Background and Aims To evaluate the effect of metformin and Nigella sativa (alone or in combination) on improving the diabetic state of rats.
Methods Male Sprague-Dawley rats weighing 180–200g had induced diabetes using alloxan (150 mg/kg), then diabetic rats were treated daily for 45 days with metformin (0.5g/Kg.b.wt), Nigella sativa (1g/Kg.b.wt) or a mixture of metformin + Nigella sativa (0.25g+1g/Kg.b.wt) in a separated three groups and compared with a group of alloxanated diabetic rats as control. HbA1c, serum glucose, lipid profile, microalbuminuria (MA), ALT, AST, insulin, SHBG and total testosterone were measured using ELISA & spectrophotometer techniques, testis and liver tissue were examined histopathologically.
Results Both metformin and Nigella sativa were comparable in reducing serum glucose of the diabetic rats, furthermore, Nigella sativa showed a hypolipidaemic effect and it also improved liver functions. The level of serum insulin was significantly increased (P<0.05) in three groups. Importantly, using the mixture of metformin and N.sativa was less effective in improving diabetic state than using metformin or N.sativa alone, although it had improved serum level of testosterone and normalized the structure of testis.
Conclusion Using either metformin or Nigella sativa alone was more effective in improving the diabetic state of rats than using them in combination, although this combination was more effective in improving both serum level of testosterone and the structure of testis. This raise basic questions about the effect of interactions that may occur on using this mixture in the treatment of diabetes that necessitate further studies.