Miao sour soup alleviates DSS-induced colitis in mice: modulation of gut microbiota and intestinal barrier function

Miao sour soup (MSS), a daily fermented food in Guizhou, China, is rich in microorganisms with various beneficial activities, including anti-inflammatory and antioxidant activities. However, the therapeutic effects of MSS on IBD remain unexplored. This study aimed to investigate the protective effect of MSS against colitis in mice. In this study, we examined the microbial community structure of MSS by metagenomic sequencing and also explored the protective effect of MSS on DSS-induced colitis in mice. We investigated the effects of MSS on intestinal inflammatory response and intestinal barrier function in mice. Finally, the changes in intestinal flora were analyzed based on the 16S rRNA gene sequencing results. Significantly, the experiment result shows that MSS ameliorated the severity of DSS-induced disease in mice by mitigating colitis-associated weight loss, reducing the disease activity index of IBD, alleviating colonic hemorrhagic lesions, increasing colon length, and improving colonic tissue damage. Moreover, MSS preserved intestinal barrier integrity and restored intestinal epithelial function in mice. Additionally, MSS modulated the structure and composition of the intestinal flora. Furthermore, MSS downregulated pro-inflammatory factors and attenuated the NF-κB p65 expression, thereby mitigating the inflammatory response. These findings highlight the protective effect of MSS against DSS-induced colitis, providing substantial scientific support for potential applications of MSS as a functional food.

Bifidobacterium longum S3 alleviates loperamide-induced constipation by modulating intestinal acetic acid and stearic acid levels in mice

Constipation is a major gastrointestinal (GI) symptom worldwide, with diverse causes of formation, and requires effective and safe therapeutic measures. In the present study, we used loperamide hydrochloride to establish a constipation model and assessed the effect of Bifidobacterium on constipation and its possible mechanism of relief. The results showed that B. longum S3 exerted a constipation-relieving effect primarily by improving the gut microbiota, enriching genera including Lactobacillus, Alistipes, and Ruminococcaceae UCG-007, and decreasing the bacteria Lachnospiraceae NK4B4 group. These changes may thereby increase acetic acid and stearic acid (C18:0) levels, which significantly increase the expression levels of ZO-1 and MUC-2, repair intestinal barrier damage and reduce inflammation (IL-6). Furthermore, it also inhibited oxidative stress levels (SOD and CAT), decreased the expression of water channel proteins (AQP4 and AQP8), significantly elevated the Gas, 5-HT, PGE2, and Ach levels, and reduced nNOS and VIP levels to improve the intestinal luminal transit time and fecal water content. Collectively, these changes resulted in the alleviation of constipation.

Study on the ameliorative effect of honeysuckle on DSS-induced ulcerative colitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Honeysuckle, first documented in the Miscellaneous Records of Famous Physicians, is known for its ability to expel toxin and cool blood to stop diarrhea. Modern pharmacological research has shown that honeysuckle has anti-inflammatory, antibacterial, antioxidant, and immune-regulating effects and is widely used in clinical practice. However, the effect of honeysuckle on ulcerative colitis (UC) is still not fully understood, which presents challenges for quality control, research and development.

AIM OF THE STUDY

This study aimed to determine the anti-inflammatory properties and mechanism of action of aqueous extracts of honeysuckle in the treatment of ulcerative colitis.

MATERIALS AND METHODS

The dextran sodium sulfate (DSS) induced-ulcerative colitis mouse model was established, and the mice were divided into five groups: the control group, the model group, and the low, medium, and high dose honeysuckle treatment groups.

RESULTS

All dose groups of honeysuckle were found to significantly reduce IL-6 and TNF-α levels and regulate DSS-induced mRNA levels of CLDN4, COX-2, IL-6, INOS, MUC-2, occludin and NLRP3. The high-dose group displayed the most effective inhibition, and a differentially expressed mRNA detection indicated abnormal mRNA expression. The 16sRNA sequencing revealed that the honeysuckle was able to significantly upregulate the abundance of beneficial bacteria and downregulate the abundance of harmful bacteria. The study of short-chain fatty acids revealed that the levels of acetic, propionic, isobutyric, valeric and isovaleric acids were significantly increased after administering honeysuckle at medium and high doses.

CONCLUSION

Honeysuckle reduces the production of pro-inflammatory cytokines, increases the content of short-chain fatty acids and restores the intestinal ecological balance, resulting in better therapeutic effects.

Bile salt hydrolase of Lactiplantibacillus plantarum plays important roles in amelioration of DSS-induced colitis

Bile salt hydrolases are thought to be the gatekeepers of bile acid metabolism. To study the role of BSH in colitis, we investigated the ameliorative effects of different BSH-knockout strains of Lactiplantibacillus plantarum AR113. The results showed that L. plantarum Δbsh 1 and Δbsh 3 treatments did not improve body weight and alleviate the hyperactivated myeloperoxidase activity to the DSS group. However, the findings for L. plantarum AR113, L. plantarum Δbsh 2 and Δbsh 4 treatments were completely opposite. The double and triple bsh knockout strains further confirmed that BSH 1 and BSH 3 are critical for the ameliorative effects of L. plantarum AR113. In addition, L. plantarum Δbsh 1 and Δbsh 3 did not significantly inhibit the increase in pro-inflammatory cytokines or the decrease in an anti-inflammatory cytokine. These results suggest that BSH 1 and BSH 3 in L. plantarum play important roles in alleviating enteritis symptoms.

Intake of Pro- and/or Prebiotics as a Promising Approach for Prevention and Treatment of Colorectal Cancer

Colorectal cancer (CRC) is the third most common type of cancer, posing a serious threat to human life. It is widely believed that dietary factors may be crucial modifiers of CRC risk, with pro-and/or prebiotics being especially promising. In this review, a synthesis of CRC prevention and treatment of strategies relying on usage of pro- and/or prebiotics supplements is given, as well as discuss mechanisms underlying the contribution of pro-and/or prebiotics to the suppression of colonic carcinogenesis. Furthermore, a framework for personalizing such supplements according to the composition of an individual's gut microbiome is suggested. Various factors including diversity of one's intestinal microflora, integrity of their intestinal barrier, and the presence of mutagenic/carcinogenic/genotoxic and beneficial compounds are known to have a prominent influence on the development of CRC; thus, clarifying the role of pro- and/or prebiotics will yield valuable insight toward optimizing interventions for enhanced patient outcomes in the future.

Effects of Bifidobacterium with the Ability of 2'-Fucosyllactose Utilization on Intestinal Microecology of Mice

In breast milk, 2'-Fucosyllactose (2'FL) is the most abundant breast milk oligosaccharide and can selectively promote the proliferation of bifidobacteria. This study aimed to explore the effect of ifidobacterial with different utilization capacities of 2'FL on the intestinal microecology of mice. Furthermore, the effects of ifidobacterial with different 2'FL utilization capabilities on mice gut microbiota under the competitive pressure of 2'FL as a carbon source were explored. Compared with the control group, 2'FL, Bifidobacterium (B.) bifidum M130R01M51 + 2'FL, B. longum subsp. Longum CCFM752, and CCFM752 + 2'FL treatments significantly decreased the food intake. Moreover, the water intake, body weight, and fecal water content in all groups showed no significant difference compared with the control group. The combination of B. longum subsp. longum CCFM752 and 2'FL can significantly increase the levels of pro-inflammatory and anti-inflammatory factors. B. bifidum M130R01M51 and mixed strains combined with 2'FL significantly increased the contents of acetic acid and isobutyric acid. The results showed that B. bifidum M130R01M51, B. breve FHuNCS6M1, B. longum subsp. longum CCFM752, and B. longum subsp. infantis SDZC2M4 combined with 2'FL significantly increased the species richness of the gut microbiota. Moreover, B. longum subsp. longum CCFM752 and B. longum subsp. infantis SDZC2M4 significantly increased the abundance of Faecalibaculum and Bifidobacterium, respectively. In conclusion, exploring the impact on intestinal microecology can provide theoretical guidance for the development of personalized prebiotics for different bifidobacteria, which has the potential to improve the ecological imbalance of infant gut microbiota.

The Effect of Probiotics on Intestinal Tight Junction Protein Expression in Animal Models: A Meta-Analysis

This study investigates the effect of probiotics supplementation on tight junction protein (TJP) expression in animal models by meta-analysis. We estimated the effect of probiotics administration in an animal inflammatory bowel disease model based on 47 collected articles from the databases, including Sciencedirect, Pubmed, Scopus, and Google Scholar. The effect size was analyzed with the standardized mean difference, and the heterogeneity of the effect sizes was assessed using Cochran’s Q test. To explain the heterogeneity, moderate analyses, such as meta-ANOVA and meta-regression, were performed using the mixed effects model. Finally, publication bias was assessed using Egger’s linear regression test. Among the evaluated items, zonula occluden (ZO)-1 showed the highest Q statistics value, and the effect sizes of all items were positive with high significance (p < 0.0001). The I2 value of all items reflected high heterogeneity (in excess of 80%). From the results of the meta-ANOVA, the factors of the heterogeneity found in the probiotics strains were investigated. Lactobacillus reuteri was identified as having the greatest effect on claudin and ZO-1 expression. The publication bias was detected by the Egger’s linear regression test, though it revealed that the occludin and ZO-1 had larger sample sizes than the claudin. In sum, this meta-analysis reveals that probiotics are effective at improving TJP expression in a gut environment of inflammatory bowel disease (IBD)-induced animal model. Our findings will interest IBD patients, as they suggest an area warranting future study.

Industrially Produced Rice Protein Ameliorates Dextran Sulfate Sodium-Induced Colitis via Protecting the Intestinal Barrier, Mitigating Oxidative Stress, and Regulating Gut Microbiota

Inflammatory bowel disease (IBD) poses a threat to health and compromises the immune system and gut microflora. The present study aimed to explore the effects of rice protein (RP) purified from rice dregs (RD) on acute colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms. Results showed that RP treatment could alleviate the loss of body weight, colon shortening and injury, and the level of disease activity index, repair colonic function (claudin-1, ZO-1 and occludin), regulate inflammatory factors, and restore oxidative balance (malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and total antioxidant capability (T-AOC)) in mice. Also, RP treatment could activate the Kelch-like ECH-associating protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway, mediate the expression of downstream antioxidant protease (NQO-1, HO-1, and Gclc), regulate gut microbiota by enhancing the relative abundance of Akkermansia and increasing the value of F/B, and adjust short-chain fatty acid levels to alleviate DSS-induced colitis in mice. Thus, RP may be an effective therapeutic dietary resource for ulcerative colitis.

Bifidobacterium longum Ameliorates Dextran Sulfate Sodium-Induced Colitis by Producing Conjugated Linoleic Acid, Protecting Intestinal Mechanical Barrier, Restoring Unbalanced Gut Microbiota, and Regulating the Toll-Like Receptor-4/Nuclear Factor-κB Signaling Pathway

This study aimed to explore the effects and differences of conjugated linoleic acid (CLA)-producing Bifidobacterium longum on the alleviation of dextran sulfate sodium (DSS)-induced colitis and to explore its patterns. Different B. longum strains were administered at 10⁹ cfu/day 7 days before DSS treatment. B. longum CCFM681 significantly increased goblet cells, mucin2 (MUC2), claudin-3, α-catenin1, and ZO-1, but neither B. longum CCFM760 nor B. longum CCFM642 had those protective effects. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were downregulated, while IL-10 was upregulated by B. longum CCFM681 but neither by B. longum CCFM760 nor by B. longum CCFM642. Moreover, B. longum CCFM681 treatment inhibited the toll-like receptor-4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, B. longum CCFM681 treatment rebalanced gut microbiota via regulating the diversity and key microorganisms. Colonic CLA concentrations in mice fed with B. longum CCFM681 were significantly higher than that of DSS-exposed mice, while those in B. longum CCFM760 and B. longum CCFM642 groups showed insignificant difference compared with the DSS group. Moreover, CLA showed a significantly positive correlation with the effectiveness of relieving colitis. B. longum CCFM681 alleviated colitis by protecting the intestinal mechanical barrier, modulating the gut microbiota, and inhibiting the TLR4/NF-κB pathway and associated pro-inflammatory cytokines. These results will help the clinical trials of probiotics and the development of functional products for colitis.

Bioactives and their metabolites from Tetrastigma hemsleyanum leaves ameliorate DSS-induced colitis via protecting the intestinal barrier, mitigating oxidative stress and regulating the gut microbiota

Tetrastigma hemsleyanum, a precious edible and medicinal plant in China, has attracted extensive research attention in recent years due to its high traditional value for the treatment of various diseases. In vitro digestion and colonic fermentation models were established to evaluate the stability of Tetrastigma hemsleyanum leaves (THL) phenolics by the HPLC-QqQ-MS/MS method. The total phenolic and flavonoid contents were degraded during digestion and fermentation. 3-caffeoylquinic acid, 5-caffeoylquinic acid, orientin and (iso)vitexin were metabolized by digestive enzymes and the gut microbiota, and absorbed in the form of glycosides and smaller phenolic acids for hepatic metabolism. The protective effects of THL on dextran sodium sulfate (DSS)-induced colitis in mice and potential mechanisms were explored. The results showed that THL supplementation increased the body weight and colon length, and the expression levels of tight junction proteins including occludin, claudin-1 and ZO-1 were up-regulated by THL. The secretions of pro-inflammatory cytokines containing IL-1β, IL-6 and TNF-α were significantly suppressed, whereas the content of anti-inflammatory cytokine IL-10 was promoted in the THL treated group. In addition, THL treatment activated the nuclear transfer of Nrf2, improved the expression of SOD, CAT, HO-1, NQO1 and GCLC, and decreased the content of MPO and MDA. It is worth noting that THL treatment significantly increased the content of short-chain fatty acids (SCFAs), increased the abundance of Ruminococcaceae, and decreased the abundance of Verrucomicrobia which is positively correlated with pro-inflammatory cytokines. These results indicated that THL effectively inhibited DSS-induced colitis by maintaining the intestinal epithelial barrier, mitigated oxidative stress through regulating the Keap1/Nrf2 signaling pathway and regulated the imbalance of the intestinal flora structure.

Green Pea (Pisum sativum L.) Hull Polyphenol Extracts Ameliorate DSS-Induced Colitis through Keap1/Nrf2 Pathway and Gut Microbiota Modulation

As a processing by-product, green pea hull (GPH) was found to be rich in phenolic components in our previous studies. In this study, UHPLC-LTQ-OrbiTrap-MS (Ultra performance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry) technique was used to quantify polyphenols, and DSS (sodium dextran sulfate)-induced colitis mouse model was established to explore the effect of GPH extracts on colitis. The results showed that quercetin and its derivatives, kaempferol trihexanside and catechin and its derivatives were the main phenolic substances in the extract, reaching 2836.57, 1482.00 and 1339.91 µg quercetin/g GPH extract, respectively; GPH extracts can improved inflammatory status, repaired colonic function, regulated inflammatory factors, and restored oxidative balance in mice. Further, GPH extracts can activate Keap1-Nrf2-ARE signaling pathway, regulate downstream antioxidant protease and gut microbiota by increasing F/B value and promoting the growth of Lactobacillaceae and Lachnospiraceae, and improve the level of SCFAs (short-chain fatty acids) to relieve DSS-induced colitis in mice. Therefore, GPH may be a promising dietary resource for the treatment of ulcerative colitis.

Linoleate Isomerase Complex Contributes to Metabolism and Remission of DSS-Induced Colitis in Mice of Lactobacillus plantarum ZS2058

A linoleate isomerase complex including myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase, and acetoacetate decarboxylase has been confirmed as the pivotal factor for conjugated linoleic acid (CLA) production in Lactobacillus plantarum. However, its role in the metabolism and health-associated benefits of Lactobacillus remain unclear. In the current study, the mild type, knockout, and complemented mutants of the linoleate isomerase complex of L. plantarum ZS2058 were used to investigate those putative effects. The metabonomic results showed that a linoleate isomerase complex could significantly influence the glycol-metabolism, lipid metabolism, and antioxidant compounds. Especially, with the stress of linoleic acid, linoleate isomerase complex knockout mutants induced the increase of several antioxidant compounds, such as glutamic acid, glycine, l-cysteine, glycerol, and l-sorbosone. Moreover, the linoleate isomerase complex played a pivotal role in ameliorating DSS-induced colitis. The knockout mutants showed effects similar to those in the DSS group, whereas complementation of the corresponding gene in the knockout mutants could restore the anti-inflammatory activity, wherein the integrity of a mucus layer was repaired, the level of pro-inflammatory cytokines decreased, and the amount of anti-inflammatory cytokines increased significantly. All the results indicated that the linoleate isomerase complex plays a key role in CLA production and metabolism as well as the health-associated benefits of L. plantarum ZS2058. These results are conducive to promote clinical trials and product development of probiotics for colitis.

Evidence from comparative genomic analyses indicating that Lactobacillus-mediated irritable bowel syndrome alleviation is mediated by conjugated linoleic acid synthesis

Irritable bowel syndrome (IBS) is a chronic intestinal disorder accompanied by low-grade inflammation, visceral hypersensitivity, and gut microbiota dysbiosis. Several studies have indicated that Lactobacillus supplementation can help to alleviate IBS symptoms and that these effects are strain-specific. Therefore, this study aimed to investigate the key physiological characteristics and functional genes contributing to the IBS-alleviating effects of Lactobacillus. An IBS model was established by subjecting C57BL/6 mice to Citrobacter rodentium ingestion and water avoidance stress. Lactobacillus strains with different physiological characteristics were administered to mice intragastrically for 4 weeks (5 × 109 CFU/0.2 mL per mouse per day). Indicators of colonic inflammation, visceral hypersensitivity, and gut microbiota were also evaluated. Finally, differences in functional genes between Lactobacillus strains were analyzed by a comparative genomic analysis, and the relationships between the physiological characteristics, functional genes, and IBS-alleviating effects of the strains were quantified using correlation analysis. Among the eight tested Lactobacillus strains, only Lactobacillus plantarum CCFM8610 significantly inhibited the expression of IL-1β, IL-6, PAR-2, and mast cell tryptase. L. plantarum CCFM8610 also significantly increased the intestinal barrier function, inhibited visceral hypersensitivity symptoms, and modulated the gut microbiota diversity and composition. The correlation analysis of factors associated with the IBS-alleviating effects of Lactobacillus revealed the ability to synthesize conjugated linoleic acid as the most strongly associated physiological characteristic and COG1028-related genes as the most strongly associated functional genes. In conclusion, these findings can facilitate the rapid screening of Lactobacillus strains with IBS-alleviating effects and lay a foundation for studies of the related mechanisms.

The ameliorative effect of Lactobacillus plantarum-12 on DSS-induced murine colitis

Some strains of lactobacilli can exert beneficial effects on a host when ingested in an adequate dose, such as immunoregulation and anti-inflammatory activities. In this study, the survival abilities under simulated gastrointestinal conditions, adhesion abilities on HT-29 cell monolayers, and hemolytic activities of four Lactobacillus plantarum strains were assessed. Among the four strains, L. plantarum-12 showed the higher survival rate under simulated gastrointestinal conditions and adhesion index on the HT-29 cell monolayers, exhibited γ-haemolytic activity and had no biological amine producing ability. L. plantarum-12 was administered to dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) Balb/c mice by oral gavage for 10 days. It was observed that the UC Balb/c mice showed symptoms of colonic atrophy, intestinal histopathological change, gut microbial disturbance, and pro-inflammatory cytokine expression. L. plantarum-12 administration remarkably attenuated DSS-induced UC in mice. L. plantarum-12 administration could restore gut microbiota by increasing beneficial bacteria such as Lactobacillus and decreasing intestinal pathogenic bacteria like Proteobacteria. L. plantarum-12 administration could improve immunity via activating the janus kinase-signal transducer and the activator of the transcription (JAK-STAT) pathway and up-regulating adenosine deaminase (ADA) and interferon-induced protein with tetratricopeptide repeats 1 protein (IFIT1), and enforce the intestinal barrier function by up-regulating mucin 2 (MUC2) protein expression. In conclusion, L. plantarum-12 could attenuate DSS-induced UC in Balb/c mice by ameliorating intestinal inflammation, and restoring the disturbed gut microbiota. L. plantarum-12 could be used as promising probiotics to ameliorate colitis.

Probiotic Effector Compounds: Current Knowledge and Future Perspectives

Understanding the mechanism behind probiotic action will enable a rational selection of probiotics, increase the chances of success in clinical studies and make it easy to substantiate health claims. However, most probiotic studies over the years have rather focused on the effects of probiotics in health and disease, whereas little is known about the specific molecules that trigger effects in hosts. This makes it difficult to describe the detailed mechanism by which a given probiotic functions. Probiotics communicate with their hosts through molecular signaling. Meanwhile, since the molecules produced by probiotics under in vitro conditions may differ from those produced in vivo, in vitro mechanistic studies would have to be conducted under conditions that mimic gastrointestinal conditions as much as possible. The ideal situation would, however, be to carry out well-designed clinical trials in humans (or the target animal) using adequate quantities of the suspected probiotic molecule(s) or adequate quantities of isogenic knock-out or knock-in probiotic mutants. In this review, we discuss our current knowledge about probiotic bacteria and yeast molecules that are involved in molecular signaling with the host. We also discuss the challenges and future perspectives in the search for probiotic effector molecules.

Bifidobacterium pseudocatenulatum Ameliorates DSS-Induced Colitis by Maintaining Intestinal Mechanical Barrier, Blocking Proinflammatory Cytokines, Inhibiting TLR4/NF-κB Signaling, and Altering Gut Microbiota

This study was designed to explore the effects and discrepancy of different CLA-producing Bifidobacterium pseudocatenulatum on relieving colitis and to investigate the potential mechanisms. B. pseudocatenulatum MY40C and CCFM680 were administered to mice with DSS-induced colitis. The content of tight junction proteins and mucin2 was significantly upregulated. TNF-α and IL-6 were downregulated, while IL-10 and PPAR-γ were upregulated. TLR4/NF-κB pathway activation was significantly inhibited. Moreover, each treated strain increased Allobaculum and decreased Sutterella, Bacteroides, and Oscillospira. The colonic conjugated linoleic acid (CLA) concentrations were significantly and positively correlated with the effectiveness of strain in relieving colitis. In conclusion, MY40C and CCFM680 supplementation alleviated DSS-induced colitis by protecting intestinal mechanical barrier, modulating gut microbiota, blocking proinflammatory cytokines, and inhibiting TLR4/NF-κB pathway. These results are conducive to promote clinical trials and product development of probiotics for colitis.

Alleviation effects of Bifidobacterium breve on DSS-induced colitis depends on intestinal tract barrier maintenance and gut microbiota modulation

PURPOSE

The study aimed to investigate the discrepancy and potential mechanisms of different CLA-producing B. breve on dextran sulphate sodium (DSS)-induced colitis.

METHODS

Colitis was induced in C57BL/6 J mice using DSS. Disease activity index (DAI), histopathological changes, epithelial barrier integrity and epithelial apoptosis were determined. Gut microbiota were gauged to evaluate the systemic effects of CLA-producing B. breve.

RESULTS

Oral administration of different B. breve showed different effects, in which B. breve M1 and B. breve M2 alleviated the inflammation induced by DSS as well as significantly increased the concentration of mucin2 (MUC2) and goblet cells, but neither B. breve M3 nor B. breve M4 had those protective effects. Meanwhile, B. breve M1 and B. breve M2 treatments significantly up-regulated the tight junction (TJ) proteins and ameliorated the epithelial apoptosis lead by DSS challenge. Moreover, inflammatory cytokines (TNF-α, IL-6) were modulated by B. breve M1 and B. breve M2, neither B. breve M3 nor B. breve M4. Furthermore, B. breve M1 and B. breve M2 reduced the abundance of Bacteroides and increased the abundance of Odoribacter, then rebalanced the damaged gut microbiota. Colonic CLA concentrations in mice fed with B. breve M1, B. breve M2, B. breve M3 and B. breve M4 decreased successively, which showed significant positive correlation with the effectiveness of relieving colitis.

CONCLUSIONS

Bifidobacterium breve M1 and B. breve M2 alleviated DSS-induced colitis by producing CLA, inhibiting the inflammatory cytokines, maintaining of the intestinal epithelial barrier and regulating the gut microbiota.

The possible mechanism of the protective effect of a sulfated polysaccharide from Gracilaria Lemaneiformis against colitis induced by dextran sulfate sodium in mice

This study aimed to investigate the possible mechanism of the protective effect of a sulfated polysaccharide (SP) from Gracilaria Lemaneiformis against colitis induced by dextran sulfate sodium (DSS). Balb/c mice were gavaged with SP for four weeks, then colon tissue, cecal contents and feces were collected for further analysis. Results showed that SP was effective for inhibiting colon shortening and oedema forming. It could alleviate colonic inflammation via down-regulating the expression of tumor necrosis factor-α (TNF-α), interleukin (IL-6, IL-1β). Besides, it enhanced the intestinal barrier by up-regulating the expression of tight junction proteins Claudin-1 and Zonula occludens-1 (ZO-1) as well as Mucin (MUC-2). The increased expression of short chain fatty acid (SCFA) receptors including G protein-coupled receptor (GPR43, GPR109A) and olfactory receptor (Olfr78), and SCFA production in feces indicated that most of SCFA were absorbed in colon, which could play positive roles in ameliorating colitis. Furthermore, the results of gut microbiota showed that Enterorhabdus, Desulfovibrio, Alistipes, Bacteroides acidifaciens had closest correlations with the strongest protective effects against colitis. Therefore, SP could alleviate DSS-induced colitis via enhancing intestinal barrier, reducing inflammation, activating SCFA receptors and regulating gut microbiota. It could be developed as functional foods which is good for gut health.

The amelioration of ulcerative colitis induced by Dinitrobenzenesulfonic acid with Radix Hedysari

Ulcerative colitis (UC) is a chronic inflammatory disease with an unknown precise etiology. This study proves that Radix Hedysari (RH) ameliorates UC. Four RH extracts were used to ameliorate UC induced by 2,4-Dinitrobenzenesulfonic acid by 7 days intervention in agreement to preliminary studies. Compared to treatment with RH extracts, the RH ethanol extract (EE) was found to be more effective in ameliorating UC. With EE, the DAI were significantly decreased. Macroscopic and histopathological assessments suggest that the colon mucosa was repaired, the organizational structure of the colon had been rebuilt. The levels of MPO, TNF-α, IL-1β, and MDA were significantly decreased (p < .01), the levels of T-SOD and CAT were significantly increased (p < .01). Moreover, the compounds in EE were analyzed by HPLC. The results show that EE can ameliorate UC, and its anti-inflammatory capability probably plays an important role. RH can act as a functional food and ameliorate UC. PRACTICAL APPLICATIONS: In this work, the ameliorative effect of RH on UC was evaluated from multiple angles. There are two practical applications of this work. On the one hand, a new approach to ameliorating UC is provided by this work. In addition, UC patients have a new option for improving their symptoms. On the other hand, this work also provides information on how best to process RH for therapeutic use. In addition, we can utilize some compounds of RH that were once considered useless and reduce the waste of natural resources.

Antiproliferation Activity and Mechanism of c9, t11, c15-CLNA and t9, t11, c15-CLNA from Lactobacillus plantarum ZS2058 on Colon Cancer Cells

Conjugated linolenic acid (CLNA) is a type of ω-3 fatty acid which has been proven to have a series of benefits. However, there is no study about the function of Lactobacillus-derived CLNA isomer. Lactobacillus plantarum ZS2058 has been proven to manifest comprehensive functions and can produce CLNA. To investigate the specific functions of CLNA produced by this probiotic bacterium, two different conjugated α-linolenic acid (CLNA) isomers were successfully isolated. These isoforms, CLNA1 (c9, t11, c15-CLNA, purity 97.48%) and CLNA2 (c9, t11, t15-CLNA, purity 99.00%), both showed the ability to inhibit the growth of three types of colon cancer cells in a time- and concentration-dependent manner. In addition, the expression of MDA in Caco-2 cells was increased by CLNA1 or CLNA2, which indicated that lipid peroxidation was related to the antiproliferation activity of CLNAs. An examination of the key protein of pyroptosis showed that CLNA1 induced the cleavage of caspase-1 and gasdermin-D, while CLNA2 induced the cleavage of caspase-4, 5 and gasdermin-D. The addition of relative inhibitors could alleviate the pyroptosis by CLNAs. CLNA1 and CLNA2 showed no effect on caspase-3, 7, 9 and PARP-1, which were key proteins associated with apoptosis. No sub-diploid apoptotic peak appeared in the result of PI single staining test. In conclusion, CLNA1 activated caspase-1 and induced Caco-2 cell pyroptosis, whereas CLNA2 induced pyroptosis through the caspase-4/5-mediated pathway. The inhibition of Caco-2 cells by the two isomers was not related to apoptosis. This is the first study on the function of Lactobacillus-derived CLNA isomer. The inhibition pathway of Lactobacillus-derived CLNA isomer on colon cancer cells were proved.

The profiling of bioactives in Akebia trifoliata pericarp and metabolites, bioavailability and in vivo anti-inflammatory activities in DSS-induced colitis mice

The fruit of Akebia trifoliata is popular in Asia, but researches concerning the phytochemicals of A. trifoliate pericarp extract (APE) and their metabolites, bioavailability, metabolism and anti-inflammatory activity in vivo are less known. In the present study, the chemical constituents of APE and their metabolites of rats after oral administration were identified using UPLC-LTQ-Orbitrap-MS/MS. A total of 18 compounds were tentatively characterized in APE, while 8 original compounds and 8 metabolites were observed in plasma, and 10 original compounds and 39 metabolites were detected in urine. Deglycosylation, glucuronidation, methylation and sulfation were the reactions that mainly occurred in the metabolism in vivo. Meanwhile, APE supplementation decreased dextran sulphate sodium (DSS)-induced colitis in mice, ameliorating epithelial barrier disruption, suppressing the proliferation and infiltration of immune cells, modulating the secretion of nitric oxide (NO) and prostaglandin E2 (PGE2), decreasing the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as regulating oxidative stress in vivo. The results suggested that APE triterpenoids and their metabolites as major contributors to anti-inflammatory activities, providing a scientific basis for the use of APE as a functional food to ameliorate colon health in humans.

Orally Administered CLA Ameliorates DSS-Induced Colitis in Mice via Intestinal Barrier Improvement, Oxidative Stress Reduction, and Inflammatory Cytokine and Gut Microbiota Modulation

Dietary supplementation with conjugated linoleic acid (CLA) has been reported to alleviate the effect of colitis in mice, but the mechanisms involved need further exploration. The study aimed to investigate how orally administered CLA alleviates dextran sulfate sodium (DSS)-induced colitis in mice. CLA was administered in five different doses: 40, 20, 10, 5, and 2.5 mg/day. Doses of CLA at 10 mg/day and higher alleviated colitis symptoms and reduced inflammation induced by DSS, in which 40, 20, and 10 mg/day CLA significantly increased the concentration of mucin2 and goblet cells, but neither 5 mg/day CLA nor 2.5 mg/day CLA had any effects. Meanwhile, 40 and 20 mg/day CLA treatments significantly upregulated the concentration of tight junction proteins (ZO-1, occludin, and claudin-3) and ameliorated epithelial apoptosis caused by DSS. Moreover, oxidative-stress-related enzymes (superoxide dismutase, glutathione peroxidase, and catalase) and inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-10, and IL-6] were modulated by 40 and 20 mg/day CLA. Furthermore, 40 mg/day CLA rebalanced the gut microbiota damaged by DSS, including reducing Bacteroides and increasing Bifidobacterium and Odoribacter. In conclusion, CLA supplementation alleviated DSS-induced colitis in a dose-dependent manner by modulating inflammatory cytokines and oxidation stress, maintaining the mucosal barrier, and reverting microbiota changes.

Lactobacillus caseiLC2W can inhibit the colonization ofEscherichia coliO157:H7in vivoand reduce the severity of colitis

L. caseiLC2W can inhibit the colonization of O157:H7 in mice and its prevention effect is stronger than the treatment effect.

Dietary supplementation of α-linolenic acid induced conversion of n-3 LCPUFAs and reduced prostate cancer growth in a mouse model

Background

α-linolenic acid (ALA) is an n-3 polyunsaturated fatty acid (PUFA) and the substrate for long-chain n-3 PUFAs. The beneficial effects of ALA on chronic diseases are still in dispute, unlike those of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Methods

The primary objective of this investigation was to evaluate the efficiency of ALA uptake from a vegetable oil source and its subsequent conversion to n-3 long-chain PUFAs (LCPUFAs) in the tissues of growing mice, and to investigate its protective role in a prostate cancer animal model. We carried out the investigation in prostate-specific Pten-knockout mice with specified low-ALA (L-ALA, 2.5%) and high-ALA (H-ALA, 7.5%) diets. Total fatty acids in blood, liver, epididymal fat pad, prostate were detected and prostate weight were adjusted for body weight (mg/25 g).

Results

We found that dietary ALA triggered significant increases in ALA, EPA, docosapentaenoic acid (DPA) and DHA levels and a significant decrease in arachidonic acid levels during the mice’s growth stage. A dose-dependent effect was observed for ALA, EPA and DPA, but not DHA. Furthermore, the average prostate weights in the L-ALA and H-ALA groups were lower than those in the control and n-6 groups, and similar to those in the EPA and n-3 groups.

Conclusions

Our data suggest that dietary supplementation with ALA is an efficient means of improving n-3 LCPUFAs in vivo, and it has a biologically effective role to play in prostate cancer, similar to that of fish oils.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0529-z) contains supplementary material, which is available to authorized users.

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