Activity of aqueous extract of the bark of Vitex doniana on uterine muscle response to drugs

The activity of Vitex doniana on the uterine muscle response was investigated. The bark of Vitex doniana was extracted in boiled water at 100 °C, and the extracted solution filtered and centrifuged with refrigeration. The extract prepared from the dry powder extract was tested on uterine muscle strip preparations. The bark extract of Vitex doniana was analysed elementally and found to contain much more potassium and phosphate than calcium, magnesium, zinc and iron. The presence of potassium ions in excess may also be partly responsible for the effect of the crude extract on uterine muscle activity. In another study, Vitex doniana extract induced graded uterine muscle contractions and also potentiated the contractile effects of prostaglandins, ergometrine and oxytocin. However, the potentiating effect was not significant on the contractile responses to acetylcholine and potassium chloride. The investigation therefore suggests that the effect of the Vitex doniana bark extract may be not only voltage operated but may act via uterotonic receptors. Therefore, the use of Vitex doniana to control postpartum bleeding after child birth may be justified. Copyright © 2005 John Wiley & Sons, Ltd.