芡实多糖的提取、抗氧化活性及对质粒DNA氧化损伤防护作用的研究

采用纤维素酶超声辅助法提取芡实多糖,由正交实验获得芡实多糖的最佳提取条件,并探究其体外抗氧化活性及对H2O2光解反应诱导质粒p BR322 DNA损伤的保护作用。结果表明芡实多糖的最佳提取条件为:料液比1∶20(g/m L)、p H3、纤维素酶用量为原料质量的2.0%、超声时间5min、提取时间3h、提取温度40℃,多糖得率为17.04%。芡实多糖清除DPPH·、羟基自由基的能力较好,IC50分别为1.78、6.96mg/m L,清除过氧化氢、超氧阴离子自由基的能力较弱,浓度为10mg/m L时,清除率分别为48.00%、20.32%。芡实多糖对抑制DNA损伤具有显著作用,在多糖水溶液质量浓度为0.08mg/m L时,具有最佳保护作用;在质量浓度大于1.0mg/m L时,对质粒DNA没有保护作用,甚至促进了DNA的损伤。综上所述,芡实多糖具有抗氧化及抑制DNA氧化损伤的能力。 

Antioxidant activity and protective effect on oxidative plasmid DNA damage of polysaccharides from Semen Euryales

The orthogonal experiment was used to optimize the extraction process of polysaccharides from Semen Euryales by cellulase ultrasonic synergistic.The antioxidant capacity and the protecting activity of polysaccharides against DNA damage caused by UV- photolysis and H2O2 treatment were also investigated. The results indicated that the optimal conditions were as follows: liquid ratio 1 ∶ 20 ( g / m L) , p H3, cellulase 2.0%, ultrasonic time 5min, extraction time 3h, temperature 40℃. Under the optimal conditions, the extraction yield achieved 17.04%. The IC50 values of polysaccharides against DPPH· and OH· were 1.78 mg / m L and 6.96 mg / m L, respectively. However, the scavenging abilities on H2O2 and O-2· were 48.00% and 20.32% at the concentration of 10.0mg /m L. In case of protecting activity against DNA damage, 0.08 mg / m L of polysaccharides was optimum. Moreover, it promoted the DNA damage while the mass concentration of polysaccharides was above 1.0mg / m L. In conclusion, Semen Euryales polysacchariides possessed antioxidant activity and protective effects on oxidative plasmid DNA damage.