白茶对弹性蛋白酶活性的抑制研究

为了解白茶对弹性蛋白酶活性的作用,测定了6个白茶样品对猪胰弹性蛋白酶(PPE)活性的抑制作用。结果表明,6个白茶样品中CB4对PPE抑制活性最强,为69.73%;且随体积分数增加,酶抑制活性增强,呈剂量依赖性抑制。白茶水提液的4个萃取层中乙酸乙酯层(WEA)的抑制活性最强,达到82.58%。CB4的多酚总量(TPs)较高,且表没食子儿茶素没食子酸酯(EGCG)、表儿茶素没食子酸酯(ECG)和咖啡碱(CAF)含量最高。WEA萃取层中TPs、EGCG、ECG和ECG含量均最高,CAF含量极低。PPE活性抑制率与TPs、EGCG和CAF含量呈极显著正相关,相关系数均大于0.90。0.1～1.0 mg/mL EGCG和0.05～2.0 mg/mL CAF对PPE无抑制活性,0.05～2.0 mg/mL没食子酸(GA)对PPE活性具有促进作用,且GA的促进作用与其浓度呈正相关。可见,白茶具有潜在抗衰老活性,但对PPE起抑制作用的活性成分不是EGCG、GA和CAF。

Studies on Anti-elastase Activity of White Tea

In order to understand the anti-elastase effect of white tea, the inhibitory effect of aqueous extract from six white tea samples (CB1-CB6) on porcine pancreatic elastase (PPE) were measured. The results showed that CB4 had the strongest inhibition on PPE among six white tea samples with inhibition rate of 69.73%. In addition, elastase inhibition activity of CB4 increased with the concentration, showing a dose-dependent manner. Among the four extraction layers, ethyl acetate (WEA) layer had the strongest inhibitory activity, reaching 82.58%. The total polyphenol (TPs) content in CB4 was high, and the contents of epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and caffeine (CAF) were the highest among six samples. Among 4 extraction layers, the contents of EGCG, ECG, ECG, and total polyphenols in WEA layer were the highest and that of CAF was very low. There were significant positive correlation between elastase inhibition rate and the contents of TPs, EGCG and CAF with correlation coefficient above 0.90. However, neither 0.1-1.0 mg/mL EGCG nor 0.05-2.0 mg/mL CAF had inhibitory effects on PPE activity. Conversely, 0.05-2.0 mg/mL GA showed a promotion effect on PPE activity, and the promoting effect of GA was positively correlated with its concentration. Therefore, it was suggested that white tea exhibited potentially anti-aging activity, but the active ingredients that inhibited PPE were not EGCG, GA and CAF.