Evaluation of Antioxidant Potentials and -Amylase Inhibition of Different Fractions of Labiatae Plants Extracts: As a Model of Antidiabetic Compounds Properties.

In an attempt to identify herbal drugs which may become useful in the prevention of diabetes, antioxidant potentials and -amylase inhibition by the ethanol extracts of two plants belonging to Lamiaceae family, and , and their different fractions were studied. Also, inhibition of -amylase by and its fractions was evaluated. All of the samples exhibited antioxidant activities, among which ethyl acetate fraction of (17.21 ± 0.17 mg GAE/g) was found to contain the highest amounts of phenols and the ethyl acetate fraction of (218 ± 2.76 mg QUE/g) had the most values of flavonoids. Ethyl acetate fraction of (IC = 3.05 ± 0.51 g/ml) was shown to have the most reducing power and the ethyl acetate fraction of (IC = 32.17 ± 1.82 g/ml) exhibited the highest DPPH radical scavenging. The ethyl acetate fraction of (99.39 ± 0.94%) showed the highest -amylase inhibitory activity which was similar to acarbose used as a standard. Mode of -amylase inhibition of the most samples was uncompetitive except for , , , and which presented competitive inhibition. The present findings showed that studied samples may have some compounds with antioxidant and antidiabetic effects.