Pharmacological Evaluation of Methanolic Extract of Nigella sativa on Hyperglycemia in Laboratory Animal Models

Abstract

Diabetes is increasingly affecting a growing number of patients and seriously reducing their quality of life. Use of conventional drugs in diabetes management is expensive, thus, unaffordable to most patients. Furthermore most of these conventional drugs are associated with undesirable side effects. Incorporation of herbal medicine into conventional healthcare system may significantly improve the overall healthcare system. Evaluation of efficacy and safety by scientific method is necessary to validate herbal medicine utilization, in most cases even where efficacy of the plants has been established the standard dosage required to bring about healing is not clear. The intraperitoneal route of herbal extract administration was found to be more effective than the oral route. Our present studies were focused on the probable anti- hyperglycemic effect of methanolic extract of Nigella sativa in long-evans rats and the statistical significance of such effect. The seeds extract was subjected to anti-diabetic study through Inhibition of Carbohydrate Absorption (six segment method) and Intenstinal Disaccharidase activity method. In six segment, the amount of sucrose unabsorbed in different GIT segments were evaluated in control rats vs. rats fed with 2.5g/kg extract at 30 minutes,1 h, 2h & 4 h. In Disaccharide activity the amount of unabsorbed sucrose in pancreatic enzymes are evaluated in control rats vs rats fed with 100mg/kg extract The extract caused a significant decreased (p<0.001) in dose dependent inhibition of glucose absorption and showed Anti-hyperglycemic effects in long-evans rats weighing from 150-200 gm. The anti-diabetic effects were estimated by measuring the amount of glucose in the samples collected after the experiment. In conclusion, these observations provide evidence and possible mechanisms of action for the anti-diabetic properties of leaves of Nigella sativa claimed in Ayurveda medicine.