ANTIINFLAMMATORY AND ANALGESIC ACTIVITY OF BACCHARIS-TRIMERA - IDENTIFICATION OF ITS ACTIVE CONSTITUENTS

The butanolic fraction (BT-II) derived from the aqueous crude extract was prepared from aerial parts of Baccharis trimera and assessed in an ti-inflammatory, analgesia, and ulcerogenesis models. Intraperitoneal pretreatment with lyophilized BT-II, at doses ranging from 40 to 100 m g/kg, markedly inhibited carrageenan- and dextran-induced inflammation (70.4-90.8 % and 25.7-77.3%, respectively) and weakly decreased C-16- paf- and arachidonic acid-induced swelling (24.9-36.7% and 0-30.6%, re spectively). No effect was observed, at the same doses, on zymosan-ind uced edema. The intraperitoneal examination indicates that the anti-ph logistic action of BT-II was not due to an irritating effect at the in jection site. Besides, BT-II reduced abdominal constrictions in mice f ollowing injection of acetic acid: at 50 mg/kg, it gave 67.4 % inhibit ion and, at 100 mg/kg, 95.1 %. The ulcerogenic assay showed that the i ncidence of ulcers after BT-II i.p. treatment was 2/6 at 50 mg/kg and 6/6 at 100 mg/kg. Ulcerogenic indices were 1.3 +/- 0.5 and 2.7 +/- 0.8 , respectively. These results indicate that B. trimera shows strong an tiinflammatory and analgesic properties which seem to be due, at least partly, to the inhibition of prostaglandin biosynthesis. The chromato graphic separation of BT-II monitored by bio-assay (carrageenan-induce d edema test in mice) was carried out. The active constituents were fo und to be mainly saponins in which echinocystic acid (or its enantiome r) is the major aglycone, and also rutin.