Antidiarrhoeal and antibacterial properties of crude aqueous stem bark extract and fractions of Parkia biglobosa (Jacq.) R. Br. Ex G. Don.

Abstract

Stem bark of Parkia biglobosa (Jacq.) R. Br. Ex G. Don (Fabaceae) is used in African traditional medicine for management of diarrhoea-related disorders. The anti-diarrhoeal and anti-microbial activities of the aqueous stem bark extract of P. biglobosa  and its fractions designated PF1-PF4   were investigated in mice and against selected diarrhoea-causing micro-organisms. The oral median lethal dose (LD50) of the extract in mice was estimated to be greater than 5000 mg/kg B.W. The extract and its column chromatographic fraction F3 significantly (p < 0.05) and dose-dependently reduced frequency of stooling in castor-oil-induced diarrhoea, castor-oil-induced intestinal fluid accumulation and intestinal transit. The crude extract as well as fractions F3 and F4 strongly inhibited growth of selected micro-organisms. The study showed that the aqueous extract possess both anti-diarrhoeal and anti-microbial activities. The anti-diarrhoeal action may be linked partly to direct inhibitory effect of the extract on the propulsive movement of the gastrointestinal tract smooth muscle, and the anti-microbial effect on the diarrhoea-causing pathogenic organisms.             Key words: Antidiarrhoeal, antimicrobial, Parkia biglobosa, fractions, castor oil.