杨梅叶多酚的自由基清除活性与防护DNA损伤的研究

Free Radical Scavenging and DNA Damage Protection Activities of Bayberry Leaf Polyphenol

基于超声辅助提取技术,采用单因素和正交试验,优化杨梅叶多酚的提取工艺。结果表明:杨梅叶多酚的最优提取条件是:温度40℃,提取时间45 min,乙醇体积分数50%,料液比为1∶25。在此条件下,杨梅叶多酚的得率为6.45 mg/g,是优化前的2.7倍。在此基础上研究了杨梅叶多酚的自由基清除活性,结果显示:杨梅叶多酚的总抗氧化能力等价于0.57 mg trolox,且多酚清除DPPH自由基、ABTS自由基、超氧阴离子、羟自由基的IC50分别为11.04,4.28,94.1,28.75μg/mL。对杨梅叶多酚对神经胶质细胞DNA损伤的保护作用的研究表明,过氧亚硝基阴离子(OONO-)能引起神经胶质细胞的DNA损伤(损伤率达43.8%)和细胞毒性(细胞存活率为49.5%),而15μg/mL杨梅叶多酚能显著抑制过氧亚硝基阴离子引发的DNA损伤(损伤率24.1%)和细胞毒性(细胞存活率75.7%)。

This study investigated the extraction process of polyphenol from bayberry leaf.According to the single factor and the orthogonal experiment,the optimum conditions for extraction were as follows： water bath at 40 ℃,50% ethanol,ultrasonic extracting for 45 min and the material-liquid ratio of 1∶25（g∶mL）.Under this condition,the polyphenol can be arrived to 6.45 mg/g,which is 2.7 times as optimization before.Further study indicated that the total antioxidant activity of polyphenol equaled 0.57 mg trolox,moreover,polyphenol can significantly scavenge DPPH（IC5011.04 μg/ mL）,ABTS（IC504.28 μg/mL）,superoxide anion（IC5094.16 μg/mL） and hydroxyl radical（IC5028.75 μg/mL）.Finally,we found that OONO-can induce DNA damage（43.8%） and cytotoxicity（cell viability 49.5%） in rat astrocyte cells,furthermore,bayberry leaf polyphenol（15 μg/mL） significantly inhibited DNA damage（24.1%） and cytotoxicity（cell viability 75.7%）.