Nigella sativa fixed and essential oil modulates glutathione redox enzymes in potassium bromate induced oxidative stress

Background: Nigella sativa is an important component of several traditional herbal preparations in various countries. It finds its applications in improving overall health and boosting immunity. The current study evaluated the role of fixed and essential oil of Nigella sativa against potassium bromate induced oxidative stress with special reference to modulation of glutathione redox enzymes and myeloperoxidase. Methods: Animals; 30 rats (Sprague Dawley) were divided in three groups and oxidative stress was induced using mild dose of potassium bromate. The groups were on their respective diets (iso-caloric diets for a period of 56 days) i.e. control and two experimental diets containing N. sativa fixed (4 %) and essential (0.3 %) oils. The activities of enzymes involved in glutathione redox system and myeloperoxidase (MPO) were analyzed. Results: The experimental diets modulated the activities of enzymes i.e. glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx) positively. Indices of antioxidant status like tocopherols and glutathione were in linear relationship with that of GPx, GR and GST (P < 0.01). MPO activities were in negative correlation with GST (P < 0.01) but positive correlation with some other parameters. Conclusions: Our results indicated that both Nigella sativa fixed and essential oil are effective in improving the antioxidant indices against potassium bromate induced oxidative stress.