Pharmacological Activity of Feverfew (Tanacetum parthenium (L.) Schultz-Bip.): Assessment by Inhibition of Human Polymorphonuclear Leukocyte Chemiluminescence In-vitro

Abstract

Abstract The bioactivity of feverfew (Tanacetum parthenium) leaf extracts has been analysed, by use of a human polymorphonuclear leukocyte (PMNL) bioassay, to assess the relative contributions of solvent extraction and parthenolide content to the biological potency of the extract. Extracts 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). Extract bioactivity, measured as inhibition of phorbol 12-myristate 13-acetate-induced, 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol)-enhanced PMNL chemiluminescence, followed a similar trend. Extracts inhibited 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 concentration to the parthenolide equivalent/PMNl-bioactivity value, for acetone–ethanol and PBS extracts were both 1:1.7. Parthenolide, although a key determinant of biological activity for T. parthenium leaf extracts based on the PMNl-bioassay, seems not to be the sole pharmacologically-active constituent. The identical and elevated bioactivity-parthenolide ratios for both organic and aqueous-phase leaf extracts suggest that a proportion of the other bioactive compounds have solubilities similar to that of parthenolide.