ABSTRACT
This study was conducted to compare between Syrian and Egyptian Nigella sativa [NS] seeds for some chemical characteristics, total phenolic contents; the percentage of the antioxidant activity and to evaluate the effect of high doses of NS crushed seeds or their extracted oils on some blood biochemical parameters as well as the architecture of liver and kidney tissues. The following results [on a dry- weight basis] were obtained for Syrian and Egyptian variety respectively, ash 3.21 and 4.57%, protein 22.3 and 22.4%, fixed oil 35.0 and 36.0%, carbohydrates 32.8 and 34.05% and essential oil 0.3 and 0.9%. The major unsaturated acids in the crude fixed oil extract of NS seeds were linoleic acid followed by oleic acid while palmitic acid was the main saturated fatty acid. The compositions of the essential oils, of the two examined samples contain the same constituents with different concentrations. Thymoquinone is more abundant in the Egyptian variety meanwhile, alpha-pinene, beta-pinene, carvacrol, alpha- terpineol, eugenol, beta-caryophillene and cavone are more abundant in the Syrian variety. The blood biochemical results revealed that the supplementation of NS crushed seeds of the two varieties or their extracted oils, with high doses showed some changes on liver functions [ which evaluated by the hepatic enzymes activity assay of ALT and AST], lowering cholesterol and triglycerides levels and displayed no effect on albumin, total protein and urea levels. A significant increase in ALP enzymatic activity was obtained that could be attributed to the effect of progesterone hormone, whereas female rats were employed to conduct the biochemical study. Meanwhile, the histological examinations for liver and kidney tissues revealed pathological changes that could be attributed to the presence of high amount of thymoquinone, this finding could explain the significant increase in lipid proxidative index as evaluated in the term of plasma malondialdehyde [MDA] especially after the administration of the Egyptian variety of NS