The possible mechanisms for the antifertility action of methanolic root extract of <em>Rumex steudelii</em>

Endalk Gebrie

Eyasu Makonnen

Legesse Zerihun

Asfaw Debella

^{Department of Pharmacology, Faculty of Medicine, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia}

^{Department of Physiology, Faculty of Medicine, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia}

^{Department of Drug Research, Ethiopian Health and Nutrition Research Institute, P. O. Box 1242, Addis Ababa, Ethiopia}

Correspondence to: Asfaw Debella Department of Drug Research, Ethiopian Health and Nutrition Research Institute, P. O. Box 1242, Addis Ababa, Ethiopia. Fax: 251-1-75 25 33, Tel: 251-1-756309 e-mail: moc.oohay@allebedwafsa

Abstract

Back ground

The practice of traditional medicine for the control of fertility in most parts of Ethiopia is based on the uses of plant medicines for many years. Rumex steudelii Hochst (Polygonaceae), locally known as “Tult” or “Yeberemelas” is one of the traditionally used antifertility plants in Ethiopia. In our previous study, the methanolic extract of R. steudelii root was found to show antifertility activity in female rats.

Objectives

The present study focused further on the possible mechanisms of the antifertility effect of the methanolic extract of R. steudelii.

Methods

The effect of the extract on implantation, the uterus weight of immature ovariectomized rats and serum estrogen-progesterone ratio was evaluated. Its effect on isolated guinea pig uterus in the presence and absence of uterine muscle contractions inhibitors was also assessed. Test for in vivo abortifacient effect was also carried out.

Results

It was found that the extract decreased the number of implantation sites significantly. At a contraceptive dose, it was also observed to have no estrogenic activity in immature rat bioassay. The extract did not affect the serum estrogen-progesterone ratio. It produced concentration dependent increase in uterine muscle contractions similar to those of the standard drug, oxytocin. Incubation of the tissue with three uterine muscle contractions inhibitors revealed that the extract produced uterine contractions perhaps by activating muscarinic and/or histaminic receptors. The in vivo abortifacient effect was not seen upon administration of both lower and higher doses of the extract in pregnant rats.

Conclusion

All these observations suggest that the extract produced antifertility effect mainly by inhibiting implantation though antiestrogen, progesterogen and uterotonic effects could as well be possible mechanisms.

Abstract

Acknowledgments

This study was kindly supported by grants from School of Graduate Study of the Addis Ababa University and Ministry of Health of Federal Democratic Government of Ethiopia. We thank to the Ethiopian Health and Nutrition Research Institute for laboratory facilities. We are grateful to Tegittu Lemma of the Department of Pharmacology, Faculty of Medicine, Addis Ababa University for handling the animals carefully.

Acknowledgments

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