Inhibition of sheep platelet arachidonate metabolism by flavonoids from Spanish and Indian medicinal herbs.
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Abstract
The influence of 22 flavonoids was studied on the arachidonic acid metabolism in sonicated sheep platelets. Flavones and flavonols possessing catechol groups inhibited 12-lipoxygenase. Sideritoflavone and quercetagetin-7-O-beta-D-glucoside were more selective than quercetin. Cirsiliol, hypolaetin, hypolaetin-8-O-beta-D-glucoside, gossypetin, gossypin, hibifolin and leucocyanidol were also 12-lipoxygenase inhibitors with some differences in potency and selectivity. Xanthomicrol was a weak cyclooxygenase inhibitor. These results suggest that lipoxygenase inhibition can play a role in the anti-inflammatory activity of hypolaetin-8-O-beta-D-glucoside, sideritoflavone, gossypin and hibifolin. On the other hand, the presence of sideritoflavone, hypolaetin-8-O-beta-D-glucoside, cirsiliol and xanthomicrol in several species of Sideritis may provide a basis for the use of such plants as anti-inflammatory agents.