Phytother Res. 1999 Feb; 13(1): 55-8.

Uterine muscle reactivity to repeated administration and phytochemistry of the leaf and seed extracts of Piper guineense.

Udoh FV.

Department of Pharmacology, College of Medical Sciences, University of Calabar, Nigeria.

The leaf and seed of Piper guineense were separately extracted and the effects of repeated treatments on rat uterine contractions and their chemical composition were investigated. Repeated treatments with the extracts enhanced spontaneous uterine muscle contractions in a dose related pattern for up to 14 days which was followed by a marked decrease in uterine response in those treated for 30 days. Similarly, the pretreatment with the extracts maximally enhanced oxytocin induced uterine contraction in those rats treated for 3 days, this was followed by a gradual reversal of the effect when treatment was repeated for up to 14 days. This enhanced uterine contraction was inhibited following treatment for 30 days. In a further study, treatment with the extracts induced a significant increase in the uterine weight similar to that seen with oestradiol. It is therefore concluded that the leaf and seed extracts of Piper guineense possess oestrogenic and oxytocic properties which might justify their usage in Nigerian traditional medicine.