Screening of plants used by southern African traditional healers in the treatment of dysmenorrhoea for prostaglandin-synthesis inhibitors and uterinerelaxing activity

Plants used by Southern African traditional healers for the treatment of me nstrual pains were screened for prostaglandin-synthesis inhibitors and the ability to reduce isolated uterine muscle contraction using the cyclooxygen ase and in vitro uterine bioassays respectively. Prostaglandins are synthes ized from arachidonic acid and the enzyme that drives this reaction is cycl ooxygenase. The excessive production of prostaglandins by the myometrium an d endometrium induces uterine contractions. Inhibition of cyclooxygenase an d hence of the prostaglandin biosynthetic pathway may lead to relief of men strual pain. Ten plants used by traditional healers for menstrual pains wer e assayed for cyclooxygenase inhibitory activity. Several plant extracts ex hibited high inhibitory activity in the assay. The highest activities were obtained with ethanolic extracts of Siphonochilus aethiopicus, Cenchrus cil iaris and Solanum mauritianum. Generally ethanolic extracts gave higher act ivity than the aqueous extracts. None of the ethanolic plant extracts were able to relax or reduce the contractions of the precontracted guinea pig ut erus. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.