AMENTOFLAVONE, A PLANT BIFLAVONE - A NEW POTENTIAL ANTIINFLAMMATORY AGENT

Biflavonoid is one of unique classes of naturally-occurring bioflavono ids. Certain biflavonoids including amentoflavone were previously repo rted to have inhibitory effect on the group II phospholipase A(2) acti vity. Amentoflavone was also found to inhibit cyclooxygenase from guin ea-pig epidermis without affecting lipoxygenase. In this study, anti-i nflammatory and analgesic activities of amentoflavone were evaluated. When amentoflavone was administered intraperitoneally, it showed a pat ent anti-inflammatory activity as determined by amelioration of croton -oil induced mouse ear edema. It also showed a potent anti-inflammator y activity in the rat carrageenan paw edema model (ED50=42 mg/kg) comp ared to the activity of prednisolone (35 mg/kg) and indomethacin (10 m g/kg). However, amentoflavone did not show a significant inhibitory ac tivity against rat adjuvant-induced arthritis, a chronic inflammatory model. In addition, amentoflavone was found to possess a potent analge sic activity in the acetic acid writhing test (ED50=9.6 mg/kg) compare d to the activity of indomethacin (3.8 mg/kg). These results suggest t hat amentoflavone may be a potential lead for a new type of anti-infla mmatory agents having dual inhibitory activity of group II phospholipa se A(2) and cyclooxygenase.