Effects of Nigella sativa Extracts on the Lipid Profile and Uncoupling Protein-1 Gene Expression in Brown Adipose Tissue of Mice

Background: Uncoupling protein-1 (UCP-1) is the index protein of the brown adipose tissue (BAT), used in the obesity studies. We evaluated the effects of thymoquinone (TQ), hydroalcoholic, and hexane extracts of Nigella sativa , on the UCP-1 gene expression in BAT, and also on the recovery from oxidative stress, due to a high-fat diet. Materials and Methods: Fifty mice were divided into five groups: the first group was fed with a usual diet and the second, third, fourth, and fifth groups with a high-fat diet, hydroalcoholic extract, hexane extract, and TQ, respectively. After completing the course, the lipid profile, paraoxonase 1 (PON1), serum total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured. UCP-1 expression in BAT was evaluated at the gene and protein level. Results: The weight of mice, receiving TQ, hydroalcoholic, and hexane extracts, was decreased ( P < 0.05), compared to the second group ( P < 0.05). MDA was increased in the second group, compared to the first group ( P < 0.05); however, TAC, liver catalase enzyme, and PON1 were decreased ( P < 0.05). Furthermore, MDA of the third, fourth, and fifth groups had decreased, and the activity of PON1, liver catalase enzyme, and the amount of TAC was increased ( P < 0.05). UCP-1 expression of the third and fourth groups was increased, compared to the second group ( P < 0.05). Conclusion: The results suggest that TQ, hydroalcoholic, and hexane extracts of N. sativa have a protective and therapeutic role in the oxidative stress, caused by high-fat diets. The hydroalcoholic and hexane extracts can induce weight loss, by positively affecting UCP-1, at the gene and protein level.