The effect of the angiotensin II receptor, type 1 receptor antagonists, losartan and telmisartan, on thioacetamide-induced liver fibrosis in rats

It has been reported previously that the density of angiotensin II receptors is increased in the rat liver in experimentally-induced fibrosis. We hypothesized that pharmacological blockade of angiotensin receptors may produce beneficial effects in models of liver fibrosis. In this study, we used the widely used thioacetamide (TAA)-induced model of liver fibrosis (300 mg/L TAA ad libitum for 12 weeks). Rats received daily injections (i.p), lasting 4 weeks of the angiotensin II type 1 receptor antagonists, losartan 30 mg/kg (TAA + L) or telmisartan 10 mg/kg (TAA + T) and were compared to rat that received TAA alone. Chronic treatment with losartan and telmisartan was associated with a significant reduction in the activity of alkaline phosphatase, and decreased concentrations of tumor necrosis factor-alpha and transforming growth factor beta-1 compared to controls. We also found a significant reduction interleukin-6 in rats receiving telmisartan (P < 0.05) but not losartan. Both treatments increased the concentration of liver glutathione along with a concomitant decrease of GSSG compared to controls. In addition, increased paraoxonase 1 activity was observed in the serum of rats receiving telmisartan group compared to the TAA alone controls. Finally, histological evaluation of liver sections revealed losartan and telmisartan treatment was associated with reduced inflammation and liver fibrosis. Taken together, these results indicate that both telmisartan and losartan have anti-inflammatory and anti-oxidative properties in the TAA model of liver fibrosis. These finding add support to a growing body of literature indicating a potentially important role for the angiotensin system in liver fibrosis and indicate angiotensin antagonists may be useful agents for fibrosis treatment.

Expression of death receptor 3 on peripheral blood mononuclear cells differes in adult IBD patients and children with newly diagnosed IBD

BACKGROUND

Interaction between TL1A and death receptor 3 (DR3) is associated with the pathogenesis of inflammatory bowel disease (IBD), although their role in the development of this disease remains not fully explained. Some studies showed elevated expression of TL1A and DR3 in inflamed intestinal tissue but currently there are no reports concerning expression of DR3 on peripheral blood mononuclear cells (PBMCs) of IBD patients which was the subject of our study.

METHODS

We performed flow cytometry analysis of DR3 expression on CD4(+), CD8(+), CD11c(+), CD14(+) or CD20(+) PBMCs of adults and children with IBD and healthy volunteers with respect to C-reactive protein (CRP) levels in blood. Blood samples were collected from pediatric patients before the beginning of therapy, whereas adults patients were undergoing anti-inflammatory IBD treatment and had much lower CRP levels.

RESULTS

With regard to appropriate healthy volunteers, children with IBD had elevated percentage of DR3-expressing CD4(+), CD8(+), CD11c(+) and CD20(+) PBMCs which, with the exception of DR3(+) CD11c(+) cells in children with ulcerative colitis, was correlated with CRP level in blood. Adult patients had increased frequency of DR3(+) CD8(+) and CD20(+) PBMCs and their CRP levels correlated only with DR3(+) CD8(+) cells.

CONCLUSIONS

In comparison to healthy volunteers, untreated children with IBD have higher percentage of DR3(+) PBMCs than adults with IBD undergoing anti-inflammatory treatment. In most of the investigated PBMCs populations, the frequency of DR3(+) cells is correlated with the level of CRP. We suggest anti-inflammatory treatment may lead to reduction in the frequency of DR3(+) PBMCs. © 2016 International Clinical Cytometry Society.

Effects of renin-angiotensin system inhibitors on fibrosis in patients with alcoholic chronic pancreatitis

Chronic pancreatitis (CP) results in impairment of exocrine as well as endocrine functions and progressive fibrosis. Previous studies, have demonstrated the presence of renin-angiotensin system receptors within different pancreatic cells. The aim of the present study was to assess the effects of renin-angiotensin system (RAS) inhibitors on serum levels of fibrosis biomarkers (matrix metalloproteinase 2 and 9 (MMP-2, MMP-9), tissue inhibitor of MMP (TIMP- 1, TIMP-2), hyaluronic acid (HA)) and fasting glucose levels in patients with alcoholic CP. Seventy seven outpatients (mean age 43 years, 62 males) with diagnosed alcoholic CP were randomly enrolled into 5 study groups depending on the RAS inhibitors administered and their doses (2.5 or 5 mg and 12.5 or 25 mg for ramipril or losartan, respectively). Venous blood was sampled monthly for a period of one year to monitor serum drug levels. MMP-2, -9, TIMP-1, TIMP-2 and HA were measured with ELISA method on the onset and at the end of the study. Only forty five patients regularly participated in follow-up visits and completed the study. The fluctuations in serum HA levels observed among patients from the remaining groups also did not reach statistical significance. Serum MMP-2 levels (P = 0.06) and MMP-2/TIMP-1 ratio (P = 0.06) showed increasing tendency in the losartan 25 mg group. High doses of ramipril and losartan statistically significantly reduced fasting glucose levels. High doses of losartan can increase the MMP-2 activity in serum of alcoholic CP patients, which potentially is likely to affect turnover of extracellular matrix proteins within the pancreas. Moreover, high doses of both RAS inhibitors decrease the fasting glucose level.

Protective effects of melatonin against thioacetamide-induced liver fibrosis in rats

The aim of this study was to determine the effect of melatonin on thioacetamide (TAA) induced liver fibrosis in rats. The antifibrotic effects of melatonin were assessed by determining activity indirect markers of fibrosis: aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), and proinflammatory cytokines: interleukin 6 (IL-6), interleukin-1beta (IL-1β), tumour necrosis factor alpha (TNF-α), transforming growth factor-beta (TGF-β) and platelet-derived growth factor (PDGF). Parameters of oxidative stress: oxidised glutathione (GSSG), reduced glutathione (GSH) and presaged activity of paraoxonase 1 (PON-1), an antioxidative enzyme were determined. Inflammatory changes and fibrosis extent were evaluated histologically. Experiments were carried out in Wistar rats. Animals were divided into 4 groups: I - controls, water ad libitum for 12 weeks, group II - TAA, 300 mg/L ad libitum for 12 weeks, III - melatonin, 10 mg/kg b.w. intraperitoneally (i.p.) daily for 4 weeks, IV - TAA, 300 mg/L ad libitum for 12 weeks followed by melatonin, 10 mg/kg/b.w. i.p. daily for 4 weeks. Results of serum determinations demonstrated significantly lower activity of AST, ALT and AP in the group receiving TAA followed by melatonin compared to the group receiving only TAA. Immunoenzymatic findings on effect of melatonin on concentration of proinflammatory cytokines confirmed these data. Biochemical examinations in liver homogenates revealed statistically significant improvement (concentration of GSH increases and concentration of GSSG decreases) in animals with TAA-induced liver damage receiving melatonin. Moreover, the activity of PON-1 toward phenyl acetate and paraoxon was increased in liver homogenates and serum in the group receiving TAA followed by melatonin compared to the TAA group without melatonin treatment. Microscopic evaluation disclosed inhibitory effects of melatonin on inflammatory changes and extent of liver fibrosis.

Effects of treatment with melatonin and tryptophan on liver enzymes, parameters of fat metabolism and plasma levels of cytokines in patients with non-alcoholic fatty liver disease--14 months follow up

Non-alcoholic fatty liver disease (NAFLD), most common chronic hepatic pathology, that occurs in the developed countries is estimated at 1/3 of the population. Amongst the numerous pathogenetic factors, oxidative stress and apoptosis of hepatocytes initiate many inflammatory processes and are involved in the progression of disease, particularly in transformation of non-alcoholic steatohepatitis (NASH) to cirrhosis. The aim of our study was to determine the effects of tryptophan and melatonin on the selected biochemical parameters in patients with NAFLD, and additionally, to evaluate the effects of tryptophan and melatonin in improvement of liver tissue in selected NAFLD patients. Seventy four patients with NAFLD confirmed by histopathological examination of liver biopsy samples, were admitted to the study. They were randomly assigned to three groups. Group I received the preparation Essentiale forte in the dose of 3 x 1 tablet per day and tryptophan 2 x 500 mg/day over the period of 14 months, group II received Essentiale forte and melatonin 2 x 5 mg/day over 14 months and group III received only Essentiale over the period of 14 months. In nine patients of groups I, II, and III, the liver biopsy was performed after 14-months of treatment period. Out of nine patients whom biopsy was performed, three of them were from group I, four from group II and two of them were from group III, respectively. After the 14-month treatment period, gamma-glutamyl transferase (GGPT) activity and levels of triglycerides and LDL-cholesterol were found to be significantly reduced in group I and II. The level of melatonin after the therapy was significantly elevated in group I and II and did not change in group III. Statistically significantly lower levels of IL-1, IL-6 and TNF-α were observed in patients receiving melatonin and tryptophan, comparing with group III treated with Essentiale forte only. These study findings demonstrate that melatonin and tryptophan substantially reduce the levels of pro-inflammatory cytokines and improve some parameters of fat metabolism in patients with NAFLD. In few patients with NASH melatonin and tryptophan reduced the inflammation in liver. We conclude that melatonin is worth considering for the therapy of NAFLD, particularly in patients with impaired fat metabolism accompanied by hypertriglyceridemia and hyper-LDL cholesterolemia.

Comparison of anti-inflammatory properties of peroxisome proliferator-activated receptor gamma agonists rosiglitazone and troglitazone in prophylactic treatment of experimental colitis

Non-specific inflammatory bowel disease (IBD), including ulcerative colitis and Crohn`s disease, is a chronic noninfectious inflammatory disease whose incidence is increasingly high, especially in the developed countries. Effective methods of its treatment and prevention of recurrences are still under investigation. Amongst the options to control effectively the inflammatory processes of the gastrointestinal tract are thiazolidinediones - peroxisome proliferator-activated receptors gamma (PPAR-γ) agonists, whose beneficial effects on macroscopic and histopathological features of colitis have been confirmed in numerous studies. In the present study, possible effects of PPAR-γ agonists rosiglitazone and troglitazone enhancing the resistance of colonic tissues to the damaging factor were examined and compared. Rats received the food with 0.01% rosiglitazone or troglitazone for 4 weeks; during the final 2 weeks, colitis-inducing 1.5% DSS (dextran sodium sulfate) was additionally administered in the drinking water. The large intestine specimens were microscopically evaluated and the levels of Th1- (IL-2, INF) and Th2-dependent (IL-4, IL-10) cytokines were determined in the serum and intestinal homogenates. Prophylactic treatment with rosiglitazone and troglitazone ameliorated colitis substantially down-regulating the microscopic inflammatory parameters. Rosiglitazone and troglitazone administered before the induction of colitis exerted comparable effects on colitis. Both substances significantly reduced the levels of pro-inflammatory cytokines and increased the levels of inflammation-limiting cytokines. We conclude that thiazolidinedione drugs are likely to be successfully used for therapy and prevention of non-specific bowel diseases.

The effects of the adenosine A3 receptor agonist IB-MECA on sodium taurocholate-induced experimental acute pancreatitis

The role of adenosine A3 receptors and their distribution in the gastrointestinal tract have been widely investigated. Most of the reports discuss their role in intestinal inflammations. However, the role of adenosine A3 receptor agonist in pancreatitis has not been well established. The aim of this study is [corrected] to evaluate the effects of the adenosine A3 receptor agonist on the course of sodium taurocholate-induced experimental acute pancreatitis (EAP). The experiments were performed on 80 male Wistar rats, 58 of which survived, subdivided into 3 groups: C--control rats, I--EAP group, and II--EAP group treated with the adenosine A3 receptor agonist IB-MECA (1-deoxy-1-6[[(3-iodophenyl) methyl]amino]-9H-purin-9-yl)-N-methyl-B-D-ribofuronamide at a dose of 0.75 mg/kg b.w. i.p. at 48, 24, 12 and 1 h before and 1 h after the injection of 5% sodium taurocholate solution into the biliary-pancreatic duct. Serum for α-amylase and lipase determinations and tissue samples for morphological examinations were collected at 2, 6, and 24 h of the experiment. In the IB-MECA group, α-amylase activity was decreased with statistically high significance compared to group I. The activity of lipase was not significantly different among the experimental groups but higher than in the control group. The administration of IB-MECA attenuated the histological parameters of inflammation as compared to untreated animals. The use of A3 receptor agonist IB-MECA attenuates EAP. Our findings suggest that stimulation of adenosine A3 receptors plays a positive role in the sodium taurocholate-induced EAP in rats.

Underexpression of LATS1 TSG in colorectal cancer is associated with promoter hypermethylation

AIM

To investigate large tumor suppressor 1 (LATS1) expression, promoter hypermethylation, and microsatellite instability in colorectal cancer (CRC).

METHODS

RNA was isolated from tumor tissue of 142 CRC patients and 40 colon mucosal biopsies of healthy controls. After reverse transcription, quantitative polymerase chain reaction (PCR) was performed, and LATS1 expression was normalized to expression of the ACTB and RPL32 housekeeping genes. To analyze hypermethylation, genomic DNA was isolated from 44 tumor CRC biopsies, and methylation-specific PCR was performed. Microsatellite instability (MSI) status was checked with PCR using BAT26, BAT25, and BAT40 markers in the genomic DNA of 84 CRC patients, followed by denaturing gel electrophoresis.

RESULTS

Decreased LATS1 expression was found in 127/142 (89.4%) CRC cases with the average ratio of the LATS1 level 10.33 ± 32.64 in CRC patients vs 32.85 ± 33.56 in healthy controls. The lowest expression was found in Dukes' B stage tumors and G1 (well-differentiated) cells. Hypermethylation of the LATS1 promoter was present in 25/44 (57%) CRC cases analyzed. LATS1 promoter hypermethylation was strongly associated with decreased gene expression; methylated cases showed 162× lower expression of LATS1 than unmethylated cases. Although high-grade MSI (mutation in all three markers) was found in 14/84 (17%) cases and low-grade MSI (mutation in 1-2 markers) was found in 30/84 (36%) cases, we found no association with LATS1 expression.

CONCLUSION

Decreased expression of LATS1 in CRC was associated with promoter hypermethylation, but not MSI status. Such reduced expression may promote progression of CRC.

Comparison of the anti-inflammatory and therapeutic actions of PPAR-gamma agonists rosiglitazone and troglitazone in experimental colitis

Non-specific inflammatory bowel diseases, including ulcerative colitis and Crohn`s disease, are chronic non-infectious diseases that showed an increase in prevalence in recent years, particularly in the developed countries. The effective methods of their treatment and prevention of recurrences are currently under investigation. One type of therapy that can prevent the inflammatory recurrence in the gastrointestinal tract is the PPAR-γ agonists thiazolidinediones. Numerous studies available in literature have confirmed the beneficial effects of thiazolidinediones (glitazones), namely rosiglitazone and troglitazone in the gut. The objective of the present study was to compare the possible effects of rosiglitazone 10 mg/kg b.w. or 30 mg/kg b.w. and troglitazone 30 mg/kg b.w. on experimental colitis induced by administration of 1.5% dextran sodium sulphate (DSS) administered in drinking water to rats. Specimens collected from the large intestine were microscopically evaluated, and concentrations of Th1- dependent (IL-2, INF) and Th2-dependent (IL-4, IL-10) cytokines were determined in the serum and intestinal homogenates. Both rosiglitazone and troglitazone have demonstrated significant anti-inflammatory properties. This observation was confirmed by histopathological and immunoenzymatic tests. The therapeutic efficacy of rosiglitazone was dose-dependent. Troglitazone resulted in significantly stronger enhancement of anti-inflammatory cytokine expression than rosiglitazone and comparable downregulation of pro-inflammatory cytokine expression compared to rosiglitazone used in a higher dose.

The decrease of serum MMP-2 activity corresponds to alcoholic cirrhosis stage

Because of numerous limitations for liver biopsy, a noninvasive marker of liver cirrhosis is sought. Promising indicators seem to be matrix metalloproteinases (MMPs) that are responsible for degradation of extracellular matrix. The aim of the study was to evaluate the gelatinase activities (MMP-2 and MMP-9) in patients with different stages of alcoholic cirrhosis. Sixty-seven outpatients who presented various stages of alcoholic cirrhosis according to Child-Turcotte-Pugh criteria and 26 healthy control subjects were enrolled. Blood samples were collected for MMP-2 and MMP-9 activities. A significant decrease of serum MMP-2 activity was noted in stages B and C of cirrhosis in comparison with control. Serum MMP-9 activity did not depend on the stage of cirrhosis. The MMP-2 levels, but not those of MMP-9, may be of value in understanding the pathogenesis and progression of alcoholic cirrhosis.

Effects of melatonin and tryptophan on healing of gastric and duodenal ulcers with Helicobacter pylori infection in humans

Melatonin (MT) and its precursor L-tryptophan (TRP) are implicated in the protection of gastric mucosa against aspirin-induced lesions and in the acceleration of healing of idiopathic gastro-duodenal ulcers, but no information is available whether these agents are also effective in healing of gastroduodenal ulcers accompanied by Helicobacter pylori (H. pylori) infection. In this study three groups A, B and C, each including 7 H. pylori-positive patients with gastric ulcers and 7 H. pylori-positive patients with duodenal ulcers, aging 28-50 years, were randomly assigned for the treatment with omeprazole 20 mg twice daily combined with placebo (group A), MT administered in a dose of 5 mg twice daily (group B) or TRP applied in a dose of 250 mg twice daily (group C). All patients underwent routine endoscopy at day 0 during which the gastric mucosa was evaluated and gastric biopsies were taken for the presence of H. pylori and histopathological evaluation. The rate of ulcer healing was determined by gastroduodenoscopy at day 0, 7, 14 and 21 after the initiation of the therapy. Plasma MT, gastrin, ghrelin and leptin were measured by specific RIA. At day 21, all ulcers were healed in patients of groups B and C but only 3 out of 7 in group A of gastric ulcers and 3 out of 7 in duodenal ulcers. Initial plasma MT showed similar low levels in all three groups but it increased several folds above initial values in ulcer patients at day 7, 14 and 21. Plasma gastrin and leptin levels showed a significant rise over initial values in patients treated with omeprazole and placebo, MT or TRP while plasma ghrelin levels were not significantly affected by these treatments. We conclude that MT or TRP added to omeprazole treatment, significantly accelerates healing rate of H. pylori infected chronic gastroduodenal ulcers over that obtained with omeprazole alone and this likely depends upon the significant rise in plasma MT and possibly also in leptin levels, both hormones involved in the mechanism of gastroprotection and ulcer healing.

Activated and inactivated PPARs-γ modulate experimentally induced colitis in rats

Background

This study sought to define the mechanism by which PPAR-γ ligands affect the course of experimentally induced colitis in rats.

Material/Methods

Inflammation was induced in Wistar rats by a single rectal administration of 2,4,6,-trinitrobenzene sulfonic acid (TNBS). The antagonist of PPARγ antagonist, bisphenol A diglycidyl ether (BADGE), was administrated intraperitoneally 120 mg/kg 4 times every other day. Rosiglitazone 8 mg/kg was administrated by gastric tube 4 times. Body weight was measured daily. After killing, the large intestinal tissue was weighed and collected for histopathologic and immunoenzymatic tests. Levels of IL-6, IL-10, and myeloperoxidase (MPO) were determined in serum and in intestinal homogenates.

Results

Rats receiving rosiglitazone had higher body weight, whereas large intestine weight/length ratio was lower; histology showed fewer inflammatory markers. Rats receiving TNBS and TNBS along with BADGE had more intensive inflammatory changes. Rosiglitazone alone decreased expression of IL-6; used with TNBS it decreased expression of MPO in intestinal tissue, yet did not increase the expression of IL-10. Decreased levels of MPO indicate reduced neutrophil-dependent immune response. The antagonist of PPAR-γ increased IL-6 in serum and decreased IL-10 in intestinal homogenates. Bisphenol A diglycidyl ether administrated to healthy animals increases serum IL-6 levels.

Conclusions

Rosiglitazone inhibits experimental inflammation; administration of its selective antagonist abolishes this protective influence. Rosiglitazone inhibits expression of proinflammatory IL-6 and does not affect IL-10. Agonists of PPARs-γ are possibilities for inflammatory bowel disease prevention. Exogenous substances blocking PPARs-γ may contribute to development or relapse of nonspecific inflammatory bowel diseases.

Effects of peroxisome proliferator-activated receptors-gamma ligands on dextran sodium sulphate-induced colitis in rats

Recent studies indicate the involvement of peroxisone proliferator-activated receptor-γ (PPAR-γ) in the inflammatory reaction. The exact mechanism of PPAR-γ action has not been elucidated. It is supposed that PPAR-γ regulates transcription of genes responsible for encoding cytokines involved in the inflammatory response. The latest studies, carried out to explain the pathogenesis of non-specific colitis, confirm beneficial effects of PPAR-γ agonists on attenuation of colon inflammation. The aim of the present study was to assess the effects of nuclear PPAR-γ activity on the course of experimental acute colitis induced by intragastric administration of dextran sodium sulphate (DSS) using the PPAR-γ agonist rosiglitazone and the antagonist BADGE in rats. Colitis in Wistar rats was induced by 1.5% DSS administered in drinking water for 8 days. Animals with induced colitis received rosiglitazone, bisphenol A diglycidyl ether (BADGE) or both substances. After decapitation, colons were macroscopically and histopathologically evaluated. Levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) were determined in serum and colon homogenates using ELISA. In rats with experimentally induced colitis receiving rosiglitazone, the inflammatory reaction was found to be markedly limited; ulceration, oedema and infiltration activity were reduced. The activated PPAR-γ inhibit the expression of proinflammatory factors, such as IL-6, TNF-α, and neutrophil chemotaxis, which was evidenced by MPO reduction in serum and colon homogenates mediated by rosiglitazone. The positive effects of rosiglitazone on expression of IL-10 were also demonstrated. During the short period of observation, BADGE did not increase histopathological inflammatory markers.

Melatonin or L-tryptophan accelerates healing of gastroduodenal ulcers in patients treated with omeprazole

Melatonin and L-tryptophan (Trp) are highly gastroprotective in humans, but no study has assessed their impact on healing of chronic gastroduodenal ulcers in humans. Three groups (A, B and C) of 14 idiopathic patients in each treatment group with gastroduodenal chronic ulcers were treated with omeprazole (20 mg twice daily) combined either with placebo (group A), melatonin (group B) or with Trp (group C). The rate of ulcer healing was determined by gastroduodenoscopy at day 0, 7, 14 and 21 after initiation of therapy. Plasma melatonin, gastrin, ghrelin and leptin were measured by RIA. On day 7, omeprazole by itself (group A) had not healed any ulcers, but four ulcers were healed with omeprazole plus melatonin and two with omeprazole plus tryptophan. At day 21, all ulcers were healed in patients treated with melatonin or Trp, but only 10-12 ulcers were healed in placebo-treated patients. After treatment with omeprazole plus melatonin (group B) or Trp (group C), plasma melatonin levels rose several-fold above initial values. Plasma gastrin level also rose significantly during treatment with omeprazole plus melatonin or Trp, but it was also significantly increased in patients treated with omeprazole plus placebo. Plasma ghrelin levels did not change significantly after treatment with melatonin or Trp, while plasma leptin increased significantly in patients treated with melatonin or Trp but not with placebo. We conclude that melatonin or Trp, when added to omeprazole treatment, accelerates ulcer healing and this likely depends mainly upon the significant increments in plasma melatonin.

Influence of the peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist, rosiglitazone and antagonist, biphenol-A-diglicydyl ether (BADGE) on the course of inflammation in the experimental model of colitis in rats

PPAR-γ plays a role in the development of immune response, particularly in inflammation. The inflammatory reaction may be stimulated or suppressed by the presence of PPAR ligands. Some researchers suggest positive influence of the PPAR-γ agonist on suppression of the intestinal inflammatory process, yet there has not been much evidence showing that the antagonist of PPAR-γ can affect the inflammatory process. The aim of the present study was to define the mechanism by which PPAR-γ ligands affect the course of experimentally induced colitis in rats. Colitis was induced in rats by rectal administration of TNBS (trinitrobenzene sulfonate). Rosiglitazone was administrated to animals at the dose of 8 mg/kg four times via an intra-gastric probe. Biphenol-A-diglicydyl ether (BADGE) was administrated intraperitoneally at the dose of 120 mg/kg, three times every second day. One group of animals received rosiglitazone together with BADGE before the induction of inflammation. Histological and ELISA examinations of large intestine samples were performed. Levels of IL-1β, IL-6, TNF-α cytokines were determined in serum and homogenates. Rats exposed to rosiglitazone had higher body weight yet lower large intestine weight. Histological findings showed less ulceration, lower expression of crypts' loss and smaller oedema. Animals, which did not receive rosiglitazone, and those receiving it together with BADGE, developed more severe inflammatory changes. Rosiglitazone decreased the expression of inflammatory cytokines, such as IL-6 and TNF-α, both in serum and in intestinal homogenates. BADGE used with TNBS did not increase the expression of inflammatory cytokines; however, applied together with rosiglitazone, it caused inflammation similar to that observed among rats with experimentally induced colitis. Rosiglitazone reduces inflammation by decreasing the expression of IL-6 and TNF-α. BADGE administered with rosiglitazone blocks the activity of PPAR-γ and abolishes the protective effects of PPAR-γ agonist.

The effects of L-tryptophan and melatonin on selected biochemical parameters in patients with steatohepatitis

Nonalcoholic fatty liver disease is the most common chronic liver disease and nonalcocholic steatohepatitis (NASH) is its advanced form. Oxidative stress and hepatocyte apoptosis may be involved in pathogenesis of NASH and particularly in progress of NASH to liver fibrosis and cirrhosis, which are initiated by the inflammation and which promote the progress of the disease. The aim of this study was to evaluate the effects of melatonin and L-tryptophan on selected biochemical parameters of blood in patients with NASH. Forty five patients with NASH, confirmed by histopathological examination of liver biopsy samples, were admitted to the study. They were divided into three groups (I, II and III). The first group (group I, n=15) received preparation Essentiale forte 3 times a day and tryptophan 500 mg twice daily for 4 weeks. In the second group (group II, n=15), Essentiale forte three times a day was administered with melatonin 5 mg applied twice a day for 4 weeks. The third group (group III, n=15) received only Essentiale forte with placebo three times a day for 4 weeks. After four-week treatment we found statistically significant reduction in GGTP, triglycerides and proinflammatory cytokine levels in the melatonin-treated (group I) and the L-tryptophan-treated patients (group II). Plasma level of melatonin was significantly elevated in groups treated with tryptophan (group I) and melatonin (group II), but remained unchanged in placebo-treated group (group III). Among patients from the third group (treated with placebo) no statistically significant differences in the measured biochemical parameters were observed. The present study suggests that melatonin and tryptophan have the significant impact on the reduction in plasma levels of proinflammatory cytokines and may be useful in the treatment of patients with NASH.

Role of melatonin in mucosal gastroprotection against aspirin-induced gastric lesions in humans

Melatonin and its precursor, l-tryptophan, have been shown to exert gastroprotective effects in animals, but their influence on the gastric damage by aspirin (ASA) in humans has been sparingly investigated. In this study, we designed to determine the effects of melatonin and l-tryptophan on ASA-induced gastric mucosal damage, gastric microbleeding, mucosal generation of prostaglandin E(2), and plasma melatonin, and gastrin levels. Three groups of healthy male volunteers (n = 30) with intact gastric mucosa received daily for 11 days either ASA alone or that combined with melatonin or tryptophan. Gastric blood loss and mucosal damage were evaluated at 3rd, 7th, and 11th days of ASA administration by endoscopy using Lanza score. ASA alone caused a marked rise of gastric damage and gastric blood loss, mainly at day 3rd and 7th, but they were significantly reduced at 11th day. Pretreatment with melatonin or tryptophan remarkably reduced ASA induced gastric lesions and microbleeding. Gastric mucosal generation of PGE(2) was suppressed by about 90% in all subjects treated with ASA alone without or with addition of melatonin or tryptophan. Plasma melatonin was markedly increased after treatment with melatonin or tryptophan plus ASA, but it was also raised significantly after application of ASA alone. Plasma gastrin levels were raised in subjects given melatonin or tryptophan plus ASA, but not in those with ASA alone. We conclude that melatonin and its precursor tryptophan given orally significantly reduce gastric lesions induced by ASA possibly due to (a) direct gastroprotective action of exogenous melatonin or that generated from tryptophan and (b) gastrin released from the gastric mucosa by melatonin or tryptophan.

Overexpression of the fragile histidine triad (FHIT) gene in inflammatory bowel disease

OBJECTIVE

FHIT gene encodes human diadenosine triphosphate hydrolase involved in the regulation of cell cycle and nucleotide metabolism and is a candidate tumor suppressor gene.

AIM

To investigate expression of FHIT gene at the mRNA and protein levels in sporadic inflammatory bowel disease (IBD).

MATERIALS AND METHODS

FHIT mRNA was quantified by the validated real-time PCR (QPCR) and FHIT protein was detected by immunohistochemistry (IHC) in mucosal biopsies of 139 ulcerative colitis (UC), 19 Crohn's disease (CD) and 37 control patients.

RESULTS

Significant FHIT gene overexpression was found in 78% of active UC but not in CD. IHC showed comparable results to QPCR.

CONCLUSION

The local up-regulation of FHIT gene and protein expression in active UC may represent an adequate response against inflammatory challenge of epithelial cell homeostasis and protect against DNA damage and cell cycle disturbances.

Altered basal and postprandial plasma melatonin, gastrin, ghrelin, leptin and insulin in patients with liver cirrhosis and portal hypertension without and with oral administration of melatonin or tryptophan

This investigation was designed to assess the effects of oral administration of melatonin (10 mg) and tryptophan (Trp) (500 mg) on fasting and postprandial plasma levels of melatonin, gastrin, ghrelin, leptin and insulin in 10 healthy controls and in age-matched patients with liver cirrhosis (LC) and portal hypertension. Fasting plasma melatonin levels in LC patients were about five times higher (102 +/- 15 pg/mL) than in healthy controls (22 +/- 3 pg/mL). These levels significantly increased postprandially in LC patients, but significantly less so in controls. Treatment with melatonin or L-Trp resulted in a further significant rise in plasma melatonin, both under fasting and postprandial conditions, particularly in LC patients. Moreover, plasma gastrin, ghrelin, leptin and insulin levels under fasting and postprandial conditions were significantly higher in LC subjects than in healthy controls and they further rose significantly after oral application of melatonin or Trp. This study shows that: (a) patients with LC and portal hypertension exhibit significantly higher fasting and postprandial plasma melatonin levels than healthy subjects; (b) plasma ghrelin, both in LC and healthy controls reach the highest values under fasting conditions, but decline postprandially, especially after oral application of melatonin or Trp; and (c) plasma melatonin, gastrin, ghrelin and insulin levels are altered significantly in LC patients with portal hypertension compared with that in healthy controls possibly due to their portal systemic shunting and decreased liver degradation.

Melatonin and its precursor L-tryptophan prevent acute gastric mucosal damage induced by aspirin in humans

Melatonin (MT) and its precursor L-tryptophan (Trp) are implicated in the protection of gastric mucosa against noxious agents. However, the role of MT and Trp on the gastric mucosal injury induced by aspirin (ASA) in human has not been investigated. Studies in animals showed that both MT and Trp given intragastrically prevents the formation of gastric mucosal lesions induced by ASA. The aim of the present study was to determine the influence of MT and Trp given orally to healthy humans on gastric mucosal lesions induced by ASA. The present study included 21 healthy, Hp-negative male volunteers with intact gastro-duodenal mucosa aging 20-50 yr. They were divided in 3 groups; group 1: 7 volunteers receiving daily 2 x 1g ASA (Polfa, Rzeszow) during 11 days; group 2: 7 healthy volunteers receiving 2x1 g ASA and MT (Lekam, Zakroczyn) (5 mg 30 min prior to ASA) during 11 days and group 3: 7 healthy volunteers receiving 2x1 g ASA and Trp (Ardeytropin, Germany) (0.5 g 30 min prior to ASA) during 11 days. Mucosal damage was evaluated at 3(rd), 7(th) and 11(th) days of ASA administration by endoscopy using Lanza score. Plasma melatonin was measured using RIA and gastric mucosal generation of PGE(2) was assessed also by RIA. ASA caused marked mucosal injury at all days of its administration except day 11(th) when only moderate lesions were evident. Pretreatment with MT or Trp alone was accompanied by a significant decrease in gastric mucosal lesion score. Gastric mucosal generation of PGE(2) was suppressed by about 90% in subjects treated with ASA without or with MT or Trp. We concluded that: MT and its precursor Trp significantly attenuate gastric mucosal lesions induced by aspirin. The action of Trp may be be mediated by MT produced in gastrointestinal tract from Trp. The gastroprotective action of MT and Trp is independent on gastric mucosal PGE2 generation.

Alcohol dehydrogenase and aldehyde dehydrogenase gene polymorphism in alcohol liver cirrhosis and alcohol chronic pancreatitis among Polish individuals

OBJECTIVE

To investigate the effects of ADH and ALDH gene polymorphism on the development of alcoholism, alcohol liver cirrhosis and alcohol chronic pancreatitis among Polish individuals.

MATERIAL AND METHODS

We determined the allele and genotype of ADH2, ADH3 and ALDH2 in 198 subjects: 57 with alcohol cirrhosis, 44 with alcohol chronic pancreatitis and 43 "healthy alcoholics"; 54 healthy non-drinkers served as controls. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method on white cell DNA.

RESULTS

In the population examined the ADH2*1 allele frequency was 97.97%. The tests did not show the ADH2*3 allele. The ADH3*1 allele frequency was 57.07%. The ADH2*1 and the ADH3*1 alleles were statistically more common among patients who abuse alcohol in comparison with the controls. The ADH2*2 allele was not detected in any of the patients with chronic alcohol pancreatitis. The ADH2*1/*1 and the ADH3*1/*1 genotypes were statistically significantly more common among the patients who abuse alcohol than in the control group. All patients were ALDH2*1/*1 homozygotic. Patients with the ADH3*1 allele and the ADH3*1/*1 genotype started to abuse alcohol significantly earlier in comparison to the patients with the ADH3*2 allele and the ADH3*2 /*2 genotype.

CONCLUSIONS

In the Polish population examined, the ADH3*1 allele and the ADH3*1/*1 genotype are conducive to the development of alcoholism, alcohol liver cirrhosis and alcohol chronic pancreatitis. However, the ADH2*2 allele is likely to protect against these conditions. Genetic polymorphism of ALDH2 shows no correlation with alcohol addiction or alcohol cirrhosis and alcohol chronic pancreatitis. The ADH3*1 allele and the ADH3*1/*1 genotype are conducive to alcohol abuse starting at a younger age.

Genetic polymorphism of alcohol dehydrogenase 3 in alcohol liver cirrhosis and in alcohol chronic pancreatitis

AIM

To find the ADH3 genotypes in the Polish population likely to be responsible for higher susceptibility to alcohol disease of the liver and chronic alcohol pancreatitis.

METHOD

The ADH3 genotype and ADH3*1 and ADH3*2 alleles frequencies were examined in 198 patients. Genotyping of the ADH3 was performed using PCR-restriction fragment length polymorphism methods on a white cell DNA.

RESULTS

The genotype ADH3*1/ADH3*1 was found to be significantly more frequent in alcohol abusers compared with non-drinkers. The examinations of the group of alcohol abusers showed that the genotype ADH3*2/ADH3*2 occurred statistically significantly less frequently in patients with chronic pancreatitis than in those without alimentary lesions (healthy drinkers). The alleles ADH3*1 and genotype ADH3*1/ADH3*1 were significantly more frequent in men than in women, whereas alleles ADH3*2 and genotype ADH3*2/ADH3*2 were more common in women.

CONCLUSIONS

The genotype ADH3*2/ADH3*2 is likely to be a protective factor for chronic pancreatitis. Variations in ADH3 genotypes may account for some of the differences in prevalence of alcohol dependence between genders in the Polish population.