Natural compounds as safe therapeutic options for ulcerative colitis

Autophagy: A potential target for natural products in the treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease primarily affecting the mucosa of the colon and rectum. UC is characterized by recurrent episodes, often necessitating lifelong medication use, imposing a significant burden on patients. Current conventional and advanced treatments for UC have the disadvantages of insufficient efficiency, susceptibility to drug resistance, and notable adverse effects. Therefore, developing effective and safe drugs has become an urgent need. Autophagy is an intracellular degradation process that plays an important role in intestinal homeostasis. Emerging evidence suggests that aberrant autophagy is involved in the development of UC, and modulating autophagy can effectively alleviate experimental colitis. A growing number of studies have established that autophagy can interplay with endoplasmic reticulum stress, gut microbiota, apoptosis, and the NLRP3 inflammasome, all of which contribute to the pathogenesis of UC. In addition, a variety of intestinal epithelial cells, including absorptive cells, goblet cells, and Paneth cells, as well as other cell types like neutrophils, antigen-presenting cells, and stem cells in the gut, mediate the development of UC through autophagy. To date, many studies have found that natural products hold the potential to exert therapeutic effects on UC by regulating autophagy. This review focuses on the possible effects and pharmacological mechanisms of natural products to alleviate UC with autophagy as a potential target in recent years, aiming to provide a basis for new drug development.

Colon-Targeted Oral Delivery of Hydroxyethyl Starch-Curcumin Microcapsules Loaded with Multiple Drugs Alleviates DSS-Induced Ulcerative Colitis in Mice

Combination therapy through colon-targeted oral delivery of multiple drugs presents a promising approach for effectively treating ulcerative colitis (UC). However, the codelivery of drugs with diverse physicochemical properties in a single formulation remains a formidable challenge. Here, microcapsules are designed based on hydroxyethyl starch-curcumin (HES─CUR) conjugates to enable the simultaneous delivery of hydrophobic dexamethasone acetate (DA) and hydrophilic cefazolin sodium (CS), yielding multiple drug-loaded microcapsules (CS/DA-loaded HES─CUR microcapsules, CDHC-MCs) tailored for colon-targeted therapy of UC. Thorough characterization confirms the successful synthesis and exceptional biocompatibility of CDHC-MCs. Biodistribution studies demonstrate that the microcapsules exhibit an impressive inflammatory targeting effect, accumulating preferentially in inflamed colons. In vivo experiments employing a dextran-sulfate-sodium-induced UC mouse model reveal that CDHC-MCs not only arrest UC progression but also facilitate the restoration of colon length and alleviate inflammation-related splenomegaly. These findings highlight the potential of colon-targeted delivery of multiple drugs within a single formulation as a promising strategy to enhance UC treatment, and the CDHC-MCs developed in this study hold great potential in developing novel oral formulations for advanced UC therapy.

Diosmin alleviates ulcerative colitis in mice by increasing Akkermansia muciniphila abundance, improving intestinal barrier function, and modulating the NF-κB and Nrf2 pathways

Ulcerative colitis is a common type of inflammatory bowel disease that affects millions of individuals around the world. Traditional UC treatment has focused on suppressing immune responses rather than treating the underlying causes of UC, which include oxidative stress, inflammation, and microbiota dysbiosis. Diosmin (DIO), a naturally occurring flavonoid, possesses antioxidant and anti-inflammatory properties. This study aimed to assess the efficacy of DIO in treating dextran-sulfate sodium (DSS)-induced colitis, and to investigate some of its underlying mechanisms, with an emphasis on Akkermansia muciniphila abundance, inflammatory markers, and intestinal barrier function. C57BL/6 mice were given 4% (w/v) DSS to induce colitis. DSS-induced mice were administered DIO (100 and 200 mg/kg) or sulfasalazine orally for 7 days. Every day, the disease activity index (DAI) was determined by recording body weight, diarrhea, and bloody stool. Changes in fecal A. muciniphila abundance, colonic MUC1 and MUC2 expression, as well as oxidative stress and inflammatory markers were all assessed. Histopathological changes, colonic PIK3PR3 and ZO-1 levels, and immunohistochemical examinations of occludin and claudin-1, were investigated. DIO administration resulted in a dose-dependent decrease in DAI, as well as increase in A. muciniphila abundance and MUC2 expression while decreasing MUC1 expression. DIO also dramatically reduced colonic oxidative stress and inflammation by regulating the NF-κB and Nrf2 cascades, restored intestinal barrier integrity by inhibiting PIK3R3 and inducing ZO-1, and improved occludin/claudin-1 gene expression and immunostaining. This study provides the first evidence that DIO preserves intestinal barrier integrity and increases A. muciniphila abundance in DSS-induced colitis. However, more research is required to explore the impact of DIO on the overall composition and diversity of the gut microbiota. Likewise, it will be important to fully understand the molecular mechanisms by which A. muciniphila maintains intestinal barrier function and its potential use as an adjuvant in the treatment of UC.

Investigating the role of thymol as a promising inhibitor of pyruvate dehydrogenase kinase 3 for targeted cancer therapy

Protein kinases have emerged as major contributors to various diseases. They are currently exploited as a potential target in drug discovery because they play crucial roles in cell signaling, growth, and regulation. Their dysregulation is associated with inflammatory disorders, cancer, and neurodegenerative diseases. Pyruvate dehydrogenase kinase 3 (PDK3) has become an attractive drug target in cancer therapeutics. In the present study, we investigated the effective role of thymol in PDK3 inhibition due to the high affinity predicted through molecular docking studies. Hence, to better understand this inhibition mechanism, we carried out a 100 ns molecular dynamics (MD) simulation to analyse the dynamics and stability of the PDK3-thymol complex. The PDK3-thymol complex was stable and energetically favourable, with many intramolecular hydrogen bond interactions in the PDK3-thymol complex. Enzyme inhibition assay showed significant inhibition of PDK3 by thymol, revealing potential inhibitory action of thymol towards PDK3 (IC50 = 2.66 μM). In summary, we established thymol as one of the potential inhibitors of PDK3, proposing promising therapeutic implications for severe diseases associated with PDK3 dysregulation. This study further advances our understanding of thymol's therapeutic capabilities and potential role in cancer treatment.

Sesame cake extract attenuates dextran sulfate sodium-induced colitis through inhibition of oxidative stress in mice

Inflammatory bowel disease (IBD) is a chronic inflammatory disease occurring in the gut causing chronic diarrhea and abdominal pain with severe complications. Sesame cake is a by-product of sesame oil production, possessing various beneficial properties; however, little is known about the effect of sesame cake extract (SCE) against IBD. The aim of this study was to investigate the protective effect of SCE against dextran sulfate sodium (DSS)-induced colitis in mice. Administration of SCE was first performed at 7 days before treating mice with 2.5% DSS to induce colitis for 7 days. SCE pretreatment improved symptoms of DSS-induced colitis. In addition, SCE ameliorated histopathological damages of the mucus layer in colon tissues and decreased pro-inflammatory cytokines in colitis-induced mice. SCE also suppressed apoptosis and oxidative stress in colitis-induced colon tissues. Together, these findings suggest that SCE could be potential nutraceuticals for treating colitis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01367-1.

Recent Updates on the Therapeutics Benefits, Clinical Trials, and Novel Delivery Systems of Chlorogenic Acid for the Management of Diseases with a Special Emphasis on Ulcerative Colitis

Ulcerative colitis (UC) is a multifactorial disorder of the large intestine, especially the colon, and has become a challenge globally. Allopathic medicines are primarily available for the treatment and prevention of UC. However, their uses are limited due to several side effects. Hence, an alternative therapy is of utmost importance in this regard. Herbal medicines are considered safe and effective for managing human health problems. Chlorogenic acid (CGA), the herbal-derived bioactive, has been reported for pharmacological effects like antiinflammatory, immunomodulatory, antimicrobial, hepatoprotective, antioxidant, anticancer, etc. This review aims to understand the antiinflammatory and chemopreventive potential of CGA against UC. Apart from its excellent therapeutic potential, it has been associated with low absorption and poor oral bioavailability. In this context, colon-specific novel drug delivery systems (NDDS)are pioneering to overcome these problems. The pertinent literature was compiled from a thorough search on various databases such as ScienceDirect, PubMed, Google Scholar, etc., utilizing numerous keywords, including ulcerative colitis, herbal drugs, CGA, pharmacological activities, mechanism of actions, nanoformulations, clinical updates, and many others. Relevant publications accessed till now were chosen, whereas non-relevant papers, unpublished data, and non-original articles were excluded. The present review comprises recent studies on pharmacological activities and novel drug delivery systems of CGA for managing UC. In addition, the clinical trials of CGA against UC have been discussed.

Casuarina glauca branchlets' extract as a potential treatment for ulcerative colitis: chemical composition, in silico and in vivo studies

Ulcerative colitis (UC) is an inflammatory bowel disease that is often resistant to current treatment options, leading to a need for alternative therapies. Herbal products have shown promise in managing various conditions, including UC. However, the potential of Casuarina glauca branchlets ethanolic extract (CGBRE) in treating UC has not been explored. This study aimed to analyze the chemical composition of CGBRE and evaluate its efficacy in UC treatment through in silico and in vivo experiments. LC-ESI-MS/MS was used to identify 86 compounds in CGBRE, with 21 potential bioactive compounds determined through pharmacokinetic analysis. Network pharmacology analysis revealed 171 potential UC targets for the bioactive compounds, including EGFR, LRRK2, and HSP90 as top targets, which were found to bind to key CGBRE compounds through molecular docking. Molecular docking findings suggested that CGBRE may be effective in the prevention or treatment of ulcerative colitis mediated by these proteins, where key CGBRE compounds exhibited good binding affinities through formation of numerous interactions. In vivo studies in rats with acetic acid-induced UC demonstrated that oral administration of 300 mg/kg CGBRE for 6 days reduced UC symptoms and colonic expression of EGFR, LRRK2, and HSP90. These findings supported the therapeutic potential of CGBRE in UC and suggested the need for further preclinical and clinical investigation.

Anti-inflammatory natural products modulate interleukins and their related signaling markers in inflammatory bowel disease: A systematic review

This review aims to identify in vivo studies investigating the potential of plant substances and their natural molecules in managing inflammatory bowel disease (IBD). Specifically, the objective is to examine the impact of these substances on interleukins and other key inflammatory signaling markers. Relevant articles published up to December 2022 were identified through a search of the PubMed, Scopus, Web of Science, and Embase databases. The search used keywords including "inflammatory bowel disease", "medicinal plants", "natural molecules", "anti-inflammatory", and "ulcerative colitis", and identified 1,878 potentially relevant articles, of which 89 were included in this review after completion of the selection process. This study provides preclinical data on natural products (NPs) that can potentially treat IBD, including ulcerative colitis. The main actions of these NPs relate to their effects on nuclear factor kappa B (NF-κB), the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway, the regulation of T helper 17/regulatory T cells balance, and oxidative stress. The ability of these NPs to inhibit intestinal inflammation appears to be dependent on lowering levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-17, via the Jun N-terminal kinase (JNK)1, NF-κβ-p65, and STAT3 pathways. In addition, NPs were shown to reduce oxidative stress and the severity of ulcerative colitis, as well as increase the activity of antioxidant enzymes. These actions suggest that NPs represent a promising treatment for IBD, and potentially have greater efficacy and safety than current treatments.

An inulin-type fructan isolated from Serratula chinensis alleviated the dextran sulfate sodium-induced colitis in mice through regulation of intestinal barrier and gut microbiota

Herein, we aimed to explore the polysaccharide material basis of Serratula chinensis and establish its beneficial effects against colitis. A neutral polysaccharide (SCP) was extracted from S. chinensis in high yield using hot water. The molecular weights were calculated by HPSEC as Mw = 2928 Da, Mn = 2634 Da, and Mw/Mn = 1.11. FT-IR and 1D/2D-NMR spectroscopic analyses confirmed that SCP was an inulin-type fructan with α-D-Glcp-(1 → [1)-β-D-Fruf-(2]17) linkages. Treatment with SCP (200 or 400 mg/kg) alleviated dextran sulfate sodium (DSS)-induced mouse colitis symptoms, including the loss of body weight, increase of disease activity index score, and shortening of colon length. Histopathological and immunofluorescence assessments revealed that SCP could reduce pathological damage to the colon, restore the number of goblet cells, increase the content of glycoproteins in goblet cells and mucins in crypts, and enhance the expression of tight junction proteins ZO-1 and occludin. In addition, metagenomic sequencing revealed that SCP could improve the dysbiosis of gut microbiomes and act on multiple microbial functions. Moreover, SCP treatment increased the content of colonic acetic acid and butanoic acid. Collectively, these results indicated that SCP could alleviate the DSS-induced colitis in mice through regulation of intestinal barrier and gut microbiota.

Whey Protein Hydrolysate Exerts Anti-Inflammatory Effects to Alleviate Dextran Sodium Sulfate (DSS)-Induced Colitis via Microbiome Restoration

Whey protein hydrolysate (WPH) has been shown to have a variety of bioactivities. This study aimed to investigate the preventive effect of WPH on dextran sodium sulfate (DSS)-induced colitis in C57BL/6J mice. The results indicated that WPH intervention for 37 days was effective in delaying the development of colonic inflammation, and high doses of WPH significantly inhibited weight loss (9.16%, n = 8, p < 0.05), protected the colonic mucosal layer, and significantly reduced the levels of inflammatory factors TNF-α, IL-6, and IL-1β in mice with colitis (n = 8, p < 0.05). In addition, WPH intervention was able to up-regulate the short-chain fatty acids secretion and restore the gut microbiome imbalance in mice with colitis. Notably, high-dose WPH intervention increased the relative abundance of norank_f_Muribaculaceae by 1.52-fold and decreased the relative abundance of Romboutsia and Enterobacter by 3.77-fold and 2.45-fold, respectively, compared with the Model group. WPH intervention protected colitis mice mainly by reversing the microbiome imbalance and regulating the major histocompatibility complex (MHC) class I pathway. This study showed that WPH has anti-inflammatory activity and a promising colitis management future.

Therapeutic Benefits of Tuna Oil by In Vitro and In Vivo Studies Using a Rat Model of Acetic Acid-Induced Ulcerative Colitis

Ulcerative colitis (UC), an inflammation of the colon lining, represents the main form of inflammatory bowel disease IBD. Nutritional therapy is extremely important in the management of ulcerative colitis. Fish oil contains long-chain omega-3 polyunsaturated fatty acids, which have beneficial effects on health, including anti-inflammatory effects. This study aims to investigate the benefits of bluefin tuna oil extracted by the Soxhlet method in vitro by determining the anti-radical and anti-inflammatory activities and in vivo by evaluating the preventive and curative effects. The experiments were carried out using two doses of oil (100 and 260 mg/kg) and glutamine (400 and 1000 mg/kg) on the acetic acid-induced UC model. UC has been induced in Wistar rats by intrarectal administration of a single dose of 1 mL acetic acid (5% v/v in distilled water). The obtained results indicate that tuna oil and glutamine have a significant anti-free radical effect. Tuna oil has a marked anti-inflammatory power based on membrane stabilization and inhibiting protein denaturation. The reduction of various UC parameters, such as weight loss, disease activity score DAS, and colonic ulceration in rats pre-treated with tuna oil and glutamine, demonstrate that these treatments have a significant effect on UC. Total glutathione GSH, superoxide dismutase SOD, and catalase activities are significantly restored in the tuna oil and glutamine groups, while lipid peroxidation has been markedly reduced.

Quinic acid ameliorates ulcerative colitis in rats, through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways

OBJECTIVE

In this study, the therapeutic effect of quinic acid (QA), which has anti-inflammatory activity, was investigated on acetic acid-induced colitis in male Wistar rats.

METHODS

Ulcerative colitis (UC) was induced in rats by acetic acid intrarectally, and the protective effects of QA in 10, 30, 60, and 100 mg/kg doses were investigated. Rats were treated for 5 days and their colon tissues were dissected out at the end. Macroscopic and histopathological examinations were performed in colon tissues. Also, the expression of inflammatory and apoptotic genes, including TLR4, IL-1β, INOS, IL-6, TNF-α, NF-κB, Caspase-3, Caspase-8, Bax, and Bcl-2, was measured. Biochemistry indices, such as malondialdehyde (MDA) and nitrite oxide (NO) content, in addition to, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), and enzymes activities were also assessed.

RESULTS

Colitis increased the levels of MDA and NO, and enhanced the inflammatory and apoptotic gene expressions, while reducing the SOD and CAT enzymes activity, and TAC levels in the colitis rats. Also, results showed that colitis was associated with the infiltration of inflammatory cells, epithelium damage, and edema in colon tissue. QA significantly ameliorated histopathological indices, oxidative stress, inflammation, and apoptosis in colitis rats.

CONCLUSION

QA ameliorated UC through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways, which results in the reduction of colitis complications, including oxidative stress, inflammation, apoptosis and histopathological injuries in rats. Therefore it can be concluded, that QA exerts its therapeutic effects through antiapoptotic, antioxidant, and anti-inflammatory properties.

Insights into Q-markers and molecular mechanism of Sanguisorba saponins in treating ulcerative colitis based on lipid metabolism regulation

BACKGROUND

Sanguisorba saponin extract (SSE) is the main active part of Sanguisorba officinalis with various pharmacological activities such as anti-inflammatory, anti-bacterial and anti-oxidant. However, its therapeutic role and underlying mechanisms for ulcerative colitis (UC) still need to be elucidated.

PURPOSE

This study aims to explore the therapeutic effect, effectiveness-material basis-quality markers (Q-markers) and prospective mechanism of function of SSE on UC.

METHODS

Fresh 2.5% dextran sulfate sodium salt (DSS) solution was placed in drinking bottles for 7 days to induce a mouse model of UC. SSE and sulfasalazine (SASP) were supplemented to mice by gavage for consecutive 7 days to investigate the therapeutic role of SSE on UC. Mouse monocyte macrophages (RAW264.7) and human normal colonic epithelial (NCM460) cells were treated with LPS to induce inflammatory responses, followed by pharmacodynamic examination with different concentrations of SSE. Hematoxylin-eosin (HE) and Alcian blue staining were conducted to evaluate the pathological damage of mice colon. Lipidomic technology was conducted to explore the differential lipids closely related to the disease process of UC. Quantitative PCR analysis, immunohistochemistry and ELISA kit were used to measure the expression levels of the corresponding proteins and pro-inflammatory factors.

RESULTS

SSE treatment could effectively reduce the elevated expressions of pro-inflammatory factors in RAW264.7 and NCM460 cells due to LPS stimulation. Intragastric administration of SSE was found to significantly alleviate the symptoms of DSS-induced colon injury and low-polar saponins in SSE. Low polarity saponins, especially ZYS-II, were proved to be the main active substances of SSE in treating UC. In addition, SSE could significantly ameliorate the aberrant lipid metabolism in UC mice. The role of phosphatidylcholine (PC)34:1 in the UC pathogenesis has been fully verified in our previous studies. Herein, SSE-dosing effectively reversed the metabolic disorder of PCs in UC mice, and increased the PC34:1 level to normal via up-regulating the expression of phosphocholine cytidylyltransferase (PCYT1α).

CONCLUSION

Our data innovatively revealed that SSE could significantly alleviate the symptoms of UC by reversing the disorder of PC metabolism induced by DSS modeling. SSE was proved for the first time to be a promising and effective candidate for UC treatment.

Preventive effect of tilapia skin collagen hydrolysates on ulcerative colitis mice based on metabonomic and 16 S rRNA gene sequencing

BACKGROUND

Tilapia skin collagen hydrolysates (TSCHs) are the product of enzymatic hydrolysis of collagen, which is mainly extracted from tilapia skin. The components of TSCHs have recently been reported to play a preventive role in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). However, it has not been illustrated whether TSCHs can prevent against DSS-induced UC via the gut microbiota and its derived metabolites.

RESULTS

TSCHs are mainly composed of amino acids, which have similar characteristics to collagen, with most having a molecular weight below 5 kDa. In a mouse model of UC, TSCHs had no toxic effect at a dose of 60 g kg^-1 and could reduce body weight changes, colon length, histopathological changes and score, and the level of the serum inflammatory cytokine interleukin (IL)-6. Concurrently, 16 S rRNA sequencing showed that TSCHs significantly reduced the abundance of Bacteroidetes and Proteobacteria at the phylum level and norank_f__Muribaculaceae and Escherichia-Shigella at the genus level, while they increased the abundance of Firmicutes at the phylum level and Lachnoclostridium, Allobaculum, Enterorhabdus, and unclassified__f__Ruminococcaceae at the genus level. Target metabolomic analysis showed that TSCHs elevated the concentration of total acid, acetic acid, propanoic acid, and butanoic acid, but reduced isovaleric acid concentrations. Moreover, Pearson correlation analysis revealed that Allobaculum, unclassified_Ruminococcaceae, and Enterorhabdus were positively correlated with acetic acid and butyric acid, but not Escherichia-Shigella.

CONCLUSION

These findings suggest that TSCHs can prevent UC by modulating gut microbial and microbiota-derived metabolites. © 2023 Society of Chemical Industry.

Three acidic polysaccharides derived from sour jujube seeds protect intestinal epithelial barrier function in LPS induced Caco-2 cell inflammation model

Normal intestinal epithelial barrier function plays a key role in the prevention of many diseases such as infectious enteritis, inflammatory bowel disease, obesity, etc. In this study, three novel acidic polysaccharides ZY-2, ZY-3 and ZY-4 were isolated from sour jujube (Ziziphus jujuba Mill. var. Spinosa) seeds and purified by DEAE Sephrose Fast Flow gel. The molecular weight of ZY-2, ZY-3 and ZY-4 was 7.76 kDa, 10.71 kDa and 8.31 kDa respectively, mainly composed of different proportions of mannose, rhamnose, glucose, glucuronic acid, galacturonic acid, galactose, xylose and arabinose. ¹H NMR and Congo red experiment results showed that the three polysaccharides mainly contained both α-type and β-type glycosidic bonds with obvious triple helix structural traits. The polysaccharides could up-regulate the expression levels of occludin and ZO-1 in LPS-induced inflammation Caco-2 cells, and reduce IL-6, IL-8, IL-1β and TNF-α significantly. In conclusion, the acidic polysaccharides from sour jujube seeds exhibited great potential in protection intestinal epithelial barrier function through anti-inflammatory effects.

2'-Fucosyllactose and 3-Fucosyllactose Alleviates Interleukin-6-Induced Barrier Dysfunction and Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Modulating the Intestinal Microbiome

Ulcerative colitis is an inflammatory bowel disease (IBD) with relapsing and remitting patterns, and it is caused by varied factors, such as the intestinal inflammation extent and duration. We examined the preventative effects of human milk oligosaccharides (HMOs) on epithelial barrier integrity and intestinal inflammation in an interleukin (IL)-6-induced cell model and dextran sodium sulfate (DSS)-induced acute mouse colitis model. HMOs including 2'-fucosyllactose (FL) and 3-FL and positive controls including fructooligosaccharide (FOS) and 5-acetylsalicylic acid (5-ASA) were orally administrated once per day to C57BL/6J mice with colitis induced by 5% DSS in the administered drinking water. 2'-FL and 3-FL did not affect the cell viability in Caco-2 cells. Meanwhile, these agents reversed IL-6-reduced intestinal barrier function in Caco-2 cells. Furthermore, 2'-FL and 3-FL reversed the body weight loss and the remarkably short colon lengths in DSS-induced acute colitis mice. Moreover, 2'-FL and 3-FL obviously protected the decreasing expression of zonula occluden-1 and occludin in colon tissue relative to the findings in the DSS-treated control group. 2'-FL and 3-FL significantly reduced IL-6 and tumor necrosis factor-α levels in serum relative to the control findings. The summary of these results shows that HMOs prevent colitis mainly by enhancing intestinal barrier function and advancing anti-inflammatory responses. Therefore, HMOs might suppress inflammatory responses and represent candidate treatments for IBD that protect intestinal integrity.

Discovery, Preliminary Structure-Activity Relationship, and Evaluation of Oleanane-Type Saponins from Pulsatilla chinensis for the Treatment of Ulcerative Colitis

To discover ulcerative colitis (UC) treatment agents, 28 oleanane-type triterpenoid saponins (1-28) including three new saponins, pulsatillosides P-R (1-3), were isolated from Pulsatilla chinensis. The isolated saponins could observably ameliorate UC by improving the intestinal epithelial cell barrier and intestinal flora in vivo. The structure-activity relationship indicated that the oligosaccharide chain at C-28 was essential for their anti-UC activities; the methyl group at the C-23 site of triterpene saponins showed important effects on anti-UC efficacy; the chain length of oligosaccharides at position C-28 had little effect on their anti-UC activities. In vivo investigation of representative saponins 1 and 13 further confirmed that 23-methyl-3,28-bisdesmosidic oleanane-type saponins inhibited the TNFα-NFκB-MLCK axis to improve the intestinal epithelial cell barrier of the colon in UC mice. These findings revealed the potential of 23-methyl-3,28-bisdesmosidic oleanane-type saponins from P. chinensis as promising candidates for the treatment of UC.

Therapeutic Effects of Aloe saponaria against Ulcerative Colitis Induced by Dextran Sulfate Sodium

Aloe vera (A. vera) has been studied as a treatment option for ulcerative colitis (UC), but there is a lack of scientific evidence showing whether treatment with Aloe saponaria (A. saponaria) can also be beneficial. To investigate the therapeutic potential of A. saponaria as a treatment for UC, clinical symptoms, histopathological characteristics of the colon, inflammatory response, and toxicity were analyzed in dextran sulfate sodium (DSS)-induced UC mice after administration of aqueous extracts of A. saponaria (AAS) for 7 days. The total polyphenol and tannin content of AAS was 272 µg/g and 163 µg/g, respectively. AAS exhibited significant antioxidant activity. Several clinical symptoms, including body weight, colon length, and hematochezia, remarkably improved in the DSS+AAS treated group compared to the DSS+Vehicle-treated group. In addition, similar improvements were detected in the histopathological characteristics and mucin-secreting ability in the colon of DSS-induced UC mice after the administration of AAS. The levels of infiltrated inflammatory cells and cytokine expression were significantly decreased in a dose-dependent manner in the colon of the DSS+AAS-treated group. These alterations in inflammatory response were accompanied by a significant recovery of the protein kinase C/extracellular signal-regulated kinase (PKC/ERK) and phosphatidylinositol-3-kinase/serine-threonine protein kinase (PI3K/Akt) signaling pathways. However, the levels of key markers for hepatotoxicity and nephrotoxicity consistently remained between those of the DSS+AAS-treated and the No groups. Therefore, the results of the present study provide novel evidence that AAS may improve the clinical symptoms and attenuate the inflammatory response in DSS-induced UC mice and does not have any significant hepatotoxicity or nephrotoxicity.

Boswellic acid coated zinc nanoparticles attenuate NF-κB-mediated inflammation in DSS-induced ulcerative colitis in rats

INTRODUCTION

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease, and until now therapeutic agents for UC still cannot exert satisfied effects. Therefore, this study aimed to investigate the ameliorative effect of boswellic acid coated zinc nanoparticles (BAs-ZnNPs) on dextran sodium sulphate (DSS) induced-UC in rats.

METHODS

Rats were divided into five groups; control, BAs-ZnNPs, DSS, DSS+BAs, and DSS + BAs-ZnNPs. The activity of alkaline phosphatase (ALP) was determined colorimetrically, while the concentration of IgM, IgG, TNF-α, IL-1β, and IL-8 were measured by ELISA. Levels of gene expression of NF-κB and COX-2 genes were evaluated by RT-qPCR, while the expression of protein levels of PI3K and STAT-3 were done by western blotting. Finally, histopathological examination of colon tissues of different groups of rats was done.

RESULTS

The depicted ball-like structure of the BAs-ZnNPs in the TEM images ranging in size from 50 to 100 nm in diameter while their formation was confirmed by UV-visible spectroscopy with a sharp peak of maximum absorbance at 266 nm. Our results revealed that BAs-ZnNPs exerted an anti-inflammatory effect in the experimental model of colitis, demonstrated histologically and biochemically as shown by the improvement of ALP, IgM, IgG, and the gene expression levels of NF-κB and COX-2. Also, this beneficial effect was associated with the reduction in the expression of TNF-α, IL-1β, IL-8, PI3K, and STAT-3. Thus, this effect improves the altered immune response associated with the colonic inflammation.

CONCLUSION

BAs-ZnNPs can be proposed as a therapeutic candidate to attenuate UC. The potential underlying mechanism includes suppression of ALP, IgM, IgG, IL-1β, and IL-8 levels via regulation of NF-κB and COX-2 gene expression and STAT-3 and PI3K protein expression in a UC rat model.

Green tea EGCG effectively alleviates experimental colitis in middle-aged male mice by attenuating multiple aspects of oxi-inflammatory stress and cell cycle deregulation

Age-dependent increased risk of inflammatory bowel diseases such as ulcerative colitis is being increasingly realized, and yet therapies targeting this disorder within the purview of aging are limited. The present study attempted to assess the efficacy of green tea epigallocatechin gallate (EGCG) consumption in preventing the severity and progression of dextran sulphate sodium (DSS)-induced ulcerative colitis in 18 months old middle-aged male mice. Acute colitis was induced in animals using DSS and protective effects of EGCG consumption were examined. Different parameters related to disease progression and molecular markers related to oxi-inflammatory stress, localized and systemic cytokine response, epithelial barrier integrity, and cell cycle progression profile were evaluated. DSS treatment induced rapid and severe symptoms of colitis such as consistently increased DAI score, shortened and inflamed colon accompanied by increased levels of inflammatory proteins (TNFα/IL-6/IL-1β) in both the colon tissue and cultured splenocytes indicating exaggerated Th1 immune response. Markers of oxidative stress increased while antioxidant defences and the expression of tight junction genes in the colonic cells were attenuated. Dysregulation in the expression of cell cycle inhibitory genes (p53/p21^WAF1/p16^Ink4a) indicated possible induction of colitis-induced dysplasia. On the other hand, EGCG consumption strongly attenuated all the measured ostensible as well as molecular markers of the disease progression as evidenced by improved DAI score, cellular antioxidant capacity, attenuated Th1 cytokine response both in the colon and cultured splenocytes, enhanced expression of tight junction genes, and cell cycle inhibitors thereby suggesting systemic effects of EGCG. Together, these observations suggest that drinking EGCG-rich green tea can be a significant way of managing the severity of colitis during aging.

Protective effects of 4‐geranyloxy‐2,6‐dihydroxybenzophenonel on DSS ‐induced ulcerative colitis in mice via regulation of cAMP / PKA / CREB and NF‐κB signaling pathways

Hypericum sampsonii Hance has traditionally been used to treat enteritis and diarrhea. As one of the main benzophenones isolated from H. sampsonii, 4-geranyloxy-2,6-dihydroxybenzophenonel (4-GDB) has been shown to possess anti-inflammatory effects. However, the therapeutic effect and potential mechanisms of 4-GDB in ulcerative colitis (UC) remain unclear. This study aimed to evaluate the role of 4-GDB in UC using a dextran sulfate sodium-induced colitis mouse model. Intragastric administration of 4-GDB (20 mg/kg/day) for 8 days significantly attenuated colonic injury, reduced the expression of inflammatory mediators, and improved colonic barrier function in mice with colitis. Furthermore, in vivo and in vitro experiments indicated that 4-GDB could activate cAMP/PKA/CREB and inhibit the NF-κB pathway. Collectively, 4-GDB may be a potential agent for treating UC by regulating the cAMP/PKA/CREB and NF-κB pathways.

pH/ROS Dual-Sensitive Natural Polysaccharide Nanoparticles Enhance "One Stone Four Birds" Effect of Rhein on Ulcerative Colitis

Rhein (RH), a natural anthraquinone compound, is considered an effective treatment candidate for ulcerative colitis (UC), whose multiple biological activities contribute to UC, including anti-inflammation, antioxidation, intestinal barrier repair, and microflora regulation. However, the application of RH is severely limited by its low water solubility, low bioavailability, and poor colonic targeting. Although some nanoparticles have been developed for the oral delivery of RH, most of them mainly highlighted only one effect of some drug delivery strategies but the above multiple biological activities. Therefore, a multiple polysaccharide-based nanodelivery system, comprising chitosan (CS) and fucoidan (FU), with pH/reactive oxygen species (ROS) sensitivity and mucosal adhesion, was developed and first used to load RH as a comprehensive treatment for UC. Briefly, RH-F/C-NPs were prepared using the polyelectrolyte self-assembly method; the average size of RH-F/C-NPs was 233.1 ± 5.7 nm, and the encapsulation rate of RH was 93.67 ± 1.60%. And it could maintain gastric stability and release RH in the colon with the designed pH/ROS sensitivity contributed by the polysaccharide-based structures. Cellular uptake experiments showed that both NCM 460 cells and RAW 264.7 cells had a good uptake of RH-F/C-NPs. Importantly, the effects of RH were highlighted in in vivo experiments, the results of which showed that RH-F/C-NPs could significantly reduce DSS-induced inflammation by inhibiting the TLR4/NF-κB-mediated anti-inflammatory pathway, the Nrf2/HO-1-mediated antioxidant pathway, colonic mucosal barrier repair, and intestinal microflora regulation. In addition, pharmacokinetic studies have shown that F/C-NPs contribute to the increase in the plasma concentration and the accumulation of RH in the colon to some extent. In short, this study is the first to develop an oral multiple polysaccharide-based nanosystem with pH/ROS dual sensitivity to study the "one stone four birds" therapeutic effect of RH on UC.

Oral delivery of curcumin via multi-bioresponsive polyvinyl alcohol and guar gum based double-membrane microgels for ulcerative colitis therapy

Anti-inflammatory drugs for ulcerative colitis (UC) treatment should specifically penetrate and accumulate in the colon tissue. Herein, a multi-bioresponsive anti-inflammatory drug (curcumin, CUR)-loaded heterogeneous double-membrane microgels (CUR@microgels) for oral administration was fabricated in this study, in which the inner core was derived from polyvinyl alcohol (PVA) and guar gum (GG) and the outer gel was decoration with alginate and chitosan by polyelectrolyte interactions. The structure and morphology of microgels were characterized. In vitro, the formulation exhibited good bio-responses at different pH conditions and sustained-release properties in simulated colon fluid with a drug-release rate of 84.6 % over 34 h. With the assistance of the outlayer gels, the microgels effectively delayed the premature drug release of CUR in the upper gastrointestinal tract. In vivo studies revealed that CUR@microgels specifically accumulated in the colon tissue for 24 h, which suggest that the interlayer gels were apt to reach colon lesion. As expected, the oral administration of microgels remarkably alleviated the symptoms of UC and protected the colon tissue in DSS-induced UC mice. The above results indicated that these facilely fabricated microgels which exhibited excellent biocompatibility and multi-bioresponsive drug release, had an apparent effect on the treatment of UC, which represents a promising drug delivery strategy for CUR in a clinical application.