PHARMACOLOGICAL ACTIVITY OF FEVERFEW (TANACETUM-PARTHENIUM (L) SCHULTZ-BIP) - ASSESSMENT BY INHIBITION OF HUMAN POLYMORPHONUCLEAR LEUKOCYTECHEMILUMINESCENCE IN-VITRO

The bioactivity of feverfew (Tanacetum parthenium) leaf extracts has b een analysed, by use of a human polymorphonuclear leukocyte (PMNL) bio assay, to assess the relative contributions of solvent extraction and parthenolide content to the biological potency of the extract. Extract s prepared in acetone-ethanol (system 1) contained significantly more parthenolide (mean+/-s.d. 1.3+/-0.2% dry leaf weight) than extracts in chloroform-PBS (phosphate-buffered saline; system 2; 0.1+/-0.04% dry leaf weight) or PBS alone (system 3; 0.5+/-0.1% dry leaf weight). Extr act bioactivity, measured as inhibition of phorbol 12-myristate 13-ace tate-induced, 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol)-enhan ced PMNL chemiluminescence, followed a similar trend. Extracts inhibit ed phorbol 12-myristate 13-acetate-induced oxidative burst by amounts which, if solely attributable to parthenolide, indicated parthenolide concentrations for the respective solvent systems of 2.2+/-0.6%, 0.2+/ -0.1% and 0.9+/-0.1% dry leaf weight. The mean ratio of parthenolide c oncentration to the parthenolide equivalent/PMNL-bioactivity value, fo r acetone-ethanol and PBS extracts were both 1:1.7. Parthenolide, alth ough a key determinant of biological activity for T. parthenium leaf e xtracts based on the PMNL-bioassay, seems not to be the sole pharmacol ogically-active constituent. The identical and elevated bioactivity-pa rthenolide ratios for both organic and aqueous-phase leaf extracts sug gest that a proportion of the other bioactive compounds have solubilit ies similar to that of parthenolide.