α-Glucosidase inhibition and antioxidant properties of Streptomyces sp.: in vitro.

Streptomyces strain isolated from the soil sediment was studied for its in vitro α-glucosidase and antioxidant properties. Morphological characterization and 16S rRNA partial gene sequencing were carried out to confirm that the strain Loyola AR1 belongs to genus Streptomyces sp. Modified nutrient glucose broth was used as the basal medium for growth and metabolites production. Ethyl acetate extract of Loyola AR1 (EA-Loyola AR1) showed 50% α-glucosidase inhibition at the concentration of 860.50 ± 2.68 μg/ml. Antioxidant properties such as total phenolic content of EA-Loyola AR1 was 176.83 ± 1.17 mg of catechol equivalents/g extracts. EA-Loyola AR1 showed significant scavenging activity on 2,2-diphenyl-picrylhydrazyl (50% inhibition (IC₅₀), 750.50 ± 1.61 μg/ml), hydroxyl (IC₅₀, 690.20 ± 2.38 μg/ml), nitric oxide (IC₅₀, 850.50 ± 1.77 μg/ml), and superoxide (IC₅₀, 880.08 ± 1.80 μg/ml) radicals, as well as reducing power. EA-Loyola AR1 showed strong suppressive effect on lipid peroxidation (IC₅₀, 670.50 ± 2.52 μg/ml). Antioxidants of β-carotene linoleate model system reveals significantly lower than butylated hydroxyanisole.