Feverfew Extract Research Articles

Effect of feverfew on phagocytosis and killing of Candida guilliermondii by neutrophils.

The in vitro effect of the herbal remedy feverfew on neutrophil function was examined. It was shown that addition of feverfew extract inhibited phagocytosis of Candida guilliermondii and its overall killing. However, intracellular killing was not affected, suggesting that the apparent defect in total killing merely reflected the failure of uptake. The implications for the in vivo effects of feverfew are discussed.

An extract of feverfew inhibits interactions of human platelets with collagen substrates

The interaction of platelets with surfaces coated with collagens of type III (C III) or IV (C IV) has been studied by measuring the deposition of 51-Cr-labeled platelets and by scanning electron microscopy (SEM). Experiments were performed using platelet-rich plasma (PRP) and suspensions of gel-filtered platelets (GFP). Platelets were deposited on C III mainly as surfacebound aggregates. In contrast they were deposited on C IV mainly as spread forms of individual cells. Formation of aggregates on C III was more extensive for PRP than for GFP; in contrast platelet spreading on C IV was more extensive for GFP than for PRP. The effects of an extract of the plant feverfew on platelet-collagen interactions were determined. Fever few extract inhibited the deposition of 51-Cr-labeled platelets on both C III and C IV in a dose-dependent way. Similar concentrations of extract were needed to inhibit the formation of surface-bound aggregates and to inhibit platelet spreading in both PRP and GFP.

Extracts of feverfew may inhibit platelet behaviour via neutralization of sulphydryl groups.

It has been suggested that extracts of feverfew may inhibit platelet behaviour via effects on platelet sulphydryl groups. In the present study we have obtained evidence for such a mode of action. Compounds that contain sulphydryl groups such as cysteine and N-(2-mercaptopropionyl)glycine prevented the inhibition of platelet behaviour by feverfew. Feverfew and parthenolide (one of the active components of feverfew) dramatically reduced the number of acid-soluble sulphydryl groups in platelets. This effect occurred at concentrations similar to those that inhibited platelet secretory activity. Feverfew itself did not induce the formation of disulphide-linked protein polymers in platelets but polymer formation occurred when aggregating agents were added to feverfew-treated platelets. Feverfew evoked changes in the metabolism of arachidonic acid that were similar to those observed in glutathione-depleted platelets.

Compounds extracted from feverfew that have anti-secretory activity contain an alpha-methylene butyrolactone unit.

Extracts of feverfew inhibit secretion of granular contents from platelets and neutrophils and this may be relevant to the therapeutic value of feverfew in migraine and other conditions. In this investigation we fractionated an extract of feverfew and obtained eleven fractions with antisecretory activity. The activity. The active fractions, together with two fractions that were devoid of anti-secretory activity, were examined using 1H NMR and infrared spectroscopy. All the active fractions (but neither of the inactive fractions) contained compounds with an alpha-methylene butyrolactone unit. Five compounds that contain this unit were identified as parthenolide, 3-beta-hydroxyparthenolide, secotanapartholide A, canin and artecanin, all of which are sesquiterpene lactones. It is very likely that these and other sesquiterpene lactones that contain an alpha-methylene butyrolactone unit are responsible for the anti-secretory activity in extracts of feverfew.

Chrysanthemum dermatitis in South Wales; diagnosis by patch testing with feverfew (Tanacetum parthenium) extract.

Chrysanthemum dermatitis in South Wales; diagnosis by patch testing with feverfew (Tanacetum parthenium) extract.

EXTRACTS OF FEVERFEW INHIBIT GRANULE SECRETION IN BLOOD PLATELETS AND POLYMORPHONUCLEAR LEUCOCYTES

Extracts of feverfew ( Tanacetum parthenium) inhibited secretory activity in blood platelets and polymorphonuclear leucocytes (PMNs). Release of serotonin from platelets induced by various aggregating agents (adenosine diphosphate, adrenaline, sodium arachidonate, collagen, and U46619) was inhibited. Platelet aggregation was consistently inhibited but thromboxane synthesis was not. Feverfew also inhibited release of vitamin B 12-binding protein from PMNs induced by the secretagogues formyl-methionyl-leucyl-phenylalanine, sodium arachidonate, and zymosan-activated serum. Feverfew did not inhibit the secretion induced in platelets or PMNs by the calcium ionophore A23187. The pattern of the effects of the feverfew extracts on platelets is different from that obtained with other inhibitors of platelet aggregation and the effect on PMNs is more pronounced than has been obtained with very high concentrations of non-steroidal anti-inflammatory agents.

Action of phospholipase A 2 on bilayers. Effect of inhibitors

Action of several solutes on the kinetics of phospholipase-A 2-catalyzed hydrolysis of the ternary codispersions containing dimyristoylphosphatidylcholine + 1-palmitoyllysophosphatidylcholine + palmitic acid is examined. The kinetics of hydrolysis is interpreted in terms of the ability of the enzyme to bind to the substrate interface. The inhibitory effect of these solutes is correlated with their ability to modify fluorescence intensity of the bound enzyme, to modify the phase-transition profile, and to inhibit aggregation / fusion of the ternary codispersions. Based on these observations, it is suggested that the solutes like n-alkanols, ketamine, alphadolone, alphaxalone, flufenamic acid, tobramycin, mepacrine, EMD 21657 and U-10029A modulate the phase equilibria in the codispersions and thus noncompetitively inhibit the phospholipase action. Inhibition by feverfew extract ( Tanacetum parthemium) is also by a similar mechanism. Lipid-soluble drugs as indomethacin had little effect on the kinetics of hydrolysis. All these inhibitors decrease the total extent of hydrolysis of the available substrate. However, none of these inhibitors have any effect on the hydrolysis of monomeric substrate or on the inactivation of the phospholipase A 2 by p-bromophenacylbromide. These observations suggest that all these inhibitors do not interact directly with the catalytic site of the free or the bound enzyme, and their effect is primarily on the enzyme-binding sites on the substrate vesicle, that is, by perturbation of lipid-protein interaction.