The Antinociceptive and Anti-Inflammatory Activities ofAspidosperma tomentosum(Apocynaceae)

Abstract

We investigated the antinociceptive and anti-inflammatory activities of the crude ethanolic extract (CEE), its fractions, and the flavonoid isorhamnetin fromAspidosperma tomentosumusing models of nociception and inflammation in mice. In the writhing test, the CEE and its fractions (except for soluble phase, CHCl3100% and EtAcO 100%) at 100 mg/kg p.o. induced antinociceptive activity. Isorhamnetin (100 μmol/kg, p.o.) was also active. In the hot plate test, only the treatment with the fractions Hex : CHCl350%, CHCl3100%, and CHCl3 : MeOH 5% (100 mg/kg, p.o.) increased the latency time, reversed by the opioid antagonist naloxone. Fractions that were active in the hot plate test did not show catalepsy condition. It was observed that CEE, all fractions, and isorhamnetin reduced the formalin effects in the neurogenic phase. In the inflammatory phase, only CEE, isorhamnetin, and CHCl3100% and CHCl3 : MeOH 5% fractions were active. CEE and all fractions, except for CHCl3 : MeOH 10% fraction, isorhamnetin, and soluble fraction were able to produce an antioedematogenic activity in the ear capsaicin-induced edema test. In the thioglycolate-induced peritonitis, only EtAcO 100% fraction was not active. The results demonstrate thatA. tomentosumhas antinociceptive and anti-inflammatory activities in animal models.