The effect of memantine on trinitrobenzene sulfonic acid-induced ulcerative colitis in mice

N-Succinylaspartic-Acid-Conjugated Riluzole Is a Safe and Potent Colon-Targeted Prodrug of Riluzole against DNBS-Induced Rat Colitis

In our previous study, riluzole azo-linked to salicylic acid (RAS) was prepared as a colon-targeted prodrug of riluzole (RLZ) to facilitate the repositioning of RLZ as an anticolitic drug. RAS is more effective against rat colitis than RLZ and sulfasalazine, currently used as an anti-inflammatory bowel disease drug. The aim of this study is to further improve colon specificity, anticolitic potency, and safety of RAS. N-succinylaspart-1-ylRLZ (SAR) and N-succinylglutam-1-ylRLZ (SGR) were synthesized and evaluated as a "me-better" colon-targeted prodrug of RLZ against rat colitis. SAR but not SGR was converted to RLZ in the cecal contents, whereas both conjugates remained intact in the small intestine. When comparing the colon specificity of SAR with that of RAS, the distribution coefficient and cell permeability of SAR were lower than those of RAS. In parallel, oral SAR delivered a greater amount of RLZ to the cecum of rats than oral RAS. In a DNBS-induced rat model of colitis, oral SAR mitigated colonic damage and inflammation and was more potent than oral RAS. Moreover, upon oral administration, SAR had a greater ability to limit the systemic absorption of RLZ than RAS, indicating a reduced risk of systemic side effects of SAR. Taken together, SAR may be a "me-better" colon-targeted prodrug of RLZ to improve the safety and anticolitic potency of RAS, an azo-type colon-targeted prodrug of RLZ.

Formulation and optimization of theophylline-loaded enteric-coated spanlastic nanovesicles for colon delivery; Ameliorate acetic acid-induced ulcerative colitis

Treatment of colon diseases presents one of the most significant obstacles to drug delivery due to the inability to deliver sufficient drug concentration selectively to the colon. The goal of the proposed study was to develop, optimize, and assess an effective colon target delivery system of theophylline-based nanovesicles (TP-NVs) surrounded by a biodegradable polymeric shell of chitosan (CS) and Eudragit L100 (EL100) for the treatment of ulcerative colitis (UC). TP-loaded nanovesicles were fabricated using the ethanol injection method and coated with CS and EL100, respectively. We used a 32-factorial design approach to optimize the concentration of CS and EL100 to minimize particle size (PS) and maximize the cumulative amount of theophylline released (CTR) after 24 h. The optimized formulation was described using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and in vitro release. In-vivo quantification of theophylline in the gastrointestinal tract and in-vivo targeting potential in a rat model of acetic acid-induced colitis were also thoroughly evaluated. The characteristics of the optimal formula predicted by the 32-factorial design approach corresponded exceptionally well with the measured PS of 271.3 nm, the zeta potential of -39.9 mV, and CTR of 3.95, and a 99.93% after 5 and 24 h, respectively. Notably, the in vivo results in the rat model of colitis showed that the formulation with an optimized coat significantly improved theophylline distribution to the colon and markedly decreased the expression of interleukin-6 and ulcerative lesions compared to a pure theophylline solution. These outcomes elucidated the feasibility of a 32-factorial design to detect the crucial interactions between the study's components. Our findings suggested that enteric-coated nanovesicles formulations with optimal coat compositions of 0.2693% (w/v) and 0.75% (w/v) of CS and EL100, respectively, were promising carriers for colonic delivery of theophylline, a rate-limiting step in the treatment of UC.

Inula viscosa ameliorates acetic acid induced ulcerative colitis in rats

Increased pro-inflammatory cytokines and oxidative stress contribute to the pathophysiology of ulcerative colitis (UC). Inula viscosa is a plant with antioxidant and anti-inflammatory properties. We investigated the effect of an ethanolic extract of I. viscosa on an experimental UC model created using acetic acid. Rats were divided into four groups of eight: group 1, control; group 2, 3% acetic acid group; group 3, 100 mg/kg sulfasalazine + 3% acetic acid group; group 4, 400 mg/kg I. viscosa + 3% acetic acid. I. viscosa and sulfasalazine were administered by oral gavage and 3% acetic acid was administered per rectum. We found that I. viscosa treatment decreased colon malondialdehyde, tumor necrosis factor-α, interleukin-1 beta and nuclear factor kappa B levels; it increased reduced glutathione, nuclear factor erythroid 2-related factor 2, heme oxygenase-1 and kelch-like ECH-associated protein 1 levels and glutathione peroxidase enzyme activity. Group 1 colon exhibited normal histological structure. Slight inflammatory cell infiltration and edema and insignificant slight erosion in crypts were detected in colon tissues of group 4. We found that I. viscosa reduced oxidative stress and inflammation, which was protective against UC by inducing the Nrf-2/Keap-1/HO-1 pathway in the colon.

A Colon-Targeted Prodrug of Riluzole Improves Therapeutic Effectiveness and Safety upon Drug Repositioning of Riluzole to an Anti-Colitic Drug

Riluzole (RLZ) is a neuroprotective drug indicated for amyotrophic lateral sclerosis. To examine the feasibility of RLZ for repositioning as an anti-inflammatory bowel disease (IBD) drug, RLZ (2, 5, and 10 mg/kg) was administered orally to rats with colitis induced by 2,4-dinitrobenzenesulfonic acid. Oral RLZ was effective against rat colitis in a dose-dependent manner, which was statistically significant at doses over 5 mg/kg. To address safety issues upon repositioning and further improve anti-colitic effectiveness, RLZ was coupled with salicylic acid (SA) via an azo-bond to yield RLZ-azo-SA (RAS) for the targeted colonic delivery of RLZ. Upon oral gavage, RAS (oral RAS) was efficiently delivered to and activated to RLZ in the large intestine, and systemic absorption of RLZ was substantially reduced. Oral RAS ameliorated colonic damage and inflammation in rat colitis and was more effective than oral RLZ and sulfasalazine, a current anti-IBD drug. Moreover, oral RAS potently inhibited glycogen synthase kinase 3β (GSK3β) in the inflamed distal colon, leading to the suppression of NFκB activity and an increase in the level of the anti-inflammatory cytokine interleukin-10. Taken together, RAS, which enables RLZ to be delivered to and inhibit GSK3β in the inflamed colon, may facilitate repositioning of RLZ as an anti-IBD drug.

Small intestinal bacterial overgrowth in Alzheimer's disease

The results of animal studies and clinical data support the gut microbiota contribution to the pathogenesis of Alzheimer’s disease (AD). The aim of this pilot study was to evaluate the prevalence of small intestinal bacterial overgrowth (SIBO) and fecal markers of intestinal inflammation and permeability in AD patients. The study was conducted in 45 AD patients and 27 controls. Data on comorbidities, pharmacotherapy, and gastrointestinal symptoms were acquired from medical records and a questionnaire. SIBO was evaluated using lactulose hydrogen breath test. Fecal calprotectin and zonulin levels were assessed by ELISA assays. The positive result of SIBO breath test was found in 49% of the AD patients and 22% of the controls (p = 0.025). The comparative analysis between SIBO-positive and SIBO-negative AD patients with respect to the degree of cognitive impairment, comorbidities and used medications did not reveal any statistically significant difference, except for less common heartburn in SIBO-positive AD patients than in SIBO-negative ones (9 vs 35%, p = 0.038). The median fecal calprotectin and zonulin levels in the AD group compared to the control group amounted to 43.1 vs 64.2 µg/g (p = 0.846) and 73.5 vs 49.0 ng/ml (p = 0.177), respectively. In the AD patients there was no association between the presence of SIBO and fecal calprotectin level. Patients with AD are characterized by higher prevalence of SIBO not associated with increased fecal calprotectin level that may be related to anti-inflammatory effect of cholinergic drugs used in the treatment of AD.

Memantine and its benefits for cancer, cardiovascular and neurological disorders

Memantine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist that was initially indicated for the treatment of moderate to severe Alzheimer's disease. It is now also considered for a variety of other pathologies in which activation of NMDA receptors apparently contributes to the pathogenesis and progression of disease. In addition to the central nervous system (CNS), NMDA receptors can be found in non-neuronal cells and tissues that recently have become an interesting research focus. Some studies have shown that glutamate signaling plays a role in cell transformation and cancer progression. In addition, these receptors may play a role in cardiovascular disorders. In this review, we focus on the most recent findings for memantine with respect to its pharmacological effects in a range of diseases, including inflammatory disorders, cardiovascular diseases, cancer, neuropathy, as well as retinopathy.

Effects of ShenLing BaiZhu San Supplementation on Gut Microbiota and Oxidative Stress in Rats with Ulcerative Colitis

The aim of this study was to evaluate the effect of gut microbiota and antioxidation of Shenling Baizhu San (SLBZS) as a supplement in a rat model of ulcerative colitis (UC) induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). Acute intestinal inflammation was induced in 40 male SD rats aged 4 weeks with 100 mg/kg TNBS, and then three dosages of SLBZS (0.5 g/kg, 1 g/kg, and 1.5 g/kg) were administered for eight days, respectively. Faecal microbiome composition was assessed by 16S rRNA high-throughput sequencing. The result indicated that SLBZS could reduce the diversity of gut microbiota and increased its abundance. At the genus level, the relative abundance of SCFAs producing bacteria including Prevotella and Oscillospira increased, while the relative abundance of opportunistic pathogens including Desulfovibrio and Bilophila decreased. Meanwhile, SLBZS could improve the lesions of colon and significantly reduce the level of MPO, increase the levels of SOD and CAT in rats' serum. These findings revealed that SLBZS was effective and possessed anticolitic activities in a rat model of UC by reducing macroscopical and microscopical colon injury, enhancing antioxidant capacity, and regulating gut microbiota.

Pathophysiologic Role of Neurotransmitters in Digestive Diseases

Neurotransmitters are special molecules that serve as messengers in chemical synapses between neurons, cells, or receptors, including catecholamines, serotonin, dopamine, and other neurotransmitters, which play an important role in both human physiology and pathology. Compelling evidence has indicated that neurotransmitters have an important physiological role in various digestive diseases. They act as ligands in combination with central or peripheral receptors, and transmits signals through chemical synapses, which are involved in regulating the physiological and pathological processes of the digestive tract organs. For instance, neurotransmitters regulate blood circulation and affect intestinal movement, nutrient absorption, the gastrointestinal innate immune system, and the microbiome. In this review, we will focus on the role of neurotransmitters in the pathogenesis of digestive tract diseases to provide novel therapeutic targets for new drug development in digestive diseases.

Suppression of Inflammatory Cytokines Expression with Bitter Melon (Momordica Charantia) in TNBS-instigated Ulcerative Colitis

Background and Objective

This study was aimed to elucidate the molecular mechanism of Momordica charantia (MCh), along with a standard drug prednisolone, in a rat model of colitis induced by trinitrobenzene sulfonic acid (TNBS).

Methods

After the induction of the experimental colitis, the animals were treated with MCh (4 g/kg/day) for 14 consecutive days by intragastric gavage. The colonic tissue expression levels of C-C motif chemokine ligand 17 (CCL-17), interleukin (IL)-1β, IL-6, IL-23, interferon-γ (IFN-γ), nuclear factor kappa B (NF-kB), and tumor necrosis factor-α (TNF-α), were determined at both mRNA and protein levels to estimate the effect of MCh. Besides, colonic specimens were analyzed histopathologically after staining with hematoxylin and eosin.

Results

The body weights from TNBS-instigated colitis rats were found to be significantly lower than untreated animals. Also, the IFN-γ, IL-1β, IL-6, Il-23, TNF-α, CCL-17, and NF-kB mRNA and protein levels were increased significantly from 1.86-4.91-fold and 1.46-5.50-fold, respectively, in the TNBS-instigated colitis group as compared to the control. Both the MCh and prednisolone treatment significantly reduced the bodyweight loss. It also restored the induced colonic tissue levels of IL-1β, IL-6, IFN-γ, and TNF-α to normal levels seen in untreated animals. These results were also supported with the histochemical staining of the colonic tissues from both control and treated animals.

Conclusion

The presented data strongly suggests that MCh has the anti-inflammatory effect that might be modulated through vitamin D metabolism. It is the right candidate for the treatment of UC as an alternative and complementary therapeutics.

Pingkui Enema Alleviates TNBS-Induced Ulcerative Colitis by Regulation of Inflammatory Factors, Gut Bifidobacterium, and Intestinal Mucosal Barrier in Rats

Background

Ulcerative colitis (UC) is a chronic recurrent inflammation of the colon, and clinical outcome of UC is still unsatisfied. Pingkui enema, a traditional Chinese medicine prescription, has been safely applied for the treatment of diarrhea and dysentery in clinic for many years. However, its mechanism is still elusive. The present study is designed to investigate the effect of Pingkui enema on trinitrobenzene sulfonic acid- (TNBS-) induced ulcerative colitis (UC) and possible mechanism in rats.

Methods

UC was induced by intracolonic instillation of TNBS in male Sprague-Dawley rats, which were treated with different dosages of Pingkui enema (low, medium, and high) or sulfasalazine for ten days. Survival rate was calculated. A clinical disease activity score was evaluated. Histological colitis severity was analyzed by hematoxylin-eosin (HE) staining. Content of Bifidobacterium in intestinal tissue was analyzed by RT-PCR. Concentration of IL-8, IL-13, TNF-α, D-lactic acid (D-LA), and diamine oxidase (DAO) in serum and contents of adhesin and receptor of Bifidobacterium adhesion in rat intestinal mucus were measured by ELISA.

Results

The results showed that Pingkui enema treatment with high dosage markedly improved the survival rate compared with untreated and sulfasalazine treated groups. All dosages of Pingkui enema reduced pathological score. High dosage of Pingkui enema and sulfasalazine treatments significantly reduced the serum concentration of IL-8, TNF-α, D-LA, and DAO and markedly increased the serum concentration of IL-13. In addition, high-dose Pingkui enema and sulfasalazine treatments increased gut content of Bifidobacterium, gut mucus expressions of adhesin, and adhesin receptor of Bifidobacterium.

Conclusions

Pingkui enema has therapeutic effect on TNBS-induced UC, and possible mechanism may be via regulation of gut probiotics (Bifidobacterium) and inflammatory factors and protection of intestinal mucosal barrier.

Therapeutic effect of gold nanoparticles on DSS-induced ulcerative colitis in mice with reference to interleukin-17 expression

Ulcerative colitis (UC) is among the most challenging human diseases. Nanotechnology has incontestable promising outcomes in inflammatory bowel diseases. This study aimed to investigate the therapeutic effect of naked gold nanoparticles (AuNPs) on dextran sodium sulphate (DSS) induced ulcerative colitis in mice. We also examined the expression of interleukin-17 (IL-17) following AuNPs treatment. Mice were randomly divided into control, DSS and DSS+ AuNPs groups. Severity of colitis was assessed by disease activity index (DAI) measurement. At the end of the experiment, the final body weights were recorded. The colon was dissected and processed for histopathological examinations by light and electron microscopes. Colon homogenates were prepared for assay of tissue malondialdehyde (MDA) and real-time PCR analysis of IL-17A. Immunohistochemical localization of IL-17A was carried out. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) detector were used to detect the presence of AuNPs in the colonic tissue of DSS+ AuNPs groups. Our results showed that AuNPs effectively targeted the colonic tissue, and reduced changes induced by DSS. The underlying mechanisms could be related to anti-oxidant effect (as evident by decreasing tissue MDA) and anti-inflammatory potential of AuNPs. Our study draws attention to as a novel therapeutic strategy for treating UC.

Preventive effect of bergenin against the development of TNBS-induced acute colitis in rats is associated with inflammatory mediators inhibition and NLRP3/ASC inflammasome signaling pathways

Ulcerative colitis is an idiopathic inflammatory bowel disease characterized by intestinal inflammation; blocking this inflammatory process may be the key to the development of new naturally occurring anti-inflammatory drugs, with greater efficiency and lower side effects. The objective of this study is to explore the effects of bergenin (BG) in TNBS (2,4,6-trinitrobenzenesulfonic acid)-induced acute colitis model in rats in order to assist in the studies for the development of novel natural product therapies for inflammatory bowel disease. 48 Wistar rats were randomized into six groups: (i) Control and (ii) TNBS control; (iii) 5-ASA 100 mg/kg/day (iv) BG 12 mg/kg/day (v) BG 25 mg/kg/day and (vi) BG 50 mg/kg/day. Colitis was induced by instillation of TNBS. Colitis was evaluated by an independent observer who was blinded to the treatment. Our results revealed that bergenin decreased the macroscopic and microscopic damage signs of colitis, and reduced the degree of neutrophilic infiltration in the colon tissue; also, it was capable to down-regulate COX-2, iNOS, IkB-α, and pSTAT3 protein expression. Similarly, using a protocol for indirect ELISA quantification of cytokines, bergenin treatment reduced IL-1β, IFN-γ and IL-10 levels, and inhibited both canonical (IL-1) and non-canonical (IL-11) NLRP3/ASC inflammasome signaling pathways in TNBS-induced acute colitis. Conclusion: Our study has provided evidence that administration of bergenin reduced the damage caused by TNBS in an experimental model of acute colitis in rats, reduced levels of pro-inflammatory proteins and cytokines probably by modulation of pSTAT3 and NF-κB signaling and blocking canonical and non-canonical NLRP3/ASC inflammasome pathways.

The effect of menthol on acute experimental colitis in rats

Menthol is an aromatic compound with high antiinflammatory activity. The purpose of the current research is to investigate the effectiveness of menthol on acetic acid induced acute colitis in rats. Animals were injected with menthol (20 and 50 and 80mg/kg, i.p.) 24h prior to induction of colitis for 3 consecutive days. Menthol at medium and higher doses similar to dexamethasone as a reference drug significantly reduced body weight loss, macroscopic damage score, ulcer area, colon weight, colon length and improved hematocrit in rats with colitis. The histopathological examination also confirmed anti-colitic effects of menthol. Menthol also reduced significantly the colonic levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6) and myeloperoxidase (MPO) activity in inflamed colons. Thus, the findings of the current study provide evidence that menthol may be beneficial in patients suffering from acute ulcerative colitis.