Activités antioxydante et anticoagulante des huiles essentielles des graines de Nigella sativa.L Algérienne

Abstract

The objective of this study is the evaluation of the antioxidant and anticoagulant activities of essential oils obtained from the seeds of Algerian Nigella sativa L cultivated in the area of Magra (M’sila) and from commercial fixed oil of Nigella sativa (oil of El-Baraka). The qualitative analysis of two essential oils by TLC revealed the presence of many components, among which: thymoquinone, carvone, thymol and/or carvacrol. The antioxidant capacity of these essential oils was evaluated in vitro by three different tests: DPPH• free radical scavenging assay, ß-carotene bleaching test and reducing power assay. The essential oils demonstrated a great capacity to trap the DPPH• radical with an IC50 equal to 88,01 and 88,65 μg/ml for the commercial and Algerian essential oils respectively. This antioxidant capacity is confirmed by the ß-carotene bleaching assay and the reducing power test. Indeed this oils are also able to inhibit lipid peroxydation with respectable percentages of about 56,13% for the essential oil of Magra and 66,72 % for commercial essential oil and they have a great reducing power with an EC50 of 132,56 and 133,37μg/ml respectively. The anticoagulant activity of Nigella sativa essential oils was also evaluated in vitro by using two tests: the test of the cephalin-kaolin time, and the test of Quick time. The times of coagulation obtained on normal plasma in the presence of these oils indicate that they carry an anticoagulant activity on the two pathways of coagulation but this activity is highly marked on the endogenous pathway than on the exogenous pathway.