Targeting gut barrier dysfunction with phytotherapies: Effective strategy against chronic diseases

Novel drug delivery systems in colorectal cancer: Advances and future prospects

Colorectal cancer (CRC) is an abnormal proliferation of cells within the colon and rectum, leading to the formation of polyps and disruption of mucosal functions. The disease development is influenced by a combination of factors, including inflammation, exposure to environmental mutagens, genetic alterations, and impairment in signaling pathways. Traditional treatments such as surgery, radiation, and chemotherapy are often used but have limitations, including poor solubility and permeability, treatment resistance, side effects, and post-surgery issues. Novel Drug Delivery Systems (NDDS) have emerged as a superior alternative, offering enhanced drug solubility, precision in targeting cancer cells, and regulated drug release. Thereby addressing the shortcomings of conventional therapies and showing promise for more effective CRC management. The present review sheds light on the pathogenesis, signaling pathways, biomarkers, conventional treatments, need for NDDS, and application of NDDS against CRC. Additionally, clinical trials, ongoing clinical trials, marketed formulations, and patents on CRC are also covered in the present review.

Hyperuricemia drives intestinal barrier dysfunction by regulating gut microbiota

Background

Hyperuricemia elevates gut permeability; however, the risk of its influence on the compromised intestinal barrier is poorly understood.

Aims

This study was carried out, aiming to elucidate the orchestrators and disruptors of intestinal barrier in hyperuricemia.

Methods

A mouse model of hyperuricemia was induced by administering adenine and oteracil potassium to mice. Allopurinol was used to decrease uric acid level, and antibiotics were administered to mice to deplete gut microbiota. Intestinal permeability was assessed using FITC-labeled dextran. Changes in gut microbial community were analyzed through 16S rRNA sequencing. IL-1β and TNF-α levels were quantified using ELISA. The expression of tight junction protein genes, TLR4, p65 and IL-1β, was determined with Q-PCR and Western blotting.

Results

Allopurinol treatment effectively reduced intestinal permeability and serum TNF-α levels. Antibiotic treatment alleviated but not abolished intestinal permeability. Uric acid alone was insufficient to increase Coca2 monolayer permeability. Allopurinol treatment altered microbial composition and suppressed opportunistic infections. Re-establishing hyperuricemia in a germfree mouse model protected mice from intestinal injury. Allopurinol and antibiotic treatments reduced TLR4 and IL-1β expressions, increased occludin and claudin-1 expressions but suppressed NF-ĸB p65 signaling. However, removing gut microbiota aggravated lipid metabolic dysfunction.

Conclusion

Gut microbiota is a direct and specific cause for intestinal barrier dysfunction.

Guizhi Shaoyao Zhimu Decoction ameliorates gouty arthritis in rats via altering gut microbiota and improving metabolic profile

BACKGROUND

The incidence of gouty arthritis (GA) has gradually increased, and modern drug therapies have obvious side effects. Guizhi Shaoyao Zhimu Decoction (GSZD), a classic prescription in Traditional Chinese Medicine for treating various osteoarthritis, has shown significant advantages in curing GA.

PURPOSE

To verify the therapeutic effect of GSZD on GA and investigate its potential pharmacological mechanism via integrated analysis of the gut microbiota and serum metabolites for the first time.

METHODS

The chemical composition of GSZD was determined using UPLC-MS. The GA rat model was established by the induction of a high-purine diet combined with local injection. We examined the effects and mechanisms of GSZD after 21 d using enzyme-linked immunosorbent assays, 16S rRNA, and non-targeted metabolomics. Finally, correlation analysis and validation experiment were performed to explore the association among the gut microbiota, serum metabolites, and GA-related clinical indices.

RESULTS

In total, 19 compounds were identified as GSZD. High-purine feedstuff with local injection-induced arthroceles were significantly attenuated after GSZD treatment. GSZD improved bone erosion and reduced the serum levels of inflammatory factors (lipopolysaccharide, tumor cell necrosis factor-α, and interleukin) and key indicators of GA (uric acid). 16S rRNA analysis indicated that GSZD-treated GA rats exhibited differences in the composition of the gut microbiota. The abundance of flora involved in uric acid transport, including Lactobacillus, Ruminococcaceae, and Turicibacter, was elevated to various degrees, whereas the abundance of bacteria involved in inflammatory responses, such as Blautia, was markedly reduced after treatment. Moreover, serum metabolite profiles revealed 27 different metabolites associated with the amelioration of GA, which primarily included fatty acids, glycerophospholipids, purine metabolism, amino acids, and bile acids, as well as primary metabolic pathways, such as glycerophospholipid metabolism and alanine. Finally, correlation analysis of the heat maps and validation experiment demonstrated a close relationship among inflammatory cytokines, gut microbial phylotypes, and metabolic parameters.

CONCLUSION

This study demonstrated that GSZD could modulate the gut microbiota and serum metabolic homeostasis to treat GA. In addition, the application of gut microbiota and serum metabolomics correlation analyses sheds light on the mechanism of Traditional Chinese Medicine compounds in the treatment of bone diseases.

Fucoxanthin alleviates lipopolysaccharide-induced intestinal barrier injury in mice

The aim of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on lipopolysaccharide (LPS)-induced intestinal barrier injury in mice. Our results demonstrated that the oral administration of Fx (50 and 200 mg per kg body weight per day) for consecutive 7 days significantly alleviated the severity of LPS-induced intestinal barrier injury in mice, as evidenced by attenuating body weight loss, improving intestinal permeability, and ameliorating intestinal morphological damage such as reduction in the ratio of the villus length to the crypt depth (V/C), intestinal epithelium distortion, goblet cell depletion, and low mucin 2 (MUC2) expression. Fx also significantly mitigated LPS-induced excessive apoptosis of intestinal epithelial cells (IECs) and curbed the decrease of tight junction proteins including claudin-1, occludin, and zonula occludens-1 in the ileum and colon. Additionally, Fx effectively alleviated LPS-induced extensive infiltration of macrophages and neutrophils into the intestinal mucosa, the overproduction of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1beta (IL-1β) and IL-6, and gasdermin D (GSDMD)-mediated pyroptosis of IECs. The underlying mechanisms might be associated with inhibiting the activation of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathways. Moreover, Fx also notably restrained intestinal reactive oxygen species (ROS), malondialdehyde and protein carbonylation levels in LPS-treated mice, and it might be mediated by activating the nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway. Overall, these findings indicated that Fx might be developed as a potential effective dietary supplement to prevent intestinal barrier injury.

Baicalin restore intestinal damage after early-life antibiotic therapy: the role of the MAPK signaling pathway

Antibiotic related intestinal injury in early life affects subsequent health and susceptibility. Here, we employed weaned piglets as a model to investigate the protective effects of baicalin against early-life antibiotic exposure-induced microbial dysbiosis. Piglets exposed to lincomycin showed a marked reduction in body weight (p < 0.05) and deterioration of jejunum intestinal morphology, alongside an increase in antibiotic-resistant bacteria such as Staphylococcus, Dolosicoccus, Escherichia-Shigella, and Raoultella. In contrast, baicalin treatment resulted in body weights, intestinal morphology, and microbial profiles that closely resembled those of the control group (p > 0.05), with a significant increase in norank_f_Muribaculaceae and Prevotellaceae_NK3B31_group colonization compared with lincomycin group (p < 0.05). Further analysis through fecal microbial transplantation into mice revealed that lincomycin exposure led to significant alterations in intestinal morphology and microbial composition, notably increasing harmful microbes and decreasing beneficial ones such as norank_Muribaculaceae and Akkermansia (p < 0.05). This shift was associated with an increase in harmful metabolites and disruption of the calcium signaling pathway gene expression. Conversely, baicalin supplementation not only counteracted these effects but also enhanced beneficial metabolites and regulated genes within the MAPK signaling pathway (MAP3K11, MAP4K2, MAPK7, MAPK13) and calcium channel proteins (ORA13, CACNA1S, CACNA1F and CACNG8), suggesting a mechanism through which baicalin mitigates antibiotic-induced intestinal and microbial disturbances. These findings highlight baicalin's potential as a plant extract-based intervention for preventing antibiotic-related intestinal injury and offer new targets for therapeutic strategies.

Good girl goes bad: Understanding how gut commensals cause disease

This review examines the complex connection between commensal microbiota and the development of opportunistic infections. Several underlying conditions, such as metabolic diseases and weakened immune systems, increase the vulnerability of patients to opportunistic infections. The increasing antibiotic resistance adds significant complexity to the management of infectious diseases. Although commensals have long been considered beneficial, recent research contradicts this notion by uncovering chronic illnesses linked to atypical pathogens or commensal bacteria. This review examines conditions in which commensal bacteria, which are usually beneficial, contribute to developing diseases. Commensals' support for opportunistic infections can be categorized based on factors such as colonization fitness, pathoadaptive mutation, and evasion of host immune response. Individuals with weakened immune systems are especially susceptible, highlighting the importance of mucosal host-microbiota interaction in promoting infection when conditions are inappropriate. Dysregulation of gut microbial homeostasis, immunological modulation, and microbial interactions are caused by several factors that contribute to the development of chronic illnesses. Knowledge about these mechanisms is essential for developing preventive measures, particularly for susceptible populations, and emphasizes the importance of maintaining a balanced gut microbiota in reducing the impact of opportunistic infections.

Oleander attenuates hepatic inflammation in a TLR4-independent manner and by favorable modulation of hepatocellular global metabolome that supports cytoprotection

ETHNOPHARMACOLOGICAL RELEVANCE

Nerium oleander is used to treat liver-associated chronic metabolic diseases in traditional medicinal systems across the globe. The hepatoprotective effects of oleander are mentioned in Indian and Chinese traditional medicinal literature.

AIM OF THE STUDY

The present study aimed to investigate the cellular mechanisms behind the hepatoprotective effects of a non-toxic dose of oleander (NO).

MATERIALS AND METHODS

The hepatoprotective effects of NO were tested against lipopolysaccharide (LPS)-treated HepG2 cells. Oxidative stress response was studied using cellular enzymatic assays, and gene expression was analyzed using qRT-PCR. HepG2 cells were pretreated with TAK-242 (pharmacological inhibitor of TLR4) to decipher the anti-inflammatory mechanisms of NO. Cell-free metabolites were analyzed using GCMS and were subjected to pathway enrichment analysis.

RESULTS

NO reduced systemic inflammation, serum lipid peroxidation byproducts, and glucose without affecting serum transaminase levels and hepatic histopathological features. NO attenuated the inflammation-induced loss of antioxidant enzyme activities and mRNA expressions of toll-like receptor-4 (TLR4)/nuclear factor κβ (NFκβ)-dependent inflammatory genes. In TAK-242 pretreated cells, LPS was unable to induce inflammatory and oxidative responses. However, NO treatment in TAK-242 pretreated cells with LPS stimulation further reduced the signs of inflammation and improved hepatoprotective activities. A comparative analysis of the intracellular global metabolome from HepG2 cells with and without NO treatment indicated NO-mediated favorable modulation of intracellular metabolic pathways that support cytoprotective activities.

CONCLUSION

NO protects HepG2 cells from LPS-induced oxidative and inflammatory injury. The hepatoprotective effects of NO are mediated by a TLR4-independent process and through a favorable modulation of the intracellular global metabolome that supports cytoprotection.

Herbal medicine and gut microbiota: exploring untapped therapeutic potential in neurodegenerative disease management

The gut microbiota that exists in the human gastrointestinal tract is incredibly important for the maintenance of general health as it contributes to multiple aspects of host physiology. Recent research has revealed a dynamic connection between the gut microbiota and the central nervous system, that can influence neurodegenerative diseases (NDs). Indeed, imbalances in the gut microbiota, or dysbiosis, play a vital role in the pathogenesis and progression of human diseases, particularly NDs. Herbal medicine has been used for centuries to treat human diseases, including NDs. These compounds help to relieve symptoms and delay the progression of NDs by improving intestinal barrier function, reducing neuroinflammation, and modulating neurotransmitter production. Notably, herbal medicine can mitigate the progression of NDs by regulating the gut microbiota. Therefore, an in-depth understanding of the potential mechanisms by which herbal medicine regulates the gut microbiota in the treatment of NDs can help explain the pathogenesis of NDs from a novel perspective and propose novel therapeutic strategies for NDs. In this review, we investigate the potential neuroprotective effects of herbal medicine, focusing on its ability to regulate the gut microbiota and restore homeostasis. We also highlight the challenges and future research priorities of the integration of herbal medicine and modern medicine. As the global population ages, access to this information is becoming increasingly important for developing effective treatments for these diseases.

Pharmacological benefits of Acacia against metabolic diseases: intestinal-level bioactivities and favorable modulation of gut microbiota

CONTEXT

Obesity-associated chronic metabolic disease is a leading contributor to mortality globally. Plants belonging to the genera Acacia are routinely used for the treatment of diverse metabolic diseases under different ethnomedicinal practices around the globe.

OBJECTIVE

The current review centres around the pharmacological evidence of intestinal-level mechanisms for metabolic health benefits by Acacia spp.

RESULTS

Acacia spp. increase the proportions of gut commensals (Bifidobacterium and Lactobacillus) and reduces the population of opportunistic pathobionts (Escherichia coli and Clostridium). Acacia gum that is rich in fibre, can also be a source of prebiotics to improve gut health. The intestinal-level anti-inflammatory activities of Acacia are likely to contribute to improvements in gut barrier function that would prevent gut-to-systemic endotoxin translocation and limit "low-grade" inflammation associated with metabolic diseases.

CONCLUSION

This comprehensive review for the first time has emphasised the intestinal-level benefits of Acacia spp. which could be instrumental in limiting the burden of metabolic disease.

Quercetin ameliorates ulcerative colitis by activating aryl hydrocarbon receptor to improve intestinal barrier integrity

Ulcerative colitis (UC) pathogenesis is largely associated with intestinal epithelial barrier dysfunction. A therapeutic approach to UC involves the repair of damaged intestinal barrier. Our study aimed to investigate whether aryl hydrocarbon receptor (AhR) mediated the intestinal barrier repair effects of quercetin to ameliorate UC. 3% dextran sulfate sodium was used to induce colitic mice, and quercetin (25, 50, and 100 mg/kg) was administered orally for 10 days to assess the therapeutic effects. In vitro, Caco-2 cells were used to explore the effect of quercetin on tight junction protein expression and AhR activation. The results showed that quercetin alleviated colitic mice by restoring tight junctions (TJs) integrity via an AhR-dependent manner (p < 0.05). In vitro, quercetin dose-dependently elevated the expressions of TJs protein ZO-1 and Claudin1, and activated AhR by enhancing the expression of CYP1A1 and facilitating AhR nuclear translocation in Caco-2 cells (p < 0.05). While AhR antagonist CH223191 reversed the therapeutic effects of quercetin (p < 0.05) and blocked quercetin-induced AhR activation and enhancement of TJs protein (p < 0.05). In conclusion, quercetin repaired intestinal barrier dysfunction by activating AhR-mediated enhancement of TJs to alleviate UC. Our research offered new perspectives on how quercetin enhanced intestinal barrier function.

The intestinal-level metabolic benefits of green tea catechins: Mechanistic insights from pre-clinical and clinical studies

BACKGROUND

The intestinal-level host-microbiota interaction has been implicated in the pathogenesis of chronic diseases. The current review is intended to provide a comprehensive insight into deciphering whether intestinal-level bioactivities mediate the overall metabolic health benefits of green tea catechins.

PURPOSE

We have comprehensively discussed pre-clinical and clinical evidences of intestinal-level changes in metabolism, microbiota, and metabolome due to catechin-rich green tea treatments, ultimately limiting metabolic diseases. Exclusive emphasis has been given to purified catechins and green tea, and discussions on extraintestinal mechanisms of metabolic health benefits were avoided.

METHODS

A literature search for relevant pre-clinical and clinical studies was performed in various online databases (e.g., PubMed) using specific keywords (e.g., catechin, intestine, microbiota). Out of all the referred literature, ∼15% belonged to 2021-2023, ∼51% were from 2011-2020, and ∼32% from 2000-2010.

RESULT

The metabolic health benefits of green tea catechins are indeed influenced by the intestinal-level bioactivities, including reduction of mucosal inflammation and oxidative stress, attenuation of gut barrier dysfunction, decrease in intestinal lipid absorption and metabolism, favorable modulation of mucosal nuclear receptor signaling, alterations of the luminal global metabolome, and mitigation of the gut dysbiosis. The results from the recent clinical studies support the pre-clinical evidences. The challenges and pitfalls of the currently available knowledge on catechin bioactivities have been discussed, and constructive directions to harness the translational benefits of green tea through future interventions have been provided.

CONCLUSION

The metabolism, metabolome, and microbiota at the intestinal epithelia play critical roles in catechin metabolism, pharmacokinetics, bioavailability, and bioactivities. Especially the reciprocal interaction between the catechins and the gut microbiota dictates the metabolic benefits of catechins.

The oral microbial odyssey influencing chronic metabolic disease

INTRODUCTION

Since the oral cavity is the gateway to the gut, oral microbes likely hold the potential to influence metabolic disease by affecting the gut microbiota.

METHOD

A thorough review of literature has been performed to link the alterations in oral microbiota with chronic metabolic disease by influencing the gut microbiota.

RESULT

A strong correlation exists between abnormalities in oral microbiota and several systemic disorders, such as cardiovascular disease, diabetes, and obesity, which likely initially manifest as oral diseases. Ensuring adequate oral hygiene practices and cultivating diverse oral microflora are crucial for the preservation of general well-being. Oral bacteria have the ability to establish and endure in the gastrointestinal tract, leading to the development of prolonged inflammation and activation of the immune system. Oral microbe-associated prophylactic strategies could be beneficial in mitigating metabolic diseases.

CONCLUSION

Oral microbiota can have a profound impact on the gut microbiota and influence the pathogenesis of metabolic diseases.

The opportunistic nature of gut commensal microbiota

The abundance of gut commensals has historically been associated with health-promoting effects despite the fact that the definition of good or bad microbiota remains condition-specific. The beneficial or pathogenic nature of microbiota is generally dictated by the dimensions of host-microbiota and microbe-microbe interactions. With the increasing popularity of gut microbiota in human health and disease, emerging evidence suggests opportunistic infections promoted by those gut bacteria that are generally considered beneficial. Therefore, the current review deals with the opportunistic nature of the gut commensals and aims to summarise the concepts behind the occasional commensal-to-pathogenic transformation of the gut microbes. Specifically, relevant clinical and experimental studies have been discussed on the overgrowth and bacteraemia caused by commensals. Three key processes and their underlying mechanisms have been summarised to be responsible for the opportunistic nature of commensals, viz. improved colonisation fitness that is dictated by commensal-pathogen interactions and availability of preferred nutrients; pathoadaptive mutations that can trigger the commensal-to-pathogen transformation; and evasion of host immune response as a survival and proliferation strategy of the microbes. Collectively, this review provides an updated concept summary on the underlying mechanisms of disease causative events driven by gut commensal bacteria.

Lactic Acid Bacteria and Aging: Unraveling the Interplay for Healthy Longevity

Lactic Acid Bacteria (LAB) are beneficial microorganisms widely utilized in food fermentation processes and as probiotic supplements. They offer multifarious health benefits, including enhancing digestion, strengthening immune mechanisms, and mitigating inflammation. Recent studies suggest that LAB might be instrumental in the anti-aging domain, modulating key molecular pathways involved in the aging continuum, such as IL-13, TNF-α, mTOR, IFN-γ, TGF-β, AMPK, and GABA. The TLR family, particularly TLR2, appears pivotal during the primary cellular interactions with bacteria and their byproducts. Concurrently, the Sirtuin family, predominantly Sirtuin-1, plays diverse roles upon cellular stimuli by bacterial components. The potential anti-aging benefits postulated include restoring gut balance, enhancing antioxidant potential, and fortifying cognitive and mental faculties. However, the current body of evidence is still embryonic and calls for expansive human trials and deeper mechanistic analyses. The safety and optimal consumption metrics for LAB also warrant rigorous evaluation. Future research trajectories should identify specific LAB strains with potent anti-aging properties and unravel the underlying biological pathways. Given the promising implications, LAB strains stand as potential dietary contenders to foster healthy aging and enrich the quality of life among the elderly population.

Glycerol monolaurate improved intestinal barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis in large yellow croaker (Larimichthys crocea) fed with high soybean oil diets

Glycerol monolaurate (GML) is a potential candidate for regulating metabolic syndrome and inflammatory response. However, the role of GML in modulating intestinal health in fish has not been well determined. In this study, a 70-d feeding trial was conducted to evaluate the effect of GML on intestinal barrier, antioxidant capacity, inflammatory response and microbiota community of large yellow croaker (13.05 ± 0.09 g) fed with high level soybean oil (SO) diets. Two basic diets with fish oil (FO) or SO were formulated. Based on the SO group diet, three different levels of GML 0.02% (SO0.02), 0.04% (SO0.04) and 0.08% (SO0.08) were supplemented respectively. Results showed that intestinal villus height and perimeter ratio were increased in SO0.04 treatment compared with the SO group. The mRNA expressions of intestinal physical barrier-related gene odc and claudin-11 were significantly up-regulated in different addition of GML treatments compared with the SO group. Fish fed SO diet with 0.04% GML addition showed higher activities of acid phosphatase and lysozyme compared with the SO group. The content of malonaldehyde was significantly decreased and activities of catalase and superoxide dismutase were significantly increased in 0.02% and 0.04% GML groups compared with those in the SO group. The mRNA transcriptional levels of inflammatory response-related genes (il-1β, il-6, tnf-α and cox-2) in 0.04% GML treatment were notably lower than those in the SO group. Meanwhile, sequencing analysis of bacterial 16S rRNA V4-V5 region showed that GML addition changed gut microbiota structure and increased alpha diversity of large yellow croaker fed diets with a high level of SO. The correlation analysis results indicated that the change of intestinal microbiota relative abundance strongly correlated with intestinal health indexes. In conclusion, these results demonstrated that 0.02%-0.04% GML addition could improve intestinal morphology, physical barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis of large yellow croaker fed diets with a high percentage of SO.

Pillars of long-term antiretroviral therapy success

BACKGROUND

Meeting the challenge of antiretroviral therapy (ART) whose efficacy can last a lifetime requires continuous updating of the virological, pharmacological, and quality of life outcomes to be pursued and a continuous review of literature data on the efficacy and tolerability of new drugs and therapeutic strategies.

METHODS

With the aim of identifying open questions and answers about the current controversies in modern ART, we adapted the Design Thinking methodology to the needs of the design phase of a scientific article, involving a team of experts in HIV care.

RESULTS

Five main pillars of treatment success were discussed: sustained virologic suppression over time; immunological recovery; pharmacological attributes; long-term tolerability and safety of ART; and people's satisfaction and quality of life. The definition of the outcomes to be achieved in each thematic area and the tools to achieve them were reviewed and discussed.

CONCLUSIONS

Long-term treatment success should be intended as a combination of HIV-RNA suppression, immune recovery, and high quality of life. To achieve this, the regimen should be well-tolerated, with high potency, genetic barrier, and forgiveness, and should be tailored by a person-centered perspective, based on individual needs, preferences, and therapeutic history.

Rise of the guardians: Gut microbial maneuvers in bacterial infections

AIMS

Bacterial infections are one of the major causes of mortality globally. The gut microbiota, primarily comprised of the commensals, performs an important role in maintaining intestinal immunometabolic homeostasis. The current review aims to provide a comprehensive understanding of how modulation of the gut microbiota influences opportunistic bacterial infections.

MATERIALS AND METHODS

Primarily centered around mechanisms related to colonization resistance, nutrient, and metabolite-associated factors, mucosal immune response, and commensal-pathogen reciprocal interactions, we discuss how gut microbiota can promote or prevent bacterial infections.

KEY FINDINGS

Opportunistic infections can occur directly due to obligate pathogens or indirectly due to the overgrowth of opportunistic pathobionts. Gut microbiota-centered mechanisms of altered intestinal immunometabolic and metabolomic homeostasis play a significant role in infection promotion and prevention. Depletion in the population of commensals, increased abundance of pathobionts, and overall decrease in gut microbial diversity and richness caused due to prolonged antibiotic use are risk factors of opportunistic bacterial infections, including infections from multidrug-resistant spp. Gut commensals can limit opportunistic infections by mechanisms including the production of antimicrobials, short-chain fatty acids, bile acid metabolism, promoting mucin formation, and maintaining immunological balance at the mucosa. Gut microbiota-centered strategies, including the administration of probiotics and fecal microbiota transplantation, could help attenuate opportunistic bacterial infections.

SIGNIFICANCE

The current review discussed the gut microbial population and function-specific aspects contributing to bacterial infection susceptibility and prophylaxis. Collectively, this review provides a comprehensive understanding of the mechanisms related to the dual role of gut microbiota in bacterial infections.

Preventive and therapeutic effects of natural products and herbal extracts on nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a common condition that is prevalent in patients who consume little or no alcohol, and is characterized by excessive fat accumulation in the liver. The disease is becoming increasingly common with the rapid economic development of countries. Long-term accumulation of excess fat can lead to NAFLD, which represents a global health problem with no effective therapeutic approach. NAFLD is a complex, multifaceted pathological process that has been the subject of extensive research over the past few decades. Herbal medicines have gained attention as potential therapeutic agents to prevent and treat NAFLD due to their high efficacy and low risk of side effects. Our overview is based on a PubMed and Web of Science database search as of Dec 22 with the keywords: NAFLD/NASH Natural products and NAFLD/NASH Herbal extract. In this review, we evaluate the use of herbal medicines in the treatment of NAFLD. These natural resources have the potential to inform innovative drug research and the development of treatments for NAFLD in the future.

Paneth cell dysfunction in radiation injury and radio-mitigation by human α-defensin 5

Introduction

The mechanism underlying radiation-induced gut microbiota dysbiosis is undefined. This study examined the effect of radiation on the intestinal Paneth cell α-defensin expression and its impact on microbiota composition and mucosal tissue injury and evaluated the radio-mitigative effect of human α-defensin 5 (HD5).

Methods

Adult mice were subjected to total body irradiation, and Paneth cell α-defensin expression was evaluated by measuring α-defensin mRNA by RT-PCR and α-defensin peptide levels by mass spectrometry. Vascular-to-luminal flux of FITC-inulin was measured to evaluate intestinal mucosal permeability and endotoxemia by measuring plasma lipopolysaccharide. HD5 was administered in a liquid diet 24 hours before or after irradiation. Gut microbiota was analyzed by 16S rRNA sequencing. Intestinal epithelial junctions were analyzed by immunofluorescence confocal microscopy and mucosal inflammatory response by cytokine expression. Systemic inflammation was evaluated by measuring plasma cytokine levels.

Results

Ionizing radiation reduced the Paneth cell α-defensin expression and depleted α-defensin peptides in the intestinal lumen. α-Defensin down-regulation was associated with the time-dependent alteration of gut microbiota composition, increased gut permeability, and endotoxemia. Administration of human α-defensin 5 (HD5) in the diet 24 hours before irradiation (prophylactic) significantly blocked radiation-induced gut microbiota dysbiosis, disruption of intestinal epithelial tight junction and adherens junction, mucosal barrier dysfunction, and mucosal inflammatory response. HD5, administered 24 hours after irradiation (treatment), reversed radiation-induced microbiota dysbiosis, tight junction and adherens junction disruption, and barrier dysfunction. Furthermore, HD5 treatment also prevents and reverses radiation-induced endotoxemia and systemic inflammation.

Conclusion

These data demonstrate that radiation induces Paneth cell dysfunction in the intestine, and HD5 feeding prevents and mitigates radiation-induced intestinal mucosal injury, endotoxemia, and systemic inflammation.

The detrimental effects of micro-and nano-plastics on digestive system: An overview of oxidative stress-related adverse outcome pathway

With the massive manufacture and use of plastics, plastic pollution-related environmental impacts have raised great concern in recent years. As byproducts of plastic fragmentation and degradation, microplastics (MPs) and nanoplastics (NPs) have been identified as novel pollutants that posed a threat to the ecosystem and humans. Since MPs/NPs could be transported via the food chain and retained in the water, the digestive system should be one of the major targets of MPs/NPs-related toxicity. Although considerable evidence has supported the digestive toxicity of MPs/NPs, the proposed mechanisms remained ambiguous due to the variety of study types, models, and endpoints. This review provided a mechanism-based perspective on MPs/NPs-induced digestive effects by adopting the adverse outcome pathway framework as a promising tool. The overproduction of reactive oxygen species was identified as the molecular initiating event in MPs/NPs-mediated injury to the digestive system. A series of detrimental effects including oxidative stress, apoptosis, inflammation, dysbiosis, and metabolic disorders were summarized as key events. Finally, the occurrence of these effects eventually led to an adverse outcome, suggesting a possible increase in the incidence of digestive morbidity and mortality.

Chemically Defined Lactobacillus plantarum Cell-Free Metabolites Demonstrate Cytoprotection in HepG2 Cells through Nrf2-Dependent Mechanism

Centering around the concept that metabolites from the gut commensals can exert metabolic health benefits along the gut-liver axis, we tested whether the cell-free global metabolome of probiotic bacteria can exert hepatoprotective benefits against H₂O₂-induced oxidative stress. Cell-free global metabolites of Lactobacillus plantarum (LPM) were isolated and untargeted metabolomics was performed. The free radical scavenging potentials of LPM were measured. The cytoprotective effects of LPM were tested on HepG2 cells. A total of 66 diverse metabolites were identified in LPM, among which saturated fatty acids, amino acids and dicarboxylic acids were highly enriched. LPM attenuated cell damage, lipid peroxidation and the levels of intracellular cytoprotective enzymes in H₂O₂-treated cells. LPM also attenuated H₂O₂-induced increased expressions of TNF-α and IL-6. However, the cytoprotective effects of LPM were diminished in cells that were pretreated with a pharmacological inhibitor of Nrf2. Our data collectively indicate that LPM can significantly attenuate oxidative damage to HepG2 cells. However, the cytoprotective effects of LPM likely depend on an Nrf2-dependent mechanism.

A toxic shrub turned therapeutic: The dichotomy of Nerium oleander bioactivities

Nerium oleander L. is a medicinal plant, used for the treatment of cancers and hyperglycemia across the world, especially in Indian sub-continent, Turkey, Morocco, and China. Although clinical studies supporting its pharmacological effects remain critically underexplored, accidental and intentional consumption of any part of the plant causes fatal toxicity in animals and humans. While the polyphenolic fraction of oleander leaves has been attributed to its pre-clinical pharmacological activities, the presence of diverse cardiac glycosides (especially oleandrin) causes apoptosis to cancer cells in vitro and results in clinical signs of oleander poisoning. Thus, the dual pharmacological and toxicological role of oleander is a perplexing dichotomy in phytotherapy. The current investigative review, therefore, intended to analyze the intrinsic and extrinsic factors that likely contribute to this conundrum. Especially by focusing on gut microbial diversity, abundance, and metabolic functions, oleander-associated pharmacological and toxicological studies have been critically analyzed to define the dual effects of oleander. Electronic databases were extensively screened for relevant research articles (including pre-clinical and clinical) related to oleander bioactivities and toxicity. Taxonomic preference was given to the plant N. oleander L. and synonymous plants as per 'The World Flora Online' database (WCSP record #135196). Discussion on yellow oleander (Cascabela thevetia (L.) Lippold) has intentionally been avoided since it is a different plant. The review indicates that the gut microbiota likely plays a key role in differentially modulating the pharmacological and toxicological effects of oleander. Other factors identified influencing the oleander bioactivities include dose and mode of treatment, cardiac glycoside pharmacokinetics, host-endogenous glycosides, plant material processing and phytochemical extraction methods, plant genotypic variations, environmental effects on the phytochemical quality and quantity, gene expression variations, host dietary patterns and co-morbidity, etc. The arguments proposed are also relevant to other medicinal plants containing toxic cardiac glycosides.

The Interaction between Flavonoids and Intestinal Microbes: A Review

In recent years, research on the interaction between flavonoids and intestinal microbes have prompted a rash of food science, nutriology and biomedicine, complying with future research trends. The gut microbiota plays an essential role in the maintenance of intestinal homeostasis and human health, but once the intestinal flora dysregulation occurs, it may contribute to various diseases. Flavonoids have shown a variety of physiological activities, and are metabolized or biotransformed by gut microbiota, thereby producing new metabolites that promote human health by modulating the composition and structure of intestinal flora. Herein, this review demonstrates the key notion of flavonoids as well as intestinal microbiota and dysbiosis, aiming to provide a comprehensive understanding about how flavonoids regulate the diseases by gut microbiota. Emphasis is placed on the microbiota-flavonoid bidirectional interaction that affects the metabolic fate of flavonoids and their metabolites, thereby influencing their metabolic mechanism, biotransformation, bioavailability and bioactivity. Potentially by focusing on the abundance and diversity of gut microbiota as well as their metabolites such as bile acids, we discuss the influence mechanism of flavonoids on intestinal microbiota by protecting the intestinal barrier function and immune system. Additionally, the microbiota-flavonoid bidirectional interaction plays a crucial role in regulating various diseases. We explain the underlying regulation mechanism of several typical diseases including gastrointestinal diseases, obesity, diabetes and cancer, aiming to provide a theoretical basis and guideline for the promotion of gastrointestinal health as well as the treatment of diseases.

Bacterial Exopolysaccharides as Emerging Bioactive Macromolecules: From Fundamentals to Applications

Microbial exopolysaccharides (EPS) are extracellular carbohydrate polymers forming capsules or slimy coating around the cells. EPS can be secreted by various bacterial genera that can help bacterial cells in attachment, environmental adaptation, stress tolerance and are an integral part of microbial biofilms. Several gut commensals (e.g., Lactobacillus, Bifidobacterium) produce EPS that possess diverse bioactivities. Bacterial EPS also has extensive commercial applications in the pharmaceutical and food industries. Owing to the structural and functional diversity, genetic and metabolic engineering strategies are currently employed to increase EPS production. Therefore, the current review provides a comprehensive overview of the fundamentals of bacterial exopolysaccharides, including their classification, source, biosynthetic pathways, and functions in the microbial community. The review also provides an overview of the diverse bioactivities of microbial EPS, including immunomodulatory, anti-diabetic, anti-obesity, and anti-cancer properties. Since several gut microbes are EPS producers and gut microbiota helps maintain a functional gut barrier, emphasis has been given to the intestinal-level bioactivities of the gut microbial EPS. Collectively, the review provides a comprehensive overview of microbial bioactive exopolysaccharides.

p-Hydroxybenzoic Acid Ameliorates Colitis by Improving the Mucosal Barrier in a Gut Microbiota-Dependent Manner

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disease characterized by intestinal inflammatory cell infiltration and intestinal mucosal damage. The mechanism by which diet contributes to the pathogenesis of IBD remains largely unknown. In this study, we explored the therapeutic effect of p-hydroxybenzoic acid (HA), a phenolic acid mainly derived from dietary polyphenols in the gut, on DSS-induced colitis. HA intervention effectively relieved the dextran sulfate sodium salt (DSS)-induced colitis, reduced inflammation, and enhanced mucosal barrier function, as evidenced by an increment of goblet cell numbers and MUC2. These effects were largely dependent on the gut microbiota (GM), as antibiotics treatment substantially attenuated the improvement of colitis by HA. On the other hand, transplantation of GM from colitis mice treated with HA significantly reduced the colitis induced by DSS. Our study demonstrates that HA ameliorates DSS-induced colitis by improving the mucosal barrier in a GM-dependent manner. This study provides new dietary choices for the prevention and treatment of IBD.

Exploring the Phosphatidylcholine in Inflammatory Bowel Disease: Potential Mechanisms and Therapeutic Interventions

BACKGROUND

Inflammatory bowel disease (IBD) is a significant health problem with an increasing financial burden worldwide. Although various treatment strategies have been used, the results were not satisfactory. More and more researches have proved that the application of phosphatidylcholine (PC) may become an alternative therapy for IBD.

OBJECTIVE

This review aims to provide an overview of the possible mechanisms of PC and promote the potential application of PC for IBD therapy further.

METHODS

A comprehensive literature search was performed in PubMed with the following keywords: 'phosphatidylcholine', 'inflammatory bowel disease', 'Crohn's disease', 'inflammation', 'ulcerative colitis', 'therapy', 'nanomedicines', 'PKCζ', 'lysophosphatidylcholine', 'microbiota' and 'drug carrier'. The logical operators "AND" and "OR" were applied to combine different sets of the search results.

RESULTS

Studies suggested that PC displays a significant effect in the treatment of IBD by modulating gut barrier function, remodeling gut microbiota structure, regulating polarization of macrophages, and reducing the inflammatory response. PC has also been exploited as a drug carrier for anticancer or anti-inflammation agents in multiple forms, which implies that PC has immense potential for IBD therapy.

CONCLUSION

PC has shown promising potential as a new therapeutic agent or a drug carrier, with a novel, stable, prolonged mechanism of action in treating IBD. However, more high-quality basic and clinical studies are needed to confirm this.

Loureirin C ameliorates ischemia and reperfusion injury in rats by inhibiting the activation of the TLR4/NF-κB pathway and promoting TLR4 degradation

Ischemic stroke is a leading cause of death and disability worldwide. Post-ischemia, microglia respond immediately to the alternations in neuronal activity and mediate inflammation. Toll-like receptor 4 (TLR4) plays a key role in this phenomenon. To explore the effect of loureirin C, an effective compound from Chinese Dragon's blood, on ischemic stroke, Sprague-Dawley rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) with/without intragastric administration of loureirin C (7, 14, and 28 mg/kg). Loureirin C alleviated MCAO/R-induced brain impairment evaluated by neurological scores (p < 0.001), brain water content (p < 0.001), and cerebral infarct volume (p = 0.001). The neuroprotective (p < 0.001) and inhibitory effects on microglial activation (p < 0.001) of loureirin C were revealed by immunofluorescence. Rescue studies with TLR4 overexpression in BV-2 microglia showed that the antiinflammatory effect of loureirin C was attributable to the inhibition of TLR4 protein expression. Moreover, co-immunoprecipitation assays showed that the binding of Triad3A, an E3 ubiquitin ligase of TLR4, was increased by loureirin C (p = 0.003). Our study demonstrates that loureirin C could be a promising therapeutic agent for the management of ischemic stroke by inhibiting microglial activation, potentially by Triad3A-mediated promotion of TLR4 ubiquitination and degradation.

Black ginseng protects against Western diet-induced nonalcoholic steatohepatitis by modulating the TLR4/NF-κB signaling pathway in mice

Black ginseng (BG) shows beneficial effects on liver injury, but the related mechanism has not been fully revealed. This study attempted to investigate the protective effects and associated mechanisms of BG against nonalcoholic steatohepatitis (NASH). Twelve ginsenosides in BG were annotated by ultrahigh performance liquid chromatography combined with high resolution mass spectrometry (UHPLC-HRMS). The Western diet (WD) together with the low-dose CCl₄ was given to mice to create the NASH model. Histopathological examination and liver/serum biochemical analysis revealed that the NASH mice displayed severe steatosis and liver damage compared with control mice. After BG administration, the serum and liver triglycerides (TG) concentrations and the serum level of low-density lipoprotein (LDL) were dramatically reduced. Besides, the BG treatment greatly decreased the serum values of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α), and the hepatic expression of fibrotic-related genes, such as alpha-smooth muscle actin (α-SMA) and collagen type I alpha 1 (Col1α1). We further discovered that BG administration could block the protein expression of toll-like receptor 4 (TLR4) and the phosphorylation of nuclear factor-kappa B p65 (NF-κB p65), indicating that BG exerted a liver protective effect via regulating the TLR4/NF-κB pathway. This study demonstrated the therapeutic efficacy and the associated mechanism of BG in the treatment of NASH, giving evidence for BG as a potential functional food to prevent NASH. PRACTICAL APPLICATIONS: BG is a type of processed ginseng product that has been used as diet supplementation and has shown favorable effects on liver injury. However, the pharmacological impact of BG on NASH has not been studied in depth. The present study showed that BG could effectively reduce WD-induced liver fibrosis and inflammation through the TLR4/NF-κB axis, which indicated that BG has the potential to be utilized as a functional herb to attenuate liver injury.

Pharmacological Activity, Pharmacokinetics, and Clinical Research Progress of Puerarin

As a kind of medicine and food homologous plant, kudzu root (Pueraria lobata (Willd.) Ohwi) is called an "official medicine" in Chinese folk medicine. Puerarin is the main active component extracted from kudzu root, and its structural formula is 8-β-D-grapes pyranose-4, 7-dihydroxy isoflavone, with a white needle crystal; it is slightly soluble in water, and its aqueous solution is colorless or light yellow. Puerarin is a natural antioxidant with high health value and has a series of biological activities such as antioxidation, anti-inflammation, anti-tumor effects, immunity improvement, and cardio-cerebrovascular and nerve cell protection. In particular, for the past few years, it has also been extensively used in clinical study. This review focuses on the antioxidant activity of puerarin, the therapy of diverse types of inflammatory diseases, various new drug delivery systems of puerarin, the "structure-activity relationship" of puerarin and its derivatives, and pharmacokinetic and clinical studies, which can provide a new perspective for the puerarin-related drug research and development, clinical application, and further development and utilization.

Comparative effects of five polymethoxyflavones purified from Citrus tangerina on inflammation and cancer

Although the Citrus tangerina cultivar “Dahongpao” (CTD) has been established as a rich source of polymethoxyflavones (PMFs) with anti-inflammatory and anti-cancer properties, their individual effects on cellular signaling remain to be elucidated. In this study, five major PMFs from the peel of CTD were isolated, including sinensetin, tetramethyl-O-scutellarin (5,6,7,4′-tetramethoxyflavone), nobiletin (5,6,7,8,3′, 4′-hexamethoxyflavone), tangeretin (5,6,7,8,4′-pentamethoxyflavone), and 5-demethylnobiletin (5-OH-6,7,8,3′,4′-pentamethoxyflavone). These PMFs were found to significantly (p < 0.05) inhibit the production of NO and biomarkers of chronic inflammation (TNF-α and IL-6). Additionally, they effectively suppressed mRNA biomarkers of acute inflammation (Cox-2 and iNOS), and to varying degrees promoted the activation of anti-inflammatory cytokines (IL-4, IL-13, TNF-β, and IL-10). Among the five PMFs, tangeretin was found to have a considerable anti-proliferative effect on tumor cell lines (PC-3 and DU145) and synergistically enhanced the cytotoxicity of mitoxantrone, partially via activation of the PTEN/AKT pathway. The findings of this study provide valuable insights into the activity of different PMF monomers and advance the understanding of the roles of PMFs in promoting apoptotic and anti-cancer effects.

Interactions between gut microbiota and berberine, a necessary procedure to understand the mechanisms of berberine

Berberine (BBR), an isoquinoline alkaloid, has been found in many plants, such as Coptis chinensis Franch and Phellodendron chinense Schneid. Although BBR has a wide spectrum of pharmacological effects, its oral bioavailability is extremely low. In recent years, gut microbiota has emerged as a cynosure to understand the mechanisms of action of herbal compounds. Numerous studies have demonstrated that due to its low bioavailability, BBR can interact with the gut microbiota, thereby exhibiting altered pharmacological effects. However, no systematic and comprehensive review has summarized these interactions and their corresponding influences on pharmacological effects. Here, we describe the direct interactive relationships between BBR and gut microbiota, including regulation of gut microbiota composition and metabolism by BBR and metabolization of BBR by gut microbiota. In addition, the complex interactions between gut microbiota and BBR as well as the side effects and personalized use of BBR are discussed. Furthermore, we provide our viewpoint on future research directions regarding BBR and gut microbiota. This review not only helps to explain the mechanisms underlying BBR activity but also provides support for the rational use of BBR in clinical practice.

Cancer-Associated Microbiota: From Mechanisms of Disease Causation to Microbiota-Centric Anti-Cancer Approaches

Helicobacter pylori infection is the only well-established bacterial cause of cancer. However, due to the integral role of tissue-resident commensals in maintaining tissue-specific immunometabolic homeostasis, accumulated evidence suggests that an imbalance of tissue-resident microbiota that are otherwise considered as commensals, can also promote various types of cancers. Therefore, the present review discusses compelling evidence linking tissue-resident microbiota (especially gut bacteria) with cancer initiation and progression. Experimental evidence supporting the cancer-causing role of gut commensal through the modulation of host-specific processes (e.g., bile acid metabolism, hormonal effects) or by direct DNA damage and toxicity has been discussed. The opportunistic role of commensal through pathoadaptive mutation and overcoming colonization resistance is discussed, and how chronic inflammation triggered by microbiota could be an intermediate in cancer-causing infections has been discussed. Finally, we discuss microbiota-centric strategies, including fecal microbiota transplantation, proven to be beneficial in preventing and treating cancers. Collectively, this review provides a comprehensive understanding of the role of tissue-resident microbiota, their cancer-promoting potentials, and how beneficial bacteria can be used against cancers.

Nimbolide attenuates gut dysbiosis and prevents bacterial translocation by improving intestinal barrier integrity and ameliorating inflammation in hepatocellular carcinoma

Gut microbiota imbalance plays a key pathological role in hepatocellular carcinoma (HCC) progression; however, the mechanism is poorly understood. We previously showed nimbolide impede tumor development by improving hepatic tight junction (TJ) proteins expression and attenuating inflammation in HCC mice. Here, we aimed to study the role of nimbolide in regulating gut microbiota imbalance and bacterial translocation (BT) through modulating intestinal TJ proteins in an experimental hepatocarcinogenesis. Nimbolide (6 mg/kg) was administered orally for 4 weeks following induction of HCC in mice at the 28th week. Nimbolide treatment attenuated the gut microbiota imbalance by decreasing 16 s rRNA levels of Escherichia coli, Enterococcus, Bacteroides and increasing Bifidobacterium, and Lactobacillus in the intestinal tissue, which was otherwise altered in HCC mice. Furthermore, nimbolide improved intestinal barrier integrity in HCC mice by upregulating TJ proteins such as occludin and ZO-1 expression and subsequently prevented hepatic BT and decreased BT markers such as LBP, sCD14, and procalcitonin in the plasma of HCC mice. Moreover, nimbolide ameliorated intestinal and hepatic inflammation by downregulating TLR4, MyD88, and NF-κB protein expression in HCC mice. Thus, nimbolide represents a novel therapeutic drug for HCC treatment by targeting the gut-liver axis, which plays an imperative role in HCC pathogenesis.

Allicin Improves Intestinal Epithelial Barrier Function and Prevents LPS-Induced Barrier Damages of Intestinal Epithelial Cell Monolayers

Gut barrier disruption is the initial pathogenesis of various diseases. We previously reported that dietary allicin improves tight junction proteins in the endoplasmic reticulum stressed jejunum. However, whether the allicin benefits the gut barrier within mycotoxin or endotoxin exposure is unknown. In the present study, IPEC-J2 cell monolayers within or without deoxynivalenol (DON) or lipopolysaccharide (LPS) challenges were employed to investigate the effects of allicin on intestinal barrier function and explore the potential mechanisms. Results clarified that allicin at 2 μg/mL increased the viability, whereas the allicin higher than 10 μg/mL lowered the viability of IPEC-J2 cells via inhibiting cell proliferation. Besides, allicin increased trans-epithelial electric resistance (TEER), decreased paracellular permeability, and enhanced ZO-1 integrity of the IPEC-J2 cell monolayers. Finally, allicin supplementation prevented the LPS-induced barrier damages via activating Nrf2/HO-1 pathway-dependent antioxidant system. In conclusion, the present study strongly confirmed allicin as an effective nutrient to improve intestinal barrier function and prevent bacterial endotoxin-induced barrier damages.

The NF-κB-regulated miR-221/222/syndecan-1 axis restores intestinal mucosal barrier function in radiation enteritis

PURPOSE

Radiation enteritis (RE) is the most common complication of pelvic radiotherapy, but proven therapies are lacking. Barrier function defects are closely associated with numerous inflammatory disorders. In this study, we investigated whether barrier dysfunction contributes to RE and whether syndecan-1 (Sdc1) protects intestinal barrier function in RE. The mechanism was also elucidated.

MATERIALS AND METHODS

Blood, urine, and tissue samples were collected from 21 patients with cervical cancer who experienced RE during radiotherapy and used to detect inflammatory responses and barrier function. The role of Sdc1 in barrier function was examined in cultured fetal human colon (FHC) cells exposed to radiation and an induced mouse RE model. Barrier function was determined by zonula occludens (ZO)-1 and occludin expression, transepithelial electrical resistance (TEER), and FITC-dextran (FD4) flux. The role of the nuclear factor (NF)-κB-P65 pathway was detected by Western blotting and chromatin immunoprecipitation. The role of miR-221/222 was assessed by real-time PCR and luciferase reporter assays.

RESULTS

Patients with RE exhibited obvious pathological and ultra-microstructural inflammatory injury and barrier disruption in the intestinal mucosa, as well as higher serum lipopolysaccharide (LPS), LPS-binding protein, and cytokine levels and a higher urine lactulose/mannitol ratio. Sdc1 overexpression in irradiated FHC cells reversed TEER suppression, repressed FD4 flux, and upregulated ZO-1 and occludin expression. Exogenous low-molecular-weight heparin supplementation in RE mice ameliorated the activity of enteritis and barrier defects. Mechanistically, irradiation-activated P65 increased the transcription of miR-221/222 via direct binding to their promoter regions, and miR-221/222 then post-transcriptionally suppressed the Sdc1 gene by binding to its 3'-untranslated region.

CONCLUSIONS

Sdc1 protects barrier function and controls inflammation during RE under transcriptional regulation by the NF-κB pathway and miR-221/222. The network including NF-κB, miR-221/222, and Sdc1 is important in the pathogenesis of RE. Sdc1 might represent a therapeutic target for novel anti-RE strategies.

Dietary Flavone Baicalein Combinate with Genipin Attenuates Inflammation Stimulated by Lipopolysaccharide in RAW264.7 Cells or Pseudomonas aeruginosa in Mice via Regulating the Expression and Phosphorylation of AKT

Mounting evidence has shown that single-targeted therapy might be inadequate to achieve satisfactory effects. Thus, drug combinations are gaining attention as they can regulate multiple targets to obtain more beneficial effects. Heat shock protein 90 (HSP90) is a molecular chaperone that assists the protein assembly and folding of client proteins and maintains their stability. Interfering with the interaction between HSP90 and its client proteins by inhibiting the latter’s activity may offer a new approach toward combination therapy. The HSP90 client protein AKT plays an important role in the inflammatory response syndrome caused by infections. In this study, the dietary flavone baicalein was identified as a novel inhibitor of HSP90 that targeted the N-terminal ATP binding pocket of HSP90 and hindered the chaperone cycle, resulting in AKT degradation. Combining baicalein with genipin, which was extracted from Gardenia jasminoides, could inhibit the pleckstrin homology domain of AKT, significantly increasing the anti-inflammatory effects both in vitro and in vivo. This synergistic effect was attributed to the reduction in AKT expression and phosphorylation. Thus, elucidating the mechanism underlying this effect will provide a new avenue for the clinical application and development of synergistic anti-inflammatory drugs.

Modulatory role of the endocannabinoidome in the pathophysiology of the gastrointestinal tract

Originating from Eastern Asia, the plant Cannabis sativa has been used for centuries as a medicinal treatment. The unwanted psychotropic effects of one of its major components, Δ⁹-tetrahydrocannabinol, discouraged its therapeutic employment until, recently, the discovery of cannabinoids receptors and their endogenous ligands endocannabinoids reignited the interest. The endocannabinoid system has lately been found to play an important role in the maintenance of human health, both centrally and peripherally. However, the initial idea of the endocannabinoid system structure has been quickly understood to be too simplistic and, as new receptors, mediators, and enzymes have been discovered to participate in a complex relationship, the new, more comprehensive term "expanded endocannabinoid system" or "endocannabinoidome", has taken over. The discovery of other endocannabinoid-like receptors, such as the G protein-coupled receptor 119 and G protein-coupled receptor 55, has opened the way to the development of potential therapeutic targets for the treatment of various metabolic disorders. In addition, recent findings have also provided evidence suggesting the potential therapeutic link between the endocannabinoidome and various inflammatory-based gut diseases, such as inflammatory bowel disease and cancer. This review will provide an introduction to the endocannabinoidome, focusing on its modulatory role in the gastrointestinal tract and on the interest generated by the link between gut microbiota, the endocannabinoid system and metabolic diseases such as inflammatory bowel disease, type-2 diabetes and obesity. In addition, we will look at the potential novel aspects and benefits of drugs targeting the endocannabinoid system.

Antiinflammatory phytochemicals against virus-induced hyperinflammatory responses: Scope, rationale, application, and limitations

Uncontrolled inflammatory responses or cytokine storm associated with viral infections results in deleterious consequences such as vascular leakage, severe hemorrhage, shock, immune paralysis, multi-organ failure, and even death. With the emerging new viral infections and lack of effective prophylactic vaccines, evidence-based complementary strategies that limit viral infection-mediated hyperinflammatory responses could be a promising approach to limit host tissue injury. The present review emphasizes the potentials of antiinflammatory phytochemicals in limiting hyperinflammatory injury caused by viral infections. The predominant phytochemicals along with their mechanism in limiting hyperimmune and pro-inflammatory responses under viral infection have been reviewed comprehensively. How certain phytochemicals can be effective in limiting hyper-inflammatory response indirectly by favorably modulating gut microbiota and maintaining a functional intestinal barrier has also been presented. Finally, we have discussed improved systemic bioavailability of phytochemicals, efficient delivery strategies, and safety measures for effective antiinflammatory phytotherapies, in addition to emphasizing the requirement of tightly controlled clinical studies to establish the antiinflammatory efficacy of the phytochemicals. Collectively, the review provides a scooping overview on the potentials of bioactive phytochemicals to mitigate pro-inflammatory injury associated with viral infections.

The intestinal 3M (microbiota, metabolism, metabolome) zeitgeist - from fundamentals to future challenges

The role of the intestine in human health and disease has historically been neglected and was mostly attributed to digestive and absorptive functions. In the past two decades, however, discoveries related to human nutrition and intestinal host-microbe reciprocal interaction have established the essential role of intestinal health in the pathogenesis of chronic diseases and the overall wellbeing. That transfer of gut microbiota could be a means of disease phenotype transfer has revolutionized our understanding of chronic disease pathogenesis. This narrative review highlights the major concepts related to intestinal microbiota, metabolism, and metabolome (3M) that have facilitated our fundamental understanding of the association between the intestine, and human health and disease. In line with increased interest of microbiota-dependent modulation of human health by dietary phytochemicals, we have also discussed the emerging concepts beyond the phytochemical bioactivities which emphasizes the integral role of microbial metabolites of parent phytochemicals at extraintestinal tissues. Finally, this review concludes with challenges and future prospects in defining the 3M interactions and has emphasized the fact that, it takes 'guts' to stay healthy.

Dehydroepiandrosterone alleviates intestinal inflammatory damage via GPR30-mediated Nrf2 activation and NLRP3 inflammasome inhibition in colitis mice

Dehydroepiandrosterone (DHEA) is a popular dietary supplement that has anti-inflammatory, anti-oxidant and immune-regulating role; meanwhile, it also can effective in the protection of inflammation diseases such as inflammatory bowel disease (IBD), but the underlying mechanisms remain elusive. Here, we demonstrated that DHEA inhibits excessive inflammation response and enhances gut barrier function via activating the G protein-coupled receptor 30 (GPR30). GPR30-induced the ERK phosphorylation and p62 accumulation led to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which subsequently inhibited the reactive oxygen species (ROS) overproduction and finally alleviated the intestinal barrier dysfunction. Furthermore, DHEA blocked the p38-induced NLRP3 inflammasome activation in both LPS-stimulated colon epithelial cells and macrophages. In addition, in vivo results showed that DHEA and GPR30 agonist G1 attenuated inflammatory responses and gut barrier dysfunction in colitis mice, while the GPR30 specific inhibitor G15 abrogated these beneficial effects of DHEA. Cumulatively, our study unveiled that DHEA is an effective anti-inflammatory agent and suggested that GPR30 could as a potential target for the treatment of IBD.

Dioscin prevents DSS-induced colitis in mice with enhancing intestinal barrier function and reducing colon inflammation

Dioscin is a natural steroid saponin derived from plants of the genus Dioscoreaceae. Previous studies have proved its effects of antibacterial, anti-inflammatory and hypolipidemic. In this study, our aim was to explore the protective effect and preliminary mechanism of Dioscin on dextran sulfate sodium (DSS)-induced colitis in mice. The results showed that Dioscin reduced DSS-induced disease activity index (DAI) increase, colon length shortening and colon pathological damage. In addition, Dioscin reduced excessive inflammation by reversing the cytokines levels, reducing intestinal macrophage infiltration and promoting macrophage polarization to M2 phenotype. At the same time, Dioscin maintained the intestinal barrier function by increasing the expression of zonula occludens-1 (ZO-1), occludin and mucin (Muc)-2. Moreover, Dioscin inhibited NF-κB, MAPK signaling and nucleotide oligomerization domain-like receptor family pyrin domain ontaining 3(NLRP3) inflammasome pathway in DSS-induced colitis. These results suggest that Dioscin is a competent candidate for ulcerative colitis (UC) therapy in the future.

Microbe-Driven Genotoxicity in Gastrointestinal Carcinogenesis

The intestinal epithelium serves as a barrier to discriminate the outside from the inside and is in constant exchange with the luminal contents, including nutrients and the microbiota. Pathogens have evolved mechanisms to overcome the multiple ways of defense in the mucosa, while several members of the microbiota can exhibit pathogenic features once the healthy barrier integrity of the epithelium is disrupted. This not only leads to symptoms accompanying the acute infection but may also contribute to long-term injuries such as genomic instability, which is linked to mutations and cancer. While for Helicobacter pylori a link between infection and cancer is well established, many other bacteria and their virulence factors have only recently been linked to gastrointestinal malignancies through epidemiological as well as mechanistic studies. This review will focus on those pathogens and members of the microbiota that have been linked to genotoxicity in the context of gastric or colorectal cancer. We will address the mechanisms by which such bacteria establish contact with the gastrointestinal epithelium-either via an existing breach in the barrier or via their own virulence factors as well as the mechanisms by which they interfere with host genomic integrity.