Effect Of Nigella Sativa Seed Extract On Glucose, Lipid Profile, Liver Function Tests, Oxidative Stress and Histological Changes In Pancreas, Kidney, Liver and Tibial Nerve In Normal and Streptozotocin Induced Diabetic Rats

Abstract

Introduction: Diabetes is a group of metabolic diseases in which there are high sugar levels over a prolonged period. Symptoms of high glucose levels lead to increased thirst, hunger and frequent urination. If left untreated, diabetes can cause many complications. Acute complications include diabetic ketoacidosis and nonketotic hyperosmolar coma. Serious long-term complications include stroke, kidney failure, cardiovascular disease, diabetic foot and diabetic retinopathy. Diabetes is due to either the pancreas not producing enough insulin or the cells of the body not responding properly to the insulin produced. Diabetes can be treated by medically, diet balance and physical activities. However plant-derived and herbal remedies continue to be popular alternative for diabetes treatment. Nigella sativa is an extensively used herb in Arab medicine and Indian system of medicine Ayurveda. The present study was conducted to assess the effect of Nigella sativa seed and thymoquinone (major bio-active component of Nigella sativa seed) in the treatment of streptozotocin induced diabetic albino Wister rats. Material and Methods: Laboratory bred adult albino Wister rats weighing between 175 - 250gm were used in the study. The acclimatized animals were divided into six groups of six rats each. Group I rats were normal control rats; group II were normal rats treated with Nigella sativa seed powder (300mg/kg body weight); group III were normal rats treated with thymoquionone(4mg/kg body weight); group IV were streptozotocin induced diabetic control rats; group V were streptozotocin induced diabetic rats treated with Nigella sativa seed powder(300mg/kg body weight) and group VI were streptozotocine induced diabetic rats treated with thymoquinone(4mg/kg body weight). The duration of study was 45 days. At the end of 45 days blood was collected for biochemical tests such as glucose, insulin, MDA, SOD, Vitamin C & E, lipid profile and liver function tests. Oral glucose tolerance test (OGTT) was performed at the end of 45 days of study in all the groups. For the histopathological observations pancreas, liver, kidney and nerve tissues were collected and processed. IAEC was taken and CPESEA guide lines were followed. Results: The diabetic untreated rats showed significant increase in serum glucose, total cholesterol, LDL – cholesterol, VLDL – cholesterol, triglycerides, AST, ALT, ASP and MDA compared with normal control rats. After treatment with Nigella sativa seed powder and thymoquinone in induced diabetic rat groups the above mentioned parameters were lowered significantly. Insulin, SOD, Vitamin C, Vitamin E and HDL – cholesterol were decreased significantly in diabetic untreated group. After treatment with Nigella sativa seed powder and thymoquinone the same parameters were increased significantly in induced diabetic rat groups. The diabetic rat groups treated with Nigella sativa seed powder and thymoquinone showed tolerance to oral glucose tolerance test (OGTT) compared with diabetic control rats. There was no significant change of any parameter between normal control rat groups and normal rat groups treated with Nigella sativa seed powder and thymoquinone. Histopathological observations of pancreas, liver and kidney of induced diabetic treated rat groups revealed that treatment with Nigella sativa seed powder and thymoquinone reversed the histopathological changes seen in induced diabetic control rats. There was no significant histopathological changesobserved between normal control rats and normal rat group treated with Nigella sativa seed powder and thymoquinone. This indicates nontoxicity of Nigella sativa seed and thymoquinone. Conclusion: The biochemical parameters in induced diabetic rats were normalised with treatment of Nigella sativa seed powder and its major bioactive component thymoquinone. There was no toxic effect observed in normal groups treated with Nigella sativa seed powder and thymoquinone. This observation was supported by non significant changes in biochemical parameters between normal control rats and normal rat groups treated with Nigella sativa seed and thymoquinone and furthermore supported by histological observations. The biochemical results and histopathological observations clearly showed beneficial effect of Nigella sativa seed powder and thymoquinone in diabetic treated groups. Hence these phytochemical substances may be considered as antidiabetic agents as well as beneficial to the overall diabetic health.