Evaluation of the inhibition of carbohydrate hydrolysing enzymes, antioxidant activity and polyphenolic content of extracts of ten African Ficus species (Moraceae) used traditionally to treat diabetes

• Published in: BMC complementary and alternative medicine 2013-05, Vol.13 (1), p.94-94, Article 94
• Main Authors: Olaokun, Oyinlola O, McGaw, Lyndy J, Eloff, Jacobus N, Naidoo, Vinny
• Format: Article
• Language: English
• Subjects: Acetone; alpha-Amylases - antagonists & inhibitors; Amylases; Analysis; Antioxidants; Antioxidants - analysis; Antioxidants - pharmacology; Biomedical research; Carbohydrate Metabolism - drug effects; Competition; Diabetes; Diabetes Mellitus - enzymology; Diabetes therapy; Enzyme Inhibitors - pharmacology; Enzymes; Ficus (Plants); Ficus - chemistry; Free radicals; Glucose; Glycoside Hydrolase Inhibitors; Hydrolysis; Hypoglycemic Agents - analysis; Hypoglycemic Agents - pharmacology; Insulin; Insulin resistance; Laboratory animals; Materia medica, Vegetable; Medicine, African Traditional; Medicine, Botanic; Medicine, Herbal; Metabolic disorders; Physiological aspects; Phytotherapy; Plant extracts; Plant Extracts - pharmacology; Polyphenols - analysis; Polyphenols - pharmacology; Rodents; Studies; Sucrase - antagonists & inhibitors
• ISSN: 1472-6882; 1472-6882
• DOI: 10.1186/1472-6882-13-94

Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain. The aim of this study was to determine the activity and to investigate the mechanism of antidiabetic activity of ten selected Ficus species through inhibition of α-amylase and α-glucosidase activity, and the possible relationship between these activities, the total polyphenolic content and the antioxidant activity. Dried acetone leaf extracts were reconstituted with appropriate solvents and used to determine total polyphenolic content antioxidant activity, α-amylase and α-glucosidase inhibitory activity. The crude acetone extract of F. lutea had the highest polyphenolic content (56.85 ± 1.82 mg GAE/g of dry material) and the strongest antioxidant activity with a TEAC value of 4.80 ± 0.90. The antioxidant activity of the acetone extracts of the Ficus species may not be ascribed to total polyphenolic content alone. The crude extract at a concentration of 0.5 mg/ml of F. lutea (64.3 ± 3.6%) had the best α-glucosidase (sucrase) inhibitory activity. The EC50 of F. lutea (290 ± 111 μg/ml) was not significantly different from that of F. sycomorus (217 ± 69 μg/ml). The α-amylase inhibitory activity of F. lutea (95.4 ± 1.2%) at a concentration of 1 mg/ml was the highest among the Ficus species screened. The EC50 for F. lutea (9.42 ± 2.01 μ g/ml), though the highest, was not significantly different (p