A systematic antidiarrhoeal evaluation of a vegetable root Begonia roxburghii and its marker flavonoids against nonpathogenic and pathogenic diarrhoea

The plant Begonia roxburghii, widely distributed in North East India, is regularly used as a vegetable and food item in these areas. The plant's roots are traditionally used in treating digestive disorders, diarrhoea, dysentery and various stomach ailments. Therefore, the main objective included scientific justification of the traditional assertions about the edible roots and its marker flavonoids from the plant in the treatment of diarrhoea, followed by deriving its mechanism. HPLC was used to standardize the ethanolic extract of B. roxburghii (EBR) with respective markers luteolin and rutin. The study revealed the similar antibacterial potential of both the markers (luteolin and rutin); however, normal faecal excretion showed the highest antisecretory potential of EBR followed by rutin. EBR at 300 mg/kg, p.o. demonstrated the highest % protection from diarrhoea in both nonpathogenic (castor oil-induced) and pathogenic (enteropathogenic E. coli-induced) diarrhoea rat models, which also restored the altered biochemical parameters, ion concentration and cytokine levels. EBR and rutin also justified their protective nature through histopathology showing less broadening of villus and intact epithelia compared to diarrhoea control rat colons. The in-silico studies validated the contribution of rutin as a major biomarker which enhanced Na+/K+–ATPase activity and stabilized the C-terminal 282-residue fragment of EPEC intimin and was also supported by findings of network pharmacology observations. The present investigation justified the traditional claim of the edible roots of B. roxburghii in treating diarrhoea, where its marker rutin played a significant role in reactivating Na+/K+-ATPase, restored electrolyte balance, and also stabilized the EPEC C-terminal.