Antiinflammatory activity of flavonoids.

Fourteen flavonoids (flavones,- flavanones and chalcones) were assayed for oral antiinflammatory activity using carrageenan-induced hind paw edema in rats. The structural features necessary for antiinflammatory activity appear to be the presence of methoxyl groups at C5 and C7 of ring A and the pyrano ring B of the flavonoid molecule. Negligible or low antiinflammatory activities were found in the chalcone derivatives. The difference in the efficacy of the flavonoids tested possibly depends on their pharmacokinetic properties.