A new flavonoid derivative, dosmalfate, attenuates the development of dextran sulphate sodium-induced colitis in mice

Ameliorative Effect of Banana Lectin in TNBS-Induced Colitis in C57BL/6 Mice Relies on the Promotion of Antioxidative Mechanisms in the Colon

Background: The global burden of inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn's disease, is constantly rising. As IBDs significantly reduce patients' quality of life, prevention and efficient treatment of IBDs are of paramount importance. Although the molecular mechanisms underlying IBD pathogenesis are still not completely understood, numerous studies indicate the essential role of oxidative stress in the progression of the diseases. Objective: The aim of this study was to investigate whether prophylactic administration of recombinant banana lectin (rBanLec) could positively affect antioxidative mechanisms in the colon and thus prevent or alleviate the severity of experimental colitis induced in C57BL/6 mice. Methods: The prophylactic potential of rBanLec, a mannose-binding lectin with immunomodulatory properties, was investigated in a model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in C57BL/6 mice. Mice received rBanLec at various doses (0.1, 1 and 10 μg/mL) before the induction of colitis. The severity of the disease was assessed by weight loss and reduction in colon length, and correlated with histopathological findings, cytokine milieu, and oxidative stress markers in the colon. Results: The obtained results revealed that pretreatment with a low dose of rBanLec (0.1 μg/mL) significantly reduced the severity of TNBS-induced colitis, as indicated by reduced weight loss, less severe histopathological damage, and a favorable anti-inflammatory cytokine milieu (increased IL-10 and TGFβ). In addition, rBanLec pretreatment improved the activity of antioxidant enzymes (SOD, CAT, and GST) and reduced markers of oxidative stress such as nitric oxide levels at the peak of the disease. In contrast, higher doses of rBanLec exacerbated inflammatory responses. Conclusions: Our findings indicate that at low doses rBanLec can alleviate the severity of colitis by modulating oxidative stress and promoting anti-inflammatory cytokine responses, positioning rBanLec as a potential candidate for treating IBDs.

Clinical development and informatics analysis of natural and semi-synthetic flavonoid drugs: A critical review

BACKGROUND

Flavonoids are one of the most important metabolites with vast structural diversity and a plethora of potential pharmacological applications, which have drawn considerable attention in the laboratory. Nevertheless, it remains uncertain how many candidates were progressed to clinical application.

AIM OF REVIEW

We carried out a critical review of natural and semi-synthetic flavonoid drugs and candidates undergoing different clinical phases worldwide by applying an adequate search method and conducted a brief cheminformatic and bioinformatic analysis. It was expected that the obtained results might narrow the screening scope and reduce the cost of drug research and development.

KEY SCIENTIFIC CONCEPTS OF REVIEW

To our knowledge, this is the most systematic summarization of flavonoid-based drugs and clinical candidates to date. It was found that a total of 19 flavonoid-based drugs have been approved for the market, and of these, natural flavonoids accounted for 52.6%. Besides, a total of 36 flavonoid-based clinical candidates are undergoing or suspended in different phases, and of these, natural flavonoids account for 44.4%. Thus, natural flavonoids remain the best option for finding novel agents/active templates, and when investigated in conjunction with synthetic chemicals and biologicals, they offer the potential to discover novel structures that can lead to effective agents against a variety of human diseases. Additionally, flavonoid-based marketed drugs have been successful in cardiovascular treatment, and the related drugs account for more than 30% of marketed drugs. However, the use of flavonoids as antineoplastic and immunomodulating agents is not likely for approximately 50% of the candidates suspended in the clinical stage. Interestingly, the marketed drugs covered a broader range of chemical spaces based on size, polarity, and three-dimensional structure compared to the clinical candidates. In addition, flavonoid glycosides with poor oral bioavailability account for 36.8% of the marketed drugs, and thus, they could be thoroughly investigated.

Unlocking the potential of flavonoid-based co-crystal and co-amorphous systems

Flavonoids are polyphenolic compounds that have multiple benefits in treating various life-threatening diseases. Despite their diverse pharmacological activities, the market potential of flavonoids is hampered due to their poor solubility and low bioavailability after oral administration. The current review highlights the role of co-crystals and co-amorphous systems (CAMs) in enhancing the solubility, permeability, bioavailability, and therapeutic efficacy of flavonoids. It also explains the significance of flavonoid-based co-formers in the formation of co-crystals and CAMs with other APIs to improve their efficacy. Future perspectives, patented formulations, commercial medications (including their phases of clinical trials), and challenges associated with the use of flavonoid-based co-crystals and CAMs are also mentioned in the review.

Exploring the potential of pH-sensitive polymers in targeted drug delivery

The pH-sensitive polymers have attained significant attention in the arena of targeted drug delivery (TDD) because of their exceptional capability to respond to alteration in pH in various physiological environments. This attribute aids pH-sensitive polymers to act as smart carriers for therapeutic agents, transporting them precisely to target locations while curtailing the release of drugs in off-targeted sites, thereby diminishing side effects. Many pH-responsive polymers in TDD have revealed promising results, with increased therapeutic efficacy and decreased toxic effects. Several pH-sensitive polymers, including, hydroxy-propyl-methyl cellulose, poly (methacrylic acid) (Eudragit series), poly (acrylic acid), and chitosan, have been broadly studied for their myriad applications in the management of various types of diseases. Additionally, the amalgamation of pH-sensitive polymers with, additive manufacturing techniques like 3D printing, has resulted in the progression of novel drug delivery systems that regulate drug release in a controlled manner. Herein, types of pH-sensitive polymers in TDD are systemically reviewed. We have briefly discussed the nanocarriers employed for the delivery of various pH-sensitive polymers in TDD. Finally, miscellaneous applications of pH-sensitive polymers are discussed thoroughly with special attention to the implication of 3D printing in pH-sensitive polymers.

Isovitexin prevents DSS-induced colitis through inhibiting inflammation and preserving intestinal barrier integrity through activating AhR

Isovitexin (ISO) is a glycosylated flavonoid obtained from Asian rice that has been reported to have anti-inflammatory effect. However, the effects of ISO on colitis have not been reported. In the present study, we aimed to explore the protective effects of isovitexin on colitis using the dextran sodium sulfate (DSS)-induced model. In vitro, the protective mechanism was investigated in TNF-α-stimulated IEC cells. Inflammatory cytokines were measured by ELISA. The signaling pathways were measured by Western blot analysis. ISO attenuated DSS-induced colitis through reducing body weight loss and colonic histological changes. Also, the levels of TNF-α and IL-1β induced by DSS were inhibited by ISO. The MPO activity induced by DSS was attenuated by ISO. In vitro, ISO inhibited IL-6 and IL-1β production in TNF-α-stimulated cells. ISO increased the expression of tight junction proteins ZO-1 and occludin. Also, ISO inhibited TNF-α-induced NF-κB activation. In addition, ISO was found to increase the expression of aryl hydrocarbon receptor (AhR). And inhibition of AhR by its antagonist CH223191 could reverse these effects of ISO. ISO inhibited DSS-induced colitis in mice through suppressing inflammation and preserving intestinal barrier integrity through activating AhR. ISO may be useful as a potential therapeutic agent for colitis.

The synbiotic mixture of Bacillus licheniformis and Saccharomyces cerevisiae extract aggravates dextran sulfate sodium induced colitis in rats

BACKGROUND

Uncertain effects of probiotics and/or prebiotics have been reported in experimental and clinical colitis. This study aims to examine the effects of a synbiotic combination comprising Bacillus licheniformis DSM 17236 and Saccharomyces cerevisiae cell wall extract on dextran sulfate sodium (DSS)-induced colitis in Sprague Dawley rats.

METHODS

Acute colitis was induced in rats by oral administration of DSS 3.5% for 7 days. Fifty rats were divided equally into five groups; one control group and the other groups were induced with colitis and treated with or without the tested synbiotic, mixed with diet, for 28 days and sulfasalazine (100 mg/kg) via intragastric tube once daily for 14 days.

RESULTS

Symptomatically, the synbiotic administration raised the disease activity index (DAI) to comparable scores of the DSS group, specially from the 2nd to 7th days post DSS intoxication. It also induced a significant (p < 0.05) amplification of WBCs, myeloperoxidase (MPO), malondialdehyde (MDA), nuclear factor kappa B (NF-kB) expression and proinflammatory cytokines tumor necrosis factor alpha (TNFα), interferon gamma (INFγ), and interleukin-1 beta (IL-1β) while depressed the antioxidant enzymes glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) when compared with the DSS and control groups. The DSS intoxicated and Synbiotic+DSS groups showed desquamations of the covering epithelium, noticeable diffuse leukocytic infiltrations, sever catarrhal enteritis, ischemic colitis with diffuse coagulative necrosis of the entire colonic mucosa. Contrarily, sulfasalazine proved to be effective in the reduction of the tested inflammatory markers and the pathological degenerative changes of the DSS ulcerative colitis.

CONCLUSION

The examined synbiotic did not ameliorate but aggravated the DSS-induced colitis, so it should be subjected to intensive experimental and clinical testing before their use in animals and human.

Pectin-zein based stigmasterol nanodispersions ameliorate dextran sulfate sodium-induced colitis in mice

Due to the insolubility of phytosterols in both water and oil, their application in the medicine and health and food industries is limited. In this study, zein and pectin were selected as wall materials of phytosterol nanoparticles to enhance the solubility and bioactivity of phytosterols. The colitis-inhibitory effects of zein-based stigmasterol nanodispersions (ZNs) and zein/pectin-based stigmasterol nanodispersions (ZPNs) were investigated in the sodium dextran sulfate (DSS)-induced colitis mouse model. The results showed that ZPNs' therapeutic effect was better than that of ZNs. According to electron microscopy observation, pectin adsorbed on the surface of zein appeared to form an elastic network structure, which increased the stability of stigmasterol nanodispersions. ZPNs not only relieved the adverse physiological symptoms of colitis in mice, but additionally prevented colonic length shortening and reduced fecal hemoglobin content. Immunohistochemical analysis showed that ZPNs could alleviate colitis by inhibiting the NF-κB signaling pathway involved in the expression of inflammatory factors TNF-α, IL-6, IL-1β, CSF-1 and coenzyme COX-2. This study suggests that supplement of nano-embedded stigmasterol based on zein and pectin has a positive therapeutic effect on alleviating colitis in mice. Such activities of nano-embedded stigmasterol in humans remain to be investigated.

Development and In Vivo Evaluation of Pectin Based Enteric Coated Microparticles Loaded with Mesalamine and Saccharomyces boulardii for Management of Ulcerative Colitis

Mesalamine is the first-line choice of drug for ulcerative colitis management. However, due to the nontargeted delivery of mesalamine, it shows side effects. The possible impact of mesalamine can be improved by coated microparticles in combination with S. boulardii for targeted delivery to the colon with the prevention of unwanted side effects. In this work, pectin-based mesalamine and S. boulardii loaded microparticles were prepared by dehydration technique and coated by an oil-in-oil solvent evaporation method and characterized by Scanning electron microscopy (SEM), X-ray diffraction, and zeta analysis. 2, 4, 6-Trinitrobenzenesulfonic acid was used for the induction of colitis. The anti-inflammatory effects of coated microparticles on Caco-2 cells were assessed by the determination of interleukin (IL)-8 concentration. In addition, the impact of coated microparticles on the concentration of colonic enzymes, including myeloperoxidase (MPO), lipid peroxides, and glutathione (GSH), were also evaluated. Moreover, hematological parameters, including white blood cell (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), were assessed. SEM data revealed that all the prepared coated microparticles had an almost spherical shape. The X-ray powder diffraction analysis of uncoated and coated microparticles showed maximum stability without any interaction. The particle size of uncoated and coated microparticles was 9.14 and 15.61 μm, respectively. The zeta potential of uncoated and coated microparticles was observed to be -26.78 and -29.36 mV, respectively. The prepared coated microparticles decreased the levels of lipid peroxides, MPO, and GSH significantly in colitis. In the Caco-2 cell culture model, the concentration of IL-8 is decreased significantly. The hematological observations confirmed that the prepared formulation showed a promising decrease in the levels of WBC, CRP, and ESR in diseased animals. Animal experiments revealed that cellulose acetate phthalate coated microparticles of mesalamine and S. boulardii significantly improved the colitis disease conditions of Wistar rats. Hence, cellulose acetate phthalate-coated microparticles of mesalamine and S. boulardii could be recommended as adjuvant therapy to achieve a synergistic effect in the management of UC. Lay summary Mesalamine is the drug of choice for the management of ulcerative colitis (UC), which inhibits mediators responsible for inflammation. We investigated the in vivo effects of cellulose acetate phthalate-coated microparticles of mesalamine with Saccharomyces boulardii (probiotic) for their efficacy against UC. Our findings evidenced that the combination of mesalamine with S. boulardii showed a synergistic effect in the 2,4,6- trinitrobenzene sulfonic acid-induced colitis model by reducing the inflammation and maintains the macroscopic features. From the observed results, it can be concluded that S. boulardii can be used to enhance the individual drug's effect in the therapeutic management of UC.

Adeno-associated virus-mediated colonic secretory expression of HMGB1 A box attenuates experimental colitis in mice

BACKGROUND

Extracellular high mobility group box 1 (HMGB1) is crucially implicated in the pathogenesis of inflammatory bowel diseases (IBDs). A box domain of HMGB1 has been identified as a specific antagonist of HMGB1. In the present study, we tested the effects of adeno-associated virus (AAV)-mediated colonic secretory expression of HMGB1 A box on murine experimental colitis.

METHODS

Self-complementary AAV-2 carrying mouse immunoglobin Gκ leader-human HMGB1 A box (AAV-HMGB1 A box) was constructed. The effects of intracolonically administered AAV-HMGB1 A box on dextran sulfate sodium (DSS)- and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis were assessed by the disease activity index (DAI), colon length, macroscopic and histological scoring, myeloperoxidase (MPO) activity, and epithelial apoptosis and complementary proliferation. Colonic immune cell infiltrates, mucosal malondialdehyde content and superoxide dismutase activity, colonic tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 levels, serum HMGB1 concentration, and colonic HMGB1 release were determined to investigate the underlying mechanisms.

RESULTS

Intracolonically administered AAV-HMGB1 A box efficiently mediated secretory expression of HMGB1 A box and led to significant decreases in DAI, macroscopic and histological scores and colonic epithelial apoptosis in both DSS- and TNBS-treated mice. Modulating inflammation-associated cytokines, such as inhibiting colonic TNF-α and IL-1β expression, decreasing HMGB1 release, and restoring colonic IL-10 levels, and thereby inhibiting inflammatory cell infiltration and alleviating oxidant damage, might be the underlying mechanism.

CONCLUSIONS

Intracolonic application of AAV-HMGB1 A box is effective in alleviating murine colitis and has therapeutic potential in human IBDs.

Dietary fructose causes defective insulin signalling and ceramide accumulation in the liver that can be reversed by gut microbiota modulation

Objective: The link between metabolic derangement of the gut-2013liver-visceral white adipose tissue (v-WAT) axis and gut microbiota was investigated. Methods: Rats were fed a fructose-rich diet and treated with an antibiotic mix. Inflammation was measured in portal plasma, ileum, liver, and v-WAT, while insulin signalling was analysed by measuring levels of phosphorylated kinase Akt. The function and oxidative status of hepatic mitochondria and caecal microbiota composition were also evaluated. Results: Ileal inflammation, increase in plasma transaminases, plasma peroxidised lipids, portal concentrations of tumour necrosis factor alpha, lipopolysaccharide, and non-esterified fatty acids, were induced by fructose and were reversed by antibiotic. The increased hepatic ceramide content, inflammation and decreased insulin signaling in liver and v-WAT induced by fructose was reversed by antibiotic. Antibiotic also blunted the increase in hepatic mitochondrial efficiency and oxidative damage of rats fed fructose-rich diet. Three genera, Coprococcus, Ruminococcus, and Clostridium, significantly increased, while the Clostridiaceae family significantly decreased in rats fed a fructose-rich diet, and antibiotic abolished these variations Conclusions: When gut microbiota modulation by fructose is prevented by antibiotic, inflammatory flow from the gut to the liver and v-WAT are reversed.

Polyunsaturated Fatty Acids Stimulate De novo Lipogenesis and Improve Glucose Homeostasis during Refeeding with High Fat Diet

Aims: The recovery of body weight after a period of caloric restriction is accompanied by an enhanced efficiency of fat deposition and hyperinsulinemia—which are exacerbated by isocaloric refeeding on a high fat diet rich in saturated and monounsaturated fatty acids (SFA-MUFA), and poor in polyunsaturated fatty acids (PUFA), and associated with a blunting of de novo lipogenesis in adipose tissue and liver. As high fat diets rich in PUFA have been shown to limit the excess fat deposition and improve glucose homeostasis, we investigated here the extent to which de novo lipogenesis in liver and adipose tissues (white and brown), as well as hepatic oxidative stress, are influenced by refeeding on diets rich in PUFA.

Design: In rats calorically restricted for 14 days and refed for 14 days on isocaloric amounts of a high fat diet rich in lard (i.e., high SFA-MUFA) or in safflower and linseed oils (rich in PUFA), we investigated energy balance, body composition, glycemic profile, and the regulation of fatty acid synthase (rate-limiting enzyme of de novo lipogenesis) in liver, white and brown adipose tissue. We also evaluated oxidative stress in liver and skeletal muscle and markers of hepatic inflammation.

Results: Rats refed the PUFA diet gained less lipids and more proteins compared to rats refed SFA-MUFA diet and showed lower amount of visceral and epididymal white adipose tissue, but increased depots of interscapular brown adipose tissue, with higher expression of the uncoupling protein 1. A significant increase in non-protein respiratory quotient and carbohydrate utilization was found in rats refed PUFA diet. Rats refed PUFA diet showed improved glucose homeostasis, as well as lower triglycerides and cholesterol levels. Fatty acid synthase activity was significantly higher in liver, white and brown adipose tissue, while lipid peroxidation and the degree of inflammation in the liver were significantly lower, in rats refed PUFA diet.

Conclusions: When considering the composition of high fat diets for nutritional rehabilitation, the inclusion of PUFA could be useful for improving protein deposition and maintaining glucose homeostasis, while limiting lipid storage in adipose tissue and oxidative stress and inflammation in the liver.

Recombinant Lactococcus lactis expressing porcine insulin-like growth factor I ameliorates DSS-induced colitis in mice

BACKGROUND

Insulin-like growth factor I (IGF-I) is one important family of growth factors, which plays key role in intestinal growth, regeneration, and damage repair. However, the low natural abundance of IGF-I limits its research opportunities and practical application in the fields of medicine and animal husbandry. In this study, a tandem repeat strategy was used to express three copies of the same pIGF-I3 protein in L. lactis. The activity of recombinant pIGF-I3 (rpIGF-I3) was further examined by a mouse model of dextran sulfate sodium (DSS)-induced colitis. In addition, the potential of recombinant L. lactis expressing pIGF-I3 to reduce inflammatory disease was evaluated.

RESULTS

pIGF-I3 could be expressed in L. lactis by the detection of SDS-PAGE and Western blot. Experimental colitis was induced in BALB/c mice by administration of 5 % DSS in drinking water, and the clinical symptoms were observed in DSS-treated mice. Oral administration of recombinant L. lactis expressing pIGF-I3 improved the colonic architecture, and significantly reduced the increase of colonic damage score (P < 0.05). Furthermore, recombinant L. lactis expressing pIGF-I3 treatment significantly reduced serum DAO activity and colonic MPO level, and elevated colonic occludin level compared to the DSS group (P < 0.05).

CONCLUSIONS

The pIGF-I3 expressed in L. lactis has good biological activity, and oral administration of recombinant L. lactis expressing pIGF-I3 attenuated the symptoms and development of DSS-induced colitis in mice. These suggested that L. lactis could be a potential host bacterium for production and delivery of IGF-I against intestinal diseases.

Adequate Dextran Sodium Sulfate-induced Colitis Model in Mice and Effective Outcome Measurement Method

Background:

Dextran sodium sulfate (DSS)-induced colitis mouse model is used for research of inflammatory bowel disease. The aim of this study was to establish the adequate conditions for DSS mice model, and to find useful tool to measure inflammation.

Methods:

The 2.5% DSS was administered to six male C57BL/6 mice and 4% DSS to eight mice at 5 or 9 weeks of age. Each group was consisted of 6 mice with control group in which vehicle was administered instead of DSS. The mice were sacrificed on the 7th day after DSS or vehicle administration. Body weight, diarrhea, and hematochezia were recorded daily. Disease activity index (DAI) score which was composed of body weight change, diarrhea, and hematochezia was measured every day. Colon length was measured after sacrifice and colon mucosal level of interleukin 1 beta (IL-1β) was measured by ELISA assay. Histological score was compared between ascending and descending colon in the DSS group.

Results:

Colon length of five- and nine-week DSS group was significantly shorter than each control group but there was no statistical significance depending on DSS concentration or age. DAI score of 4% DSS group in nine-week was significantly higher than that five-week (P = 0.012) but there was no difference between 2.5% and 4% DSS group. The level of IL-1β in DSS mice was much higher than control group (P < 0.01), but there was no difference among several DSS groups. The histological score was higher in the descending colon than in the ascending colon but there was no statistical difference between each pair of DSS groups.

Conclusions:

The 4% DSS mice in nine-week was adequate for DSS-induced colitis model. DAI score was useful tool and descending colon was more appropriate site for histological evaluation of colitis than ascending colon.

Xilei san ameliorates experimental colitis in rats by selectively degrading proinflammatory mediators and promoting mucosal repair

Xilei san (XLS), a herbal preparation widely used in China for erosive and ulcerative diseases, has been shown to be effective in ulcerative colitis (UC). The present experiments were conducted to assess its efficacy and determine its mechanism of action in a rat model that resembles human UC. The model was induced by adding 4% dextran sulfate sodium (DSS) to the rats' drinking water for 7 days. XLS was administered daily by retention enema from day 2 to day 7; the rats were sacrificed on day 8. The colon tissues were obtained for further experiments. A histological damage score and the activity of tissue myeloperoxidase were used to evaluate the severity of the colitis. The colonic cytokine levels were detected in a suspension array, and epithelial proliferation was assessed using Ki-67 immunohistochemistry. Intrarectal administration of XLS attenuated the DSS-induced colitis, as evidenced by a reduction in both the histological damage score and myeloperoxidase activity. It also decreased the levels of proinflammatory cytokines, but increased the mucosal repair-related cytokines. In addition, the epithelial Ki-67 expression was upregulated by XLS. These results suggest that XLS attenuates DSS-induced colitis by degrading proinflammatory mediators and promoting mucosal repair. XLS could be a potential topical treatment for human UC.

Cooked navy and black bean diets improve biomarkers of colon health and reduce inflammation during colitis

Common beans contain non-digestible fermentable components (SCFA precursors) and phenolic compounds (phenolic acids, flavonoids and anthocyanins) with demonstrated antioxidant and anti-inflammatory potential. The objective of the present study was to assess the in vivo effect of cooked whole-bean flours, with differing phenolic compound levels and profiles, in a mouse model of acute colitis. C57BL/6 mice were fed a 20 % navy bean or black bean flour-containing diet or an isoenergetic basal diet (BD) for 2 weeks before the induction of experimental colitis via 7 d dextran sodium sulphate (DSS, 2 % (w/v) in the drinking-water) exposure. Compared with the BD, both bean diets increased caecal SCFA and faecal phenolic compound concentrations (P< 0·05), which coincided with both beneficial and adverse effects on colonic and systemic inflammation. On the one hand, bean diets reduced mRNA expression of colonic inflammatory cytokines (IL-6, IL-9, IFN-γ and IL-17A) and increased anti-inflammatory IL-10 (P< 0·05), while systemically reduced circulating cytokines (IL-1β, TNFα, IFNγ, and IL-17A, P< 0·05) and DSS-induced oxidative stress. On the other hand, bean diets enhanced DSS-induced colonic damage as indicated by an increased histological injury score and apoptosis (cleaved caspase-3 and FasL mRNA expression) (P< 0·05). In conclusion, bean-containing diets exerted both beneficial and adverse effects during experimental colitis by reducing inflammatory biomarkers both locally and systemically while aggravating colonic mucosal damage. Further research is required to understand the mechanisms through which beans exert their effects on colonic inflammation and the impact on colitis severity in human subjects.

pH-sensitive nanoparticles of curcumin-celecoxib combination: evaluating drug synergy in ulcerative colitis model

Inflammatory bowel diseases, which largely comprise ulcerative colitis (UC) and Crohn's disease, are increasingly posing as a global threat because of the incompetence of the current therapy in the entire patient population. This necessitates the identification of alternative therapeutic molecules or their combinations, which may serve as effective first-line or maintenance therapeutics. In this quest, celecoxib, a selective cyclooxygenase-2 inhibiting nonsteroidal anti-inflammatory agent and curcumin, a natural antioxidant and anti-inflammatory agent, have both been found to be useful in alleviating UC. Furthermore, studies involving their combination have proved synergistic action of these two agents. In the current investigation, we have formulated pH-sensitive nanoparticles of curcumin-celecoxib combination as a potential therapy for UC. Synergistic action of the drug combination, delivery advantages of nanosized carriers, and pH-sensitive nature of the polymer were collectively hypothesized to reduce the overall toxicity and total dose of celecoxib and provide enhanced efficacy for mitigating UC. The hypothesis was confirmed in a UC model in rats, where pH-sensitive nanoparticles of the drug combination were found to be more efficacious than nanoparticles of either drugs or drug/s suspension. Further, the blank nanoparticles did not exhibit any therapeutic effect, thereby confirming efficacy of the drug combination for treating UC.

Dietary supplementation of an ellagic acid-enriched pomegranate extract attenuates chronic colonic inflammation in rats

Dietary polyphenols present in Punica granatum (pomegranate), such as ellagitannins and ellagic acid (EA) have shown to exert anti-inflammatory and antioxidant properties. This study was designed to evaluate the effects of a dietary EA-enriched pomegranate extract (PE) in a murine chronic model of Cronh's disease (CD). Colonic injury was induced by intracolonic instillation of trinitrobenzensulfonic acid (TNBS). Rats were fed with different diets during 30 days before TNBS instillation and 2 weeks before killing: (i) standard, (ii) PE 250 mg/kg/day, (iii) PE 500 mg/kg/day, (iv) EA 10 mg/kg/day and (v) EA 10 mg/kg/day enriched-PE 250 mg/kg/day. Inflammation response was assessed by histology and MPO activity and TNF-α production. Besides, colonic expressions of iNOS, COX-2, p38, JNK, pERK1/2 MAPKs, IKBα and nuclear p65 NF-κB were studied by western blotting. MPO activity and the TNF-α levels were significantly reduced in dietary fed rats when compared with TNBS group. Similarly, PE and an EA-enriched PE diets drastically decreased COX-2 and iNOS overexpression, reduced MAPKs phosporylation and prevented the nuclear NF-κB translocation. Dietary supplementation of EA contributes in the beneficial effect of PE in this experimental colitis model and may be a novel therapeutic strategy to manage inflammatory bowel disease (IBD).

Emu Oil: a novel therapeutic for disorders of the gastrointestinal tract?

Gastrointestinal diseases characterized by inflammation, including the inflammatory bowel diseases, chemotherapy-induced mucositis and non-steroidal anti-inflammatory drug-induced enteropathy, currently have variably effective treatment options, highlighting the need for novel therapeutic approaches. Recently, naturally-sourced agents including prebiotics, probiotics, plant-extracts and marine-derived oils known to possess anti-inflammatory and anti-oxidant properties have been investigated in vitro and in vivo. However, animal-derived oils are yet to be extensively tested. Emu Oil is extracted from the subcutaneous and retroperitoneal fat of the Emu, a flightless bird native to Australia, and predominantly comprises fatty acids. Despite the limited rigorous scientific studies conducted to date, with largely anecdotal claims, Emu Oil, when administered topically and orally, has been shown to possess significant anti-inflammatory properties in vivo. These include a CD-1 mouse model of croton oil-induced auricular inflammation, experimentally-induced polyarthritis and dextran sulfate sodium-induced colitis. Recently, Emu Oil has been demonstrated to endow partial protection against chemotherapy-induced mucositis, with early indications of improved intestinal repair. Emu Oil could therefore form the basis of an adjunct to conventional treatment approaches for inflammatory disorders affecting the gastrointestinal system.

Effects of curcumin and Ginkgo biloba on matrix metalloproteinases gene expression and other biomarkers of inflammatory bowel disease

Treatment of inflammatory bowel disease (IBD) by synthetic active ingredients leads to many side effects. The objective of this study was to manage IBD using natural products as curcumin and Ginkgo biloba. Rats were divided into four groups (control, IBD, curcumin treated, and ginkgo treated). Inflammation was assessed by determination of myeloperoxidase, matrix metalloproteinases, metalloproteinase-1 inhibitor, nitric oxide, hydroxyproline, tumor necrosis factor-alpha, ceruloplasmin, and histopathological scoring. IBD induction significantly increased all measured parameters. Treated groups had significantly lower levels when compared with the IBD group. In conclusion, curcumin and ginkgo were effective in prevention and treatment of IBD.

STW 5 is effective in dextran sulfate sodium-induced colitis in rats

PURPOSE

An herbal preparation, STW 5, used clinically in functional dyspepsia and irritable bowel syndrome, has been shown to possess properties that may render it useful in inflammatory bowel disease (IBD). The present work was conducted to study its effectiveness in a rat model of IBD.

METHODS

An experimental model reflecting ulcerative colitis in man was adopted, whereby colitis was induced in Wistar rats by feeding them 5 % dextran sulfate sodium (DSS) in drinking water for one week. STW 5 and sulfasalazine (as a reference standard) were administered orally daily for 1 week before colitis induction and continued during DSS feeding. The animals were then sacrificed, and the severity of colitis was evaluated macroscopically and microscopically. Colon samples were homogenized for determination of reduced glutathione, tumor necrosis factor-α, and cytokine-induced neutrophil chemoattractant-3 as well as myeloperoxidase, glutathione peroxidase, and superoxide dismutase. In addition, colon segments were suspended in an organ bath to test their reactivity towards carbachol, KCl, and trypsin.

RESULTS

STW 5 and sulfasalazine were both effective in preventing the shortening of colon length and the increase in both colon mass index and total histology score as well as the changes in biochemical parameters measured except changes in dismutase activity. DSS-induced colitis led to marked depression in colonic responsiveness to the agents tested ex vivo, an effect which was normalized by both drugs.

CONCLUSIONS

The findings point to a potential usefulness of STW 5 in the clinical setting of ulcerative colitis.

Inhibition of tumor necrosis factor and nitrosative/oxidative stresses by Ziziphora clinopoides (Kahlioti); a molecular mechanism of protection against dextran sodium sulfate-induced colitis in mice

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune genetic and environmental factors. The authors were interested in examining the protective effect of Ziziphora clinopoides methanolic extract, an Iranian folk herbal medicine, on inflammatory mediators in experimental colitis. Colitis in NMRI mice was induced by oral administration of dextran sodium sulfate (DSS, 3%). Z. clinopoides was administrated orally at doses of 75, 150, and 300 mg/kg/day for 7 days. The level of lipid peroxidation (LP), total antioxidant capacity (TAC), total thiol molecules (TTM), antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT), and nitric oxide (NO) as a marker of nitrosative stress, and tumor necrosis factor alpha (TNF-alpha) as a mediator of inflammation and apoptosis were measured in the colon homogenate. Treatment by DSS increased bowel LP, NO, and TNF-alpha while decreasing TAC, SOD, CAT, and TTM. All measured parameters were improved by Z. clinopoides treatment and reached close to normal levels. The present study further supports the role of oxidative/nitrosative stresses and TNF-alpha in the pathogenesis of colitis and protective effects of this herb. The data are promising for further preclinical studies directed towards understanding mechanism of action and cross-species and cross-model comparisons for potential protective effects.

Dietary polyphenols can modulate the intestinal inflammatory response

Inflammatory bowel diseases (IBD) arise from multiple causes, including environmental factors, gut microflora, immunity, and genetic predispositions. In the course of IBD, immune homeostasis and intestinal mucosa barrier integrity are impaired. Among natural preventive treatments that have been identified to date, polyphenols appear as promising candidates. They have been shown to protect against several diseases, including cardiovascular diseases and cancers, and they have anti-inflammatory properties in non-intestinal models. This paper will review the literature that has described to date some effects of polyphenols on intestinal inflammation. Studies, conducted using in vivo and in vitro models, provide evidence that pure polyphenolic compounds and natural polyphenolic plant extracts can modulate intestinal inflammation.

Prophylactic role of curcumin in dextran sulfate sodium (DSS)-induced ulcerative colitis murine model

We have addressed in this study the possible protective role of the main principle of turmeric pigment; curcumin on a murine model of ulcerative colitis (UC). Colitis was induced by administration of dextran sulfate sodium (DSS) (3% W/V) in drinking water to male Swiss albino rats for 5 consecutive days. DSS challenge induced UC model that was well characterized morphologically and biochemically. DSS produced shrinkage of colon length and increased the relative colon weight/length ratio accompanied by mucosal edema and bloody stool. Histologically, DSS produced submucosal erosions, ulceration, inflammatory cell infiltration and crypt abscess as well as epithelioglandular hyperplasia. The model was confirmed biochemically, and the test battery entailed elevated serum tumor necrosis factor (TNF-alpha) and colonic activity of myleoperoxidase (MPO). Colonic glutathione-S-transferase (GST) activity and its substrate concentration; GSH, were notably reduced, while lipid peroxidation, expressed as malondialdehyde (MDA) level, and total nitric oxide (NO) were significantly increased. Prior administration of curcumin (100mg/kg, IP) for 7 consecutive days ahead of DSS challenge mitigated the injurious effects of DSS and ameliorated all the altered biochemical parameters. These results suggest that curcumin could possibly have a protective role in ulcerative colitis probably via regulation of oxidant/anti-oxidant balance and modulation of the release of some inflammatory endocoids, namely TNF-alpha and NO.

Can emu oil ameliorate inflammatory disorders affecting the gastrointestinal system?

Emu oil possesses significant anti-inflammatory properties in vivo, primarily when applied topically. However, to date, the evidence supporting its therapeutic application has been largely anecdotal, and significant batch-to-batch variations in potency have been reported. Nevertheless, the anti-inflammatory properties of emu oil suggest therapeutic promise for the adjunctive treatment of a range of disparate gastrointestinal diseases and disorders characterised by inflammatory processes. These include the idiopathic condition inflammatory bowel disease, chemotherapy-induced mucositis, non-steroidal anti-inflammatory drug enteropathy and the various infective enteritides (i.e. fungal, bacterial and viral gastroenteritis). Although rigorous scientific investigations are in their infancy, the evidence for emu oil efficacy in extra-intestinal disorders, supported by limited in vivo investigations of other naturally sourced oils, identifies emu oil as a possible adjunct to conventional treatment approaches for inflammatory disorders affecting the gastrointestinal system.

Amelioration of dextran sulfate sodium-induced colitis in mice by oral administration of β-caryophyllene, a sesquiterpene

beta-Caryophyllene (BCP), a naturally occurring plant sesquiterpene, was examined for anti-inflammatory activity in a mouse model of experimental colitis induced by dextran sulfate sodium (DSS). Colitis was induced by exposing male BALB/c mice to 5% DSS in drinking water for 7 days. BCP in doses of 30 and 300 mg/kg was administered orally once a day, beginning concurrently with exposure to DSS. The body weight and colon length were measured, and histological damage and myeloperoxidase (MPO) activity as well as inflammatory cytokines were assessed in both serum and colonic tissue after 7 days of treatment with DSS. The DSS treatment damaged the colonic tissue, increased MPO activity and inflammatory cytokines, lowered the body weight, and shortened the length of the colon. Oral administration of BCP at 300 mg/kg significantly suppressed the shortening of colon length and slightly offset the loss of body weight. BCP treatment (300 mg/kg) also significantly reduced the inflammation of colon and reversed the increase in MPO activity that had been induced by exposure to DSS. Further, BCP significantly suppressed the serum level of IL-6 protein (a 55% reduction) as well as the level of IL-6 mRNA in the tissue. These results demonstrate that BCP ameliorates DSS-induced experimental colitis, and may be useful in the prevention and treatment of colitis.

Rosiglitazone, a PPARgamma ligand, modulates signal transduction pathways during the development of acute TNBS-induced colitis in rats

Recent studies have shown that peroxisome proliferator-activated receptor gamma (PPARgamma), a highly nuclear receptor expressed in the colon, may participate in the control of inflammation, especially in regulating the production of immunomodulatory and inflammatory mediators, cellular proliferation and apoptosis. In order to delve into the anti-inflammatory mechanisms and signalling pathways of PPARgamma agonists, we have studied the effects of rosiglitazone, a PPARgamma agonist on the extent and severity of acute ulcerative colitis caused by intracolonic administration of 2,4,6-trinitribenzene sulfonic acid (TNBS) in rats. The inflammatory response was assessed by gross appearance, myeloperoxidase (MPO) activity, tumour necrosis factor alpha (TNF-alpha) levels and a histological study of the lesions. We determined prostaglandin E2 production as well as the cyclooxygenases (COX)-1 and -2 expressions by immunohistochemistry and Western blotting. The nuclear factor kappa (NF-kappaB) p65 and p38 mitogen-activated protein kinase (MAPK) expression levels were also measured by Western blotting. Finally, since PPARgamma agonists modulate apoptosis, we tried to clarify its effects under early acute inflammatory conditions. Inflammation following TNBS induction was characterized by increased colonic wall thickness, edema, diffuse inflammatory cells infiltration, necrosis reaching an ulcer index (UI) of 9.66+/-0.66 cm(2) and increased MPO activity and TNF-alpha colonic levels. Rosiglitazone treatment significantly reduced the morphological alteration associated with TNBS administration and the UI with the highest dose. In addition, the degree of neutrophil infiltration and the cytokine levels were significantly ameliorated. Rosiglitazone significantly reduced the rise in the prostaglandin (PG) E(2) generation compared with TNBS group. The COX-1 levels remained stable throughout the treatment in all groups. The COX-2 expression was elevated in TNBS group; however rosiglitazone administration reduced the COX-2 overexpression. A high expression of NF-kappaB p65 and p38 MAPK proteins appeared in colon mucosa from control TNBS-treated rats; nevertheless, PPARgamma agonist treatment drastically decreased them. There were no significant changes in apoptosis after rosiglitazone treatment when compared to TNBS group. In conclusion, rosiglitazone seems to modulate the acute colitis through NF-kappaB p65 and p38 MAPK signalling pathways.

The effects of resveratrol, a phytoalexin derived from red wines, on chronic inflammation induced in an experimentally induced colitis model

Neutrophil infiltration, proinflammatory cytokines, eicosanoid generation and oxidative stress have been implicated in colitis. Resveratrol is a polyphenolic compound found in grapes and wine, with multiple pharmacological actions, including anti-inflammatory, antioxidant, antitumour and immunomodulatory activities. In a previous report, we documented that resveratrol decreases the degree of inflammation associated with acute experimental colonic inflammation, but its effects on chronic experimental colitis remain undetermined. The aim of this research was to investigate the effects of resveratrol on the chronic colonic injury caused by intracolonic instillation of trinitrobenzenesulphonic acid (TNBS) in rats. The inflammatory response was assessed by histology and myeloperoxidase activity. Tumour necrosis factor alpha (TNF-alpha) production, histological and histochemical analysis of the lesions were also carried out. We determined the production of prostaglandin (PG) E2 and D2 in colon mucosa, as well as cyclooxygenase (COX)-1 and -2 and nuclear transcription factor NF-kappa B (NF-kappaB) p65 protein expression. Finally, since resveratrol has been found to modulate apoptosis, we intended to elucidate its effects on colonic mucosa under chronic inflammatory conditions. Resveratrol (10 mg kg(-1) day(-1)) significantly attenuated the damage score and corrected the disturbances in morphology associated to injury. In addition, the degree of neutrophil infiltration and the levels of TNF-alpha were significantly ameliorated. Resveratrol did not modify PGD2 levels but returned the decreased PGE2 values to basal levels and also reduced COX-2 and the NF-kappaB p65 protein expression. Furthermore, treatment of rats with resveratrol caused a significant increase of TNBS-induced apoptosis in colonic cells. In conclusion, resveratrol reduces the damage in chronic experimentally induced colitis, alleviates the oxidative events, returns PGE2 production to basal levels and stimulates apoptosis in colonic cells.

Curcumin, a Curcuma longa constituent, acts on MAPK p38 pathway modulating COX-2 and iNOS expression in chronic experimental colitis

Ulcerative colitis (UC) is a nonspecific inflammatory disorder characterized by oxidative and nitrosative stress, leucocyte infiltration and up-regulation of pro-inflammatory cytokines. Mitogen-activated protein kinases (MAPKs), such as the p38 and the c-Jun N-terminal kinase (JNK) modulate the transcription of many genes involved in the inflammatory process. Curcumin is a polyphenol derived from Curcuma longa, which is known to have anti-inflammatory activity. The aim of this study was to study the effects and mechanisms of action of curcumin, on chronic colitis in rats. Inflammation response was assessed by histology and myeloperoxidase activity (MPO). We determined the production of Th1 and Th2 cytokines and nitrites in colon mucosa, as well as the expression of inducible nitric oxide synthase (iNOS), cyclo-oxygenase(COX)-1 and-2 by western blotting and inmmunohistochemistry. Finally, we studied the involvement of MAPKs signaling in the protective effect of curcumin in chronic colonic inflammation. Curcumin (50-100 mg/kg/day) were administered by oral gavage 24 h after trinitrobenzensulfonic acid (TNBS) instillation, and daily during 2 weeks before sacrifice. Curcumin significantly attenuated the damage and caused substantial reductions of the rise in MPO activity and tumour necrosis factor alpha (TNF)-alpha. Also curcumine was able to reduce nitrites colonic levels and induced down-regulation of COX-2 and iNOS expression, and a reduction in the activation of p38 MAPK; however, no changes in the activation of JNK could be observed. In conclusion, we suggest that inhibition of p38 MAPK signaling by curcumin could explain the reduced COX-2 and iNOS immunosignals and the nitrite production in colonic mucosa reducing the development of chronic experimental colitis.

Benefits of Zataria multiflora Boiss in Experimental Model of Mouse Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested to examine the effect of total extract from Zataria multiflora Boiss, a folk medicinal plant on prevention and treatment of experimental IBD. Z. multiflora was administered (400, 600, 900 p.p.m.) through drinking water to IBD mice induced by intrarectal administration of acetic acid. Prednisolone was used as the standard drug for comparison. Biochemical, macroscopic and microscopic examinations of colon were performed. Biochemical evaluation of inflamed colon was done using assay of myeloperoxidase (MPO) activity and thiobarbituric acid reactive substances (TBARS) concentration as indicators of free radical activity and cell lipid peroxidation. The activity of MPO and lipid peroxidation products (TBARS) increased in acetic acid-treated groups while recovered by pretreatment of animals with Z. multiflora (400–900 p.p.m.) and prednisolone. Z. multiflora (600 and 900 p.p.m.) and prednisolone-treated groups showed significantly lower score values of macroscopic and microscopic characters when compared with the acetic acid-treated group. The beneficial effect of Z. multiflora (900 p.p.m.) was comparable with that of prednisolone. The antioxidant, antimicrobial and anti-inflammatory potentials of Z. multiflora might be the mechanisms by which this herbal extract protects animals against experimentally induced IBD. Proper clinical investigation should be carried out to confirm the activity in human.

Protection by Ziziphora clinopoides of acetic acid-induced toxic bowel inflammation through reduction of cellular lipid peroxidation and myeloperoxidase activity

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested in examining the effect of a total extract from Ziziphora clinopoides, an Iranian folk herbal medicine, in the prevention and control of experimental mouse IBD. Z. clinopoides was administered (75, 150, 300 mg/kg) through drinking water to mice, which dispensed a toxic dose of acetic acid intrarectally. Prednisolone was used as the standard drug for comparison. Biochemical, macroscopic and microscopic examinations of the colon were performed. Biochemical evaluation of the inflamed colon was carried out using assays of myeloperoxidase (MPO) activity and thiobarbituric acid reacting substances (TBARS) as indicators of free radical activity and cellular lipid peroxidation. Results indicated that the activity of MPO and lipid peroxidation products (TBARS) increased in acetic acid-treated groups, while recovered by pretreatment of animals with Z. clinopoides (75-300 mg/kg) and prednisolone. All doses of Z. clinopoides and prednisolone-treated groups showed significant lower score values of macroscopic and microscopic characters when compared to the acetic acid-treated group. The beneficial effect of Z. clinopoides (300 mg/kg) was comparable to that of prednisolone. It is concluded that Z. clinopoides inhibits acetic acid toxic reactions in the mouse bowel through inhibition of cellular oxidative stress. Proper clinical investigation should be carried out to confirm the same activity in human.

Interleukin-1beta targets interleukin-6 in progressing dextran sulfate sodium-induced experimental colitis

Inflammatory bowel disease (IBD) is an immunologically mediated disorder that is characterized by chronic, relapsing, and inflammatory responses. Dextran sulfate sodium (DSS)-induced experimental colitis in mice has been recognized as a useful model for human IBD and interleukin (IL)-1beta is a key cytokine in the onset of IBD. The purpose of the present study was to clarify which pro-inflammatory mediators are targeted by IL-1beta in mice with DSS-induced colitis. First, we found that DSS markedly induced IL-1beta production in both dose- and time-dependent manners (P < 0.05 and P < 0.01, respectively) in murine peritoneal macrophages (pMphi), while that of tumor necrosis factor-alpha was insignificant. Further, the expressions of mRNA and protein for IL-1beta were increased in colonic mucosa and pMphi from mice that received drinking water containing 5% DSS for 7 days (P < 0.01, each). In addition, the expressions of IL-6, granulocyte macrophage-colony stimulating factor, inducible nitric oxide synthase, and cyclooxygenase-2 mRNA were also time dependently increased (P < 0.01, each). Furthermore, administration of rIL-1beta (10 microg/kg, i.p.) significantly induced the expressions of IL-1beta and IL-6 mRNA in colonic mucosa from non-treated mice (P < 0.01). Anti-mIL-1beta antibody treatments (50 microg/kg, i.p.) attenuated DSS-induced body weight reduction and shortening of the colorectum (P < 0.05, each), and abrogated the expressions of IL-1beta and IL-6 mRNA in colonic mucosa (P < 0.01, each). Our results evidently support the previous findings that IL-1beta is involved in the development of DSS-induced experimental colitis in mice, and strongly suggest that IL-1beta targets itself and IL-6 for progressing colonic inflammation.

Rosiglitazone, an agonist of peroxisome proliferator-activated receptor gamma, reduces chronic colonic inflammation in rats

Recent studies have shown the implication of the peroxisome proliferator-activated receptor gamma (PPARgamma) in control of inflammation, immune and apoptotic responses during early experimental colitis. However, there is little information about the effects of these agents on colonic mucosa under chronic inflammatory conditions. In this study, we have evaluated the effects of rosiglitazone, a PPAR-gamma agonist, on the chronic injury caused by intra-colonic administration of trinitrobenzensulfonic acid (TNBS) in rats. Rosiglitazone (1 and 5mg/kg p.o.) was administered by oral gavage, 24h after TNBS instillation and daily during 2 weeks before killing the rats. Colons were removed for histological and biochemical analysis. Administration of rosiglitazone corrected the disorders in morphology associated to lesions, significantly reduced the ulceration index, the rise of myeloperoxidase (MPO) and the levels of tumour necrosis factor alpha (TNF-alpha). In addition, rosiglitazone treatment increased prostaglandin (PG)E(2) production and returned PGD(2) to basal levels. Also, reduced cyclooxygenase (COX)-2 and nuclear transcription factor NF-kappa B (NF-kappaB) p65 proteins expression. Furthermore, treatment of rats with rosiglitazone caused a significant increase of TNBS-induced apoptosis. In summary, rosiglitazone exerts protective effects in chronic experimental colitis. The anti-inflammatory effects seem to be related to impairment of neutrophil function, absence of up-regulation of TNF-alpha and decrease of nuclear NF-kappaB p65 expression. Our results also suggest that the activation of the PPARgamma pathway reduces COX-2 overexpression, returns the increased PGD(2) values to basal levels and induces a significant increase of TNBS-induced apoptosis. We conclude that rosiglitazone represents a novel approach to the treatment of ulcerative colitis.

Roles of Glutathione in dextran sodium sulphate-induced colitis in mice

AIM: To investigate the expression of glutathione (GSH) in dextran sodium sulphate(DSS)-induced colitic mucosa and its relationship with cytokine secretion as well as mucosal injury.

METHODS: BALB/c mice in DSS group (n = 10) were fed with 50 g/L DSS to induce experimental colitis and those in normal controls (n = 10) were fed with distilled water. All the mice were killed after 7 days. The pathological changes of the colonic tissues were examined while immunohi-stochemstry was performed with GSH1 antibody to determine the GSH expression. ELISA was used to detect the expression of IL-4 and IFN-γ.

RESULTS: The manifestations of acute colitis such as weight decrease, diarrhea and bloody stool appeared in mice of DSS group. focal crypt lesionsPathologically, focal crypt distortion, granulocyte and macrophage invasion were observed. The level of GSH in DSS group was significantly lower than that in control group (20.6 vs 3.14±1.0, t = 3.95, P = 0.01), whereas the expression of IL-4 was marked higher (38.7±4.7 vs 28.7±6.7, t = 3.16, P = 0.009). The content of IFN-γ was decreased in DSS group (P>0.05).

CONCLUSION: Low expression of GSH is related to the increase of IL-4, decrease of IFN-γ and mucosal injury in DSS-induced colitis in mice.