Comparative pre- and post-treatment effects of Nigella sativa oil on lipid profile and antioxidant enzymes in a rat model of diabetes mellitus

Background: Lipid profile dysregulation and oxidative stress are important risk factors for cardiovascular disease in diabetic individuals. Nigella Sativa (NS) oil has been reported to have a favorable effect on triglycerides (TG) in rat models of diabetes mellitus. There is a dearth of information available about preventive or corrective use to manage and ameliorate diabetes. Aim: This study sought to ascertain the comparative pre and post-treatment effects of the oil on TG, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein, and key antioxidant enzymes levels in diabetic rats. Methods: Thirty (30) Wistar rats were divided into 6 groups of 5 rats each as follows: Group I rats took normal chow ad libitum and served as Control. Group II rats were induced with diabetes using streptozocin (50 mg/Kg BW). Group III and IV rats were pre-administered with 0.5 and 1 ml of the oil, respectively, before induction, whereas Group V and VI rats were treated with 0.5 and 1 ml of the oil after induction. The listed parameters were assessed in the plasma at the end of the study. Results: Diabetes induction caused a significant increase in the TG level. There was no significant change in the oxidative stress parameters. Only post-administration caused a significant reduction in TG level, whereas both pre and post-administrations caused a significant improvement in HDL levels. Both pre- and post-administrations caused an increase in superoxide dismutase and catalase levels when causing a significant reduction in malondialdehyde level. Conclusion: Post-induction treatment may be more effective in the correction of lipid dysregulation and oxidative stress in diabetes. Keywords: Antioxidant enzymes, atherogenic index, diabetes, lipid profile, Nigella sativa