Rhubarb-Evoke Mucus Secretion through Aggregation and Degranulation of Mast Cell in the Colon of Rat: In vivo and ex vivo studies

WenTongGanPi decoction alleviates diarrhea-predominant irritable bowel syndrome by improving intestinal barrier

ETHNOPHARMACOLOGICAL RELEVANCE

WenTongGanPi Decoction (WTGPD) is a representative medical practice of the Fuyang School of Traditional Chinese Medicine (TCM), which originated from the classical Lu's Guizhi method. WTGPD places emphasis on the balance and functionality of yang qi, and is effective in treating TCM symptoms related to liver qi stagnation and spleen yang deficiency. In TCM, diarrhea-predominant irritable bowel syndrome (IBS-D) is often diagnosed as liver depression and spleen deficiency, and the use of WTGPD has shown significant therapeutic effect. However, the underlying mechanism of WTGPD treating IBS-D remains unclear.

AIM OF THE STUDY

To explore the effect and mechanism of WTGPD in the treatment of IBS-D.

MATERIALS AND METHODS

An IBS-D model with liver depression and spleen deficiency was constructed by chronic immobilization stress stimulation and sennae folium aqueous gavage. The impact of WTGPD on IBS-D rats was evaluated through measurements of body weight, fecal water content, and abdominal withdrawal reflex (AWR). Intestinal permeability was assessed using hematoxylin-eosin (HE), alcian blue-periodic acid schiff (AB-PAS), immunofluorescence (IF) staining, and quantitative real-time PCR (qRT-PCR). The components of WTGPD were analyzed using UPLC-Q-TOF-MS. The underlying mechanisms were investigated through network pharmacology, transcriptomics sequencing, western blot (WB), molecular docking, and 16S rRNA sequencing.

RESULTS

WTGPD treatment effectively alleviated diarrhea and abnormal pain in IBS-D rats (P < 0.05). It enhanced the intestinal barrier function by improving colonic structure and increasing the expression of tight junction proteins (P < 0.05). A total of 155 components were identified in WTGPD. Both network pharmacology and transcriptomics sequencing analysis highlighted MAPK as the key signaling pathway in WTGPD's anti-IBS-D effect. The WB results showed a significant decrease in p-p38, p-ERK and p-JNK expression after WTGPD treatment (P < 0.0001). Guanosine, adenosine and hesperetin in WTGPD may be involved in regulating the phosphorylation of p38, ERK and JNK. Additionally, WTGPD significantly enhanced microbial diversity and increased the production of colonic valeric acid in IBS-D rats (P < 0.01).

CONCLUSION

In conclusion, our findings suggest that WTGPD can effectively alleviate IBS-D and improve intestinal barrier likely via inhibiting MAPK signal pathway and improving micobial dysbiosis.

Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice

CONTEXT

Bombax ceiba Linnaeus (Bombacaceae) is known as silk cotton tree, the flowers of which are used in many medicinal applications.

OBJECTIVE

To investigate the therapeutic effect of B. ceiba flower aqueous extracts (BCE) against loperamide-induced constipation and characterize the chemical composition of BCE.

MATERIALS AND METHODS

Sixty male Kunming mice were divided into control (saline), model (10 mg/kg loperamide + saline), phenolphthalein (10 mg/kg loperamide + 10 mg/kg phenolphthalein) and different dosage of BCE (10 mg/kg loperamide + 40, 80 and 160 mg/kg BCE, respectively) groups, and received intragastric administrations for eight days. Faecal water content, number of faeces, first black-stool defecation time and gastrointestinal transit rates were evaluated. Various biochemical and molecular biomarkers were assessed in blood and colon. UPLC-ESI-QTOF-MS/MS was used to tentatively identify the composition of the BCE.

RESULTS

BCE treatment (160 mg/kg) could increase faecal water (15.75%), faeces number (11.65%), gastrointestinal transit rate (25.37%) and decrease first black-stool defecation time (24.04%). The BCE (80 mg/kg) increased the serum level of motilin (30.62%), gastrin (54.46%) and substance P (18.99%), and decreased somatostatin (19.47%). Additionally, the BCE (160 mg/kg) reduced the mucosal damage, restored colonic goblet cell function, down-regulated the protein expression of AQP₃ (33.60%) and increased c-kit protein expression (11.63%). Twelve known compounds, including protocatechuic acid, chlorogenic acid and rutin, previously reported in B. ceiba, were identified in the BCE.

DISCUSSION AND CONCLUSIONS

This study suggested that BCE is a promising agent for the treatment of constipation.

Rhubarb extract rebuilding the mucus homeostasis and regulating mucin-associated flora to relieve constipation

In clinical trials, rhubarb extract (Rb) was demonstrated to efficiently alleviate constipation. We would like to find out the underlying mechanism of rhubarb relieving constipation. However, there are few studies on the effects of rhubarb on colonic mucus secretion and constipation. The aim of this study was to investigate the effects of rhubarb on colonic mucus secretion and its underlying mechanism. The mice were randomly divided into four groups. Group I was the control group and Group II was the rhubarb control group, with Rb (24 g/kg body weight [b.w.]) administered through intragastric administration for three days. Group III mice were given diphenoxylate (20 mg/kg b.w.) for five days via gavage to induce constipation. Group IV received diphenoxylate lasting five days before undergoing Rb administration for three days. The condition of the colon was evaluated using an endoscope. Particularly, the diameter of blood vessels in the colonic mucosa expanded considerably in constipation mice along with diminishing mucus output, which was in line with the observation via scanning electron microscope (SEM) and transmission electron microscope (TEM). We also performed metagenomic analysis to reveal the microbiome related to mucin gene expression level referring to mucin secretion. In conclusion, Rb relieves constipation by rebuilding mucus homeostasis and regulating the microbiome.

A novel purgative mechanism of multiflorin A involves changing intestinal glucose absorption and permeability

BACKGROUND

Multiflorin A (MA) is a potential active ingredient of traditional herbal laxative, Pruni semen, with unusual purgative activity and an unclear mechanism, and inhibiting intestinal glucose absorption is a promising mechanism of novel laxatives. However, this mechanism still lacks support and a description of basic research.

PURPOSE

This study aimed to determine the main contribution of MA to the purgative activity of Pruni semen and elucidate the effect intensity, characteristics, site, and mechanism of MA in mice, and determine the novel mechanism of traditional herbal laxatives from the perspective of intestinal glucose absorption.

METHODS

We induced diarrhoea in mice by administering Pruni semen and MA, and the defecation behaviour, glucose tolerance, and intestinal metabolism were analysed. The effects of MA and its metabolite on peristalsis of the intestinal smooth muscle were evaluated using an intestinal motility assay in vitro. Intestinal tight junction proteins, aquaporins, and glucose transporters expression were analysed using immunofluorescence; gut microbiota and faecal metabolites were analysed using 16S rRNA and liquid chromatography-mass spectrometry.

RESULTS

MA administration (20 mg/kg) induced watery diarrhoea in over half of the experimental mice. The activity of MA in lowering peak postprandial glucose levels was synchronous with purgative action, with the acetyl group being the active moiety. MA was metabolised primarily in the small intestine, where it decreased sodium-glucose cotransporter-1, occludin, and claudin1 expression, then inhibited glucose absorption, resulting in a hyperosmotic environment. MA also increased the aquaporin3 expression to promote water secretion. Unabsorbed glucose reshapes the gut microbiota and their metabolism in the large intestine and the increasing gas and organic acid promoted defecation. After recovery, the intestinal permeability and glucose absorption function returned, and the abundance of probiotics such as Bifidobacterium increased.

CONCLUSION

The purgative mechanism of MA involves inhibiting glucose absorption, altering permeability and water channels to promote water secretion in the small intestine, and regulating gut microbiota metabolism in the large intestine. This study is the first systematic experimental study on the purgative effect of MA. Our findings provide new insight into the study of novel purgative mechanisms.

Supplementation with sesame oil suppresses genotoxicity, hepatotoxicity and enterotoxicity induced by sodium arsenite in rats

BACKGROUND

Sesame oil, an edible essential oil, is known to be rich in unsaturated fatty acids, vitamins and lignans with several reported health-promoting benefits. Acute arsenic poisoning produces toxic hepatitis, bone marrow depression and adverse gastrointestinal responses. In this study, we investigated the protective effect of sesame seed oil (SSO) against genotoxicity, hepatotoxicity and colonic toxicity induced by sodium arsenite (SA) in Wistar rats.

METHODS

Twenty-eight male Wistar albino rats were randomly allocated into four groups: control, SA only (2.5 mg/kg), SA + SSO (4 ml/kg) and SSO alone for eight consecutive days. Liver function and morphology, bone marrow micronuclei induction, colonic histopathology, mucus production and immune expression of Bcl-2, carcinoembryonic antigen (CEA), MUC1 and cytokeratins AE1/AE3 were evaluated.

RESULTS

SA provoked increased serum activities of liver enzymes, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and caused severely altered morphology of hepatic and colonic tissues with increased frequency of micronucleated polychromatic erythrocytes (MnPCEs/1000PCE) in the bone marrow. In addition, SA triggered increased expression of colonic CEA and MUC1 but weak Bcl-2 immunoexpression. However, cotreatment with SSO demonstrated protective activities against SA-induced damage, as indicated by significantly reduced serum ALT and AST, fewer micronucleated bone marrow erythrocytes and well-preserved hepatic and colonic morphologies compared to the SA-treated rats. Furthermore, SSO protected the colonic mucosa by boosting mucus production, elevating anti-apoptotic Bcl-2 expression and reducing CEA expression. GC-MS analysis of SSO revealed that it was predominated by linoleic acid, an omega-3 fatty acid, and tocopherols.

CONCLUSIONS

Our data indicated that SSO protected the liver, colon and bone marrow potentially via anti-inflammatory and anti-apoptotic activities. The data suggest that sesame oil has potential therapeutic applications against chemical toxicities induced by arsenic.

Underlying beneficial effects of Rhubarb on constipation-induced inflammation, disorder of gut microbiome and metabolism

Background: Constipation is a common syndrome and a worldwide healthy problem. Constipation patients are becoming younger, with a 29.6% overall prevalence in children, which has captured significant attention because of its epigenetic rejuvenation and recurrent episodes. Despite the usage of rhubarb extract to relieve constipation, novel targets and genes implicated in target-relevant pathways with remarkable functionalities should still be sought for. Materials and methods: We established a reliable constipation model in C57B/6N male mice using intragastric administration diphenoxylate, and the eligible subjects received 600 mg/25 g rhubarb extract to alleviate constipation. Resultant constipation was morphological and genetically compared with the specimen from different groups. Results: Constipation mice exhibited thicker muscle layers, higher levels of cytokines, including IL-17 and IL-23, and lower content of IL-22. Bacterial abundance and diversity varied tremendously. Notably, the alterations were reversed following rhubarb extract treatment. Additionally, Constipation also had a substantial impact on short-chain fatty acids (SCFAs), medium- and long-chain fatty acids (MLCFAs), and the expression of SCFA receptors, GPR41 and GPR43. Conclusion: This thesis has provided insight that rhubarb extract promoted the flexibility of collagen fiber, reduced pro-inflammatory cytokines, enhanced anti-inflammatory cytokines, and maintained gut microflora balance with potential impacts on the fatty acid and polyamine metabolism.

Bidirectional effects and mechanisms of traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

The bidirectional property of traditional Chinese medicines (TCMs) was recorded in the classic work Medicine Origin (Yi Xue Qi Yuan) as early as the Jin and Yuan dynasties of ancient China. Since then, this imperative theory has been applied to guide the clinical application of TCMs. Studies have been performed to investigate this phenomenon only over the last three decades. A limited number of reviews on the bidirectional role of TCMs have been published, and almost all current studies are published in the Chinese language.

AIM OF THE REVIEW

The aim of this review is to provide the first comprehensive evidence regarding the bidirectional effects and the underlying mechanisms of TCMs and their active compounds.

MATERIALS AND METHODS

Information relevant to opposing pharmacological activities or opposing properties exerted by TCM prescriptions, herbal medicines, and their active compound, as well as their mechanisms was summarized by searching Chinese and English databases, including the Chinese National Knowledge Infrastructure (CNKI), Wan Fang Data, Chinese Scientific Journal Database (VIP), Google Scholar, PubMed, Web of Science, Science Direct, and Wiley Online Library.

RESULTS

Although the bidirectional regulation of TCMs has been applied in the clinic since ancient times in China, only limited reviews have been published in Chinese. The existing data showed that bidirectional effects can be found in TCM prescriptions, herbal medicines, and pure active compounds. Additionally, the bidirectional role of TCMs was primarily reported in the modulation of immune function, blood circulation and hemostasis, gastrointestinal motility, the central nervous system and blood pressure. This may because the therapeutic outcomes of these disorders are more obvious than those of other complicated diseases. Intriguingly, some herbal medicines have multiple bidirectional activities; for instance, Panax ginseng C. A. Meyer showed bidirectional regulation of immune function and the central nervous system; Astragalus membranaceus can bidirectionally regulate blood pressure and immune function; and Rheum officinale Baill exerts bidirectional effects on blood circulation and hemostasis, gastrointestinal motility and immune function. The mechanisms underlying the bidirectional effects of TCMs are largely attributed to the complexity of herbal constituents, dosage differences, the processing of herbal medicine, and compatibility of medicines, the physiological conditions of patients and adaptogenic effects.

CONCLUSION

Uncovering the bidirectional effects and mechanisms of TCMs is of great importance for both scientific research and clinical applications. This review may help to facilitate the recognition of the bidirectional role of TCMs, to explain some seemingly-opposite phenomena in the pharmacological study of herbal medicines and to provide guidance for TCM practitioners.

Glycosylation Analysis of Feline Small Intestine Following Toxoplasma gondii Infection

Simple Summary

Toxoplasma gondii has a serious impact on public health and the economic development of animal husbandry. Glycosylation, especially N-glycosylation, the pattern modification of proteins, is closely related to the biological functions of proteins, and our study used it to analyze glycosylation alterations in the small intestine of cats infected with T. gondii. The results of the present study showed that 56 glycosylated peptides were upregulated and 37 glycosylated peptides were downregulated. Additionally, we also identified eight N-glycosylated proteins of T. gondii including eight N-glycopeptides and eight N-glycosylation sites. Moreover, the protein eEF2 and its corresponding peptide sequence were identified, with GO terms (i.e., cellular process and metabolic process, cell and cell part, and catalytic activity) that were significantly enriched in the T. gondii MAPK pathway. In addition, the Clusters of Orthologous Groups of proteins (COG) function prediction results showed that posttranslational modification, protein turnover, and chaperones (11%) had the highest enrichment for T. gondii. The host proteins ICAM-1 and PPT1 and the endoplasmic reticulum stress pathway may play an important role in the glycosylation of T. gondii-infected hosts. Our study may provide a new target for T. gondii detection to prevent the spread of T. gondii oocysts in the future.

Abstract

Toxoplasma gondii (T. gondii) is responsible for severe human and livestock diseases, huge economic losses, and adversely affects the health of the public and the development of animal husbandry. Glycosylation is a common posttranslational modification of proteins in eukaryotes, and N-glycosylation is closely related to the biological functions of proteins. However, glycosylation alterations in the feline small intestine following T. gondii infection have not been reported. In this study, the experimental group was intragastrically challenged with 600 brain cysts of the Prugniuad (Pru) strain that were collected from infected mice. The cats’ intestinal epithelial tissues were harvested at 10 days post-infection and then sent for protein glycosylation analysis. High-performance liquid chromatography coupled to tandem mass spectrometry was used to analyze the glycosylation alterations in the small intestine of cats infected with T. gondii. The results of the present study showed that 56 glycosylated peptides were upregulated and 37 glycosylated peptides were downregulated in the feline small intestine infected by T. gondii. Additionally, we also identified eight N-glycosylated proteins of T. gondii including eight N-glycopeptides and eight N-glycosylation sites. The protein A0A086JND6_TOXGO (eEF2) and its corresponding peptide sequence were identified in T. gondii infection. Some special GO terms (i.e., cellular process and metabolic process, cell and cell part, and catalytic activity) were significantly enriched, and the Clusters of Orthologous Groups of proteins (COG) function prediction results showed that posttranslational modification, protein turnover, and chaperones (11%) had the highest enrichment for T. gondii. Interestingly, eEF2, a protein of T. gondii, is also involved in the significantly enriched T. gondii MAPK pathway. The host proteins ICAM-1 and PPT1 and the endoplasmic reticulum stress pathway may play an important role in the glycosylation of Toxoplasma-infected hosts. This is the first report showing that T. gondii oocysts can undergo N-glycosylation in the definitive host and that eEF2 is involved, which may provide a new target for T. gondii detection to prevent the spread of T. gondii oocysts in the future.

An Unexpected Alteration Colonic Mucus Appearance in the Constipation Model via an Intestinal Microenvironment

Due to the lack of research between the inner layers in the structure of colonic mucous and the metabolism of fatty acid in the constipation model, we aim to determine the changes in the mucous phenotype of the colonic glycocalyx and the microbial community structure following treatment with Rhubarb extract in our research. The constipation and treatment models are generated using adult male C57BL/6N mice. We perform light microscopy and transmission electron microscopy (TEM) to detect a Muc2-rich inner mucus layer attached to mice colon under different conditions. In addition, 16S rDNA sequencing is performed to examine the intestinal flora. According to TEM images, we demonstrate that Rhubarb can promote mucin secretion and find direct evidence of dendritic structure-linked mucus structures with its assembly into a lamellar network in a pore size distribution in the isolated colon section. Moreover, the diversity of intestinal flora has noticeable changes in constipated mice. The present study characterizes a dendritic structure and persistent cross-links have significant changes accompanied by the alteration of intestinal flora in feces in models of constipation and pretreatment with Rhubarb extract.

Rhubarb anthraquinone glycosides protect against cerebral ischemia-reperfusion injury in rats by regulating brain-gut neurotransmitters

Rhubarb anthraquinone glycosides (RAGs) have been proven to have significant therapeutic effects on ischemic stroke, and this effect may be related to the microbiome-gut-brain axis. In this study, an HPLC-FLD method was established to measure brain-gut neurotransmitters of rats with cerebral ischemia-reperfusion injury (CIRI), to explore whether the mechanism of RAGs against CIRI is related to the microbiome-gut-brain axis. A Shimadzu ODS-3 C₁₈ column was used for chromatographic separation, and 5-hydroxytryptamine (5-HT), 5-hydroxy indole acetic acid (5-HIAA), glutamic acid (Glu), aspartic acid (Asp), and γ-aminobutyric acid (GABA) were determined simultaneously. The results showed that there is an excellent linear relationship (R² ≥ 0.9990) and a high separation degree in the HPLC-FLD method. Whereas the contents of Asp and Glu in the brain and colon increased (p < 0.05), the contents of 5-HT, 5-HIAA, and GABA in the brain and colon decreased (p < 0.05) after CIRI. RAGs could effectively reduce the contents of Asp and Glu (p < 0.05), and increase the contents of 5-HT, 5-HIAA, and GABA in the brain and colon (p < 0.05). Combined with the previous experimental results, we can speculate that RAGs can regulate intestinal flora disorder caused by CIRI, and then regulate the imbalance between the release and decomposition of neurotransmitters caused by intestinal flora disorder.

Functional Metabolomics Analysis Elucidating the Metabolic Biomarker and Key Pathway Change Associated With the Chronic Glomerulonephritis and Revealing Action Mechanism of Rhein

Chronic glomerulonephritis (CGN) as the culprit of kidney failure can increase the mortality of critically ill patients and seriously threatens people’s health all over the world. This study using metabolomics strategy is to reveal the potential therapeutic mechanism-related targets to evaluate the effects of rhein (RH) on CGN rats. Changes of serum metabolites and pathways were analyzed by non-targeted metabolomic method based on liquid chromatography-mass spectrometry (LC-MS) combined with ingenuity pathway analysis. In addition, the levels of biochemical indicators were also detected. A total of 25 potential biomarkers were identified to express serum metabolic turbulence in CGN animal model, and then 16 biomarkers were regulated by RH trending to the normal states. From metabolite enrichment and pathway analysis, pharmacological activity of RH on CGN were mainly involved in six vital metabolic pathways including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, arachidonic acid metabolism, tricarboxylic acid cycle (TCA cycle), alanine, aspartate, and glutamate metabolism, arginine and proline metabolism. It suggested CGN treatment with RH, which may be mediated via interference with metabolic pathway such as amino acid metabolism, arachidonic acid metabolism, and TCA cycle to regulating inflammation, oxidation response and immune regulation against CGN. It showed that metabolomics method offer deeply insight into the therapeutic mechanisms of natural product.