Oral glucose tolerance test with methanol extract of leaves of Ocimum minimum L. (Lamiaceae) in Swiss albino mice

Abstract

Background: Diabetes is a metabolic disorder characterized by high blood sugar caused due to either insufficient production of insulin from the pancreas or development of insulin resistance, which causes polyuria, polydipsia, and polyphagia. In recent years, the disorder is increasing at a rapid rate in virtually all countries of the world. Existing conventional drugs suffer from problems of non-affordability, adverse effects, and non-availability in particularly rural and remote areas of developing countries like Bangladesh. As a result scientists are continually striving for discovery of new anti-diabetic drugs, which can fulfill the needs of all diabetic patients. Methods and Findings: The Ocimum genera within the Lamiaceae family contains a number of plants reported to possess anti-diabetic properties. However, very little is known about the pharmacological including anti-diabetic properties of Ocimum minimum L., the leaves of which are chewed by the indigenous people in the Chittagong Hill Tracts region in the south-eastern part of Bangladesh to control diabetes. Oral glucose tolerance test (OGTT) was conducted with Swiss albino mice and methanol extract of Ocimum minimum, using glibenclamide (a standard anti-diabetic drug) as the comparison drug. The methanolic extract of Ocimum minimum (MEOM) showed only significant anti-hyperglycemic activity at a dose of 400 mg/kg body weight; at that dose blood glucose was lowered by nearly 19%. By comparison, glibenclamide at a dose of 10 mg/kg lowered blood glucose by 37%. Conclusions: Methanol extract of Ocimum minimum leaves did not show any remarkable lowering of blood glucose in OGTT except at high doses. However, the plant has an advantage of growing profusely in the Chittagong Hill Tracts region, which is mountainous, forested, and inhabited by a number of indigenous communities with little contact with modern medical facilities. As such, the inhabitants of this region can chew, if necessary, as much as possible of the leaves of Ocimum minimum and bring their blood glucose under control.