Evaluation of antinociceptive and anti-inflammatory effects of pent aclethra macroph ylla (benth.) Aqueous extracts in mice

ABSTRACT

This study was carried out to evaluate the cytotoxicity and the anti-trichomonal, antinociceptive, anti-inflammatory and antimalarial effects of aqueous extracts of Pentaclethra macrophylla (Benth). The efficacy of the extracts (fruit-pericarp, bark, leaf and seed) against the flagellate Trichomonas gallinae was determined by using metronidazole as a reference drug. The parasite was isolated from the crop of domestic pigeon and incubated for 24hrs. . Minimal lethal concentrations (MLCs) of three of the four extracts (fruit-pericarp, bark and seed) ranged between 100-1000g/ml while the parasite was not sensitive to the leaf extract. The . cytotoxicity _test revealed that the bark was highly toxic (256.4l) followed by the fruit-pericarp (80.1 µl). In the antinociceptive and anti-inflammatory tests, oedema formation in the lungs was significantly (P<0.05) suppressed in seed, fruitpericarp, and leaf extracts. The seed and leaf extracts significantly (P<0.05) . suppressed oedema formation in the carrageenin induced right paw oedema test; while the reduction observed in the fruit-pericarp was not significant (P>0.05), The number of leucocytes counted from the exudates collected in . the pleural cavity showed a significant (P<0.05) reduction in the three extracts. In the flicktail immersion test, all the three extracts showed increased reaction time and were significant (P<0.05). These observations revealed that Pentaclethra macrophylla aqueous extracts have anti-inflammatory and antinociceptive effects. There was no anti- malaria activity observed in the extracts. This was because of the rise in the level of parasitemia and a decrease in survival rate of the test groups with respect to the control.