Some aspects of the inhibitory activity of hypolaetin-8-glucoside in acute inflammation.

Hypolaetin-8-glucoside (H-8-G) has been examined for its mode of action in several models of acute inflammation. Its anti-inflammatory activity in carrageenan-induced inflammation of the rat hind-paw is not affected either by adrenalectomy or by phentolamine given with propranolol. H-8-G and its aglycone, hypolaetin, did not antagonize the actions of histamine, 5-hydroxytryptamine (5-HT), bradykinin or prostaglandin E2 (PGE2) on various smooth muscle preparations in-vitro, but protected erythrocytes from heat-induced lysis. The glycoside was more potent than troxerutin on capillary permeability increased by histamine and exerted inhibitory effects on protein exudation, leucocyte migration and beta-glucuronidase activity in the carrageenan air pouch, thereby showing some difference from indomethacin. These results are discussed in relation to the features of non-steroidal anti-inflammatory drugs (NSAID) and flavonoid anti-inflammatory actions.