ABSTRACT
The anti-inflammatory activity of the volatile oil [v.o.] of Nigella sativa L. seeds and its active principle thymoquinone has been examined using carrageenan-induced oedema in rat hind paws and cotton seed pellet granuloma in rats. Both the v.o. and thymoquinone were found to produce a significant dose-dependent anti-inflammatory effect as evidenced by the significant inhibition of oedema formation and reduction of the granuloma weight. The v.o. [0.66 ml and 1.55 ml/Kg, Lp.] inhibited rat hind paw oedema formation by 64.12% and 96.26%, while thymoquinone [0.5, 1.0, 5 mg/Kg, Lp.] caused a reduction of38.85%, 56.63% and 104.88%, respectively. Indomethacin [3 and 9 mg/Kg, Lp.] inhibited the oedema by 46.90% and 67.83%, respectively. In addition, the v.o. [0.33 ml and 0.66 ml/Kg, Lp.] inhibited granuloma formation by 17.64% and 46.86%, while thymoquinone [3 and 5 mg/Kg, i.p.] reduced granuloma weight by 13.04% and 48.09%. These effects were nearly comparable to indomethacin [3 mg/Kg, i.p.] which reduced granuloma weight by 34.37%. It was suggested that the anti-inflammatory activity of the v.o. of Nigella sativa seeds may be due to inhibiting the generation of eicosanoids and lipid peroxidation