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

Soluble Dietary Fiber of Hawthorn Relieves Constipation Induced by Loperamide Hydrochloride by Improving Intestinal Flora and Inflammation, Thereby Regulating the Aquaporin Ion Pathway in Mice

Dietary fiber can be fermented and utilized by gut microbiota to reshape the gut microbiota, thereby alleviating constipation. This experiment mainly studied the physicochemical functions of hawthorn soluble dietary fiber (HSDF)and its effect and mechanism in alleviating constipation in mice. Forty-five mice were divided into blank control group C, model group M, positive control HS group, low-dose LHSDF group (1 g/kg/bw), and high-dose HHSDF group (2 g/kg/bw). The mice were modeled at a dose of 10 mg/kg/bw of loperamide hydrochloride for 7 days, while the remaining groups were orally administered an equal amount of distilled water and test samples. After continuous gavage for 45 days we performed a bowel movement test, and then continued gavage for 7 days and performed a small intestine propulsion test and indicator testing. The results showed that HSDF is mainly composed of galacturonic acid, belonging to the type I crystal structure, with a loose surface resembling a snowflake, a small molecular weight, and strong water-holding and antioxidant abilities. Animal experiments showed that compared with group M, HSDF significantly upregulated AQP3 and AQP8 by 52.67% and 164.54%, respectively, and downregulated AQP9 protein expression by 45.88%, thereby promoting intestinal peristalsis. It can also alleviate constipation by increasing the levels of excitatory hormones such as MTL, GAS, and SP in the gastrointestinal tract, and reducing the levels of inhibitory hormones such as SS, NO, and MDA. In addition, HSDF can reduce the levels of inflammatory factors such as IL-6 and PL-1 β, increase the content of various short-chain fatty acids, alleviate intestinal inflammation, maintain intestinal integrity, and promote defecation. It can also promote the growth of probiotics such as Bacteroides, inhibit the growth of harmful bacteria such as Bifidobacterium and Lactobacillus, and alter the diversity of gut microbiota.

Oligosaccharides from Asparagus cochinchinensis for ameliorating LPS-induced acute lung injury in mice

Asparagi radix is an edible herb with medicinal properties and is now widely used in clinical applications for improving pulmonary inflammation. However, the lung-protective effect and the active constituents of Asparagi radix are yet to be elucidated. Herein, the potential pulmonary protective effect of the oligosaccharides of Asparagi radix was investigated. We firstly identified eighteen oligosaccharides with different degrees of polymerization from Asparagi radix using HPLC-QTOF MS. Oligosaccharides were analysed for 20 samples of Asparagi radix collected from various regions in China using HILIC-ELSD and were found to stably exist in this herb. In this study, we found that AROS significantly reduced NO production and effectively down-regulated the mRNA expression of IL-6, IL-1β and TNF-α in RAW 264.7 cells, thereby reducing the inflammatory response induced by LPS. AROS also inhibited LPS-stimulated intracellular ROS production. A murine model of lipopolysaccharide (LPS)-induced acute lung injury was used to evaluate the in vivo anti-inflammatory and lung protective efficacies of AROS. AROS ameliorated the damage to the pulmonary cellular architecture pathological injury and lung edema. AROS significantly decreased the levels of cytokines IL-6, TNF-α and IL-1β; the levels of MPO and MDA; and superoxide dismutase consumption in vivo. This effect of oligosaccharides can explain the traditional usage of Asparagus cochinchinensis as a tonic medicine for respiratory problems, and oligosaccharides from Asparagi radix used as a natural ingredient can play an important role in protecting lung injury.

Constituent analysis, laxative activity, and toxicological evaluation of methanol extract of noni fruit (Morinda citrifolia L., Rubiaceae)

Noni fruits have gained considerable popularity as dietary supplements. However, the major constituents, the laxative activity, and the toxicity of Noni fruit remains still unknown. The purpose of the present study was, therefore, to analyze the constituents of methanol extract of Noni fruit by UPLC-MS, and further evaluate laxative activity and safety aspects of this Noni fruit-derived products in mice. UPLC-MS analysis identified eleven major constituents from this Noni fruit extract. Administration of this extract obviously shortened the time of first fecal excrement, significantly increased the total number and the weight of stools, and remarkably restored the intestinal transit to normal level in the constipated mice, with low toxicity to liver and kidney, and meanwhile, the abundance, composition, and function of gut microbiota remained homeostasis. These results revealed the laxative activity of the methanol extract of Noni fruit with low toxicity and no influence on gut microbiota.

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.

Blueberry and Blackberry Anthocyanins Ameliorate Metabolic Syndrome by Modulating Gut Microbiota and Short-Chain Fatty Acids Metabolism in High-Fat Diet-Fed C57BL/6J Mice

In this study, blueberry (Vaccinium ssp.) anthocyanins (VA) and blackberry (Rubus L.) anthocyanins (RA) were used to investigate the effects on metabolic syndrome (MetS) and the potential mechanisms. Importantly, all of the data presented in this study were obtained from experiments conducted on mice. As a result, VA and RA reduced body weight gain and fat accumulation while improving liver damage, inflammation, glucose, and lipid metabolism induced by a high-fat diet. Moreover, VA and RA regulated the gut microbiota composition, decreasing the pro-obesity and proinflammation bacteria taxa, such as the phylum Actinobacterium and the genera Allobaculum and Bifidobacterium, and increasing those negatively associated with obesity and inflammation, such as the phylum Bacteroidetes and the genera Prevotella and Oscillospira. Additionally, the supplementation with VA and RA reversed the elevated levels of valeric, caproic, and isovaleric acids observed in the high-fat diet (HFD) group, bringing them closer to the levels observed in the Chow group. This reversal indicated that alterations in the composition and abundance of gut microbiota may contribute to the restoration of short-chain fatty acids (SCFAs) levels. Additionally, PICRUSt2 exhibited that cyanamino acid metabolism and betalain biosynthesis might be the major metabolic pathways in the HVA group compared with the HFD group, while in the HRA group, it was the phosphotransferase system. These findings suggest that VA and RA can ameliorate MetS by modulating the gut microbiota and production of SCFAs.

The Tian-Men-Dong decoction suppresses the tumour-infiltrating G-MDSCs via IL-1β-mediated signalling in lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) Tian-Men-Dong decoction (TD) has been able to effectively treat lung cancer in China for thousands of years. TD improves the quality of life in lung cancer patients by promoting nourishment of yin and reducing dryness, clearing the lung and removing toxins. Pharmacological studies show that TD contains active antitumour ingredients, but its underlying mechanism remains unknown.

AIM OF THE STUDY

This study aims at exploring potential mechanisms of TD in the treatment of lung cancer by regulating granulocytic-myeloid-derived suppressor cells (G-MDSCs).

MATERIALS AND METHODS

An orthotopic lung cancer mouse model was generated by intrapulmonary injection with LLC-luciferase cells in immunocompetent C57BL/6 mice or immunodeficient nude mice. TD/saline was orally administered once to the model mice daily for 4 weeks. Live imaging was conducted to monitor tumour growth. Immune profiles were detected by flow cytometry. H&E and ELISA were applied to test the cytotoxicity of the TD treatment. RT-qPCR and western blotting were performed to detect apoptosis-related proteins in G-MDSCs. A neutralizing antibody (anti-Ly6G) was utilized to exhaust the G-MDSCs via intraperitoneal injection. G-MDSCs were adoptively transferred from wild-type tumour-bearing mice. Immunofluorescence, TUNEL and Annexin V/PI staining were conducted to analyse apoptosis-related markers. A coculture assay of purified MDSCs and T cells labelled with CFSE was performed to test the immunosuppressive activity of MDSCs. The presence of TD/IL-1β/TD + IL-1β in purified G-MDSCs cocultured with the LLC system was used for ex vivo experiments to detect IL-1β-mediated apoptosis of G-MDSCs.

RESULTS

TD prolonged the survival of immune competent C57BL/6 mice in an orthotopic lung cancer model, but did not have the same effect in immunodeficient nude mice, indicating that its antitumour properties of TD are exerted by regulating immunity. TD induced G-MDSC apoptosis via the IL-1β-mediated NF-κB signalling cascade leading to effectively weaken the immunosuppressive activity of G-MDSCs and promote CD8⁺ T-cell infiltration, which was supported by both the depletion and adoptive transfer of G-MDSCs assays. In addition, TD also showed minimal cytotoxicity both in vivo and in vitro.

CONCLUSION

This study reveals for the first time that TD, a classic TCM prescription, is able to regulate G-MDSC activity and trigger its apoptosis via the IL-1β-mediated NF-κB signalling pathway, reshaping the tumour microenvironment and demonstrating antitumour effects. These findings provide a scientific foundation the clinical treatment of lung cancer with TD.

New insight on the enteric cholinergic innervation of the pig colon by central and peripheral nervous systems: reduction by repeated loperamide administration

Introduction

The central and peripheral nervous systems provide cholinergic innervation in the colon. The ability to assess their neuroanatomical distinctions is still a challenge. The pig is regarded as a relevant translational model due to the close similarity of its enteric nervous system (ENS) with that of human. Opioid-induced constipation is one of the most common side effects of opioid therapy.

Methods

We developed an approach to differentiate the central and peripheral cholinergic innervation of the pig colon using double immunolabeling with a novel mouse anti-human peripheral type of choline acetyltransferase (hpChAT) antibody combined with a rabbit anti-common type of ChAT (cChAT) antibody, a reliable marker of cholinergic neurons in the central nervous system. We examined their spatial configurations in 3D images of the ENS generated from CLARITY-cleared colonic segments. The density was quantitated computationally using Imaris 9.7. We assessed changes in the distal colon induced by daily oral treatment for 4  weeks with the μ opioid receptor agonist, loperamide (0.4 or 3  mg/kg).

Results

The double labeling showed strong cChAT immunoreactive (ir) fibers in the cervical vagus nerve and neuronal somata and fibers in the ventral horn of the sacral (S2) cord while hpChAT immunoreactivity was visualized only in the ENS but not in the vagus or sacral neural structures indicating the selectivity of these two antibodies. In the colonic myenteric plexus, dense hpChAT-ir neurons and fibers and varicose cChAT-ir fibers surrounding hpChAT-ir neurons were simultaneously visualized in 3D. The density of cChAT-ir varicose fibers in the outer submucosal plexus of both males and females were higher in the transverse and distal colon than in the proximal colon and in the myenteric plexus compared to the outer submucosal plexus and there was no cChAT innervation in the inner submucosal plexus. The density of hpChAT in the ENS showed no segmental or plexus differences in both sexes. Loperamide at the highest dose significantly decreased the density hpChAT-ir fibers + somata in the myenteric plexus of the distal colon.

Discussion

These data showed the distinct density of central cholinergic innervation between myenteric and submucosal plexuses among colonic segments and the localization of cChAT-ir fibers around peripheral hpChAT neurons in 3D. The reduction of cholinergic myenteric innervation by chronic opiate treatment points to target altered prokinetic cholinergic pathway to counteract opiate constipation.

Comparison of the laxative effects of Korean Gochujang containing different microbiota on loperamide-induced constipation in ICR mice

The prevalence of constipation, one of the common gastrointestinal (GI) diseases, has been gradually increasing. Gochujang, a traditional Korean fermented paste, has various microbiota and exerts diverse health beneficial effects. However, the ameliorative effect of Gochujang on constipation is unexplored. Seven-week-old ICR mice were divided into five groups: the normal group, the loperamide (LOP) group, the LOP + mosapride citrate (3 mg per kg BW, MOSA) treated group, the LOP + BMG Gochujang (2 g per kg BW) group, and the LOP + VMG Gochujang (2 g per kg BW) group. Gochujang alleviated constipation by increasing defecation frequency and water content in feces by reducing AQP3 mRNA expression. Additionally, Gochujang increased GI transit time and excitatory neurotransmitter levels and decreased inhibitory neurotransmitter levels. Moreover, Gochujang reduced mitogen-activated protein kinase (MAPK) activation and increased the c-Kit/SCF signaling pathway, suggesting that Gochujang regulates the enteric nervous system (ENS). Interestingly, BMG and VMG differently influenced the gut microbiota composition. Both Gochujang groups significantly decreased the Bacteroidetes and Firmicutes ratio compared to the LOP group. However, among Firmicutes genera, Acetatifactor was only reduced in BMG, and VMG only decreased Caproiciproducens and Acutalibacter. In summary, Gochujang effectively alleviated LOP-induced constipation outcomes regardless of their different microbial communities by ameliorating GI motility and changing the gut microbiota composition.

Multi-strain probiotics alleviate loperamide-induced constipation by adjusting the microbiome, serotonin, and short-chain fatty acids in rats

Constipation is one of the most common gastrointestinal (GI) disorders worldwide. The use of probiotics to improve constipation is well known. In this study, the effect on loperamide-induced constipation by intragastric administration of probiotics Consti-Biome mixed with SynBalance® SmilinGut (Lactobacillus plantarum PBS067, Lactobacillus rhamnosus LRH020, Bifidobacterium animalis subsp. lactis BL050; Roelmi HPC), L. plantarum UALp-05 (Chr. Hansen), Lactobacillus acidophilus DDS-1 (Chr. Hansen), and Streptococcus thermophilus CKDB027 (Chong Kun Dang Bio) to rats was evaluated. To induce constipation, 5 mg/kg loperamide was intraperitoneally administered twice a day for 7 days to all groups except the normal control group. After inducing constipation, Dulcolax-S tablets and multi-strain probiotics Consti-Biome were orally administered once a day for 14 days. The probiotics were administered 0.5 mL at concentrations of 2 × 10⁸ CFU/mL (G1), 2 × 10⁹ CFU/mL (G2), and 2 × 10¹⁰ CFU/mL (G3). Compared to the loperamide administration group (LOP), the multi-strain probiotics not only significantly increased the number of fecal pellets but also improved the GI transit rate. The mRNA expression levels of serotonin- and mucin-related genes in the colons that were treated with the probiotics were also significantly increased compared to levels in the LOP group. In addition, an increase in serotonin was observed in the colon. The cecum metabolites showed a different pattern between the probiotics-treated groups and the LOP group, and an increase in short-chain fatty acids was observed in the probiotic-treated groups. The abundances of the phylum Verrucomicrobia, the family Erysipelotrichaceae and the genus Akkermansia were increased in fecal samples of the probiotic-treated groups. Therefore, the multi-strain probiotics used in this experiment were thought to help alleviate LOP-induced constipation by altering the levels of short-chain fatty acids, serotonin, and mucin through improvement in the intestinal microflora.

Fu Brick Tea Alleviates Constipation via Regulating the Aquaporins-Mediated Water Transport System in Association with Gut Microbiota

This study aimed to investigate the amendatory effects of Fu brick tea aqueous extract (FTE) on constipation and its underlying molecular mechanism. The administration of FTE by oral gavage (100 and 400 mg/kg·bw) for 5 weeks significantly increased fecal water content, improved difficult defecation, and enhanced intestinal propulsion in loperamide (LOP)-induced constipated mice. FTE also reduced colonic inflammatory factors, maintained the intestinal tight junction structure, and inhibited colonic Aquaporins (AQPs) expression, thus normalizing the intestinal barrier and colonic water transport system of constipated mice. 16S rRNA gene sequence analysis results indicated that two doses of FTE increased the Firmicutes/Bacteroidota (F/B) ratio at the phylum level and increased the relative abundance of Lactobacillus from 5.6 ± 1.3 to 21.5 ± 3.4% and 28.5 ± 4.3% at the genus level, subsequently resulting in a significant elevation of colonic contents short-chain fatty acids levels. The metabolomic analysis demonstrated that FTE improved levels of 25 metabolites associated with constipation. These findings suggest that Fu brick tea has the potential to alleviate constipation by regulating gut microbiota and its metabolites, thereby improving the intestinal barrier and AQPs-mediated water transport system in mice.

Asparagus cochinchinensis: A review of its botany, traditional uses, phytochemistry, pharmacology, and applications

Asparagus cochinchinensis (Lour.) Merr. (A. cochinchinensis) is a traditional herbal medicine that is used to treat constipation, fever, pneumonia, stomachache, tracheitis, rhinitis, cataract, acne, urticaria. More than 90 compounds have been identified from different structural types in A. cochinchinensis, including steroidal saponins, C21-steroides, lignans, polysaccharides, amino acids, etc. These bioactive ingredients make A. cochinchinensis remarkable for its pharmacological effects on anti-asthma, anti-inflammatory, anti-oxidation, anti-tumor, improving Alzheimer’s disease, neuroprotection, gut health-promoting and so on. Moreover, A. cochinchinensis also plays an important role in food, health product, cosmetic, and other fields. This review focused on the research publications of A. cochinchinensis and aimed to summarize the advances in the botany, traditional uses, phytochemistry, pharmacology, and applications which will provide reference for the further studies and applications of A. cochinchinensis.

Asparagus cochinchinensis alleviates disturbances of lipid metabolism and gut microbiota in high-fat diet-induced obesity mice

Asparagus cochinchinensis is a valuable traditional Chinese medicine that has anti-inflammatory ability and effectively regulates the dysbiosis within the body. Obesity is usually characterized by chronic low-grade inflammation with aberrant gut microbiota. However, the role of Asparagus cochinchinensis against obesity remains unknown. Therefore, a high-fat diet (HFD)-induced obese mouse model with or without aqueous extract from Asparagus cochinchinensis root (ACE) treatment was established herein to determine whether ACE alleviated obesity and its involved mechanisms. Our results showed that ACE administration significantly decreased the weight gain and relieved dyslipidemia induced by HFD Treatment of ACE also improved glucose tolerance and insulin resistance in obese animal model, and remarkably decreased inflammation and lipogenesis in the liver and adipose. Moreover, administration of ACE significantly reshaped the gut microbiota of obese mice. These findings together suggest that ACE has beneficial effect against HFD-induced obesity and will provide valuable insights for the therapeutic potential of ACE against obesity and may aid in strategy-making for weight loss.

Dioscin ameliorates slow transit constipation in mice by up-regulation of the BMP2 secreted by muscularis macrophages

Objectives

The loss of enteric neurons has been shown to be a major cause of slow transit constipation (STC). Gut microbiota and muscularis macrophages (MMs) are associated with the enteric nervous system (ENS) development and gastrointestinal (GI) motility. This study aimed to investigate whether Dioscin (DIO) increased GI motility and inhibited neuron loss by modulating gut microbiota profile, improving inflammation in the ENS microenvironment.

Materials and Methods

The STC model was established by loperamide. The alteration of the gut microbiota was analyzed by 16S rDNA sequencing. The longitudinal muscle and myenteric plexus (LMMP) from the colon were prepared for flow cytometry, immunofluorescence, western blot, and qRT-PCR.

Results

DIO increased the stool number, stool water content and shortened whole gut transit time, helped to recover the gut microbial diversity and microbiota community structure, and increased the abundance of Muribaculaceae in STC mice. Compared with the STC group, the number of MMs and the level of the iNOS, IL-6, and TNFα genes were significantly decreased following DIO treatment. Moreover, DIO may increase the number of HuC/D⁺ neurons per ganglion by up-regulating the BMP2 secreted by MMs and activating the BMP2/p-Smad1/5/9 signaling pathway. Furthermore, the level of excitatory neurotransmitter AchE in colon tissues exhibited a substantial increase in the DIO group. However, the level of inhibitory neurotransmitter VIP was markedly decreased.

Conclusion

Our results provide that DIO increases GI motility and inhibits neuron loss by modulating gut microbiota profile, improving inflammation in the ENS microenvironment and up-regulating the BMP2 secreted by MMs.

Therapeutic potential of traditional Chinese medicine against atherosclerosis: Targeting trimethylamine N-oxide

BACKGROUND

Recent studies have shown that plasma trimethylamine-N-oxide (TMAO) level is highly correlated with the risk of atherosclerosis (AS), and the elevated level is significantly positively correlated with the incidence of AS.

PURPOSE

The purpose of this article is to offer a useful summary of the correlation between TMAO and AS, and the effect of herbal monomers, herbal extracts, and formulas on anti-atherosclerosis mediated by TMAO.

METHOD

The data contained in this article comes from PubMed, Web of Science, and China National Knowledge Infrastructure.

RESULTS

This review discusses the main mechanism of AS induced by TMAO, including endothelial dysfunction, macrophage foaming, platelet reactivity, and cholesterol metabolism, and summarizes 6 herb monomers, 5 herb extracts, and 2 formulas that have been tested for their anti-TMAO activity.

CONCLUSION

The current understanding of possible ways to reduce TMAO generation is discussed, with the effect and potential of herb monomers, herb extracts, and formulas highlighted.

Increased NOX1 and DUOX2 expression in the colonic mucosa of patients with chronic functional constipation

To determine whether oxidative stress and inflammation are associated with constipation by examining the expression of the main producers of reactive oxygen species, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, and pro-inflammatory cytokines in the colon of patients with chronic functional constipation. The colonic biopsies were collected from 32 patients with chronic functional constipation and 30 healthy subjects who underwent colonoscopy. Colonic mucosal histology was observed. Interleukin (IL)-1β, IL-6, IL-8 messenger RNA (mRNA), and 4 members of NADPH oxidase (NOX1, NOX2, DUOX2, and NOX4) protein and mRNA were assessed by immunohistochemistry, western blotting, and reverse transcription polymerase chain reaction. The tissues from both patients and healthy subjects showed normal histological structure without increase of inflammatory cells. NOX1 protein and mRNA levels were significantly increased compared to controls (P < .05). DUOX2 protein, but not mRNA, was increased by 2-fold compared to controls (P < .05). The levels of NOX2 and NOX4 protein and mRNA demonstrated no significant difference between patients and control subjects. The levels of IL-1β and IL-6 mRNA were significantly higher in constipation patients (P < .05), while IL-8 mRNA level was no different between the 2 groups. NADPH oxidase and pro-inflammatory cytokine might be involved in the pathogeneses of chronic functional constipation.

Preclinical Studies to Evaluate the Gut Stimulatory Activity of Aloe Musabbar

Background

Constipation is a common functional gastrointestinal disorder. Medicines derived from nature are routinely used to treat it. The present study evaluates the gut stimulatory activity of Aloe musabbar (processed powder of Aloe vera) using in vitro and in vivo models for gut stimulatory activity.

Materials and Methods

In vitro tests were conducted on isolated rat colon, guinea pig ileum, and rabbit jejunum, while in vivo study was performed using mice intestinal transit time. Aloe musabbar (A. musabbar) was tested at doses 0.2–200 mg/mL (in-vitro study) and 86.6 mg/kg (in vivo study). In vitro studies were done in the presence and absence of atropine sulphate (1 ng/ml). The results were statistically analyzed, and p < 0.05 was considered to indicate the significance.

Results

A. musabbar exhibited dose-dependent increase in the smooth muscle contraction of isolated gut tissues. Presence of atropine minimized the contractile responses and shifted the dose-response curves towards the right-hand side. The intestinal transit time in mice was observed to be increased significantly (p < 0.01) in A. musabbar-treated animals, when compared with normal animals.

Conclusion

A mild smooth muscle contraction induced by A. musabbar suggests that it can stimulate intestinal bowel movement without causing spasms. The diminished responses in the presence of atropine indicated that the gut stimulatory activity could be mediated partially through parasympathetic innervations. More studies are needed to determine the precise mechanism of action including the specific active ingredient responsible for the gut stimulatory activity.

The Anti-Constipation Effects of Raffino-Oligosaccharide on Gut Function in Mice Using Neurotransmitter Analyses, 16S rRNA Sequencing and Targeted Screening

Raffino-oligosaccharide (ROS), the smallest oligosaccharide of the raffinose family, is a novel food ingredient. However, the anti-constipation effects of ROS remain obscure. This study investigates the anti-constipation effects of ROS based on the loperamide-induced mice model and reveals the underlying mechanism using constipation parameters, neurotransmitter level, 16S rRNA sequencing, and the targeted screening strategy. The prevention effects were firstly investigated by the gastro-intestinal transit rate experiment (50 mice) and defecation status experiment (50 mice), which were divided into five groups (n = 10/group): blank, model, and low-, medium- and high-dose ROS. Furthermore, the slow-transit constipation experiment (blank, model, and high-dose ROS, n = 10/group) was conducted to illustrate the underlying mechanism. The results showed that ROS aided in preventing the occurrence of constipation by improving the gastro-intestinal transit rate and the defecation frequency in mice, and ROS significantly reduced the serum levels of vasoactive intestinal peptide (VIP). In addition, ROS regulated the diversity and structure of intestinal flora. Among them, one specific family and six specific genera were significantly regulated in constipated mice. The targeted screening revealed that 29 targets related to the anti-constipation effects of ROS, indicating ROS may play a role by regulating multiple targets. Furthermore, the network pharmacology analysis showed that Akt1, Stat3, Mapk8, Hsp90aa1, Cat, Alb, Icam1, Sod2, and Gsk3b can be regarded as the core anti-constipation targets. In conclusion, ROS could effectively relieve constipation, possibly by inhibiting the level of neurotransmitters and regulating the gut flora in mice. This study also provides a novel network pharmacology-based targeted screening strategy to reveal the anti-constipation effects of ROS.

Preclinical experimental models for assessing laxative activities of substances/products under investigation: a scoping review of the literature

Constipation is a common gastrointestinal problem worldwide. Its impact on health can range from an unpleasant problem to being seriously troublesome. When lifestyle modification fails to deal with constipation, laxatives are the mainstay of therapy. There are several types of laxatives currently available; however, there still remains a need for better laxatives because certain currently available laxatives are not appropriate for or accessible to some patients. Preclinical experiments to study the laxative potential of substances/products of interest are vital to improving that situation. The selection of appropriate experimental models for assessing the laxative activities of substances/products under investigation is crucial to achieving valid and meaningful results. This article provides a scoping review of the literature, outlining, and summarizing models currently being used in preclinical experiments assessing the laxative activities of substances/products under investigation. The review includes both screening models, e.g., the isolated organ bath system, in vivo fecal assessment and intestinal transit assay, and confirmation models, e.g., in vivo constipation models. Chemical substances/drugs used to induce constipation in in vivo constipation models, e.g., loperamide, diphenoxylate, montmorillonite, and clonidine, as well as standard laxative agents used as a positive control in experimental models, e.g., bisacodyl, carbachol, lactulose, sodium picosulfate, castor oil, phenolphthalein, and yohimbine, are described in detail. The purpose of this article is to assist researchers in the design and implementation of preclinical experimental models for assessing laxative activities of substances/products under investigation to achieve valid and meaningful preclinical results prior to experimentation in humans.

Bamboo shavings derived O-acetylated xylan alleviates loperamide-induced constipation in mice

BSH-1 is an O-acetylated xylan obtained from bamboo shavings. This study determined the protective effects of BSH-1 against loperamide (Lop)-induced constipation in mice. Mice received BSH-1 by gavage daily for 14 days. In constipated mice, BSH-1 significantly shortened the defecation time and raised the gastrointestinal (GI) transit rate, stool production, and cecal concentration of short-chain fatty acids (SCFAs). BSH-1 regulated the serum levels of gut hormones and neurotransmitters. BSH-1 also significantly altered the cecal microbiota of the constipated mice by increasing the abundance of potentially beneficial bacteria (e.g., Lactobacillus, Roseburia, and Bacteroidales_S24-7) and decreasing potentially pathogenic bacteria (e.g., Alloprevotella and Staphylococcus). Furthermore, colonic transcriptome analysis revealed that BSH-1 significantly reversed the expression changes of genes related to intestinal motility, water and ion transport, inflammation and cancer in constipated mice. Our findings indicated that BSH-1 effectively relieved Lop-induced constipation in mice and could be potentially used for constipation treatment.

Dietary synbiotic ameliorates constipation through the modulation of gut microbiota and its metabolic function

The purpose of this study is to investigate the mitigatory effect of a novel synbiotic (SBT) on constipation from the perspective of gut microbiome and metabolome. Here, intake of SBT effectively attenuated diphenoxylate-induced constipation, recuperated colonic epithelial integrity and increased serum levels of gastrointestinal excitatory neurotransmitters (P substance, vasoactive intestinal peptide, motilin, gastrin and serotonin). 16S rRNA sequencing showed that SBT intake rehabilitated the composition and functionality of gut microbiota. Relative abundances of short-chain fatty acids (SCFAs)-producing bacteria including Lactobacillus, Faecalibaculum and Bifidobacterium were elevated by administration of SBT. The gas chromatography-mass spectrometry analysis confirmed that fecal concentrations of propionate and butyrate were significantly increased in the rats intervened with SBT. In addition, SBT ingestion reduced the relative levels of opportunistic pathogens, such as Oscillibacter, Parasutterella and Parabacteroides. Microbial functional prediction showed that the relative abundances of lipopolysaccharide (LPS) biosynthesis and arachidonic acid metabolism were downregulated with SBT administration, which were in accordance with the serum metabolomics results. Furthermore, serum levels of LPS, tumour necrosis factor alpha and interleukin 6 were significantly decreased, indicating that SBT supplementation suppressed inflammatory responses. Therefore, this study demonstrated that consumption of SBT ameliorated constipation possibly by regulating gut microbiota, promoting the SCFAs production and inhibiting inflammatory responses in rats. Our study also indicated that SBT may provide a novel alternative strategy for the treatment of constipation clinically in future.

Lactobacillus plantarum PS128 Promotes Intestinal Motility, Mucin Production, and Serotonin Signaling in Mice

Lactobacillus plantarum PS128 has been reported as a psychobiotic to improve mental health through the gut–brain axis in experimental animal models. To explore its mechanism of action in the gut, this study aimed to analyze the effects of L. plantarum PS128 ingestion on naïve and loperamide (Lop)-induced constipation mice. We found that, in the two mouse models, the weight, number, and water content of feces in the L. plantarum PS128 group were higher than those in the vehicle control group. Histological observation revealed that L. plantarum PS128 increased the level of colonic mucins including the major mucin MUC2. In addition, the charcoal meal test showed that L. plantarum PS128 significantly increased the small intestine transit in naïve mice, but not in the Lop-treated mice. Since intestinal serotonin has been found to modulate motility, we further analyzed the expression of genes related to serotonin signal transduction in the small intestine of naïve mice. The results showed that L. plantarum PS128 significantly altered the expression levels of Tph1, Chga, Slc6a4, and Htr4, but did not affect the expression levels of Tph2, Htr3a, and Maoa. Furthermore, immunohistochemistry revealed that L. plantarum PS128 significantly increased the number of serotonin-containing intestinal cells in mice. Taken together, our results suggest that L. plantarum PS128 could promote intestinal motility, mucin production, and serotonin signal transduction, leading to a laxative effect in mice.

Comparative study of the laxative effects of konjac oligosaccharides and konjac glucomannan on loperamide-induced constipation in rats

Dietary fiber is the basic therapeutic method to relieve the symptoms of chronic constipation. The aim of this study was to compare the laxative effect of konjac glucomannan (KGM) and konjac oligosaccharides (KOS) on constipated rats. KGM and KOS were administered to loperamide-induced constipated rats at dosages of 100 mg per kg bw and 400 mg per kg bw for 15 days. Feces were collected to evaluate the defecation function. X-ray imaging and an electrophysiological system were used to determine gastrointestinal (GI) motility. Immunohistochemistry and western blotting were used to measure the protein levels. Magnetic resonance imaging (MRI) was performed to assess flatulence. Our results demonstrated that low-dose KOS (L-KOS) exerted the best laxative effect. Compared to the normal control (NC) group, the fecal number in the L-KOS group increased by 39.4%, and the fecal weight significantly increased by 31.9% which was higher than those in the low-dose KGM (L-KGM) and high-dose KGM (H-KGM) groups. The fecal moisture content and transit scores were significantly increased only in the L-KOS group. Meanwhile, less GI gas was produced by KOS. Additionally, further investigations suggested that KOS could upregulate the protein expression of stem cell factors (SCF)/c-kit, and significantly promoted the secretion of mucus. In conclusion, compared to KGM, KOS had a conspicuous laxative effect especially at a low dosage. The potential laxative mechanisms of KOS probably are regulating the SCF/c-kit signalling pathway and increasing mucus secretion. These findings indicated that as a kind of functional oligosaccharide, KOS is more conducive to alleviating constipation compared to polysaccharides.

Dysbiosis of Fecal Microbiota From Complement 3 Knockout Mice With Constipation Phenotypes Contributes to Development of Defecation Delay

Significant phenotypes for constipation were detected in complement 3 (C3) knockout (KO) mice, although no research has been conducted on an association with alteration of gut microbiota. To investigate the effects of dysbiosis on fecal microbiota from C3 KO mice with constipation, the composition of fecal microbiota was characterized in mid-colons of 16-week-old C3 KO mice, and their function for defecation delay development was examined after fecal microbiota transplantation (FMT) of C3 KO mice. Some significant alterations in constipation phenotypes, including stool parameters and histopathological structure, were detected in 16-week-old C3 KO mice compared to those of wild-type (WT) mice. Fecal microbiota of C3 KO mice exhibited decreases in Anaerocolumna, Caecibacterium, Christensenella, Kineothrix, and Oscillibacter populations and increases in Prevotellamassilia, Reuthenibacterium, Prevotella, Eubacterium, Culturomica, Bacteroides, and Muribaculum populations. In FMT study, key stool parameters, including weight and water content, were remarkably declined in a transplanted KO (KFMT) group of antibiotics-induced depletion of microbiota (AiDM)-WT and AiDM-KO mice, and a similar change was observed in fecal morphology. However, intestine length decreased in only the KFMT group of AiDM-WT mice compared with that of AiDM-KO mice. The mucosal layer and muscle thickness were commonly decreased in the KFMT group of AiDM-WT and AiDM-KO mice, and significant alterations in the crypt structure of Lieberkuhn and molecular regulators, including AQP8, C-kit, and 5-HT, were observed in the same group. Taken together, results of the present study indicate that dysbiosis of fecal microbiota from C3 KO mice with constipation phenotypes has a key role in the induction and regulation of defecation delay.

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.

Pediococcus pentosaceus B49 from human colostrum ameliorates constipation in mice

Constipation is a prevalent and burdensome gastrointestinal (GI) disorder that seriously affects the quality of human life. This study evaluated the effects of the P. pentosaceus B49 (from human colostrum) on loperamide (Lop)-induced constipation in mice. Mice were given P. pentosaceus B49 (5 × 109 CFU or 5 × 1010 CFU) by gavage daily for 14 days. The result shows that P. pentosaceus B49 treatment relieved constipation in mice by shortening the defecation time, increasing the GI transit rate and stool production. Compared with the constipation control group, the P. pentosaceus B49-treated groups showed decreased serum levels of inhibitory neurotransmitters (vasoactive intestinal peptide and nitric oxide), increased serum levels of excitatory neurotransmitters (acetylcholinesterase, motilin, and gastrin), and elevated cecal concentration of short chain fatty acids (SCFAs). Analysis of cecal microbiota reveals that P. pentosaceus B49 was colonized in the intestine of constipated mice, and altered the cecal microbiota by increasing beneficial SCFAs-producing bacteria (i.e., Lactobacillus, Ruminococcaceae_UCG-014, and Bacteroidales_S24-7) and decreasing potential pathogenic bacteria (i.e., Staphylococcus and Helicobacter). Moreover, transcriptome analysis of the colon tissue shows that P. pentosaceus B49 partly normalized the expression of genes related to GI peristalsis (i.e., Ache, Chrm2, Slc18a3, Grp, and Vip), water and electrolyte absorption and transport (i.e., Aqp4, Aqp8, and Atp12a), while down-regulating the expression of pro-inflammatory and pro-oncogenic genes (i.e., Lbp, Lgals2, Bcl2, Bcl2l15, Gsdmc2, and Olfm4) in constipated mice. Our findings indicate that P. pentosaceus B49 effectively relieves constipation in mice and is a promising candidate for treating 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.

Buzhongyiqi Decoction Protects Against Loperamide-Induced Constipation by Regulating the Arachidonic Acid Pathway in Rats

Constipation is a common gastrointestinal disorder without effective treatment approach. Buzhongyiqi decoction (BZYQD) is a classical formula that has been commonly used for gastrointestinal disorders for nearly 1,000 years. In this study, we aimed to investigate the protective effect of BZYQD against loperamide-induced constipation and its potential mechanism. Rats with loperamide-induced constipation were orally administered BZYQD. BZYQD treatment obviously increased the small intestinal transit rate and alleviated colon tissue pathological damage. Subsequently, serum metabolomics study was performed to identify the metabolites affected by BZYQD. Metabolomics identified that the levels of 17 serum metabolites, including prostaglandin E₂ (PGE₂), arachidonic acid (AA), and inositol, were significantly changed in BZYQD-treated group compared with those in the loperamide-induced group. Pathway analysis revealed that those metabolites were mainly associated with arachidonic acid metabolism, biosynthesis of unsaturated fatty acids, ascorbate and aldarate metabolism, inositol phosphate metabolism. Additionally, BZYQD treatment down-regulated the cyclooxygenase-2 expression and decrease production of the proinflammatory mediator PGE₂. Further study revealed that BZYQD administration decreased serum levels of the inflammatory factors IL-1β and TNF-α, inhibited phosphorylation of the nuclear transcription factor NF-κB, and down-regulated expression of the inflammatory factors IL-1β and IL-6 in the constipated rat colon. Moreover, BZYQD treatment also increased serum levels of inositol, motilin and gastrin, and promoted gastrointestinal motility. In conclusion, the present study suggested that BZYQD exerted a protective effect against loperamide-induced constipation, which may be associated with its role in regulation of multiple metabolic pathways.

Effects of Allium mongolicum Regel and Its Flavonoids on Constipation

Constipation is a common bowel disease in adults with the symptoms of dry stool or difficulty passing stool. Compared with medication therapy, patients show more compliance with the diet therapy, and thus the diet therapy normally exhibits better therapeutic effect. Allium mongolicum Regel s a perennial herb of Liliaceae native to Mongolia, Kazakhstan, and China, which is traditionally used for constipation. In this paper, we partly clarify the effectiveness of A. mongolicum on constipation from two aspects, including maintaining colon water content and increasing intestinal transit. In loperamide-induced constipation mice model, nine days oral administration of A. mongolicum 50% ethanolic extract increased luminal side water content and regulated intestinal movement rhythm to normalize stools. The activity at least partly related to down-regulation of colon aquaporins 3 (AQP3) expression, and up-regulation and activation of G protein alpha (Gα) and phosphoinositide 3-kinases (PI3K). Further, activities on intestine movements were tested using compounds isolated from A. mongolicum. Three kinds of major flavonoids significantly increased cellular calcium flux in HCT116 cells and promoted mice intestine smooth muscle contraction. The activity may be related to M choline receptor, μ opioid receptor, 5-HT3 receptor, and inositol 1,4,5-trisphosphate (IP3) receptor.

Lactobacillus plantarum CQPC02-Fermented Soybean Milk Improves Loperamide-Induced Constipation in Mice

This study determined the ameliorative effects of the novel microorganism, Lactobacillus plantarum CQPC02 (LP-CQPC02), fermented in soybean milk, on loperamide-induced constipation in Kunming mice. High-performance liquid chromatography revealed that LP-CQPC02-fermented soybean milk (LP-CQPC02-FSM) had six types of soybean isoflavones, whereas Lactobacillus bulgaricus-fermented soybean milk (LB-FSM) and unfermented soybean milk (U-FSM) only had five types of soybean isoflavones. LP-CQPC02-FSM also contained more total and active soybean isoflavones than LB-FSM and U-FSM. Results from mouse experiments showed that the defecation factors (quantity, fecal weight and water content, gastrointestinal transit ability, and time to first black stool) in the LP-CQPC02-FSM-treated mice were better than those in the LB-FSM- and U-FSM-treated mice. The serum and small intestinal tissue experiments showed that soybean milk increased the motilin, gastrin, endothelin, acetylcholinesterase, substance P, vasoactive intestinal peptide, and glutathione levels and decreased the somatostatin, myeloperoxidase, nitric oxide, and malondialdehyde levels compared with the constipated mice in the control group. The LP-CQPC02-FSM also showed better effects than those of LB-FSM and U-FSM. Further results showed that LP-CQPC02-FSM upregulated cuprozinc-superoxide dismutase (Cu/Zn-SOD), manganese superoxide dismutase (Mn-SOD), catalase (CAT), c-Kit, stem cell factor (SCF), glial cell-derived neurotrophic factor (GDNF), neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), and aquaporin-9 (AQP9) and downregulated the expression levels of transient receptor potential cation channel subfamily V member 1 (TRPV1), inducible nitric oxide synthase (iNOS), and aquaporin-3 (AQP3) in the constipated mice. LP-CQPC02-FSM increased the Bacteroides and Akkermansia abundances and decreased the Firmicutes abundance in the feces of the constipated mice and decreased the Firmicutes/Bacteroides ratio. This study confirmed that LP-CQPC02-FSM partially reversed constipation in mice.