Abstract: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.
