The effect of fennel essential oil on uterine contraction as a model for dysmenorrhea, pharmacology and toxicology study

Increasing the ectopic uterine motility is the major reason for primary dys menorrhea. This motility is the basis for several symptoms including for pa in is the main complaints of patients with primary dismenorrhea. There are several mechanisms, which initiate dysmenorrhea. Therefore, different compo unds can be employed to control its symptoms. In long-term therapy, combina tion of oestrogens and progestins may be useful. In short-term therapy, dys menorrhea sometimes non-steroidal anti-inflammatory drugs (NSAIDs) are used . Most of NSAIDs in long-term therapy show severe adverse effects. In an at tempt to find agents with less adverse effect the fennel essential oil (FEO ) was chosen for this investigation. In this article, effects of FEO on the uterine contraction and estimation of LD,, in rat were described. For asse ssment of pharmacological effects on the isolated rat uterus, oxytocin (0.1 , 1 and 10 mu/ml) and prostaglandin E-2 (PGE(2)) (5 x 10(-1) M) were employ ed to induce muscle contraction. Administration of different doses of FEO r educed the intensity of oxytocin and PGE(2) induced contractions significan tly (25 and 50 mug/ml for oxytocin and 10 and 20 mug/ml PGE(2), respectivel y). FEO also reduced the frequency of contractions induced by PGE2 but not with oxytocin. LD50 of FEO was obtained in the female rats by using moving average method. The estimated LD50 was 1326 mg/kg. No obvious damage was ob served in the vital organs of the dead animals. (C) 2001 Elsevier Science I reland Ltd. All rights reserved.