The antinociceptive activity of the Maytenus rigida Mart. (Celastraceae) ethanol ext. and its Et acetate fraction as well as of (-)-4'-methylepigallocatechin (1), a previously isolated compd., was demonstrated in vivo. ED50 for 1 in the writhing test was 14.14 mg/kg. The acetic acid-induced writhing was inhibited by 98.4, 84.4, and 58.3%, resp., when mice were treated with the ethanol ext., Et acetate fraction, and 1. In the hot plate test, mice pretreated with 1 showed significantly increased reaction times (60-89%). Oral administration of 1 significantly inhibited first and second phases of the formalin-induced pain (50 and 26.5%, resp.), whereas indomethacin inhibited only the second phase of the test (41.2%). Ethanol ext. and its fraction showed effects on inflammatory pain, while neurogenic and inflammatory pain suppression by 1 is a strong indication of the presence of both central and peripheral effects and suggests its analgesic and anti-inflammatory potential.
Antinociceptive effects of an extract, fraction and an isolated compound of the stem bark of Maytenus rigida
PIZZA, Cosimo;PIACENTE, Sonia;MONTORO, Paola;
2012-01-01
Abstract
The antinociceptive activity of the Maytenus rigida Mart. (Celastraceae) ethanol ext. and its Et acetate fraction as well as of (-)-4'-methylepigallocatechin (1), a previously isolated compd., was demonstrated in vivo. ED50 for 1 in the writhing test was 14.14 mg/kg. The acetic acid-induced writhing was inhibited by 98.4, 84.4, and 58.3%, resp., when mice were treated with the ethanol ext., Et acetate fraction, and 1. In the hot plate test, mice pretreated with 1 showed significantly increased reaction times (60-89%). Oral administration of 1 significantly inhibited first and second phases of the formalin-induced pain (50 and 26.5%, resp.), whereas indomethacin inhibited only the second phase of the test (41.2%). Ethanol ext. and its fraction showed effects on inflammatory pain, while neurogenic and inflammatory pain suppression by 1 is a strong indication of the presence of both central and peripheral effects and suggests its analgesic and anti-inflammatory potential.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
