Agmatine ameliorates acetic acid-induced colitis in rats: involvement of nitrergic system

Agmatine attenuates the severity of immunometabolic disorders by suppressing macrophage polarization: an in vivo study using an ulcerative colitis mouse model

Agmatine, an endogenous polyamine generated by the gut microbiota, positively affects host lifespan by regulating mononuclear cell or macrophage function. Although the regulatory pathways governing monocyte/macrophage differentiation have been well studied, the influence of the microbiome and its metabolites on monocyte/macrophage function have not been fully elucidated. To address this, we aimed to investigate the mechanisms whereby agmatine inhibits immunometabolic disorders using the colon of ulcerative colitis (UC) model mice. Agmatine (10 mM) attenuated pathological damage to colonic tissue and significantly improved the survival rate of UC model mice. In particular, treatment of UC model mice with 0.4, 2, and 10 mM agmatine resulted in mortality rates of 70 %, 20 %, 10 %, and 0 %, respectively. In a macrophage-depletion model, agmatine regulated the inflammatory microenvironment by affecting macrophages: it reduced the proportion of M1 macrophages and increased that of M2 macrophages in UC model mice. In cultured macrophages, agmatine inhibited lipopolysaccharide-induced inflammatory cytokine and NO secretion, as detected by enzyme-linked immunosorbent assay and the Griess assay, respectively. Agmatine partially reduced inflammatory factor production by inhibiting histone deacetylase, as detected by fluorometric assay. These findings provide evidence that agmatine efficiently suppresses macrophage polarization in UC mice, highlighting its potential as an anti-inflammatory agent against UC.

Canagliflozin ameliorates ulcerative colitis via regulation of TLR4/MAPK/NF-κB and Nrf2/PPAR-γ/SIRT1 signaling pathways

Ulcerative colitis (UC) is one of the most common subtypes of inflammatory bowel disease (IBD) that affects the colon and is characterized by severe intestinal inflammation. Canagliflozin is a widely used antihyperglycemic agent, a sodium-glucose cotransporter-2 (SGLT2) inhibitor that enhances urinary glucose excretion. This study aims to provide insights into the potential benefits of canagliflozin as a treatment for UC by addressing possible cellular signals. Acetic acid (AA; 4% v/v) was administered intrarectally to induce colitis. Canagliflozin is given orally at a dose of 10 mg/kg/day. Canagliflozin attenuates inflammation in AA-induced colitis, evidenced by significant and dose-dependently downregulation of p38 MAPK, NF-κB-p65, IKK, IRF3, and NADPH-oxidase as well as colonic levels of IL-6 and IL-1β and MPO enzymatic activity. Canagliflozin mitigates colonic oxidative stress by decreasing MDA content and restoring SOD enzymatic activities and GSH levels mediated by co-activating of Nrf2, PPARγ, and SIRT1 pathways. Moreover, an in-silico study confirmed that canagliflozin was specific to all target proteins in this study. Canagliflozin's binding affinity with its target proteins indicates and confirms its effectiveness in regulating these pathways. Also, network pharmacology analysis supported that canagliflozin potently attenuates UC via a multi-target and multi-pathway approach.

Faba beans with enhanced antioxidant activity ameliorate acetic acid-induced colitis in experimental rats

Faba beans are among the legumes that are of the greatest importance due to their high nutritional value. In addition to the essential nutrients that faba beans contain, they also contain bioactive compounds such as phenolics and flavonoids that are considered as potent natural antioxidants. Ulcerative colitis (UC) is an inflammatory bowel disease in which oxidative stress plays an essential role in the pathophysiology. The aim of the current study was to evaluate the antioxidant activity of faba bean seeds harvested from plants grown from seeds pre-treated with selenium, garlic husk extract and/or lemon peel extract and to evaluate their in vivo effects in a rat model of UC. 54 female rats were divided randomly into nine groups (n = 9). All groups were given the different tested treatments 14 days prior to UC induction using acetic acid (intra-rectal injection of 2 ml, 4% v/v in saline). Our results revealed that the treatment of faba bean seeds with a mixture of selenium, garlic husk extract and lemon peel extract before planting led to a significant increase in selenium, nitrogen, potassium, total protein, phenolic and flavonoid content in the harvested faba bean seeds with a subsequent enhancement of their antioxidant capacity. Consumption of such faba beans showed potential protective and therapeutic effects during experimental colitis by reducing colonic oxidative stress and increasing colonic antioxidant defense mechanisms. Further research is required to understand the mechanisms by which faba beans influence colitis, their effects on various inflammatory biomarkers and their impact on the severity of colitis in humans.

Anti-inflammatory Effects of Ivermectin in the Treatment of Acetic Acid-Induced Colitis in Rats: Involvement of GABAB Receptors

BACKGROUND

Recent investigations have proposed the potential role of gamma-aminobutyric acid (GABA) in regulating motility and immunity of the gastrointestinal system.

AIMS

We aimed to investigate the anti-inflammatory effects of ivermectin (IVM) through GABAB receptors following acetic acid-induced colitis in rats.

METHODS

In a controlled experimental study, we enrolled 78 male Wistar rats (13 groups; 6 rats/group). After colitis induction using acetic acid (4%), IVM, baclofen (a standard GABAB agonist) or the combination of both agents was delivered to rats orally (by gavage), with the same dosage continued for 5 days. The control group received the vehicle, and prednisolone (a standard anti-inflammatory agent) was administered in a separate group as the positive control. Colon samples were collected on the sixth day for histopathological evaluations and measurement of myeloperoxidase (MPO) activity, TNF-α levels, and p-NF-ĸB p65, COX-2 and iNOS expression levels.

RESULTS

The greatest recovery was found after administering IVM 0.5, baclofen 0.5, or IVM 0.2 + baclofen 0.2 mg/kg/day (ulcer index [UI] = 1.4 ± 0.4, 1.7 ± 0.6, and 1.4 ± 0.3, respectively; p  < 0.001 vs. the control [UI = 6.5 ± 0.7]). Histopathological evaluations revealed a significant decrease in the inflammation severity in the three above-mentioned groups. P-NF-ĸB p65, COX-2, and iNOS expression, MPO activity, and TNF-α levels also decreased dramatically following treatment with IVM 0.5, baclofen 0.5, or the combination therapy (p < 0.001 vs. the control).

CONCLUSIONS

IVM exerted promising anti-inflammatory effects in treating acetic acid-induced colitis in rats. Its synergistic effect with baclofen also signified the possible involvement of GABAB receptors in this process.

Bunium persicum essential oil reduced acetic acid-induced rat colitis through suppression of NF-κB pathway

Objective:

The aim of this study was to evaluate the anti-inflammatory effect of B. persicum essential oil on colonic inflammation and the role of suppression of NF-κB pathway in rat colitis induced by acetic acid solution.

Materials and Methods:

Induction of acute colitis was done by intra-luminal instillation of 2 ml of acetic acid (4%) diluted in normal saline. Two hours after colitis induction, 0.2% tween 80 in normal saline, prednisolone (4 mg/kg) or B. persicum essential oil (100, 200, and 400 mg/kg) were administered to the rats orally and continued for 5 consecutive days. The severity of macroscopic and microscopic damages was assessed. Myeloperoxidase and TNF-α activity was evaluated by biochemical analysis and ELISA respectively and protein expression of p-NF-κB was assessed by immunohistochemistry (IHC).

Results:

Prednisolone and B. persicum essential oil (100, 200, and 400 mg/kg) decreased macroscopic and microscopic injuries compared to the acetic acid group. On the other hand, prednisolone and B. persicum essential oil (200 and 400 mg/kg) decreased the activity of MPO and TNF-α in the colon tissue of rats compared with the acetic acid group. Furthermore, they suppressed the expression of p-NF-κB protein induced by acetic acid administration.

Conclusion:

It is suggested that the anti-inflammatory effect of B. persicum essential oil on acetic acid-induced colitis in rats may be due to the suppression of NF-κB pathway.

Trifluoperazine reduces cuprizone-induced demyelination via targeting Nrf2 and IKB in mice

Multiple sclerosis (MS) is one of the most common neurodegenerative diseases. In this disease, the immune system attacks oligodendrocyte cells and the myelin sheath of myelinated neurons in the central nervous system, causing their destruction. These conditions lead to impaired conduction of nerve impulses and are manifested by symptoms such as weakness, fatigue, visual and motor disorders. This study aimed to evaluate the ability of trifluoperazine (TF) to improve cuprizone-induced behavioral and histopathological changes in the prefrontal cortex of C57BL/6 male mice. Demyelination was induced by adding 0.2% cuprizone (CPZ) to the standard animal diet for 6 weeks. Three doses of TF (0.5, 1 and 2 mg/kg/day; i.p.) were given once daily for the last 2 weeks of treatment. Treatment with CPZ induced a weight loss during 6 weeks of treatment compared to the control group, which was reversed by the administration of TF. Behavioral tests (pole test and rotarod performance test) showed a decrease in motor coordination and balance in the group treated with CPZ (P < 0.01). Treatment with TF during the last two weeks was able to improve these motor deficiencies. Histopathological examination also evidenced an increase in demyelination in the CPZ group, which was improved by TF administration. In addition, CPZ intake significantly decreased the cerebral cortex levels of p-Nrf2 (P < 0.001) and increased the levels of p-IKB (P < 0.001) and, these changes were normalized in the TF groups. TF administration also reversed the increased levels of nitrite and the reduced activity of the antioxidant enzyme superoxide dismutase associated with CPZ exposure. TF can to reduce the harmful effects of CPZ by reducing the demyelination and modulating the Nrf2 and NF-kB signaling pathways.

Molsidomine alleviates acetic acid-induced colitis in rats by reducing oxidative stress, inflammation and apoptosis

Ulcerative colitis (UC) is a subcategory of intestinal inflammatory bowel disease characterized by up-regulation of proinflammatory cytokines and oxidative stress. The current study was designed to assess the probable protective effect of the nitric oxide (NO) donor, molsidomine, in experimental colitis model in rats. Rats were haphazardly classified into four groups: control, acetic acid, acetic acid + molsidomine (1 mg/kg) and acetic acid + molsidomine (2 mg/kg). Molsidomine (1 and 2 mg/kg/day) was administered by intra-peritoneal injection for 7 days prior to induction of UC. On the 8th day, colitis was induced by intra-rectal instillation of 2 ml of (4% v/v) acetic acid in normal saline using a pediatric plastic catheter. The rats were sacrificed 1 day following colitis induction, blood samples were obtained; colons and livers were isolated then underwent macroscopic, biochemical, histopathological and immunohistochemical examination. Pretreatment with molsidomine significantly reduced disease activity index, colon mass index, colonic macroscopic and histological damage. Besides, molsidomine significantly reduced the serum levels of alanine transaminase (ALT) (58.7 ± 8.9 & 59.7 ± 8 vs 288.75 ± 31.4 in AA group) and aspartate transaminase (AST) (196.2 ± 37.4 & 204 ± 30 vs 392.7 ± 35.6 in AA group). Moreover, molsidomine effectively decreased malondialdehyde (MDA) and total nitrate/nitrite (NOx) contents, and up regulated the enzymatic activity of superoxide dismutase (SOD) and glutathione level (GSH) in colonic and hepatic tissues. With regard to anti-inflammatory mechanisms, molsidomine suppressed tumor necrosis factor-alpha (TNF-α) (792.5 ± 16.7 & 448 ± 12.1 vs 1352.5 ± 45.8 in AA group) in colonic tissues and (701 ± 19 & 442.5 ± 22.5 vs 1501 ± 26 in AA group) in hepatic tissues as well as nuclear transcription factor kappa B (NF-kB/p65) levels (416.2 ± 4.1 & 185.5 ± 14.2 vs 659.2 ± 11.5 in AA group) in colonic tissues and (358 ± 6.2 & 163.5 ± 9.6 vs 732.5 ± 5.5 in AA group) in hepatic tissues. In addition, molsidomine significantly decreased inducible nitric oxide synthase (iNOS) levels (8.1 ± 0.1 & 4.9 ± 0.1 vs 16 ± 0.1 in AA group) in colonic tissues and (8.6 ± 0.3 & 6.1 ± 0.1 vs 17.8 ± 0.1 in AA group) in hepatic tissues, and myeloperoxidase (MPO) contents (10.5 ± 0.4 & 6.6 ± 0.3 vs 20.9 ± 0.6 in AA group) in colonic tissues and (13.1 ± 0.2 & 6.3 ± 0.06 vs 23.9 ± 1.4 in AA group) in hepatic tissues at p > 0.05. Furthermore, it suppressed apoptosis by reducing expression of Caspase 3 and Bax in colonic and hepatic tissues. Therefore, molsidomine might be a promising candidate for the treatment of UC.

Formulation, Development and Evaluation of Budesonide Oral Nano-sponges Using DOE Approach: In Vivo Evidences

Purpose: The prevalent types of idiopathic inflammatory bowel disease are ulcerative colitis (UC) and Crohn’s disease, which affects a large number of populations. Budesonide (BUD) is a glucocorticoid with potent anti-inflammatory activity but low systemic efficacy because of high receptor affinity and rapid diversion. To overcome low efficacy and availability, a novel BUD nano-sponges was formulated using quasi- solvent diffusion and Eudragit S-100 as polymer. It was then investigated for the effect of process variables using Box-Behnken design.

Methods: The BUD Nano sponges were evaluated for particle size, particle size, polydispersity, percent drug entrapment, drug release pattern. The formulation was evaluated by an in vivo study using male Wistar rats and parameters such as clinical activity score, colon/body weight ratio (C/B ratio), macroscopic ulceration (damage score) activity were performed. Finally, histopathological examination was performed on colon tissue samples.

Results: The formulation showed better efficacy and availability as compared with the available formulations of BUD, which indicates the good efficacy of the formulated nanosponges. The clinical activity score was attenuated by the formulated nanosponges in the Wistar rats. The colon to body weight ratio was significantly reduced as compared with the control formulation. The histopathology of colon treated with nanosponges showed normal structure and architecture of the colon.

Conclusion: The results of the present work confirmed the utility of BUD nano-sponges as novel carriers in management IBD.