Gallotannin-Enriched Extract Isolated from Galla Rhois May Be a Functional Candidate with Laxative Effects for Treatment of Loperamide-Induced Constipation of SD Rats

Effects of brown seaweed oligosaccharides on obesity and constipation managements

Brown seaweed oligosaccharides (BSO) have demonstrated potential as nutraceuticals with cholesterol-lowering, anti-obesity, and anti-constipation properties. In this study, we initially examined how BSO impact body weight, blood lipid levels, and adipose tissue in a rat model of obesity induced by a high-fat diet. Our findings revealed that BSO administration significantly attenuated body weight gain, ameliorated dyslipidemia, and reduced visceral adiposity. Additionally, we evaluated the prophylactic efficacy of BSO in a loperamide hydrochloride-induced constipation mouse model by assessing defecation parameters and gastrointestinal motility. Our results indicated that BSO intervention significantly increased fecal pallet output and fecal water content, as well as improved intestinal transit. In conclusion, this study lays the foundation for a deeper understanding of how BSO may influence obesity and constipation, offering novel insights into its potential safe and efficacious clinical applications.

Antioxidant and Laxative Effects of Methanol Extracts of Green Pine Cones (Pinus densiflora) in Sprague-Dawley Rats with Loperamide-Induced Constipation

Oxidative stress is the key cause of the etiopathogenesis of several diseases associated with constipation. This study examined whether the green pine cone can improve the symptoms of constipation based on the antioxidant activities. The changes in the key parameters for the antioxidant activity and laxative effects were examined in the loperamide (Lop)-induced constipation of Sprague-Dawley (SD) rats after being treated with the methanol extracts of green pine cone (MPC, unripe fruits of Pinus densiflora). MPC contained several bioactive compounds, including diterpenoid compounds such as dehydroabietic acid, taxodone, and ferruginol. In addition, it exhibited high scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals. These effects of MPC successfully reflected the improvement in nicotinamide adenine dinucleotide phosphate oxidase (NADP) H oxidase transcription, superoxide dismutase (SOD) levels, and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation levels in the mid colon of Lop+MPC-treated SD rats. Furthermore, significant improvements in the stool parameters, gastrointestinal (GI) transit, intestine length, and histopathological structure of the mid colon were detected in the Lop-induced constipation rats after MPC treatment. The other parameters, including the regulators for the adherens junction (AJ) and tight junction (TJ), and GI hormone secretion for laxative effects, were improved significantly in Lop+MPC-treated SD rats. These effects were also verified in Lop+MPC-treated primary rat intestine smooth muscle cells (pRISMCs) through analyses for antioxidant defense mechanisms. Overall, the finding of this study offers novel scientific evidence that MPC could be considered as a significant laxative for chronic constipation based on its antioxidant activity.

Complement C3-Deficiency-Induced Constipation in FVB/N-C3em1Hlee/Korl Knockout Mice Was Significantly Relieved by Uridine and Liriope platyphylla L. Extracts

Complement component 3 (C3) deficiency has recently been known as a cause of constipation, without studies on the therapeutic efficacy. To evaluate the therapeutic agents against C3-deficiency-induced constipation, improvements in the constipation-related parameters and the associated molecular mechanisms were examined in FVB/N-C3em1Hlee/Korl knockout (C3 KO) mice treated with uridine (Urd) and the aqueous extract of Liriope platyphylla L. (AEtLP) with laxative activity. The stool parameters and gastrointestinal (GI) transit were increased in Urd- and AEtLP-treated C3 KO mice compared with the vehicle (Veh)-treated C3 KO mice. Urd and AEtLP treatment improved the histological structure, junctional complexes of the intestinal epithelial barrier (IEB), mucin secretion ability, and water retention capacity. Also, an improvement in the composition of neuronal cells, the regulation of excitatory function mediated via the 5-hydroxytryptamine (5-HT) receptors and muscarinic acetylcholine receptors (mAChRs), and the regulation of the inhibitory function mediated via the neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) were detected in the enteric nervous system (ENS) of Urd- and AEtLP-treated C3 KO mice. Therefore, the results of the present study suggest that C3-deficiency-induced constipation can improve with treatment with Urd and AEtLP via the regulation of the mucin secretion ability, water retention capacity, and ENS function.

Improvement of the intestinal epithelial barrier during laxative effects of phlorotannin in loperamide-induced constipation of SD rats

BACKGROUND

Disruptions of the intestinal epithelial barrier (IEB) are frequently observed in various digestive diseases, including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This study assessed the improvement in the IEB during the laxative activity of phlorotannin (Pt) harvested from Ecklonia cava in constipation by examining the changes in the expression of the regulatory proteins for the tight junction (TJ) and adherens junction (AJ), and inflammatory cytokines in Sprague Dawley (SD) rats with loperamide (Lm)-induced constipation after a Pt treatment.

RESULTS

The Pt treatment induced laxative activity, including the improvement of feces-related parameters, gastrointestinal transit rate, and histological structure of the mid colon in Lm-treated SD rats. In addition, significant recovery effects were detected in the histology of IEB, including the mucus layer, epithelial cells, and lamina propria in the mid colon of Lm + Pt treated SD rats. The expression levels of E-cadherin and p120-catenin for AJ and the ZO-1, occludin, and Claudin-1 genes for TJ in epithelial cells were improved remarkably after the Pt treatment, but the rate of increase was different. Furthermore, the Pt treatment increased the expression level of several inflammatory cytokines, such as TNF-α, IL-6, IL-1β, IL-13, and IL-4 in Lm + Pt treated SD rats.

CONCLUSIONS

These results provide the first evidence that the laxative activity of Pt in SD rats with Lm-induced constipation phenotypes involve improvements in the IEB.

Similarities and differences in constipation phenotypes between Lep knockout mice and high fat diet-induced obesity mice

CRISPR-Cas9-mediated leptin (Lep) knockout (KO) mice exhibited prominent phenotypes for constipation, even though they were not compared with other model animals. This study compared the stool excretion, gastrointestinal motility, histological structure, mucin secretion, and enteric nerve function in Lep KO and high fat diet (HFD)-treated mice to determine if there were differences in their phenotypes for constipation. Most obesity phenotypes, including fat weight, adipocyte size, expression of lipolytic proteins (HSL, perilipin, and ATGL), and glucose concentrations, were detected similarly in the Lep KO and HFD-treated mice. They showed a similar decrease in the excretion parameters, including the stool number, weight, and water content, while the same pattern was detected in the gastrointestinal motility and intestinal length. A similar decrease in the mucosal layer thickness, muscle thickness, ability for mucin secretion, and expression of water channel (aquaporin 3 and 8) genes was detected in the mid-colon of the Lep KO and HFD-treated mice, but the alteration rate in some levels was greater in the HFD-treated group than the Lep KO mice. On the other hand, the levels of c-kit, nNOS, NSE, and PGP9.5 expression for the enteric neurons and intestitial cells of Cajal (ICC) were remarkably lower in the mid-colon of the HFD-treated mice than in the Lep KO mice, but the level of most proteins in both groups remained lower than those in the control group. A similar alteration pattern in the expression of muscarinic acetylcholine receptors (mAChRs) and serotonin receptors was detected in the Lep KO and HFD-treated mice. These results suggest that most phenotypes for obesity-induced constipation were similarly detected in the Lep KO and HFD-treated mice, but there was a difference in the regulatory function of the enteric nervous system (ENS).

Dose-dependent Action of Zingiber officinale on Colonic Dysmotility and Ex Vivo Spontaneous Intestinal Contraction Modulation

Ginger (Zingiber officinale) rhizomes are commonly used in foods and employed for many ailments including gastrointestinal disorders. Our main objective was to evaluate the effect of Zingiber officinale aqueous extract (ZOAE) on gastrointestinal (GI) physiological motility and colonic dysmotility. Thereby, Wistar rats were given loperamide (LP, 3 mg/kg, b.w.) and ZOAE (75, 150, and 300 mg/kg, b.w.) or yohimbine (YOH, 2 mg/kg, b.w.). ZOAE-action on intestinal secretion was assessed using Ussing chamber technique and intestinal motility with isometric transducer. GI-transit (GIT) and gastric emptying (GE) were evaluated with the charcoal meal test and the red phenol methods. ZOAE-bioactive components were analyzed by liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS). Constipation was induced with LP and the different indicators such as stool composition, GIT, oxidative stress biological parameters, and colonic mucosa histological alteration were performed. Anti-constipation effect of ZOAE was confirmed on stool composition, GIT (53.42% to 85.57%), GE (55.47% to 98.88%), and re-established oxidative balance. ZOAE induces an amplitude increase of spontaneous intestinal contraction with EC50 of 10.52 μg/mL. No effect of ZOAE was observed on electrogenic transport of intestinal fluid. These findings suggest that ZOAE-bioactive candidates might exert an anti-constipation action and spontaneous intestinal contraction modulation.

Dysregulation of the Enteric Nervous System in the Mid Colon of Complement Component 3 Knockout Mice with Constipation Phenotypes

Complement component 3 (C3) contributes to neurogenesis, neural migration, and synaptic elimination under normal and disease conditions of the brain, even though it has not been studied in the enteric nervous system (ENS). To determine the role of C3 in the regulatory mechanism of ENS during C3 deficiency-induced constipation, the changes in the markers of neuronal and interstitial cells of Cajal (ICCs), the markers for excitatory and inhibitory transmission of ENS, and expression of C3 receptors were analyzed in the mid colon of C3 knockout (KO) mice at 16 weeks of age. Prominent constipation phenotypes, including the decrease in stool parameters, changes in the histological structure, and suppression of mucin secretion, were detected in C3 KO mice compared to wildtype (WT) mice. The expression levels of the neuron specific enolase (NSE), protein gene product 9.5 (PGP9.5), and C-kit markers for myenteric neurons and ICCs were lower in the mid colon of C3 KO mice than WT mice. Excitatory transmission analysis revealed similar suppression of the 5-hydroxytryptamine (5-HT) concentration, expression of 5-HT receptors, acetylcholine (ACh) concentration, ACh esterase (AChE) activity, and expression of muscarinic ACh receptors (mAChRs), despite the mAChRs downstream signaling pathway being activated in the mid colon of C3 KO mice. In inhibitory transmission analysis, C3 KO mice showed an increase in the nitric oxide (NO) concentration and inducible nitric oxide synthase (iNOS) expression, while neuronal NOS (nNOS) expression, cholecystokinin (CCK), and gastrin concentration were decreased in the same mice. Furthermore, the levels of C3a receptor (C3aR) and C3bR expression were enhanced in the mid colon of C3 KO mice compared to the WT mice during C3 deficiency-induced constipation. Overall, these results indicate that a dysregulation of the ENS may play an important role in C3 deficiency-induced constipation in the mid colon of C3 KO mice.

Laxative Effects of Phlorotannins Derived from Ecklonia cava on Loperamide-Induced Constipation in SD Rats

This study investigated the laxative effects of phlorotannins (Pt) derived from Ecklonia cava (E. cave) on chronic constipation by evaluating alterations in stool parameters, gastrointestinal motility, histopathological structure, mucin secretion, gastrointestinal hormones, muscarinic cholinergic regulation, and fecal microbiota in SD rats with loperamide (Lop)-induced constipation subjected to Pt treatment. Stool-related parameters (including stool number, weight, and water contents), gastrointestinal motility, and length of intestine were significantly enhanced in the Lop+Pt-treated group as compared to the Lop+Vehicle-treated group. A similar recovery was detected in the histopathological and cytological structure of the mid-colon of Lop+Pt-treated rats, although the level of mucin secretion remained constant. Moreover, rats with Lop-induced constipation subjected to Pt treatment showed significant improvements in water channel expression, gastrointestinal hormone secretions, and expression of muscarinic acetylcholine receptors M2/M3 (mAChRs M2/M3) and their mediators of muscarinic cholinergic regulation. Furthermore, the Lop+Pt-treated group showed a significant recovery of Bifidobacteriaceae, Muribaculaceae, Clostridiaceae, and Eubacteriaceae families in fecal microbiota. Taken together, these results provide the first evidence that exposure of SD rats with Lop-induced constipation to Pt improves the constipation phenotype through the regulation of membrane water channel expression, GI hormones, the mAChR signaling pathway, and fecal microbiota.

Galla Chinensis, a Traditional Chinese Medicine: Comprehensive review of botany, traditional uses, chemical composition, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Galla chinensis (GC), a traditional Chinese medicine (TCM), has a wide range of pharmacological properties which have been widely used for more than 1400 years. Based on shape, GC is divided into two groups: jiaobei and dubei. It is a bitter, sour, cold and astringent substance which is usually used for treating diarrhea, constipation, bleeding, cough, vomiting, sweating, hemorrhoids, and anal and uterine prolapse. It is distributed in Japan, North Korea, and all parts of China.

AIM OF STUDY

This study was aimed at carrying out a comprehensive overview of the current status of research on Galla chinensis (GC) for better understanding of it characteristics, while providing a clear direction for future studies. It has aroused the interest of researchers, leading to development of medicinal value, expansion of its application, and provision of wider and more effective drug choices. This study was focused on the traditional uses, botany, chemical composition, pharmacology and toxicology of GC. Finally, the study focused on possible future research directions for GC.

MATERIALS AND METHODS

A comprehensive analysis was done based on academic papers, pharmaceutical monographs, ancient medicinal works, and drug standards of China. This review used Galla and Galla chinensis as keywords for retrieval of information on GC from online databases such as PubMed, Elsevier, CNKI, Web of Science, Google Scholar, SCI hub, and Baidu academic.

RESULTS

It was found that the chemical constituents of GC included tannins, phenolic acid, amino acids and fatty acid, with polyphenol compounds (especially tannins and gallic acid) as the distinct components. In vitro and in vivo studies revealed that GC exerted numerous biological effects such as anti-caries, antibacterial, antiviral, anticancer, and antioxidant effects. The therapeutic effect of GC was attributed mainly to the biological properties of its bioactive components.

CONCLUSIONS

GC is an important TCM which has potential benefit in the treatment of a variety of diseases. However, the relationship amongst the structure and biological activity of GC and its components, mechanism of action, toxicity, pharmacokinetics and target organs need to be further studied. Quality control and quality assurance programs for GC need to be further developed. There is need to study the dynamics associated with the accumulation of chemical compounds in GC as well as the original plants and aphid that form GC.

The potential of Quercetin to protect against loperamide-induced constipation in rats

Constipation is the most common gastrointestinal complaint all over the world, and it is a risk factor of colorectal cancer. In this study, the protective of Quercetin against loperamide-induced constipation and its potential mechanism in a rat model were investigated. Results showed that Quercetin at 25 mg/kg and 50 mg/kg could significantly (p < .05) increase the intestinal transit rate, motilin, gastrin, substance P levels, and concentration of short-chain fatty acids (SCFAs), reduce the somatostatin levels, and improve the gastrointestinal peristalsis of rats. In addition, the expression levels of enteric nerve-related factors, glial cell line-derived neurotrophic factor (GDNF), transient receptor potential vanilloid 1 (TRPV1), nitric oxide synthase (NOS), c-Kit, stem cell factor (SCF), and aquaporin 3 (AQP3) were examined by RT-qPCR and/or Western blot analysis. The results suggest that Quercetin relieves loperamide-induced constipation by increasing the levels of interstitial cells of Cajal markers (c-Kit and SCF), as well as AQP3. In conclusion, the present study suggested that Quercetin exerted a protective effect against loperamide-induced constipation, which may be associated with its role in regulation of multiple signal pathways.

Novel Characterization of Constipation Phenotypes in ICR Mice Orally Administrated with Polystyrene Microplastics

Indirect evidence has determined the possibility that microplastics (MP) induce constipation, although direct scientific proof for constipation induction in animals remains unclear. To investigate whether oral administration of polystyrene (PS)-MP causes constipation, an alteration in the constipation parameters and mechanisms was analyzed in ICR mice, treated with 0.5 μm PS-MP for 2 weeks. Significant alterations in water consumption, stool weight, stool water contents, and stool morphology were detected in MP treated ICR mice, as compared to Vehicle treated group. Also, the gastrointestinal (GI) motility and intestinal length were decreased, while the histopathological structure and cytological structure of the mid colon were remarkably altered in treated mice. Mice exposed to MP also showed a significant decrease in the GI hormone concentration, muscarinic acetylcholine receptors (mAChRs) expression, and their downstream signaling pathway. Subsequent to MP treatment, concentrations of chloride ion and expressions of its channel (CFTR and CIC-2) were decreased, whereas expressions of aquaporin (AQP)3 and 8 for water transportation were downregulated by activation of the mitogen-activated protein kinase (MAPK)/nuclear factor (NF)-κB signaling pathway. These results are the first to suggest that oral administration of PS-MP induces chronic constipation through the dysregulation of GI motility, mucin secretion, and chloride ion and water transportation in the mid colon.

Effects of Gallotannin-Enriched Extract of Galla Rhois on the Activation of Apoptosis, Cell Cycle Arrest, and Inhibition of Migration Ability in LLC1 Cells and LLC1 Tumors

Gallotannin (GT) and GT-enriched extracts derived from various sources are reported to have anti-tumor activity in esophageal, colon and prostate tumors, although their anti-tumor effects have not been determined in lung carcinomas. To investigate the anti-tumor activity of GT-enriched extract of galla rhois (GEGR) against lung carcinomas, alterations in the cytotoxicity, apoptosis activation, cell cycle progression, migration ability, tumor growth, histopathological structure, and the regulation of signaling pathways were analyzed in Lewis lung carcinoma (LLC1) cells and LLC1 tumor bearing C57BL/6NKorl mice, after exposure to GEGR. A high concentration of GT (69%) and DPPH scavenging activity (IC50=7.922 µg/ml) was obtained in GEGR. GEGR treatment exerted strong cytotoxicity, cell cycle arrest at the G2/M phase and subsequent activation of apoptosis, as well as inhibitory effects on the MAPK pathway and PI3K/AKT mediated cell migration in LLC1 cells. In the in vivo syngeneic model, exposure to GEGR resulted in suppressed growth of the LLC1 tumors, as well as inhibition of NF-κB signaling and their inflammatory cytokines. Taken together, our results provide novel evidence that exposure to GEGR induces activation of apoptosis, cell cycle arrest, and inhibition of cell migration via suppression of the MAPK, NF-κB and PI3K/AKT signaling pathways in LLC1 cells and the LLC1 syngeneic model.

Long-Term Administration of Anthraquinone Rhein on Induction of Constipation in Sprague-Dawley Rats via SCF/c-Kit Signaling Pathways

Background and Study Aims. It has been shown that abuse of laxatives is becoming a serious problem; therefore, a comprehensive understanding of its effect and possible mechanism on colon motility is essential to select effective treatments and avoid their abuse. Herein, we aimed to investigate the long-term stimulation of rhein on induction of constipation in rats and its underlying mechanisms. Materials and Methods. After establishing rat models of constipation, the rats were randomly divided into two equal subgroups and administered daily with normal saline (model control group) or 10 ml/kg PEG4,000 (PEG-treated group). Simultaneously, normal Sprague-Dawley (SD) rats were administered with normal saline (normal group). Physiological and fecal parameters were calculated, and intestinal transmission function was evaluated. After scarification, colonic tissues were freshly prepared for histological localization detected by immunohistochemical analysis and for the expression of stem cell factor (SCF) and c-kit proteins determined by western blot assay. Results. Following the initiation of rhein-induced rat constipation, body weight was lost slightly, the first time of black stool discharge was obviously longer, and the fecal moisture and number of fecal pellets decreased distinctly as compared with normal group. A decreased expression of SCF and c-kit was detected in model control group in comparison with normal group. Notably, compared with model control group, neither the alterations of fecal parameters and intestinal transmission function were effectively restored, nor the expression of SCF and c-kit was markedly elevated after administration of PEG4,000 for 30 d. Conclusion. Long-term stimulation of rhein can develop the constipation via SCF/c-kit signaling pathway, yet the symptoms of constipation and colon power cannot be alleviated or restored by PEG4,000. Collectively, these findings strongly suggest that long-term use of anthraquinone laxatives should be avoided for clinical treatment of constipation.

Antioxidant activity and laxative effects of tannin-enriched extract of Ecklonia cava in loperamide-induced constipation of SD rats

To investigate the role of tannin-enriched extracts of Ecklonia cava (TEE) on the regulation of oxidative balance and laxative activity in chronic constipation, we investigated alterations after exposure to TEE, on constipation phenotypes, muscarinic cholinergic regulation, and oxidative stress responses in the transverse colons of SD rats with loperamide (Lop)-induced constipation. This extract contains high levels of total condensed tannin content (326.5 mg/g), and exhibited high inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. TEE treatment induced significant improvements in reactive oxygen species (ROS) production, superoxide dismutase (SOD) expression and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation in primary smooth muscles of rat intestine cells (pRISMCs) and transverse colon of constipation model. Also, Lop+TEE treated groups showed alleviated outcomes for the following: most stool parameters, gastrointestinal transit, and intestine length were remarkably recovered; a similar recovery pattern was observed in the histopathological structure, mucin secretion, water channel expression and gastrointestinal hormones secretion in the transverse colon; expressions of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators on muscarinic cholinergic regulation were significantly recovered. Taken together, these results provide the first evidence that TEE stimulates oxidative stress modulation and muscarinic cholinergic regulation when exerting its laxative effects in chronic constipation models.

Deficiency of complement component 3 may be linked to the development of constipation in FVB/N-C3em1Hlee /Korl mice

Alterations in complement component 3 (C3) expression has been reported to be linked to several bowel diseases including Crohn's disease, inflammatory bowel disease, and ulcerative colitis; however, the association with constipation has never been investigated. In this study, we aimed to investigate the correlation between C3 regulation and constipation development using a C3 deficiency model. To achieve these, alterations in stool excretion, transverse colon histological structure, and mucin secretion were analyzed in FVB/N-C3em1Hlee /Korl (C3 knockout, C3 KO) mice with the deletion of 11 nucleotides in exon 2 of the C3 gene. The stool excretion parameters, gastrointestinal transit, and intestine length were remarkably decreased in C3 KO mice compared with wild-type (WT) mice, although there was no specific change in feeding behavior. Furthermore, C3 KO mice showed a decrease in mucosal and muscle layer thickness, alterations in crypt structure, irregular distribution of goblet cells, and an increase of mucin droplets in the transverse colon. Mucin secretion was suppressed, and they accumulated in the crypts of C3 KO mice. In addition, the constipation phenotypes detected during C3 deficiency were confirmed in FVB/N mice treated with C3 convertase inhibitor (rosmarinic acid (RA)). Similar phenotypes were observed with respect to stool excretion parameters, gastrointestinal transit, intestine length, alterations in crypt structure, and mucin secretion in RA-treated FVB/N mice. Therefore, the results of the present study provide the first scientific evidence that C3 deficiency may play an important role in the development of constipation phenotypes in C3 KO mice.

Aster tataricus alleviates constipation by antagonizing the binding of acetylcholine to muscarinic receptor and inhibiting Ca2+ influx

BACKGROUND

The dried root and rhizome of Aster tataricus (RA), is a traditional Chinese medicine has been used for more than 2000 years with the function of antitussive, expectorant and antiasthmatic. Ancient books and modern pharmacological researches demonstrated that RA may have the function of moistening intestines and relieving constipation, but there was a lack of systematic evidence. The aim of this study was to comprehensively evaluate the efficacy and possible mechanisms of ethanol extract of Aster tataricus (ATE) in treating constipation from in vivo to in vitro.

METHODS

In vivo, the ATE was studied in loperamide-induced constipation of mice. In vitro, different concentrations of ATE was tested separately or cumulatively on spontaneous and agonists-induced contractions of isolated rat duodenum strips.

RESULTS

In vivo, at doses of 0.16, 0.8 g/mL, ATE showed significantly promotion of the small intestinal charcoal transit, decrease of the amount of remnant fecal, and increase of the content of fecal water in colon. In addition, ATE could effectively relieve colonic pathological damage caused by loperamide as well. In vitro, with the cumulative concentration increase of ATE from 0.8 to 6.4 mg/mL, it could significantly decrease the contraction caused by KCl or Ach, and gradually restore to near base tension value.Meanwhile, it could also partially but significantly inhibit the contractions induced by Ach and CaCl2 on rat duodenum in a concentration related manner.

CONCLUSIONS

Taking all these findings together, it could be speculated that ATE may attenuate constipation mainly through antagonizing the binding of acetylcholine to muscarinic receptor, inhibiting Ca2+ influx and anti-inflammation.

Bacosides enrichment does not improve the anti-amnesic effect of Bacopa monnieri: behavioural and biochemical evidences

Bacopa monnieri (L.) Wettst. (BM) has been traditionally used in Ayurveda for improving memory and cognitive deficits which is also evidenced through experimental and clinical studies. The neuropharmacological properties of BM are attributed to "bacosides", a complex mixture of saponin compounds. BM extracts enriched with bacosides offers commercial advantage due to perceived higher efficacy. However, there is no scientific data to support the same. In the present study, methanolic extract of BM (BME) was compared with bacosides enriched (BME-EF) vis a vis bacosides free fraction (BME-FF). Potential antioxidant and cholinesterase inhibitory activity has been evaluated using in vitro and in vivo methods. BME showed not only the highest anti-amnesic efficacy but also antioxidant and cholinesterase inhibitory activity, followed by either BME-FF or BME-EF. Interestingly, no significant differences were found in between the groups. These findings dispel the notion that bacosides enrichment enhances anti-amnesic efficacy and also suggests the contribution of other components.

Physicochemical properties and laxative effects of polysaccharides from Anemarrhena asphodeloides Bge. in loperamide-induced rats

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese herbal medicine, Anemarrhena asphodeloides Bge. possesses the effects of nourishing yin, moistening dryness, clearing lungs and relieving fire. Simultaneously, it has been used to treat constipation for more than one thousand years in China. However, modern medical studies are limited and lacking on its therapeutic mechanism.

AIM OF THE STUDY

This current study was aimed to investigate the laxative activities and explore the potential mechanism of Anemarrhena asphodeloides Bge. polysaccharides (AABP) in loperamide-induced constipation rats.

MATERIALS AND METHODS

The structure of AABP was determined by using infrared spectrum, high performance gel permeation chromatography (HPGPC), and high performance liquid chromatography (HPLC). Real-time quantitative polymerase chain reaction (PCR), multitudinous methods were adopted to explore the underlining therapeutic mechanism of AABP in treating constipation, including enzyme-linked immunosorbent assay (ELISA), histopathological, immunohistochemistry and western blotting.

RESULTS

In the present study, the average molecular weight of AABP was determined as 1.11 × 10³ kDa. The primary monosaccharide compositions were analyzed including D-mannose, L-rhamnose, D-galacturonic acid, D-glucose, D-galactose and L-arabinose (1, 0.04, 0.53, 0.11, 0.33, 0.25, respectively) by high-performance liquid chromatography (HPLC). AABP significantly increased the levels of gastrin (Gas), motilin (MTL), substance P (SP), 5-hydroxytryptamine (5-HT) and vasoactive intestinal peptide (VIP), and decreased the NO content of loperamide-induced rats to ameliorate constipation in the rats. Whilst, AABP repaired the damaged colons by regulating PCNA and ICAM-1 protein expressions. Additionally, AABP up-regulated the levels of SCF, c-Kit, AQP3 and VIP as well as down-regulated the expressions of AQP8, AQP4 and PGE2.

CONCLUSION

The present findings suggested that AABP were the laxative active ingredients isolated from Anemarrhena asphodeloides Bge., which could treat constipation through regulating the gastrointestinal hormones and neurotransmitters to improve the intestinal motility and water metabolism.

Constipation in Tg2576 mice model for Alzheimer's disease associated with dysregulation of mechanism involving the mAChR signaling pathway and ER stress response

BACKGROUND

Although constipation has been researched in various neurological disorders, including Parkinson's disease (PD) and spinal cord injury (SCI), the pathological mechanism of this symptom has not been investigated in Alzheimer's disease (AD) associated with loss of nerve cells in the brain. This study was undertaken to gain scientific evidences for a molecular correlation between constipation and AD.

METHODS

To understand the etiology, we measured alterations in various constipation parameters, muscarinic acetylcholine receptors (mAChRs) and endoplasmic reticulum (ER) stress response, in 11-month-old Tg2576 transgenic (Tg) mice showing AD-like phenotypes.

RESULTS

A high accumulation of amyloid beta (Aβ) peptides, a key marker of AD pathology, were detected in the cortex and hippocampus of Tg mice. Furthermore, significant alterations were observed in various constipation parameters including stool weight, histological structure, cytological structure and mucin secretion in Tg2576 mice. Moreover, M2 and M3 expression and the downstream signaling pathways of mAChRs were decreased in the Tg group, as compared with non-Tg (NT) group. Furthermore, activation of ER stress proteins and alteration of ER structure were also detected in the same group.

CONCLUSIONS

The results of the present study provide strong novel evidence that the neuropathological constipation detected in Tg2576 mice is linked to dysregulation of the mAChR signaling pathways and ER stress response.

Laxative Effect of Spicatoside A by Cholinergic Regulation of Enteric Nerve in Loperamide-Induced Constipation: ICR Mice Model

Researches on spicatoside A (SpiA)-containing natural products suggest the possibility of SpiA as a potential laxative to alleviate chronic constipation. However, no studies have been conducted with single compound administration of SpiA. To verify the laxative effects and mechanism of action of SpiA on chronic constipation, we investigated alterations in the excretion parameters, histological structure, and cholinergic regulation of the enteric nerve in the colons of Institute of Cancer Research (ICR) mice with loperamide (Lop)-induced constipation after exposure to 20 mg/kg of SpiA. Decrease in the number, weight and water contents of stools in the Lop+Vehicle treated group significantly recovered after SpiA treatment, and alterations in the histological structure and transmission electron microscopy (TEM) images were improved in the Lop+SpiA treated group. Similar recovery effects were observed in the ability for mucin secretion and expression of the membrane water channel gene (aquaporin 8, AQP8). Furthermore, significant improvements were observed in the acetylcholinesterase (AChE) activity and acetylcholine receptors' (AChRs) downstream signaling pathway after treatment of SpiA. The levels of gastrointestinal (GI) hormones including cholecystokinin (CCK) and gastrin were also remarkably enhanced in the Lop+SpiA treated group as compared to the Lop+Vehicle treated group. The expression of receptor tyrosine kinase (C-kit) and protein gene product 9.5 (PGP9.5) in Cajal and neural cells, as well as the phosphorylation of myosin light chain (MLC) in smooth muscle cells, were recovered after SpiA exposure. Taken together, the results of the present study provide the first strong evidence that SpiA improves chronic constipation through muscarinic cholinergic regulation of the enteric nerve in a Lop-induced constipation ICR mice model.

Anti-Inflammatory Response and Muscarinic Cholinergic Regulation during the Laxative Effect of Asparagus cochinchinensis in Loperamide-Induced Constipation of SD Rats

Several types of saponins and herbal plants containing saponins have been reported to have anti-inflammatory or laxative activities. To verify the therapeutic effects of saponin-enriched extracts of Asparagus cochinchinensis (SPA) on the anti-inflammatory response and on the cholinergic regulation in the gastrointestinal system, an alteration on the constipation phenotypes, on the inflammatory responses, and on the muscarinic cholinergic regulation were investigated in the transverse colons of Sprague Dawley (SD) rats with loperamide (Lop)-induced constipation after the treatment of SPA. Significant increases were observed on the total number of stools, the gastrointestinal transit, the thickness of the mucosal layer, the flat luminal surface, the number of paneth cells, and the lipid droplets in the Lop + SPA-treated group as compared to the Lop + Vehicle-treated group. SPA treatment induced the recovery of inflammatory cytokines (TNF-α, IL-1β) and IL-6), inflammatory mediators (NF-κB and iNOS), the total number of infiltered mast cells, and mucin secretion. Also, some similar improvements were observed on the levels of acetylcholine esterase (AChE) activity and on the phosphorylation of myosin light chains (MLC) as well as the expression of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators. The results presented herein provide the first strong evidence that SPA stimulates anti-inflammatory responses and the muscarinic cholinergic regulation when exerting its laxative effects in the chronic constipation of Lop-induced models.

Synergic Laxative Effects of an Herbal Mixture of Liriope platyphylla, Glycyrrhiza uralensis, and Cinnamomum cassia in Loperamide-Induced Constipation of Sprague Dawley Rats

Constipation is an acute or chronic illness attributed to various causes, ranging from lifestyle habits to side effects of a disease. To improve the laxative effects of some traditional medicines, herbal mixtures of Liriope platyphylla, Glycyrrhiza uralensis, and Cinnamomum cassia (LGC) were evaluated for their mechanism of action and therapeutic effects in loperamide (Lop)-induced constipated Sprague Dawley rats by examining alterations in excretion parameters, histological structure, mucin secretion, and related protein levels. Food intake and water consumption were constant for all animals. We observed that the Lop+LGC-treated group had significantly greater excretion of stool and urine than was observed in the Lop+Vehicle-treated group. Administration of LGC in the constipation model restored the intestinal transit ratio to normal levels, and increased the number of goblet cells, mucosal layer, and muscle thickness. Mucin secretion was greater in the Lop+LGC-treated group than in the Lop+Vehicle-treated group, and the expression of MUC2 and AQP8 genes were also increased. In addition, reverse transcription polymerase chain reaction and Western blot revealed an increase in the muscarinic acetylcholine receptors (mAChRs) in the Lop+LGC-treated group compared to the Lop+Vehicle-treated group. Furthermore, compared with the Lop+Vehicle-treated group, treatment with LGC reduced the phosphorylation of PKC and PI3K, and expression of Gα protein, but increased levels of IP3. Our results suggest that the traditional herbal mixture of LGC induces a potent laxative effect in Lop-induced constipation through mucosal tissue changes and mucin production. We also demonstrated that the laxative effect of LGC is closely related to the expression of mAChR and its downstream signals, suggesting the possibility of developing a constipation-laxative agent using LGC.

Regulation of gastrointestinal hormones during laxative activity of gallotannin-enriched extract isolated from Galla Rhois in loperamide-induced constipation of SD rats

Regulation of gastrointestinal hormones have been reported in animal models for constipation undergoing laxative therapy when administered herbal products. We undertook to investigate whether the laxative activity of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) affects the regulation of gastrointestinal hormones, by examining the concentration of four hormones and the activation of their receptors in the loperamide (Lop)-induced constipation model. Stool parameters, including number, weight and water content, were significantly recovered in the Lop+GEGR treated group, relative to the Lop+vehicle treated group; however, food intake and water consumption were maintained at a constant level. Also, a similar recovery was detected for thickness of mucosa, muscle and flat luminal surface in the Lop+GEGR treated group. Furthermore, concentration of the four gastrointestinal hormones evaluated, namely, cholecystokinin (CCK), gastrin (GAS), somatostatin (SS) and motilin (MTL), were lower in the Lop+vehicle treated group than the No treated group, but were remarkably enhanced in the Lop+GEGR treated group. Moreover, the downstream signaling pathway of MTL and SS receptors were recovered after GEGR administration. Results of the present study therefore indicate that the laxative effects of GEGR treatment may be tightly related with the regulation of gastrointestinal hormones in the Lop-induced constipation model.

Quercetin promotes gastrointestinal motility and mucin secretion in loperamide-induced constipation of SD rats through regulation of the mAChRs downstream signal

CONTEXT

Quercetin (QCT) has been known as a potential therapeutic strategy for gastrointestinal diseases because it contributes to the stabilization of mast cells, the prevention of histamine release and modulation of CaCC chloride channel.

OBJECTIVE

We investigated the laxative effect and action mechanism of QCT in Lop-induced constipation model.

MATERIALS AND METHODS

Constipation of SD rats was induced by subcutaneous injection of loperamide (Lop) (4 mg/kg weight) in 0.5% Tween 20 twice a day for three days. After 24 h, the constipation group was further treated with 1× PBS (Lop + Vehicle treated group), 10 mg/kg of QCT (Lop + LQCT treated group), 20 mg/kg of QCT (Lop + MQCT treated group) or 40 mg/kg QCT (Lop + HQCT treated group) at once. At 24 h after QCT treatment, the constipation phenotypes were measured and the transverse colon was collected from SD rats.

RESULTS

The gastrointestinal motility, the number of stools and histological structures were significantly recovered in Lop + QCT treated group compared with the Lop + Vehicle treated group. Also, above activity of epithelial cells and smooth muscle cells were regulated by the mRNA expression of the muscarinic acetylcholine receptors M2 and M3 (mAChR M2 and M3) and some mediators of their downstream signalling pathway. Finally, laxative effects of QCT on mAChR signalling pathway were significantly inhibited by the treatment of mAChR antagonist in primary smooth muscle of rat intestine cells (pRISMCs).

CONCLUSIONS

This study provides the first strong evidence that QCT can be considered an important candidate for improving chronic constipation induced by Lop treatment in animal models.

Anti-ulcer effect of Gallarhois extract with anti-oxidant activity in an ICR model of ethanol/hydrochloride acid-induced gastric injury

Gallarhois (GR) is a traditional oriental herbal medicine with various pharmacological effects; however, its effect on gastric ulcer has not been previously explored. We firstly investigated the component and antioxidant activity of GR extract (EtGR) by HPLC analysis and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The results showed that EtGR consisted of gallotannin (68.7%), gallic acid (27.2%) and methyl gallate (4.1%) and that it had a high antioxidant value (IC50 value; 1.93 μg/mL). To evaluate the possible anti-gastric ulcer potential of EtGR, we investigated the effects of EtGR in the model of ethanol/hydrochloric acid (EtOH/HCl)-induced gastric ulcer. Gross and histological gastric lesions, biochemical and gene expression parameters were taken into consideration. The results showed that EtOH/HCl treatment produced mucosal injuries with morphological and histological damage, whereas EtGR co-treatment reduced the gastric injuries. EtGR treatment also decreased the contents of malonaldehyde (MDA) activity relative to the vehicle group. Moreover, EtGR decreased the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and cyclo-oxygenase-2 (COX-2) expression. Finally, EtGR did not induce any specific toxicity in the livers or kidneys of the EtOH/HCl-induced gastric ulcer model. These results suggest that EtGR had stronger antioxidant activity and could be a new useful natural drug for gastroprotection against gastric ulcer. Moreover, these findings provide a scientific basis for the development of drugs from traditional oriental herbal medicines.

Therapeutic effect of protease-activated receptor 2 agonist SLIGRL-NH2 on loperamide-induced Sprague-Dawley rat constipation model and the related mechanism

Purpose

To investigate the therapeutic effects of protease-activated receptor 2 (PAR-2) agonist SLIGRL-NH₂ on loperamide-induced Sprague-Dawley (SD) rat constipation animal models.

Materials and methods

Loperamide was injected subcutaneously to induce constipation twice a day for 3 days. SD rats (n = 30) were randomly divided into five groups: non-constipation group (control, n = 6), constipation group (constipation, n = 6), constipation + SLIGRL-NH₂ low-dosage group (SLIGRL-NH₂ low, n=6), constipation + SLIGRL-NH₂ high-dosage group (SLIGRL-NH₂ high, n = 6), and constipation + prucalopride (positive control, n = 6). The SLIGRL-NH₂ low group and SLIGRL-NH₂ high group were administered with 2.5 μmol/kg and 5 μmol/kg SLIGRL-NH₂, respectively, and the prucalopride group received 2 mg/kg prucalopride. The control and constipation group received 1× PBS under the same pattern. SLIGRL-NH₂ and prucalopride were orally administrated once daily for 7 days. On the final day of oral administration, food intake, water intake, the number of stool pellets, weight, and fecal water content was calculated; moreover, the colons of rats in different groups were collected and histological features were examined by hematoxylin and eosin staining; furthermore, the expression of anoctamin-1 was determined by Immunohistochemical methods, and the expressions of c-kit and PAR-2 were examined using real-time quantitative polymerase chain reaction and Western blot methods; finally, the expressions of neurotransmitter vasoactive intestinal peptide (VIP) and substance P (SP) were examined using enzyme-linked immuno-sorbent assay methods.

Results

The feeding and excretion behaviors, intestinal transit ratio, and the histological feature of the colon in the constipated rats were all improved by SLIGRL-NH₂ treatment; moreover, SLIGRL-NH₂ treatment induced significant increase in the expression of PAR-2 and also increased number of interstitial Cajal cells. Furthermore, SLIGRL-NH₂ also decreased the contents of the inhibitory neurotransmitter VIP and increased the expression of the excitatory neurotransmitter SP. High dose of SLIGRL-NH₂ has shown similar anti-constipation effects as prucalopride.

Conclusion

These results suggested that SLIGRL-NH₂ can enhance gastrointestinal transit and alleviate in rats with loperamide-induced constipation.

The combination of Cassia obtusifolia L. and Foeniculum vulgare M. exhibits a laxative effect on loperamide-induced constipation of rats

Chronic constipation is a functional gastrointestinal disease that is detrimental to the quality of patient life. Cassia obtusifolia L. (CO) and Foeniculum vulgare M. (FV) are commonly used as medicinal foods in many countries. We aimed to examine the laxative effect and their underlying mechanism of CO and FV mixture on loperamide (lop)-induced constipated rats. To determine the laxative effects of these compounds, Sprague-Dawley rats were divided into six groups: the control, lop-induced constipated (2mg/kg), and three doses (100, 300, and 500mg/kg) of CO and FV mixture-, and Bisacodyl (bis, 3.3mg/kg)-treated groups. The mixture of CO and FV and bis were orally administered once a day for 4 weeks. For induction of constipation, the lop were treated with a dose of 2 mg/kg twice a day on the 3^rd week after treatments of CO and FV extracts and bis. The results were revealed that the CO and FV mixture has the laxative effects more than those in CO and FV-alone treatments on constipated rats by determining the stool parameters, including stool number and weight. Indeed, stool parameters, such as, stool number, weight, and water contents and colonic peristalsis from the intestinal transit length and ratio were dramatically improved by CO and FV mixture treatment. Histological study also revealed that CO and FV mixture enhanced the thicknesses of mucosa and muscular layers of the colon in constipated rats. For their underlying mechanism, the mRNAs and proteins expression of muscarinic acetylcholine receptors (mAchR) M2 and M3 and their downstream signaling were preserved by CO and FV mixture treatment in constipated rats. Therefore, this study suggests that treatment with CO and FV mixture has beneficial effects against constipation. We further suggest that CO and FV mixture may be utilized as an alternative therapeutic strategy for constipation.