Analgesic and anti-inflammatory activities of Polygonum stagninum.

The n-hexane, ethyl acetate (EtOAc), and methanol extracts of the aerial parts of Polygonum stagninum Buch.-Ham. ex Meissn. (Polygonaceae), a Bangladeshi medicinal plant, were assessed for analgesic and anti-inflammatory properties in experimental mice and/or rat models. In the acetic-acid-induced writhing test in mice, all extracts displayed a dose dependent analgesic effect. The most potent analgesic activity was observed with the EtOAc extract at the dose of 400 mg/kg body weight, with an inhibition of writhing response of 50.3% compared to 62.2% for the positive control aminopyrine. Among the extracts, n-hexane extract at the doses of 200 and 400 mg/kg body weight showed the highest levels of anti-inflammatory activity after 2 h, with the inhibition of paw edema of 60.1% and 64.1%, respectively, and this effect was much better than that of the conventional anti-inflammatory agent phenylbutazone (maximum inhibition of 38.3% after 4 h).

Antinociceptive, anti-inflammatory and diuretic properties of Polygonum barbatum (L.) Hara var. barbata / Propriedades antinociceptiva, antiinflamatória e diurética dos extratos de P. barbatum (L.) Hara var. barbata

The antinociceptive, anti-inflammatory and diuretic properties of the extracts of P. barbatum (L.) Hara var. barbata, Polygonaceae, at the doses of 200 and 400 mg/kg body weight, were evaluated in mice/rat models using, respectively, the acetic-acid-induced writhing method, the carrageenan-induced edema test and the Lipschitz method. In the acetic-acid-induced writhing test in mice, all extracts displayed a dose dependent analgesic effect. The most potent analgesic activity was observed with the petroleum ether extract at the dose of 400 mg/kg body weight with an inhibition of writhing response 46.8 percent compared to 62.2 percent for the positive control aminopyrine. Petroleum ether extract at the dose of 400 mg/kg body weight also displayed the highest levels of anti-inflammatory activity after 2 h with the 39.3 percent inhibition of paw edema, and this effect was better than the effect observed by the conventional anti-inflammatory agent phenylbutazone (maximum inhibition of 38.3 percent after 4 h). All extracts increased urine volume in a dose-dependent manner, and the ethyl acetate extract showed a significant level of diuresis comparable to that of the standard diuretic agent furosemide.

As propriedades antinociceptiva, antiinflamatória e diurética dos extratos de P. barbatum (L.) Hara var. barbata, Polygonaceae, nas doses de 200 e 400 mg/kg de peso corpóreo foram avaliadas em modelos utilizando camundongos/ratos, respectivamente, o método de contorções induzidas por ácido acético, o teste de edema induzido por carragenina e o método de Lipschitz. No método de contorções induzidas por ácido acetic, todos os extratos apresentaram efeito nociceptivo dose dependente. O efeito nociceptivo mais potente foi observado com o extrato de éter de petróleo na dose de 400 mg/kg com uma inibição das contorções de 46,8 por cento comparado com o controle positivo de aminopirina de 62,2 por cento. O extrato de éter de petróleo na dose de 400 mg/kg também mostrou maior atividade antiinflammatoria após 2 h com 39,3 por cento de inibição do edema de pata, e este efeito foi maior que o observado para o agente antiinflamatório convencional fenilbutazona (inibição máxima de 38,4 por cento após 4 h). Todos os extratos aumentaram o volume de urina de maneira dose dependente e o extrato acetato de etila mostrou um nível de significância de diurese comparável ao agente diurético padrão, furosemida.