Rhubarb Tannins Extract Inhibits the Expression of Aquaporins 2 and 3 in Magnesium Sulphate-Induced Diarrhoea Model

Abstract

Tannins, a group of major active components of Chinese rhubarb and widely distributed in nature, have a significant antidiarrhoeal activity. Aquaporins (AQPs) 2 and 3 play important roles in regulating water transfer during diarrhoea. The present study aims to determine the effect of the total tannins extract of rhubarb on aquaporins (AQPs) 2 and 3 in diarrhoea mice and HT-29 cells both induced by magnesium sulphate (MgSO4). Our results showed that rhubarb tannins extract (RTE) significantly decreased the faecal water content in colon and evaluation index of defecation of diarrhoea mice. Interestingly, RTE could markedly reduce the mRNA and protein expression levels of AQPs 2 and 3 in apical and lateral mucosal epithelial cells in the colons of diarrhoea mice and HT-29 cells both induced by MgSO4 in a dose-dependent manner. Furthermore, RTE suppressed the production of cyclic monophosphate- (cAMP-) dependent protein kinase A catalytic subunits α (PKA C-α) and phosphorylated cAMP response element-binding protein (p-CREB, Ser133) in MgSO4-induced HT-29 cells. Our data showed for the first time that RTE inhibit AQPs 2 and 3 expression in vivo and in vitro via downregulating PKA/p-CREB signal pathway, which accounts for the antidiarrhoeal effect of RTE.

Beneficial effects of consumption of acerola, cashew or guava processing by-products on intestinal health and lipid metabolism in dyslipidaemic female Wistar rats

“…The guava by-products showed the highest IDF content and IDF/SDF ratio. In addition, the guava and cashew by-products presented high amounts of tannins (16,55) , which have been shown to have antisecretory activity, inducing decreased intraluminal fluid, increased water reabsorption, reduced intestinal motility and, consequently, reduced moisture in faeces (56) . Diets presenting IDF/SDF ratio in the range of 1•0-2•3 typically present better capability of modulating physiological processes (10) .…”

Functional Components of Carob Fruit: Linking the Chemical and Biological Space

“…It is not the first time that tannins are considered responsible for anti-diarrheal action. Liu et al proved through in vivo and in vitro techniques that the tannin extract of rhubarb downregulates the PKA/p-CREB pathway and consequently the expression of Aquaporins 2 and 3 which control the water transfer inside the cells [89]. Wursch (1991) also patented a dietetic product with anti-diarrheic activity that the particulated carob pod contains at least 20% by weight, based upon dry matter, of water-insoluble tannins [90].…”

Preparation of Galla Chinensis Oral Solution as well as Its Stability, Safety, and Antidiarrheal Activity Evaluation

“…Tannin-rich carob pod (which contains 40% tannins) produced an effect in acute-onset diarrhea [ 15 ]. Rhubarb tannins extract (which contains 55.69% equivalent of gallic acid) could inhibit MgSO 4 -induced diarrhea [ 16 ]. Galla Rhois tannin extract (tannin accounts for 45.8%) reduced the incidence of diarrhea in postweaning piglets [ 17 ].…”