Extracts from the trunk bark of Distemonanthus benthamianus Baillon. (Caesalpiniaceae) developed antidiarrhoeal activities in rats and mice

Distemonanthus benthamianus is used in Cameroon to treat diarrhoeal episodes. The study aimed to evaluate its antidiarrhoeal potential in Wistar rats and BALB/c mice. Extracts were preliminary investigated for phytochemical components, total phenols quantification and DPPH scavenging activity. Their effects were also evaluated against castor oil-induced diarrhoea, prostaglandin-E1-induced fluid accumulation, charcoal meal motility test, as well as against magnesium sulphate-induced diarrhoea and electrolytes regulation. The methanolic extract contains alkaloids, flavonoids, polyphenols, saponins, sterols, tannins and triterpenes while aqueous extract was devoid of sterols and triterpenes. Phenolic compounds were more concentrated in methanolic extract, which also developed significant DPPH scavenging effects. In castor oil-induced diarrhoea, significant (p < 0.001) reduction in diarrhoeal stools frequency was observed with 100, 200 and 300 mg/kg of aqueous extract, while 400 mg/kg of methanolic extract exhibited maximum effect. Total stools frequency was significantly (p < 0.001) reduced with doses of 300 and 400 mg/kg of extracts. Maximum protection was obtained with 400 mg/kg of both extracts in magnesium sulphate-induced diarrhoea. That dose significantly (p < 0.001) reduced Na+ excretion, while Ca2+ excretion was significantly (p < 0.001) increased with 100 mg/kg of aqueous extract. Both extracts significantly (p < 0.01, p < 0.001) reduced the intestinal fluids mass and volume similarly compared to the negative control groups. The gut motility was significantly (p < 0.001) reduced with 100 and 200 mg/kg of methanolic and aqueous extracts, respectively. Extracts are therefore antidiarrhoeal remedies candidates, since they provoked a decrease in intestinal motility, associated with fluid and electrolytes regulation across the gut.