Abstract

• The present work concerns with the investigation of some bioactive constituents and anti-diarrhoeal activity of flower and bark of Buch-Ham. (Yin-gat-gyi). The preliminary phytochemical investigation reveals the presence of –amino acids, carbohydrates, flavonoids, glycosides, organic acids, phenolic compounds, reducing sugars, saponins, steroids and terpenoids in flower while observing alkaloids, carbohydrates, glycosides, organic acids, phenolic compounds, saponins, starch, steroids, tannins and terpenoids in barks. Three organic constituents: benzoic acid (compound I) (0.004%, colourless needle shape), kaempferol (compound II) (0.002%, yellow amorphous form, m.pt = 275-280C) from EtOAc crude extracts of flower and stigmasterol (compound III) (0.0003%, colourless crystals, m.pt = 167-170C) from EtOAc crude extract of bark of YGG have been isolated by using thin layer chromatography and column chromatographic separation methods. antidiarrhoeal activity of compound I, compound II, 95 % ethanol and aqueous extracts of YGG were carried out by using castor oil–induced mice models. The mean frequency of defecation in four hours was found to be significantly decreased by both extracts, compound I, compound II and standard drug loperamide compared with that of control in castor oil – induced diarrhoeal in mice (p<0.005-p<0.001). The percent inhibitions of defecation within four hours for 95 % ethanol extract (1g/kg bw), aqueous extract (4g/kg bw), compound I (5mg/kg bw), compound II (6mg/kg bw) and standard drug loperamide (6mg/kg bw) were 74.41 %, 69.61 %, 57.61 %, 84.78 % and 69.61 %, respectively. It was found that the percent inhibitions of defecation for 95 % ethanol extract (1g/kg bw) and compound II (6mg/kg bw) were higher than that of the standard drug loperamide. Aqueous extract (4g/kg bw), 95 % ethanol extract (1g/kg), compound I and compound II were found to be significantly reduced both volumes and weights of the intestinal fluids secretion, comparable to the effect of the standard drug loperamide in castor oil induced enteropooling test (p < 0.05 – p < 0.001). In the investigation of the intestinal transit test, the percent inhibition of all aqueous extracts and 95 % ethanol extracts (1 g/kg bw and 0.5 g/kg bw), compound I (5 mg/kg bw) and compound II (6 mg/kg bw) on intestinal transits were higher than that of standard drug loperamide (p < 0.001). From these results, the anti-diarrhoeal index in percents for aqueous extracts (4g/kg bw, 2g/kg bw, 1g/kg bw), 95% ethanol extract (1g/kg bw), compound I (5mg/kg bw), compound II (6mg/kg bw) and standard drug loperamide (6mg/kg bw) were found to be 175.82 %, 168.01 %, 115.44 %, 238.53 %, 146.17 % and 285.99 % and 104.3 % respectively. It indicated that both extracts, compound I and compound II were more effective than standard drug loperamide in antidiarrhoeal activity since the higher the anti-diarrhoeal index (%), the more potent in antidiarrhoeal activity. It may be inferred that aqueous and ethanolic extracts of flower of YGG and isolated kaempferol may be used in the formulation of antidiarrhoeal medicine.