Lubricating gut pill (LGP), a traditional Chinese formula, had been conformed to improve the loperamide-induced rat constipation by stimulation of Cl(-) secretion, but its mechanism has not been fully explored. Thus, the purpose of this study was to identify the action sites of LGP-stimulated Cl(-) secretion across rat distal colonic mucosa.
Rat distal colonic mucosa was mounted in Ussing chambers and short circuit current (I(SC)), apical Cl(-) current and basolateral K(+) current were recorded. Intracellular cyclic adenosine monophosphate (cAMP) content and protein kinase A (PKA) activity were determined with ELISA kit and the non-radioactive PepTag test, respectively.
LGP at 800μg/ml elicited a sustained increase in Cl(-) secretory response, which was inhibited by CFTR(inh)172, a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor. Permeabilizing apical membrane with nystatin revealed that LGP-stimulated basolateral K(+) current was significantly inhibited by KCNQ1 K(+) channel inhibitor chromanol 293B. LGP-stimulated I(SC) was markedly reduced by pretreatment with cis-N-[2-phenylcyclopentyl]-azacyclotridec-1-en-2amine (MDL-12,330A) and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89), but not with inhibitors of Ca(2+)-dependent signaling pathway. Treatment of tissue with LGP resulted in an increase in intracellular cAMP level and the activation in protein kinase A. The E-prostanoid(4) (EP)(4) receptor antagonist L-161,982 completely eliminated LGP-induced response.
The results showed that LGP enhances Cl(-) and fluid secretion via prostanoid receptor signaling and also cAMP and protein kinase A pathway, subsequently triggering the activation of apical Cl(-) channels mostly CFTR and basolateral cAMP-dependent K(+) channel.
"In constipation, marked decreases in fecal discharge and delayed fecal pellet transit in the large intestinal lumen caused by absorption of water into the fecal pellets are observed; accordingly, the water content of the discharged fecal pellets is decreased markedly. Therefore, these changes in fecal parameters, including discharged fecal pellet number and water content, have been used as indices of the effects of various laxative agents [37, 41]. The increases in discharged fecal pellet number and water content in the constipated rats induced by treatment with either FRe dosage, the liquid yoghurt single formula, or the three BFRe concentrations were considered direct evidence of the beneficial laxative effects of these agents. "
[Show abstract][Hide abstract] ABSTRACT: Aim. The objective was to evaluate the synergistic effects of fermented rice extracts (FRe) on the laxative and probiotic properties of yoghurt in rats with loperamide-induced constipation. Methods. After constipation induction, yoghurt containing FRe (BFRe; 0.05%, 0.1%, or 1%) was administered orally once per day for 6 days. Results. Loperamide treatment caused marked decreases in fecal pellet numbers and water content discharged, as well as in the surface mucosal thickness of the colonic lumen, intestinal charcoal transit ratio, thickness, and number of mucous-producing goblet cells in the colonic mucosa, whereas it increased the remnant fecal pellet number and the mean diameter of the colonic lumen. However, this loperamide-induced constipation was ameliorated by treatment with FRe, yoghurt single formula, or 0.05%, 0.1%, or 1% BFRe (10 mL/kg). Additionally, the viable numbers of Lactobacillus in the cecal contents and feces were markedly higher than those in constipated rats. Moreover, greater probiotic and laxative effects were detected in BFRe-treated rats than in rats treated with equivalent doses of yoghurt or FRe single formula. Conclusion. The results suggest that addition of FRe to liquid yoghurt will enhance the probiotic and beneficial laxative effects of yoghurt in the digestive tract, without causing side effects.
Evidence-based Complementary and Alternative Medicine 08/2014; 2014:878503. DOI:10.1155/2014/878503 · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It was evaluated the synergistic effects of fermented rice extracts (FRe) on the laxative and probiotic effects of yogurt in normal rats. Commercial liquid yogurt (Bulgaris™) containing 0.05%, 0.10%, and 1.0% FRe (BFRe) was administered orally to normal rats daily for 10 days. Compared with the vehicle control, the three BFRe treatments exhibited highly significant increases in fecal pellet numbers, water content, thickness of surface mucous in the colonic lumen, intestinal charcoal transit ratio, thickness of the colonic mucosa, and mucous-producing goblet cells; decreased numbers and mean diameters of fecal pellets remaining in the colonic lumen were detected compared with the vehicle control, and numbers of viable Lactobacilli in cecum contents and feces were dramatically higher than those in vehicle control rats. More favorable probiotic and laxative effects were detected in rats treated with 0.1% and 1.0% BFRe compared with equal doses of liquid yogurt or FRe alone. Therefore, appropriate concentrations of BFRe may be highly effective for alleviating constipation and provide a complementary natural approach to reducing lifestyleinduced constipation.
Toxicology and Environmental Health Sciences 06/2014; 6(2):87-98. DOI:10.1007/s13530-014-0192-y
[Show abstract][Hide abstract] ABSTRACT: Ethnopharmacological relevance:
Rhein is a pharmacological active component found in Rheum palmatum L. that is the major herb of the San-Huang-Xie-Xin-Tang (SHXXT), a medicinal herbal product used as a remedy for constipation. Here we have investigated the comparative pharmacokinetics of rhein in normal and constipated rats. Microarray analysis was used to explore whether drug-metabolizing genes will be altered after SHXXT treatment.
Materials and methods:
The comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats was studied by liquid chromatography with electrospray ionization tandem mass spectrometry (LC-MS/MS). Gene expression profiling in drug-metabolizing genes after SHXXT treatment was investigated by microarray analysis and real-time polymerase chain reaction (RT-PCR).
A validated LC-MS/MS method was applied to investigate the comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats. The pharmacokinetic results demonstrate that the loperamide-induced constipation reduced the absorption of rhein. Cmax significantly reduced by 2.5-fold, the AUC decreased by 27.8%; however, the elimination half-life (t1/2) was prolonged by 1.6-fold. Tmax and mean residence time (MRT) were significantly prolonged by 2.8-fold, and 1.7-fold, respectively. The volume of distribution (Vss) increased by 2.2-fold. The data of microarray analysis on gene expression indicate that five drug-metabolizing genes, including Cyp7a1, Cyp2c6, Ces2e, Atp1b1, and Slc7a2 were significantly altered by the SHXXT (0.5 g/kg) treatment.
The loperamide-induced constipation reduced the absorption of rhein. Since among the 25,338 genes analyzed, there were five genes significantly altered by SHXXT treatment. Thus, information on minor drug-metabolizing genes altered by SHXXT treatment indicates that SHXXT is relatively safe for clinical application.
Journal of Ethnopharmacology 07/2014; 155(2). DOI:10.1016/j.jep.2014.07.022 · 3.00 Impact Factor
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