Evaluation of in-vivo antidiarrhoeal and in-vitro antibacterial activities of the root extract of Brucea antidysenterica J. F. Mill (Simaroubaceae)

Background: Diarrhoea has been the major cause of death especially in children of developing countries. Brucea antidysenterica is one of the several medicinal plants used traditionally for the treatment of diarrhoea in Ethiopia. Hence, the present study was undertaken to investigate the antidiarrhoeal and antibacterial activities of the root extract of B. antidysenterica.

Methods: Plant material was extracted by maceration technique using 80% methanol. The antidiarrhoeal activity was tested using castor oil-induced diarrhoea, castor oil-induced charcoal meal test, and castor oil-induced enteropooling models in mice. Whilst, the antibacterial activity of the crude extract was evaluated using agar well diffusion and broth microdilution methods.

Results: The 80% methanolic crude extract significantly delayed the diarrhoeal onset at the two higher doses (p < 0.001) and it has also inhibited the number and weight of faecal output at all tested doses as compared with the negative control. Moreover, it showed a significant anti-motility effect (p < 0.001) at all tested doses. Whereas it displayed a significant reduction in the weight and volume of intestinal contents at the doses of 200 and 400 mg/kg (p < 0.01). The highest concentration (800 mg/mL) of test extract showed maximum zone of inhibition in all tested standard strains of bacteria (18.3 mm-22 mm). While MIC and MBC values (0.39 mg/mL and 1.56 mg/mL) showed that S. flexneri was the most susceptible pathogen for test extract.

Conclusion: The study revealed that the root extract of B. antidysenterica has antidiarrhoeal and antibacterial activities.

Keywords: Agar well diffusion; Antibacterial; Antidiarrhoeal; Brucea antidysenterica; Castor oil.