevented the production of nitric oxide, as well as the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) interleukin-1β (IL-1β) , interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) mRNA in LPS-stimulated RAW 264.7 macrophages. Interestingly, the results are similar to findings by anti-inflammatory agent, quercetin except TNF-α mRNA which positive effect on the expression. The findings provide RBE are good antioxidant and anti-inflammatory agent, and may to stopping oxidative stress and inflammatory-mediated carcinogenesis.
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