A bioactivity-guided study on the anti-diarrheal activity of Polygonum chinense Linn

Abstract

Ethnopharmacological relevance: Polygonum chinense Linn., a folk medicine, has long been used for the treatment of diarrhea and enteritis in southwestern China. However, the components responsible for its anti-diarrheal activity are still poorly understood.

Aim of the study: To determine anti-diarrheal activities of Polygonum chinense L. and to identify its active components through bioactivity-guided isolation technique.

Materials and methods: Animals were orally administered with the extract of Polygonum chinense L. The anti-diarrheal effects of 75% ethanol extract, four fractions with different polarities from 75% ethanol extract, different eluates collected from Diaion HP-20 macroporous resin chromatography, ellagic acid and corilagin, were examined based on mouse models of castor oil- and magnesium sulfate-induced diarrhea.

Results: The results showed that the 75% ethanol extract of Polygonum chinense L. exhibited significant anti-diarrheal activities in a dose-dependent manner in two mouse models. Through in vivo bioactivity-guided fractionation processes, n-butanol and aqueous fractions were found to exhibit prominent anti-diarrheal activities, and two major compounds, ellagic acid and corilagin, from these active fractions were found to possess anti-diarrheal effects.

Conclusion: Present study provides evidence of the utilization of Polygonum chinense L. for diarrhea, and ellagic acid and corilagin are two components contributing to the anti-diarrheal effect.

Keywords: 25%/50%/95% ethanol subfraction; AF; ASF; Anti-diarrheal activity; BF; CMC-Na; Corilagin; EE; EF; ESF25/50/95; Ellagic acid; HPLC; LC-UV-MS-MS; MDI; MSR; PF; Polygonum chinense Linn.; TLC; UHPLC; UV; aqueous fraction; aqueous subfraction; ethanol extract; ethyl acetate fraction; high-performance liquid chromatography; liquid chromatography-ultraviolet-tandem mass spectrometry; maximum absorption wavelength; mean diarrheal index; mean stool grade; mean stool rate; n-butanol fraction; petroleum ether fraction; retention time; sodium carboxymethylcellulose; t(R); thin layer chromatography; ultra high-performance liquid chromatography; ultraviolet; λ(max).