Pharmacological studies on sesame and nigella sativa fixed oils: effects on the sensitivities of the adrenoceptors baroreceptors, platelets and the uterus of the rat

ABSTRACT

The aim of this study is to unravel the effects of short-term treatment [2 weeks] with sesame oil [S.O., 6 and 12 ml Kg[-1]. Day [-1], i.p.] and Nigella sativa fixed oil [N.O. 2 and 2 ml Kg[-1] Day[-1] i.p.] on some cardiovascular, platelets and reproductive parameters in normal and/or streptozotocin hyperglycemic diabetic rats [NR and DR, respectively]. Both S.O. and N.O. significantly suppressed [alpha] -adrenoceptor-mediated phenylephrine-induced rise in the arterial blood pressure in NR only. S.O. significantly sensitized the arterial baroreceptors, whereas N.O. significantly suppressed it in NR only. None of the oils affected this parameter in the DR. Both oils significantly enhanced isoprenaline-induced hypotension in both NR and DR without any effect on isoprenaline-induced tachycardia. Both oils suppressed adenosine diphosphate [ADP]-induced platelets aggregation in both NR and DR. The suppression was more significant in DR. Both oils enhanced significantly arachidonic acid [0.714 mg Kg[1] i.v.] -induced hypotension in NR. Both oils significantly suppressed PGE[2-] and oxytocin-induced uterine contractions of the diethylstilbesterol-treated uteri of the NR. S.O. but not N.O. significantly enhanced the percentage of bias to cysts implantation in NR. None of the oils induced any teratogenic effects or induced significant changes in the gestation length, litter size, male to female ratio, resorption rate or placental weights in NR. However, N.O. significantly increased the foetal weight. In conclusion, the results point to the potential usefulness of both S.O. and N.O. in conditions that benefit from desensitization of [alpha1] adrenoceptors, [Beta2] sensitization of -adrenoceptors and uterine PGE[2] and oxytocin receptors. Furthermore, S.O.-induced sensitization of the baroreceptors may be beneficial in those conditions associated with a decrease in arterial baroretlexes. In addition, both oils seemed to be safe during pregnancy with S.O. having the additional potential advantage of enhancing the implantation rate