title: Antinociceptive properties of steroids isolated from Phyllanthus corcovadensis in mice.
abstract: The antinociceptive actions of the steroid compounds isolated from the leaves, stems, and roots of P. corcovadensis have been investigated in mice. Stigmasterol, stigmasterol acetate, beta-sitosterol, and aspirin (3-100 mk/kg, i.p.) inhibited, in a dose-related manner, acetic acid-induced abdominal constriction in mice with ID50s of 16, 11, 9, and 24 mg/kg, respectively. In the formalin test, stigmasterol and stigmasterol acetate (10-100 mg/kg, i.p.) caused graded inhibition of both the neurogenic (first phase) and inflammatory phases (second phase) of formalin-induced pain. However, both compounds were more effective in relation of the second phase of the formalin test with ID50 values of 26 and 41 mg/kg, respectively. Furthermore, both steroids failed to affect the edematogenic response of the formalin test. Given orally, stigmasterol and stigmasterol acetate (50-200 mg/kg) also exhibited significant though less potent analgesic action against both acetic acid- and formalin-induced nociception in mice. In addition, stigmasterol (up to 100 mg/kg, i.p.), in contrast to morphine (10 mg/kg, s.c.), had no analgesic effect in either tail-flick or hot-plate models. These findings suggest that stigmasterol and beta-sitosterol may account, at least in part, for the antinociceptive actions reported previously for the hydroalcoholic extract of Phyllanthus corcovadensis.
mesh_terms: D000700:Analgesics / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D008297:Male; D051379:Mice; D010146:Pain / Q000503:physiopathology*; D018515:Plant Leaves; D018517:Plant Roots; D018547:Plant Stems; D010946:Plants, Medicinal; D013256:Steroids / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000700:Analgesics; D013256:Steroids