Effect of dietary supplemental black cumin seeds on antioxidant activity in broilers

Lipid peroxidation is an autocatalytic mechanism leading to oxidative destruction of cellular membranes (8). Their destruction can lead to cell death and also to the production of toxic and reactive aldehyde metabolites, known as free radicals. Among these free radicals, malondialdehyde (MDA) is the most important (32). MDA is the main final product of lipid peroxidation and has been often used for determining oxidation damage (34) which is indicated by high levels of MDA. Black cumin (Nigella sativa) is widely grown in different parts of the world and it has been used to promote health (especially in the Middle East and Southeast Asia) as a digestive and appetite stimulant (16, 17), analgesic (22), anthelmintic (9) and antimicrobial (13), antidiabetic (4), anticancer (35), anti-inflammatory (3), spasmolytic and bronchodilator (15), hepatoprotective (25), renal protective (23) and antioxidant properties (6, 7, 24). The seeds of black cumin contain a volatile oil (0.5-1.6%), a fixed oil (35.6-41.6%), proteins (22.7%) and exogenic amino acids (2). The active constituents of the seeds include a volatile oil consisting of carvone, an unsaturated ketone, terpene or d-limonene also called carvene, ·­pinene and p-cymene (20). Pharmacologically active constituents of volatile oil are thymoquinone, dithymoquinone, thymohydroquinone and thymol (14). Black cumin seed oil and its main active constituent, thymoquinone, are reported to inhibit peroxidation in mice (19), rats (24) rabbits (28). Studies on the antioxidant status of black cumin in poultry have been very limited. The aim of the present study was to investigate the antioxidative effects of black cumin seeds in broilers. For this purpose, different amounts of black cumin seed were used to supplement broiler diets and MDA and vitamin E levels in serum, breast muscles, and liver and heart muscles were determined.