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.

Background: Diabetes mellitus (DM) is an endocrinological disorder characterized by increased blood glucose, which in turn leads to increased oxidative stress and development of other complicated disorders. The disorder is caused either by non-production of insulin by pancreatic -cells or development of insulin resistance. In recent years, diabetes is increasing rapidly. Although high blood glucose (hyperglycemia) is controllable through anti-diabetic drugs and/or insulin injection, rural people in Bangladesh prefer plant-based traditional medicines dispensed by traditional medicinal practitioners. Methods and findings: The present study objective was to conduct oral glucose tolerance test (OGTT) in glucose-challenged mice with methanol extract of Hibiscus sabdariffa calyces (MEHS); the calyces are widely used in Bangladesh for controlling hyperglycemia. At doses of 100, 200 and 400 mg per kg body weight, MEHS reduced blood glucose level by 55.8, 62.0 and 62.77%, respectively compared to control mice, which were untreated. Glibenclamide, by comparison, reduced blood glucose level by 61% at a dose of 10 mg per kg body weight. Furthermore, in silico molecular docking studies showed that a number of phytochemicals present in Hibiscus sabdariffa calyces have predicted low binding energies for human -amylase (PDB number: 2QV4) with the potential for inhibiting hyperglycemia. Conclusions: (MEHS) reduced blood glucose by nearly 63% at a dose of 400 mg/kg, which was comparable to that of glibenclamide at a dose of 10 mg/kg. In silico studies further indicated that a number of phytochemicals of the calyces of Hibiscus sabdariffa merits further evaluation towards new anti-diabetic drug discovery.