Maria Słomka

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

Abstract:  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 E2, 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 PGE2 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.

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

Abstract:  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.

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.

Abstract:  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.

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.

Association of Serum Adiponectin, Leptin, and Resistin Concentrations with the Severity of Liver Dysfunction and the Disease Complications in Alcoholic Liver Disease

Background and aims. There is growing evidence that white adipose tissue is an important contributor in the pathogenesis of alcoholic liver disease (ALD). We investigated serum concentrations of total adiponectin (Acrp30), leptin, and resistin in patients with chronic alcohol abuse and different grades of liver dysfunction, as well as ALD complications. Materials and Methods. One hundred forty-seven consecutive inpatients with ALD were prospectively recruited. The evaluation of plasma adipokine levels was performed using immunoenzymatic ELISA tests. Multivariable logistic regression was applied in order to select independent predictors of advanced liver dysfunction and the disease complications. Results. Acrp30 and resistin levels were significantly higher in patients with ALD than in controls. Lower leptin levels in females with ALD compared to controls, but no significant differences in leptin concentrations in males, were found. High serum Acrp30 level revealed an independent association with advanced liver dysfunction, as well as the development of ALD complications, that is, ascites and hepatic encephalopathy. Conclusion. Gender-related differences in serum leptin concentrations may influence the ALD course, different in females compared with males. Serum Acrp30 level may serve as a potential prognostic indicator for patients with ALD.

Genetic polymorphism of alcohol-metabolizing enzyme and alcohol dependence in Polish men

Alcohol dependence poses a serious medical and sociological problem. It is influenced by multiple environmental and genetic factors, which may determine differences in alcohol metabolism. Genetic polymorphism of the enzymes involved in alcohol metabolism is highly ethnically and race dependent. The purpose of this study was to investigate the differences, if present, in the allele and genotype frequency of alcohol dehydrogenase 1B (ADH1B), ADH1C and the microsomal ethanol-oxidizing system (MEOS/CYP2E1) between alcohol-dependent individuals and controls and also to determine if these genotypes cause a difference in the age at which the patients become alcohol dependent. The allele and genotype frequencies of ADH1B, ADH1C, and CYP2E1 were determined in 204 alcohol dependent men and 172 healthy volunteers who do not drink alcohol (control group). Genotyping was performed by PCR-RFLP methods on white cell DNA. ADH1B*1 (99.3%) and ADH1C*1 (62.5%) alleles and ADH1B*1/*1 (N = 201) and ADH1C*1/*1 (N = 85) genotypes were statistically more frequent among alcohol-dependent subjects than among controls (99.3 and 62.5%, N = 201 and 85 vs 94.5 and 40.7%, N = 153 and 32, respectively). Differences in the CYP2E1 allele and genotype distribution between groups were not significant. The persons with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes became alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes (28.08, 25.67 years vs 36.0, 45.05, 34.45 years, respectively). In the Polish men examined, ADH1C*1 and ADH1B*1 alleles and ADH1C*1/*1 and ADH1B*1/*1 genotypes favor alcohol dependence. The ADH1B*2 allele may protect from alcohol dependence. However, subjects with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes become alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes.

The BARD score and the NAFLD fibrosis score in the assessment of advanced liver fibrosis in nonalcoholic fatty liver disease

Summary Background Non-alcoholic fatty liver disease (NAFLD) refers to a very wide clinical spectrum. Advanced fibrosis that accompanies disease leads to the development of cirrhosis and hepatocellular carcinoma. Thus, identification of patients with advanced fibrosis is essential. The aim of the present study was to compare the usefulness of NAFLD fibrosis and BARD scores in predicting fibrosis in NAFLD and to determine the risk factors of advanced fibrosis. Material/Methods The study included 126 patients with NAFLD. Fibrosis in liver biopsy was scored on a 5-point scale. The BARD and the NAFLD fibrosis scores were compared with the biopsy findings. Results Liver biopsy revealed 27 patients with advanced and 99 with mild/moderate fibrosis. Advanced fibrosis was statistically significantly more common in older patients with obesity, AST/ALT ratio ≥0.8, diabetes mellitus, and thrombocytes ≤200×103/L. Positive predictive value, negative predictive value and AUROC curve for BARD score, and NAFLD fibrosis score were 68.57%, 96.70%, 0.865 and 70.59%, 98.11%, 0.919, respectively. Conclusions Both scores are capable of ruling out advanced fibrosis and markedly reducing the need for liver biopsies in patients with NAFLD. Obesity, diabetes mellitus, thrombocytes ≤200×103/L, advanced age and AST/ALT ratio ≥0.8 are the risk factors of advanced fibrosis.

Prevalence of spontaneous bacterial peritonitis in asymptomatic inpatients with decompensated liver cirrhosis - a pilot study.

PURPOSE To assess the prevalence of spontaneous bacterial peritonitis (SBP) in asymptomatic patients with decompensated liver cirrhosis. MATERIAL AND METHODS Patients (pts) with symptoms of decompensation of liver cirrhosis, ascites, and no signs indicating SBP were included to our study. Exclusion criteria include: 1/ clinical symptoms of infection, 2/ developing de novo or worsening hepatic encephalopathy, 3/ gastrointestinal bleeding within the last month, 4/ renal failure, 5/ antibiotic treatment or norfloxacin prophylaxis at admission. About 60 ml of ascitic fluid were drawn for lab examination. Pathologic assessment for atypical cells was also performed. RESULTS 37 patients fulfilled inclusion criteria. Their mean age was 56.2 ± 12.1. The Child-Pugh classification revealed 13 (35.1%) patients of class B and 24 (64.9%) patients of class C. The mean Model for End-Stage Liver Disease score in this group was 16.6 ± 6.8. The mean ascitic protein content was 1.85 ± 1.09 g/dL and mean neutrophil count 144.8 ± 445.1/mm3. Ascitic fluid analysis revealed: signs of bacterascites in 6 of 37 (16.2%) pts; neutrocytic ascites in 1 of 37 (2.7%) pts; and 2 of 37 (5.4%) pts met criteria for SBP. C-reactive protein level was the best predictor of infection [SBP(+) 47.9 ± 40.9 versus SBP(-) 11.7 ± 5.1; p= 0.0005]. CONCLUSIONS The prevalence of SBP in asymptomatic cirrhotics with ascites is low. We observed the trend towards more frequent occurrence of the infection in patients suffered from severe liver disease (Child-Pugh C group).

Can we expect progress in the treatment of fibrosis in the course of chronic pancreatitis

Chronic pancreatitis (CP) is a necroinflammatory process characterized by loss of both exocrine and endocrine function. To date, the disease has been treated symptomatically. Real advances in CP management can be expected once the pathophysiology of the disease is elucidated and individual stages of its development are properly managed. A key role in the CP pathogenesis is played by activation of pancreatic stellate cells (PSCs) that cooperate with the remaining pancreatic cells. All these cells produce cytokines, growth factors, angiotensin and other substances, which paracrinally or autocrinally induce further, persistent activation of PSCs. The activated PSCs are capable of producing and modifying the extracellular matrix. An optimal therapeutic preparation should exert beneficial effects on all the above-mentioned phenomena observed in CP. The most promising treatment modalities include blocking of the renin-angiotensin system (RAS), activation of peroxisome proliferator-activated receptors gamma (PPAR-γ), influence on the remaining PSC signaling pathways, blocking of substances produced by activated PSCs, and antioxidants. The findings of many recent experimental studies are highly encouraging; however, their efficacy should be confirmed in well-designed clinical trials.

Erythropoietin inhibits liver gelatinases during galactosamine-induced hepatic damage in rats

Matrix metalloproteinase (MMP)-2 and -9 (gelatinases) participate in extracellular protein remodeling. Moreover, they are involved in the development of hepatic fibrosis. The goal of this study was to evaluate liver gelatinase activities after erythropoietin (Epo) treatment (1U/dose, sc) in experimentally damaged livers of rats treated with D-galactosamine (Gal, 800 mg/kg/dose, ip). Sixty rats were divided into six equal groups: I - received 5 doses of Epo and a single dose of Gal [the experiment duration (ED): 10 days]; II - received 5 doses of Epo and 3 doses of Gal (ED: 14 days); III - received only 5 doses of Epo (ED: 9 days); IV - received 3 doses of Gal (ED: 5 days);V - received a single dose of Gal (ED: 1 day); VI - control group (ED: 9 days). The animals were sacrificed and the livers were collected 48 h after the last drug administration. The activity of gelatinases was measured using gelatin zymography. No fluctuations in gelatinase activities were observed after the administration of a single dose of Gal in comparison to the control group. However, a significant increase in gelatinase activities was observed after treatment with three doses of Gal. Five doses of Epo administrated before Gal treatment prevented elevated gelatinase activities: MMP-9 activity was comparable to control, and MMP-2 activity was decreased (group II). The gelatinase activities was lower in group I and II in comparison to the control group. These results revealed that Epo decreases MMP-2 and MMP-9 activity, suggesting that it is a hepatoprotective agent against hepatic damage induced by galactosamine injection.