Abstract

ORAL GLUCOSE TOLERANCE AND ANTINOCICEPTIVE ACTIVITY EVALUATION OF METHANOLIC EXTRACT OF VIGNA UNGUICULATA SSP. UNGUICULATA BEANS

Tasneem Quader Tazin, Jannatul Ferdous Rumi1, Shahnaz Rahman, Abdullah Al- Nahain, Rownak Jahan, Mohammed Rahmatullah*

ABSTRACT

Background. Vigna unguiculata ssp. unguiculata is a popular vegetable in Bangladesh with beans of the plant forming the edible portion. The objective of this study was to scientifically analyze the antihyperglycemic and antinociceptive properties of methanol extract of beans of the plant. Methods. Oral glucose tolerance test (OGTT) was used to determine antihyperglycemic activity. Antinociceptive activity was determined by observed decreases in abdominal constrictions in intraperitoneally administered acetic acid-induced pain model in mice. Results. Administration of methanol extract of beans led to dose-dependent and significant reductions in blood glucose levels in glucose-loaded mice. At doses of 50, 100, 200 and 400 mg per kg body weight, the extract reduced blood glucose levels by 24.8, 32.2, 42.0, and 51.7%, respectively compared to control animals. By comparison, a standard antihyperglycemic drug, glibenclamide, when administered at a dose of 10 mg per kg body weight, reduced blood glucose level by 55.2%. In antinociceptive activity tests, the extract at the above four doses reduced the number of abdominal constrictions by 30.0, 33.3, 36.7, and 43.3%, respectively. A standard pain relieving (antinociceptive) drug, aspirin, reduced the number of writhings by 40.0 and 56.7%, respectively, when administered at doses of 200 and 400 mg per kg body weight. Conclusion. Antihyperglycemic and antinociceptive activities have not previously been reported for beans of this species. Since the plant is widely available in Bangladesh, the beans can be a good source for lowering blood sugar in diabetic patients and for alleviating pain.

Keywords: Antihyperglycemic, Vigna unguiculata, OGTT, antinociceptive, Fabaceae.