Analgesic and antiinflammatory activities of Ageratum conyzoides in rats

✍ Scribed by José Franco G. Magalhães; Cyntia F. G. Viana; Antonio Gilson M. Aragão Júnior; Vanessa G. Moraes; Ronaldo A. Ribeiro; Marcus R. Vale

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 176 KB
• Volume: 11
• Category: Article
• ISSN: 0951-418X
• DOI: 10.1002/(sici)1099-1573(199705)11:3<183::aid-ptr63>3.0.co;2-8

✦ Synopsis

The water soluble fraction (WSF) obtained from a hydroalcohol extract of A. conyzoides, a medicinal plant used in Brazilian folk medicine, was evaluated for possible analgesic and antiinflammatory activities. It was demonstrated that WSF (20-50 mg/kg; i.p.) treatment reduced the articular incapacitation induced by carrageenin (300 g) in rats. In this model, naloxone (2 mg/kg) blocked the analgesic action of morphine (2 mg/ kg) but did not change the WSF antinociceptive effect. It suggests that endogenous opioids are not involved in the WSF antinociceptive effect. The neutrophil migration induced by carrageenin (300 g) injection into rat peritoneal cavities and into 6-day-old subcutaneous air-pouches was significantly inhibited (p < 0.05) by WSF pretreatment (30 and 50 mg/kg; s.c.). At the same dose WSF also inhibited (p < 0.05) the carrageenin (400 g/paw)-induced oedema, but failed to modify the oedema induced by dextran (100 g/paw). Furthermore, the increase in the cutaneous vascular permeability induced by the potent leukocyte chemotactic agent LTB 4 (39 ng co-injected with 500 ng iloprost, i.d.) was significantly blocked by WSF (30 mg/kg; i.p.). However, in the same dose WSF caused a 2-fold increase in the vascular permeability induced by histamine (10 g), a direct vasoactive mediator. These results suggest that WSF can inhibit the inflammatory reactions induced by neutrophil mobilizing stimuli.