大枣多糖抗氧化及抗炎活性的研究

本研究通过建立1,1-二苯基-2-苦基肼基(DPPH)自由基、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐（ABTS）自由基、羟基自由基、还原力等4种体外模型研究大枣多糖的抗氧化活性；建立脂多糖（LPS）诱导的巨噬细胞RAW264.7模型研究大枣多糖的抗炎活性。实验结果表明，大枣多糖具有较强的抗氧化活性，对DPPH自由基、ABTS自由基、羟基自由基的半抑制浓度IC50分别为0.9、2.8、1.1 mg/mL；总还原力为1.0时，对应的Vc和大枣多糖浓度分别为0.08 mg/mL和2.95 mg/mL，大枣多糖的抗氧化活性呈浓度依赖性。高剂量的大枣多糖能够显著降低RAW264.7细胞中炎症因子如环氧合酶-2（COX-2），肿瘤坏死因子-α（TNF-α），白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的含量，表明大枣多糖具有较强的抗炎活性。大枣多糖可望作为抗氧化剂和抗炎制剂应用于功能性食品和医药工业。
In this study, antioxidant activity of a jujube polysaccharide from Zizyphus jujuba Mill was investigated by establishing 4 kinds of in vitro models, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl radical (?OH) scavenging activities as well as reducing power assay. The model of macrophage RAW264.7 induced by lipopolysaccharide (LPS) was established to study the anti-inflammatory activity of jujube polysaccharide. The results showed that jujube polysaccharide had strong antioxidant activity and the IC50 of jujube polysaccharide on the DPPH?, ABTS and ?OH free radicals were 0.9, 2.8 and 1.1 mg/mL, respectively. The antioxidant activity of jujube polysaccharide exhibited a dose-dependent manner. When the value of total reducing power reached 1.0, the corresponding Vc and jujube polysaccharide concentrations were 0.08 mg/mL and 2.95 mg/mL, respectively. High doses of jujube polysaccharide could significantly reduce the levels of inflammatory cytokines including cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in RAW264.7 cells, which showed that jujube polysaccharide had strong anti-inflammatory activity. Jujube polysaccharide was expected as an antioxidant and anti-inflammatory agents used in functional food and medicine industry.