Evaluation of biological activity of Polygala boliviensis in experimental models

The plants of the genus Polygala (Polygalaceae) are employed in folk medicine for the treatment of several pathologies, including disorders of the bowel and kidney, as anesthetic, expectorant and anti-inflammatory. The present study was undertaken to investigate the antiedematogenic and antinociceptive activities of methanolic extract of Polygala boliviensis A. W. Benn (MEPB) in mice. The antinociceptive activity of MEPB was evaluated using the writhing, formalin and tail immersion tests. The carrageenan-induced paw edema test was used to assess the antiedematogenic activity of MEPB. Mice motor performance was evaluated in the rota rod and open field tests and the acute toxicity evaluated over 14 days. High-performance liquid chromatography was used to determine the fingerprint chromatogram of MEPB. Oral administration of MEPB (75- 600mg/kg) reduced the number of writhing induced by acetic acid. In the formalin test, the oral pre-treatment with MEPB (75 - 600 mg/kg) produced a dose-related inhibition only of the late phase. MEPB (300 and 600 mg/kg) reduced the carrageenan-induced paw edema. In contrast, the treatment with MEPB (300 and 600 mg/kg) did not prevent the thermal nociception in the tail immersion test. MEPB (600 mg/kg)-treated mice did not show any motor performance alterations. Over the study duration of 14 days, there were no mortality or toxic signs recorded in the group mice given 6000 mg/kg of MEPB. The present study demonstrates, for the first time, the antinociceptive and antiedematogenic properties of Polygala boliviensis.