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

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.

Metabolite profiling of plasma and urine from rats with TNBS-induced acute colitis using UPLC-ESI-QTOF-MS-based metabonomics--a pilot study

The incidence of inflammatory bowel disease, a relapsing intestinal condition whose precise etiology is still unclear, has continually increased over recent years. Metabolic profiling is an effective method with high sample throughput that can detect and identify potential biomarkers, and thus may be useful in investigating the pathogenesis of inflammatory bowel disease. In this study, using a metabonomics approach, a pilot study based on ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was performed to characterize the metabolic profile of plasma and urine samples of rats with experimental colitis induced by 2,4,6-trinitrobenzene sulfonic acid. Acquired metabolic profile data were processed by multivariate data analysis for differentiation and screening of potential biomarkers. Five metabolites were identified in urine: two tryptophan metabolites [4-(2-aminophenyl)-2,4-dioxobutanoic acid and 4,6-cihydroxyquinoline], two gut microbial metabolites (phenyl-acetylglycine and p-cresol glucuronide), and the bile acid 12α-hydroxy-3-oxocholadienic acid. Seven metabolites were identified in plasma: three members of the bile acid/alcohol group (cholic acid, 12α-hydroxy-3-oxocholadienic acid and cholestane-3,7,12,24,25-pentol) and four lysophosphatidylcholines [LysoPC(20:4), LysoPC(16:0), LysoPC(18:1) and LysoPC(18:0)]. These metabolites are associated with damage of the intestinal barrier function, microbiota homeostasis, immune modulation and the inflammatory response, and play important roles in the pathogenesis of inflammatory bowel disease. Our results positively support application of the metabonomic approach in study of the pathophysiological mechanism of inflammatory bowel disease.