Protective Effect of Nigella sativa Seed Extract and its Bioactive Compound Thymoquinone on Streptozotocin-induced Diabetic Rats



The lack of a substantial breakthrough in the treatment of diabetes, a global issue, has led to an ongoing quest for herbs that contain bioactive elements with hypoglycemic properties.



To investigate the potential protective effect of Nigella sativa seeds ethanol extract and its active ingredient, thymoquinone, on streptozotocin-induced diabetic rats.



To induce diabetes, the male Wistar rats were administered an intraperitoneal injection of STZ at a dosage of 90mg/kg body weight in 0.9 percent normal saline after being fasted for 16 hours and made diabetic Group 1; 7 rats non-diabetic control (saline-treated), Group 2; 7 untreated diabetic rats, Group 3; 7 diabetic rats treated orally with N. sativa
 extract at a dose of 100mg/kg body weight, Group 4; 7 diabetic rats treated orally with thymoquinone at a dose of 10mg/kg body weight and Group 5; 7 diabetic rats treated orally with Metformin at a dose of 5mg/kg body weight. After the treatment of 28 days, all groups were examined for body weight and biochemical alterations.



The results showed a significant decrease in blood glucose, urea, creatinine, uric acid, total protein, total cholesterol, low-density lipoprotein, and very low-density lipoprotein, while high-density lipoprotein was increased. Hepatic enzymes, alanine transaminase, aspartate aminotransferase, and alkaline phosphate were also normalized and significantly increased body weight.



These preliminary findings demonstrate that the ethanol extract of N. sativa seeds and its active ingredient, thymoquinone have a protective effect against streptozotocin-induced diabetic rats. The present study opens new vistas for the use of N. sativa and its bioactive compound, thymoquinone, regarding its clinical application as a new nontoxic antidiabetic agent for managing diabetes mellitus.
