Anti-inflammatory and analgesic effects of cucurbitacins from Wilbrandia ebracteata

The anti-inflammatory and antinociceptive actions of the CH2Cl2 extract and semipurified fraction (F-III) from roots of Wilbrandia ebracteata Cogn. have been investigated in rats and mice. The CH2Cl2 extract (1-10 mg/kg, i.p.; ID50 5 mg/kg) and (3-30 mg/kg, p.o.; ID50 15 mg/kg) inhibited, in a dose-related manner, carrageenan-induced paw edema in rats. The subfraction (F-III) from CH2Cl2 extract and compounds isolated as cucurbitacin B and E also inhibited carrageenan-induced edema. The CH2Cl2 extract and F-III also exhibited significant analgesic action in acetic acid-induced pain in mice. In the formalin test, the CH2Cl2 extract (0.3-10 mg/kg, i.p.) and (3-30 mg/kg, p.o.) caused inhibition of the neurogenic (first phase) and inflammatory phase (second phase) of formalin-induced pain. However, the CH2Cl2 extract was more effective in relation to the second phase than in inhibition of the formalin-induced edema. These findings suggest that CH2Cl2 extract has potent anti-inflammatory and analgesic action and that F-III and cucurbitacin B and E may account for these actions.