Walaa Wadie

Modulation of TGF-β/Smad and ERK signaling pathways mediates the anti-fibrotic effect of mirtazapine in mice

&NA; Serotonin (5‐HT) has been implicated as a key driver of liver fibrosis, acting via 5‐HT2 receptor activation in the hepatic stellate cells. The current study was conducted to investigate the effects of mirtazapine, a 5‐HT2A antagonist, in a mouse model of liver fibrosis. Mice received thioacetamide (TAA, 150 mg/kg/biweekly, ip) for nine successive weeks for induction of liver fibrosis. Administration of mirtazapine significantly improved the plasma aminotransferases, reduced hepatic 5‐HT concentration and ameliorated TAA‐induced liver fibrosis, as demonstrated by reduced portal blood pressure, liver procollagen I content and &agr; alpha smooth muscle actin expression. Moreover, hepatic collagen deposition was markedly decreased in mirtazapine‐treated mice as evaluated by Massons trichrome staining. Mirtazapine provided an antifibrotic environment by decreasing the liver content of transforming growth factor‐&bgr;1 (TGF‐&bgr;1), and protein kinase C as well as the expression of phosphorylated‐Smad3 (p‐Smad) and phosphorylated extracellular signal‐regulated kinases 1 and 2 (p‐ERK1/2). Additionally, oxidative stress was largely mitigated by mirtazapine as manifested by decreased liver lipid peroxidation and NADPH oxidase 1 along with glutathione replenishment. The current study indicates that mirtazapine suppressed 5‐HT–mediated TGF‐&bgr;1/Smad3 and ERK1/2 signaling pathways as well as oxidative stress that contribute to the progression of liver fibrosis. Graphical abstract Figure. No caption available. HighlightMirtazapine attenuates thioacetamide‐induced liver fibrosis in mice.Mirtazapine decreases the liver content of TGF‐&bgr;1 and PKC.Mirtazapine reduces the expression of p‐Smad3 and p‐ERK1/2.

Bacteria-Derived Compatible Solutes Ectoine and 5α-Hydroxyectoine Act as Intestinal Barrier Stabilizers to Ameliorate Experimental Inflammatory Bowel Disease.

Earlier studies showed that the compatible solute ectoine (1) given prophylactically before induction of colitis by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats prevented histological changes induced in the colon and the associated rise in inflammatory mediators. This study was therefore conducted to investigate whether ectoine (1) and its 5α-hydroxy derivative (2) would also be effective in treating an already established condition. Two days after inducing colitis in rats by instilling TNBS/alcohol in the colon, animals were treated orally once daily for 1 week with either 1 or 2 (50, 100, 300 mg/kg). Twenty-four hours after the last drug administration rats were sacrificed. Ulcerative lesions and colon mass indices were reduced by 1 and 2 in a bell-shaped manner. Best results were obtained with 100 mg/kg ectoine (1) and 50 mg/kg 5α-hydroxyectoine (2). The solutes normalized the rise in myeloperoxidase, TNFα, and IL-1β induced by TNBS but did not affect levels of reduced glutathione or ICAM-1, while reducing the level of fecal calprotectin, an established marker for inflammatory bowel disease. The findings indicate that the naturally occurring compatible solutes ectoine (1) and 5α-hydroxyectoine (2) possess an optimum concentration that affords maximal intestinal barrier stabilization and could therefore prove useful for better management of human inflammatory bowel disease.

Novel sequential stress model for functional dyspepsia: Efficacy of the herbal preparation STW5.

BACKGROUND Many screening procedures for agents with potential usefulness in functional dyspepsia (FD) rely on animals exposed to stress early in life (neonatal maternal separation, NMS) or in adulthood (restraint stress, RS). PURPOSE Since many clinical cases of FD have been associated with stress in early life followed by stress in adulthood, a sequential model simulating the clinical situation is described. To explore the validity of the model, the efficacy of STW5, a multicomponent herbal preparation of proven usefulness in FD, was tested. STUDY DESIGN/METHODS A sequential stress model established where rats are exposed to NMS after birth followed later by RS in adulthood. Stress hormones and ghrelin were measured in plasma, while responsiveness of stomach fundus strips to smooth muscle stimulants and relaxants was assessed ex-vivo. The effectiveness of treatment with STW5 a few days before and during exposure to RS in preventing changes induced by the stress model is reported and compared to its efficacy when used in animals subjected to RS alone. RESULTS Responses to both stimulants and relaxants were reduced to various extents in the studied models, but treatment with STW5 tended to normalize gastric responsiveness. Plasma levels of ghrelin, corticosterone releasing factor, and corticosterone were raised by RS as well as the sequential model. Treatment with STW5 tended to prevent the deranged parameters. CONCLUSION The sequential stress model has a place in drug screening for potential usefulness in FD as it simulates more the clinical setting. Furthermore, the findings shed more light on the mechanisms of action of STW5 in FD.

Effect of Niacin on Inflammation and Angiogenesis in a Murine Model of Ulcerative Colitis

Butyrate and niacin are produced by gut microbiota, however butyrate has received most attention for its effects on colonic health. The present study aimed at exploring the effect of niacin on experimental colitis as well as throwing some light on the ability of niacin to modulate angiogenesis which plays a crucial role of in the pathogenesis of inflammatory bowel disease. Rats were given niacin for 2 weeks. On day 8, colitis was induced by intrarectal administration of iodoacetamide. Rats were sacrificed on day 15 and colonic damage was assessed macroscopically and histologically. Colonic myeloperoxidase (MPO), tumour necrosis factor (TNF)-α, interleukin (IL)-10, vascular endothelial growth factor (VEGF), angiostatin and endostatin levels were determined. Niacin attenuated the severity of colitis as demonstrated by a decrease in weight loss, colonic wet weight and MPO activity. Iodoacetamide-induced rise in the colonic levels of TNF-α, VEGF, angiostatin and endostatin was reversed by niacin. Moreover, niacin normalized IL-10 level in colon. Mepenzolate bromide, a GPR109A receptor blocker, abolished the beneficial effects of niacin on body weight, colon wet weight as well as colonic levels of MPO and VEGF. Therefore, niacin was effective against iodoacetamide-induced colitis through ameliorating pathologic angiogenesis and inflammatory changes in a GPR109A-dependent manner.

Vinpocetine mitigates proteinuria and podocytes injury in a rat model of diabetic nephropathy

ABSTRACT Podocyte injury and glomerular basement membrane thickening have been considered as essential pathophysiological events in diabetic nephropathy. The aim of this study was to investigate the possible beneficial effects of vinpocetine on diabetes‐associated renal damage. Male Wistar rats were made diabetic by injection of streptozotocin (STZ). Diabetic rats were treated with vinpocetine in a dose of 20 mg/kg/day for 6 weeks. Treatment with vinpocetine resulted in a marked decrease in the levels of blood glucose, glycosylated haemoglobin, creatinine, blood urea nitrogen, urinary albumin and albumin/creatinine ratio along with an elevation in creatinine clearance rate. The renal contents of advanced glycation end‐products, interleukin‐10, tissue growth factor‐&bgr;, nuclear factor (NF)‐&kgr;B and Ras‐related C3 botulinum toxin substrate 1 (Rac 1) were decreased. Renal nephrin and podocin contents were increased and their mRNA expressions were replenished in vinpocetine‐treated rats. Moreover, administration of vinpocetine showed improvements in oxidative status as well as renal glomerular and tubular structures. The current investigation revealed that vinpocetine ameliorated the STZ‐induced renal damage. This beneficial effect could be attributed to its antioxidant and antihyperglycemic effects parallel to its ability to inhibit NF‐&kgr;B which eventually modulated cytokines production as well as nephrin and podocin proteins expression. Graphical abstract Figure. No Caption available.

Evidence for the Effectiveness of STW 5 in an Experimental Model of Ulcerative Colitis

G A A b st ra ct s patients were re-assigned to LL (n=84) or LP (n=86) group. Mean changes from baseline at all treatment weeks were statistically significant in all treatment groups for stool consistency, abdominal discomfort/pain, and SBM frequency (p<0.003). L group had statistically significant improvement in stool consistency compared to P group in almost a half of the 12 weekly visits (p<0.03). Similar significant improvements were observed at Weeks 13, 14, and 15 for the LL group (p<0.05). L group had statistically significant mean reduction from baseline in abdominal discomfort/pain at Weeks 10 and 11 compared to P group (p<0.05). Significant results were further observed at Weeks 13, 15, and 16 for the LL group (p<0.04). These results were not seen in the LP group. The range of increase from baseline in SBM frequency at Period I was 2.1-2.9 and 1.4-2.5 for the L and P groups, respectively. LL group had a range of 2.6-3.2, whereas the range for LP group and P group were 2.0-2.7 and 2.12.5, respectively. CONCLUSION: Lubiprostone provided significant improvement in stool consistency, abdominal discomfort/pain, and SBM frequency for standard treatment of 12 weeks, and consistent results of all outcomes were observed during 16 weeks of treatment. Moreover, longer term treatment provided significant reduction in abdominal discomfort/ pain.

Galantamine anti-colitic effect: Role of alpha-7 nicotinic acetylcholine receptor in modulating Jak/STAT3, NF-κB/HMGB1/RAGE and p -AKT/Bcl-2 pathways

Vagal stimulation controls systemic inflammation and modulates the immune response in different inflammatory conditions, including inflammatory bowel diseases (IBD). The released acetylcholine binds to alpha-7 nicotinic acetylcholine receptor (α7 nAChR) to suppress pro-inflammatory cytokines. This provides a new range of potential therapeutic approaches for controlling inflammatory responses. The present study aimed to assess whether galantamine (Galan) anti-inflammatory action involves α7 nAChR in a 2,4,6-trinitrobenzene sulfonic acid (TNBS) model of colitis and to estimate its possible molecular pathways. Rats were assigned into normal, TNBS, sulfasalazine (Sulfz), Galan treated (10 mg/kg), methyllycaconitine (MLA; 5.6 mg/kg), and MLA + Galan groups. Drugs were administered orally once per day (11 days) and colitis was induced on the 8th day. Galan reduced the TNBS-induced ulceration, colon mass index, colonic MDA, neutrophils adhesion and infiltration (ICAM-1/MPO), inflammatory mediators (NF-κB, TNF-α, HMGB1, and RAGE), while increased the anti-apoptotic pathway (p-Akt/Bcl-2). Mechanistic study revealed that Galan increased the anti-inflammatory cytokine IL-10, phosphorylated Jak2, while reduced the inflammation controller SOCS3. However, combining MLA with Galan abrogated the beneficial anti-inflammatory/anti-apoptotic signals. The results of the present study indicate that Galan anti-inflammatory/-apoptotic/ -oxidant effects originate from the stimulation of the peripheral α7 nAChR, with the involvement of the Jak2/SOCS3 signaling pathway.

Cilostazol disrupts TLR-4, Akt/GSK-3β/CREB, and IL-6/JAK-2/STAT-3/SOCS-3 crosstalk in a rat model of Huntington's disease

Countless neurodegenerative diseases are associated with perverse multiple targets of cyclic nucleotide signalling, hastening neuronal death. Cilostazol, a phosphodiesterase-III inhibitor, exerts neuroprotective effects against sundry models of neurotoxicity, however, its role against Huntington’s disease (HD) has not yet been tackled. Hence, its modulatory effect on several signalling pathways using the 3-nitropropionic acid (3-NP) model was conducted. Animals were injected with 3-NP (10 mg/kg/day, i.p) for two successive weeks with or without the administration of cilostazol (100 mg/kg/day, p.o.). Contrary to the 3-NP effects, cilostazol largely preserved striatal dopaminergic neurons, improved motor coordination, and enhanced the immunohistochemical reaction of tyrosine hydroxylase enzyme. The anti-inflammatory effect of cilostazol was documented by the pronounced reduction of the toll like receptor-4 (TLR-4) protein expression and the inflammatory cytokine IL-6, but with a marked elevation in IL-10 striatal contents. As a consequence, cilostazol reduced IL-6 downstream signal, where it promoted the level of suppressor of cytokine signalling 3 (SOCS3), while abated the phosphorylation of Janus Kinase 2 (JAK-2) and Signal transducers and activators of transcription 3 (STAT-3). Phosphorylation of the protein kinase B/glycogen synthase kinase-3β/cAMP response element binding protein (Akt/GSK-3β/CREB) cue is another signalling pathway that was modulated by cilostazol to further signify its anti-inflammatory and antiapoptotic capacities. The latter was associated with a reduction in the caspase-3 expression assessed by immunohistochemical assay. In conclusion the present study provided a new insight into the possible mechanisms by which cilostazol possesses neuroprotective properties. These intersecting mechanisms involve the interference between TLR-4, IL-6-IL-10/JAK-2/STAT-3/SOCS-3, and Akt/GSK-3β/CREB signalling pathways.

Sodium selenite ameliorates both intestinal and extra-intestinal changes in acetic acid-induced colitis in rats

Selenium and its derivatives including sodium selenite (sod sel) belong to the group of essential trace elements needed for proper health and nutrition. They are fairly safe and possess antioxidant and anti-inflammatory properties. The aim of present investigation was to elucidate the effect of sod sel on experimental colitis model in rats. Colitis was induced by intrarectal instillation of 4% (v/v) acetic acid. Two hours later, sod sel was given to rats on a daily basis for 15 consecutive days. Clinical symptoms, colon mass index, spleen weight inflammatory markers, hematological, biochemical, macroscopic, and histological changes were determined. Sod sel markedly ameliorated colitis as evidenced by a significant decrease in macroscopic and microscopic score, disease activity index, colon mass index, and spleen weight. Treatment with sod sel attenuated oxidative stress in the colon by normalizing the colonic content of nitric oxide, malondialdehyde, and reduced glutathione, as well as the activities of catalase, superoxide dismutase, and junctional adhesion molecule (JAM-a). In addition, it significantly reduced colonic myeloperoxidase content, the intercellular adhesion molecule (ICAM-1), and the proinflammatory cytokines; TNF-α, IL-1β. Moreover, sod sel normalized hematological parameters, serum transaminases, and kidney and liver function enzymes. The current study indicates that sod sel was effective in ameliorating the intestinal and extra-intestinal manifestation in acetic acid-induced colitis through its antioxidant, anti-inflammatory, and immunomodulatory effects.

Tu1440 Discovering New Underlying Mechanisms in the Treatment of Functional Dyspepsia With the Herbal Preparation, STW5 Using a Novel Sequential Stress Model

Introduction A small subset of patients with cyclical vomiting syndrome (CVS) appear to be at risk for frequent hospital readmissions. Predictors of hospital readmissions in CVS patients are not known. We hypothesized that history of psychiatric comorbidity, opioid drug use, lack of insurance, and African American ethnicity influence readmissions. Methods A retrospective review of a prospectively maintained database of CVS patients seen at the Medical College of Wisconsin (MCW) was performed. Only patients residing in the greater Milwaukee area were included to accurately assess hospitalizations and length of hospital stay. Number of hospitalizations during the year prior to and after the initial clinic visit at MCW was determined. Patients were classified into two groups, high utilizers (HU: >= 2 admissions/year) and low utilizers (LU: <2 admissions/year) based on the number of hospitalizations during the first year of follow up. Socio-demographic data, disease and discharge characteristics were assessed for both groups starting from the initial clinic visit to the end of follow up period. Comparison between the two groups was performed using a Students t-test and Chi square test. Results There were a total of 118 patients of whom most were female (70.3% vs. 29.6%), Caucasian (72.8% vs. 23.7%), unmarried (60.1% vs. 34.7%), and privately insured (62.2% vs. 33.3%). Mean follow up period was 3.16 years (+/2.08). After the initial clinic visit and during the first year of follow up, number of hospitalizations and length of stay were reduced by 50% in both groups (HU and LU) compared to the year prior (p<0.0001). The length of stay during the first year of follow up (5.8 vs 1.3 days, p=0.0006), average yearly length of stay (4.6 vs 0.8 days, p<0.0001), and average yearly admissions (1.6 vs 0.27, p<0.0001) remained significantly higher in HU compared to LU. HU were more likely to be African American (48.1% vs 16.4%, p=0.002) and have a history of current opioid use (36.3% vs 17.6%, p=0.03) compared to LU (Table 1). Patients who were discharged without follow up appointments were 33% more likely to be hospitalized during the remainder of the follow up period (p=0.0003).There were no significant differences in age, gender, psychiatric comorbidity and insurance status between the two groups. Conclusions African American race, and opioid use were associated with increased hospital readmissions. Reasons for this disparity in health care utilization are unclear and warrant further investigation as addressing these issues can potentially improve health care outcomes. Table 1. Predictors of hospitalization in patients with cyclical vomiting syndrome