Plant polyphenols have antioxidant capacity and alpha-glucosidase inhibition supporting the prevention and treatment of diabetes. This study was conducted to determine the content of total polyphenols, free radical scavenging and alpha-glucosidase inhibition of the extracted leaves (eugenia leaves (V), guava leaves (0), lotus leaves (S) and the VOS mixture. The results showed that total polyphenol content of eugenia, guava, lotus was 263.1 mg/g
339.5 mg/g
288.4 mg/g, respectively. The free radical scavenging (at final concentrations of 0.12 mg/ml) and the inhibition of alpha-glucosidase (at final concentrations of 0.4 mg/ml) of eugenia, guava, lotus was 63.6 percent and 67.6 percent, 69.8 percent and 68.7 percent, 65.6 percent and 65.4 percent
respectively. Mixtures of vas with the optimized ratio of mixture of 1:3:1 had the polyphenol content of 319.6 mg catechin/g
their ability of free radical scavenging was 72.3 percent (at 0.12 mg/ml)
the inhibition of alpha-glucosidase was 70.5 percent (at 0.4 mg/ml). VOS mixture could be considered as promising material for functional foods for the prevention and treatment of diabetes.