CURCUMIN, A MAJOR COMPONENT OF FOOD SPICE TURMERIC (CURCUMA-LONGA) INHIBITS AGGREGATION AND ALTERS EICOSANOID METABOLISM IN HUMAN BLOOD-PLATELETS

In traditional medicine, Ayurveda, several spices and herbs are held t o possess medicinal properties. Earlier we have reported that extracts from several spices, including turmeric, inhibit platelet aggregation and modulate eicosanoid biosynthesis. Due to their eicosanoid-modulat ing property, it was suggested that the spices may serve to provide cl ues to drugs directed to arachidonic acid (AA) pathway enzymes as phar macological targets. Curcumin, a major component of turmeric, inhibite d platelet aggregation induced by arachidonate, adrenaline and collage n. This compound inhibited thromboxane B-2 (TXB(2)) production from ex ogenous [C-14] arachidonate in washed platelets with a concomitant inc rease in the formation of 12-lipoxygenase products. Moreover, curcumin inhibited the incorporation of [C-14]AA into platelet phospholipids a nd inhibited the deacylation of AA-labelled phospholipids (liberation of free AA) on stimulation with calcium ionophore A23187. Curcumin's a nti-inflammatory property may, in part, be explained by its effects on eicosanoid biosynthesis.