Capsaicin, The Vanilloid Receptor TRPV1 Agonist in Neuroprotection: Mechanisms Involved and Significance

Hot peppers, also called chilli, chilli pepper, or paprika of the plant genus Capsicum (family Solanaceae), are one of the most used vegetables and spices worldwide. Capsaicin (8-methyl N-vanillyl-6-noneamide) is the main pungent principle of hot green and red peppers. By acting on the capsaicin receptor or transient receptor potential cation channel vanilloid subfamily member 1 (TRPV1), capsaicin selectively stimulates and in high doses defunctionalizes capsaicin-sensitive chemonociceptors with C and Aδ afferent fibers. This channel, which is involved in a wide range of neuronal processes, is expressed in peripheral and central branches of capsaicin-sensitive nociceptive neurons, sensory ganglia, the spinal cord, and different brain regions in neuronal cell bodies, dendrites, astrocytes, and pericytes. Several experimental and clinical studies provided evidence that capsaicin protected against ischaemic or excitotoxic cerebral neuronal injury and may lower the risk of cerebral stroke. By preventing neuronal death, memory impairment and inhibiting the amyloidogenic process, capsaicin may also be beneficial in neurodegenerative disorders such as Parkinson's or Alzheimer's diseases. Capsaicin given in systemic inflammation/sepsis exerted beneficial antioxidant and anti-inflammatory effects while defunctionalization of capsaicin-sensitive vagal afferents has been demonstrated to increase brain oxidative stress. Capsaicin may act in the periphery via the vagal sensory fibers expressing TRPV1 receptors to reduce immune oxidative and inflammatory signalling to the brain. Capsaicin given in small doses has also been reported to inhibit the experimentally-induced epileptic seizures. The aim of this review is to provide a concise account on the most recent findings related to this topic. We attempted to delineate such mechanisms by which capsaicin exerts its neuronal protective effects. We also aimed to provide the reader with the current knowledge on the mechanism of action of capsaicin on sensory receptors.

Toxicokinetic Study of a Gastroprotective Dose of Capsaicin by HPLC-FLD Method

BACKGROUND

A low dose of capsaicin and its natural homologs and analogs (capsaicinoids) have shown to prevent development of gastric mucosal damage of alcohol and non-steroid anti-inflammatory drugs. Based on this experimental observation, a drug development program has been initiated to develop per os applicable capsaicin containing drugs to eliminate gastrointestinal damage caused by non-steroid anti-inflammatory drugs.

METHODS

As a part of this program, a sensitive and selective reverse-phase high-performance liquid chromatography-based method with fluorescence detection has been developed for quantification of capsaicin and dihydrocapsaicin in experimental dog's plasma.

RESULTS

The method was evaluated for a number of validation characteristics (selectivity, repeatability, and intermediate precision, LOD, LOQ, and calibration range). The limit of detection (LOD) was 2 ng/mL and the limit of quantification (LOQ) was 10 ng/mL for both capsaicin and dihydrocapsaicin. The method was used for analysis of capsaicin and dihydrocapsaicin in the plasma samples obtained after per os administration of low doses (0.1, 0.3, and 0.9 mg/kg bw) of Capsaicin Natural (USP 29) to the experimental animals.

CONCLUSIONS

The obtained results indicated that the administered capsaicinoids did not reach the general circulation.

Molecular pharmacological approaches to effects of capsaicinoids and of classical antisecretory drugs on gastric basal acid secretion and on indomethacin-induced gastric mucosal damage in human healthy subjects (mini review)

BACKGROUND

Actions of various drugs have been tested on the gastric acid basal secretion and on the drug (Indomethacin)- induced gastric mucosal damage; however their physiological and pharmacological mechanisms have not been compared.

AIMS

The effects of capsaicinoids, atropine, cimetidine, omeprazole, famotidine and ranitidine were studied on gastric basal acid output, whereas the gastric mucosal preventive effects of capsaicinoids (capsaicin), atropine and cimetidine were tested on the indomethacin-induced gastric mucosal microbleedings in human healthy subjects. Results were presented by molecular pharmacological method; affinity (pD) and intrinsic activity (α-values) were calculated. Intrinsic activity curves are based on comparison to atropine effect (α(atropine)= 1.00). For evaluation of physiological and pharmacological effects of compounds molar doses of pD(2) (necessary doses to produce 50% inhibition) and pA(2) (50% inhibion on intrinsic activity) were calculated from affinity and intrinsic activity curves.

RESULTS

The pD(2) values for compounds were as follows: 5.88 for capsaicinoids, 5.40 for atropine , 2.23 for cimetidine, 3.33 for ranitidine, 3.77 for famotidine and 3.97 for omeprazole. α - value results for compounds were: 0.76 for capsaicinoids, and 1.00 for atropine, cimetidine, ranitidine, famotidine and omeprazole all equal to 1.00 on gastric acid basal secretion. The pD(2) values on indomethacin-induced gastric mucosal microbleeding were found as follows: 6.00 for capsaicinoids, 5.50 for atropine, and 3.50 for cimetidine, meanwhile α-values resulted 0.76 for capsaicinoids, 1.00 for atropine and cimetidine.

CONCLUSIONS

Comparison classical antisecretory drugs acting on different pathways but in much more higher molar concentrations. The atropine and capsaicinoids act in about the same molar concentration which suggests a significant physiological role for capsaicin sensitive afferent nerves in the regulation of gastric basal acid secretion and in the prevention of chemically- induced gastric mucosal protection in human healthy subjects, suggesting a novel physiological pathway in regulation. These results clearly indicate the molecular pharmacological backgrounds of actions of classical antisecretory drugs and physiological role of capsaicin- sensitive afferent nerves in human healty subjects on the gastric basal secretion and on the prevention of drug-induced gastric mucosal damage.

Capsaicin-sensitive afferentation represents an indifferent defensive pathway from eradication in patients with H. pylori gastritis

AIM: To study the role of capsaicin-sensitive afferent nerves in Helicobacter pylori (H. pylori) positive chronic gastritis before and after eradication.

METHODS: Gastric biopsy samples were obtained from corpus and antrum mucosa of 20 healthy human subjects and 18 patients with H. pylori positive chronic gastritis (n = 18) before and after eradication. Traditional gastric mucosal histology (and Warthin-Starry silver impregnation) and special histochemical examinations were carried out. Immunohistochemistry for capsaicin receptor (TRVP1), calcitonin gene-related peptide (CGRP) and substance P (SP) were carried out by the labeled polymer immunohistological method (Lab Vision Co., USA) using polyclonal rabbit and rat monoclonal antibodies (Abcam Ltd., UK).

RESULTS: Eradication treatment was successful in 16 patients (89%). Seven patients (7/18, 39%) remained with moderate complaints, meanwhile 11 patients (11/28, 61%) had no complaints. At histological evaluation, normal gastric mucosa was detected in 4 patients after eradication treatment (4/18, 22%), and moderate chronic gastritis could be seen in 14 (14/18, 78%) patients. Positive immuno-staining for capsaicin receptor was seen in 35% (7/20) of controls, 89% (16/18, P < 0.001) in patients before and 72% (13/18, P < 0.03) after eradication. CGRP was positive in 40% (8/20) of controls, and in 100% (18/18, P < 0.001) of patients before and in 100% (18/18, P < 0.001) after eradication. The immune-staining of gastric mucosa for substance-P was positive in 25% (5/20) of healthy controls, and in 5.5% (3/18, P > 0.05) of patients before and in 0% of patients (0/18, P > 0.05) after H. pylori eradication.

CONCLUSION: Distibution of TRVP1 and CGRP is altered during the development of H. pylori positive chronic gastritis. The immune-staining for TRVP1, CGRP and SP rwemained unchanged before and after H. pylori eradication treatment. The capsaicin-sensitive afferentation is an independent from the eradication treatment. The 6 wk time period might not be enough time for the restituion of chronic H. pylori positive chronic gastritis. The H. pylori infection might not represent the main pathological factor in the development of chronic gastritis

Serum prohepcidin levels in chronic inflammatory bowel diseases

BACKGROUND AND AIMS

One of the major symptoms of chronic inflammatory bowel diseases is anemia. The two most common diseases are Crohn's disease and ulcerative colitis. Anemia may develop due to intestinal bleeding, iron absorption disturbances, or high levels of inflammatory cytokines. It is not clear whether or not hepcidin, the only known hormone regulating cellular iron uptake in mammals is involved. The transcription of hepcidin is controlled by the iron status of the body, hypoxia, and/or inflammation. This study was meant to find relationship between serum prohepcidin levels and clinical parameters of iron homeostasis or inflammatory state in patients suffering from Crohn's disease or ulcerative colitis.

METHODS

Serum prohepcidin levels were measured with ELISA in 72 patients diagnosed with ulcerative colitis and 30 patients suffering from Crohn's disease.

RESULTS

In both groups serum iron levels were lower, while levels of C-reactive protein were higher than in the healthy controls. Serum prohepcidin levels showed no significant differences compared to those in the control group. In the affected patients only weak correlations were observed between prohepcidin levels and diagnostic parameters: in Crohn's disease prohepcidin levels correlated positively with transferrin levels, total iron-binding capacity, transferrin saturation, activity index, and serum albumin levels, while in ulcerative coltitis prohepcidin levels were related to transferrin levels and transferrin saturation.

CONCLUSION

It seems obvious that serum prohepcidin level determination in itself is not a satisfactory diagnostic or prognostic measure in anemia of chronic inflammatory bowel diseases.

Cellular mechanisms of beta-carotene-induced gastric cytoprotection in indomethacin-treated rats

Indomethacin (IND) is a non-steroidal anti-inflammatory agent which is widely used in the treatment of various inflammatory disorders. The drug causes gastrointestinal injury in humans and experimental animals. The aim of these studies was to examine the time course correlation between the macroscopic appearance of mucosal damage, tissue level of PGE(2) and adenosine nucleotide metabolism during the development of indomethacin (IND)-induced mucosal damage and its prevention by beta-carotene.The observations were carried out on both sexes of CFY-strain rats, weighing 180-200 g. Gastric mucosal damage was produced by subcutaneous administration of IND (20 mg/kg). beta-Carotene (Hoffman-La Roche, Switzerland) was given intragastrically at the time of IND administration at doses of 0.01, 0.1, 1 and 10 mg/kg. The animals were sacrificed at 0, 1, 2, 3 and 4 h after IND administration when the number and severity of mucosal lesions were noted and the tissue levels of ATP, ADP, AMP, cAMP, lactate and PGE(2) were measured from the total homogenate of gastric mucosa. The ratio of ADP/ATP, the values of the adenylate pool (ATP+ADP+AMP), and 'energy charge' [(ATP+0.5ADP)/(ATP+ADP+AMP)] were calculated.It was found that: (a) gastric mucosal lesions appear macroscopically 2 h after IND administration; (b) the tissue level of ATP decreased, while ADP was increased 1 h after administration; (c) the most significant decrease in cAMP was found 1 h after IND administration, and thereafter its level returned to baseline; (d) beta-carotene dose-dependently prevented the IND-induced mucosal damage and elevated the cAMP level, but it did not alter the mucosal PGE(2) level 3 or 4 h after IND administration; (e) beta-carotene produced an elevation in ATP and a decrease in ADP level; (f) no significant changes were found in 'energy charge' of the gastric mucosa in IND-treated animals.The development of gastric mucosal damage due to IND was associated with increased energy liberation, i.e. transformation of ATP into ADP, and decreased ATP-cAMP transformation. The significant decrease in cAMP preceded the macroscopic appearance of mucosal damage. The increase in ATP-cAMP transformation is involved in the development of beta-carotene-induced gastric cytoprotection.

Plasma carnitine ester profiles in Crohn's disease and ulcerative colitis patients with different IGR2230a_1 genotypes

An association has been repeatedly demonstrated between inflammatory bowel disease (IBD) and the IBD5 locus in the 5q31 chromosomal region. The aim of the present study was to examine the prevalence of the IGR2230a_1 intronic nucleotide polymorphism of the slc22a5 gene (coding for the OCTN2 carnitine transporter protein) lying within this region, and its possible relationship with the carnitine metabolism in Hungarian IBD patients and controls. We genotyped by restriction fragment length polymorphism 200 Crohn's disease (CD) and 246 ulcerative colitis (UC) patients, as well as 187 healthy controls. From plasma samples we determined detailed carnitine ester profiles of 76 CD, 43 UC patients and 45 control persons using electrospray ionization triple quadruple tandem mass spectrometry. The distribution of the genotypes was not significantly different in the CD or the UC group compared with the controls. We found no significant alterations of the carnitine profile in the carrier/non-carrier or the homozygote/non-homozygote comparisons in both the CD and the UC groups, stratified by IGR2230a_1 genotype. Our data suggest that this polymorphism alone is not associated with CD and UC in the Hungarian population, and has no effect on the carnitine metabolism.

Capsaicin research as a new tool to approach of the human gastrointestinal physiology, pathology and pharmacology

BACKGROUND

Capsaicin has been found to act on the capsaicin sensitive afferent nerves in animal experiments.

AIM

The specific action of capsaicin on sensory afferent nerves affecting gastrointestinal (GI) functions was investigated in human GI physiology and pathology using pharmacological approaches.

MATERIALS AND METHODS

Observations were carried out in 98 normal healthy human subjects and in 178 patients with different gastrointestinal diseases (gastritis, erosions, ulcer, polyps, cancer, inflammatory bowel diseases, colorectal polyps, cancers). The gastric secretory responses and their chemical composition, gastric emptying, sugar loading test, gastric transmucosal potential difference (GTPD) were investigated following with administration of (a) capsaicin alone, (b) ethanol alone or with capsaicin, and (c) indomethacin-induced gastric mucosal microbleeding with or without capsaicin, both before and after 2 weeks capsaicin treatment. Immunohistochemical investigations were performed to establish the presence of the capsaicin (vanillinoid) receptor (TRVP1), CGRP and SP in the whole GI tract. Conventional molecular pharmacological methods were applied to study the effects of capsaicin and other drugs for their inhibitory effects on the gastric basal acid output.

RESULTS

Capsaicin decreased the gastric basal output, enhanced the "non parietal" (buffering) component of gastric secretory responses, gastric emptying, release of glucagon. Capsaicin prevents the indomethacin- and ethanol-induced gastric mucosal injury, while capsaicin itself enhanced the gastric transmucosal potential difference (GTPD). The capsaicin reactive receptors, TRVP1, CGRP, SP were detected in the GI mucosa in patients with different GI disorders, but their presence varied in acute and chronic GI disorders.

CONCLUSION

Application of capsaicin offers a new research tool for understanding the vanilloid-related events of human GI functions in relation to normal physiology and in disease states and the use of pharmacological agents affecting these receptor mediated changes.

No association of the cytotoxic T-lymphocyte associated gene CTLA4 +49A/G polymorphisms with Crohn’s disease and ulcerative colitis in Hungarian population samples

AIM: The goal of the current work was to analyse the prevalence of the +49A/G variant of the cytotoxic T-lymphocyte antigen 4 gene (CTLA4) in Hungarian patients with Crohn’s disease (CD) and ulcerative colitis (UC).

METHODS: A total of 130 unrelated subjects with CD and 150 with UC, and 170 matched controls were genotyped for the single nucleotide polymorphism (SNP). The genotypes were determined by using PCR/RFLP test.

RESULTS: The G allele frequency and the prevalence of the GG genotype were 38.1% and 12.3% in the CD group, 40.6% and 18.6% in the UC patients, and 37.4% and 15.9% in the control group, respectively.

CONCLUSION: The results of the current study show that carriage of the +49G SNP in heterozygous or in homozygous form does not confer risk either for CD or for UC in the Hungarian population.

Gastrointestinal cytoprotection: from basic science to clinical perspectives

An essential point of cytoprotection is that the prostaglandins are able to prevent chemical-induced gastric mucosal damage without affecting gastric acid secretion, this being originally suggested as a property specific to prostaglandins. Since then gastrointestinal cytoprotection has been shown with various agents (anticholinergic agents, H(2)RA, growth factors) and retinoids the latter differing from the actions of vitamin A. In examining the various components of gastrointestinal cytoprotection we have performed studies in isolated cells, stable cell lines, animal experiments, healthy human subjects, and in patients with gastrointestinal diseases. Our attention has focused on the effects of cytoprotective agents on cellular viability, mitochondrial and DNA damage, oxygen free radicals, natural antioxidant systems, mucosal biochemistry, vascular events, gastrointestinal mucosal protection as well as in their prevention of different human diseases. This paper gives a short overview on the different approaches for the exploring gastrointestinal cytoprotection.

Plasma carnitine ester profiles in Crohn's disease patients characterized for SLC22A4 C1672T and SLC22A5 G-207C genotypes

Crohn's disease (CD) is a chronic inflammatory bowel disorder caused by environmental and genetic factors. The purpose of this study was to analyse the possible influence of functional variants of genes of OCTN cation transporters on the carnitine ester profile of patients with CD. Genotyping for SLC22A4 1672C --> T, SLC22A5-207G --> C mutations and three common NOD2 variants (R702W, G908R and 1007finsC) were performed in 100 adult CD patients and in ninety-four healthy controls by direct sequencing. The carnitine ester profile was determined using ESI triple quadrupole tandem MS. Contrary to the NOD2/CARD15 mutations, none of the SLC variants showed increased prevalence in the CD group, the prevalence of TC haplotype did not differ between the patients and the controls. In the mixed group of CD patients the fasting propionyl- (0.243 (sem 0.008) v. 0.283 (sem 0.014) micromol/l), butyryl- (0.274 (sem 0.009) v. 0.301 (sem 0.013)) and isovalerylcarnitine (0.147 (sem 0.006) v. 0.185 (sem 0.009)) levels were decreased; while the level of octenoyl- (0.086 (sem 0.006) v. 0.069 (sem 0.005)), myristoleyl- (0.048 (sem 0.003) v. 0.037 (sem 0.003)), palmitoyl- (0.140 (sem 0.005) v. 0.122 (sem 0.004)) and oleylcarnitine (0.172 (sem 0.006) v. 0.156 (sem 0.008); P < 0.05 in all comparisons) were increased. After sorting the patients into SLC22A genotype-specific subgroups, no significant differences could be observed between them. The carnitine ester profile data suggest selective involvement of the carnitine esters in CD patients, probably due to their altered metabolism.

Molecular pharmacological approach to drug actions on the afferent and efferent fibres of the vagal nerve involved in gastric mucosal protection in rats

BACKGROUND

Gastric mucosal protection is associated with the actions of anti-ulcer drugs or agents affecting on the afferent and/or efferent nerve fibres of the vagal nerve.

AIMS

1. To identify the dose-response curves of drugs (compounds) on the afferent vanilloid-receptor (capsaicin or resiniferatoxin-sensitive) and on efferent secretion (atropine, pirenzepine, cimetidine, ranitidine, famotidine, omeprazole, esomeprazole) basal gastric acid and stimulated gastric secretion in relation to the chemically-induced gastric mucosal damage in rats; 2. To determine the ED50 (pD2) and pA2 on the calculation of affinity and intrinsic affinity curves for these agonists/antagonists, as an indication of relative potency of effects.

MATERIALS AND METHODS

The observations were carried out in rats (30 different models).

RESULTS

The ED50 values for affinities of capsaicin, resiniferatoxin were obtained in nmol/kg b.w. range, whereas the values were in the nmol/kg to micromol/kg b.w. ranges for effects on the gastric basal, stimulated (bethanechol, pentagastrin, histamine) gastric secretion, and the gastric mucosal damage-produced by different ulcerogenic agents (ethanol, HCl, aspirin, indomethacin).

CONCLUSION

From the observations, that agents acting on vanilloid (capsaicin) receptors were the most potent inhibitors of acid secretion and gastric lesions from necrotizing agents, suggests that the capsaicin sensitive afferent nerves have a primary place in the efferent regulated events leading to initiation of gastric mucosal damage.

Prevalence of SLC22A4, SLC22A5 and CARD15 gene mutations in Hungarian pediatric patients with Crohn’s disease

AIM: To investigate the frequency of the common NOD2/CARD15 susceptibility variants and two functional polymorphisms of OCTN cation transporter genes in Hungarian pediatric patients with Crohn’s disease (CD).

METHODS: A cohort of 19 unrelated pediatric and 55 unrelated adult patients with Crohn’s disease and 49 healthy controls were studied. Genotyping of the three common CD-associated CARD15 variants (Arg702Trp, Gly908Arg and 1007finsC changes) with the SLC22A4 1672C→T, and SLC22A5 -207G→C mutations was performed by direct sequencing of the specific regions of these genes.

RESULTS: At least one CARD15 mutation was present in 52.6% of the children and in 34.5% of the adults compared to 14.3% in controls. Surprisingly, strongly different mutation profile was detected in the pediatric versus adult patients. While the G908R and 1007finsC variants were 18.4% and 21.1% in the pediatric group, they were 1.82% and 11.8% in the adults, and were 1.02% and 3.06% in the controls, respectively. The R702W allele was increased approximately two-fold in the adult subjects, while in the pediatric group it was only approximately 64% of the controls (9.09% in the adults, 2.63% in pediatric patients, and 4.08% in the controls). No accumulation of the OCTN variants was observed in any patient group versus the controls.

CONCLUSION: The frequency of the NOD2/CARD15 susceptibility variants in the Hungarian pediatric CD population is high and the profile differs from the adult CD patients, whereas the results for SLC22A4 and SLC22A5 mutation screening do not confirm the assumption that the carriage of these genotypes means an obligatory susceptibility to CD.

Crohn's disease is associated with polymorphism of CARD15/NOD2 gene in a Hungarian population

Crohn's disease (CD) is commonly classified as an immune-mediated disorder, but genetic and environmental factors seem to be important in its pathogenesis. Mutations within the CARD15/NOD2 gene have been associated with CD in the Caucasian population. The aim of our work was to investigate the allele frequency and clinical impact of the three common mutations in Hungarian CD patients and healthy controls. Seventy-four CD patients and 107 controls were examined. The genotyping of the three common CARD15/NOD2 mutations (Arg702Trp, Gly908Arg, and Leu1007fsinsC) was carried out by restriction fragment length polymorphism (RFLP) and amplification refractory mutation system (ARMS) techniques. The demographic and clinical parameters were correlated with chi(2) analysis. The overall prevalence of CARD15/NOD2 mutations in the Hungarian CD patients (33.78%) was significantly higher than in healthy control individuals (16.23%) (P < 0.025). The allele frequency of the Gly908Arg mutation did not differ, but the Arg702Trp and Leu1007fsinsC mutation were more common in CD patients than in controls. The onset of CD occurs about three years earlier in CARD15/NOD2 carriers. Carriage of the Arg702Trp and Leu1007fsinsC allele within the CARD15/NOD2 gene is associated with CD. These data are in line with similar findings showing a role of the CARD15/NOD2 protein in the etiopathogenesis of CD. The genotyping of these mutations might be used to identify high-risk patients.

Capsaicin and glucose absorption and utilization in healthy human subjects

Although many animal experiments (under different experimental circumstances) have been performed, however, to date there have been no human studies of the role of capsaicin-sensitive afferent nerves in carbohydrate metabolism. The glucose loading test (administration of 75 g orally given glucose) was evaluated in 14 human healthy subjects by the simultaneous measurement of plasma level of glucose, C-peptide and glucagon every 15 min for 4 h without and with (ED50) oral application of capsaicin. The plasma level of glucose increased significantly from 30 to 150 min, and the plasma glucagon level increased from 90 to 180 min after the glucose loading when capsaicin administered. The plasma levels of insulin and C-peptide increased from 90 to 165 min after glucose loading but there were no significant difference between the results obtained without and with capsaicin administration. It is concluded that the capsaicin increases the glucose absorption from the gastrointestinal tract and increases the glucagon release (independently of the hormonal antagonist regulation by insulin released after glucose) loading during glucose loading tests carried out in human healthy subjects.

Immunohistochemical distribution of vanilloid receptor, calcitonin-gene related peptide and substance P in gastrointestinal mucosa of patients with different gastrointestinal disorders

The immunohistochemical distribution of capsaicin/vanilloid (transient receptor potential vanilloid 1, TRPV1) receptors and neuropeptides (CGRP, SP) was studied in the gastrointestinal mucosal biopsies of patients with gastritis, erosions, ulcers, polyps, adenocarcinoma, chronic inflammatory bowel diseases, polyps without and with hyperplasia, dysplasia and adenocarcinoma in colon. The studies were carried out in 127 patients and 30 people with only functional dyspepsia (without any histological alteration). The results were: (1) the positivity of TRPV1 receptor and CGRP was detected, and weak participation of SP was detected in patients with different gastric diseases; (2) the presence of TRPV1, CGRP and SP could be detected in chronic inflammation of bowel disease; (3) SP could not detected in patients with colon polyps, dysplasia and adenocarcinoma; (4) the presence of TRPV1 and CGRP was proved in colon dysplasia and adenocarcinoma. We conclude that (1) the immunohistochemical distribution of TRPV1, CGRP and SP differs in gastrointestinal diseases of the upper and lower tract, and (2) the participation of TRPV1, CGRP and SP differs significantly in these different gastrointestinal diseases.

Participation of vanilloid/capsaicin receptors, calcitonin-gene-related peptide and substance P in gastric protection of omeprazole and omeprazole-like compounds

The effects of omeprazole and different omeprazole-like compounds, associated with anti-ischaemic, antioxidant and poly(adenosine-diphosphate-ribose) polymerase (PARP) inhibitory properties, on the gastric acid secretion (4 h pylorus-ligated) and indomethacin-induced gastric mucosal damage connected with the specific immunohistochemical distribution of TRPV1, CRGP and SP during the effects of these compounds, were studied. The observations were carried out in CFY-strain rats (180-210 g), according to the standard methods and the above-mentioned parameters were studied in these experimental circumstances without and with application of different compounds. We found that: (1) all of the compounds dose-dependently inhibited the gastric acid secretion and mucosal damage; (2) the expression of TRPV1 receptor, CGRP and SP decreased significantly in both pylorus-ligated and indomethacin-treated animals and (3) the expression of TRPV1 and CGRP was reduced. Meanwhile, no change was obtained in SP expression during the gastric mucosal protection produced by omeprazole and omeprazole-like compounds. The conclusions were that (1) a functional overlap exists between the capsaicin-sensitive afferent and efferent vagal nerve during omeprazole effects; (2) chemical modification of omeprazole molecule offers a new pathway to obtain a new drug for the introduction in the clinical practice.

Involvement of serum retinoids and Leiden mutation in patients with esophageal, gastric, liver, pancreatic, and colorectal cancers in Hungary

AIM

To analyze the serum levels of retinoids and Leiden mutation in patients with esophageal, gastric, liver, pancreatic, and colorectal cancers.

METHODS

The changes in serum levels of retinoids (vitamin A, alpha- and beta-carotene, alpha- and beta-cryptoxanthin, zeaxanthin, lutein) and Leiden mutation were measured by high liquid performance chromatography (HPLC) and polymerase chain reaction (PCR) in 107 patients (70 males/37 females) with esophageal (0/8), gastric (16/5), liver (8/7), pancreatic (6/4), and colorectal (30/21 including 9 patients suffering from in situ colon cancer) cancer. Fifty-seven healthy subjects (in matched groups) for controls of serum retinoids and 600 healthy blood donors for Leiden mutation were used.

RESULTS

The serum levels of vitamin A and zeaxanthin were decreased significantly in all groups of patients with gastrointestinal (GI) tumors except for vitamin A in patients with pancreatic cancer. No changes were obtained in the serum levels of alpha- and beta-carotene, alpha- and beta-cryptoxanthin, zeaxanthin, lutein in patients with GI cancer. The prevalence of Leiden mutation significantly increased in all groups of patients with GI cancer.

CONCLUSION

Retinoids (as environmental factors) are decreased significantly with increased prevalence of Leiden mutation (as a genetic factor) in patients before the clinical manifestation of histologically different (planocellular and hepatocellular carcinoma, and adenocarcinoma) GI cancer.

[Immunology of HCV infection: the causes of impaired cellular immune response and the effect of antiviral treatment]

BACKGROUND

The outcome of HCV infection and the response to antiviral treatment depend on both viral and host factors. Host immune response contributes not only to viral control, clinical recovery and protective immunity, but also to chronic hepatitis and liver cirrhosis. Establishing immunological status and identifying pretreatment immunological factors associated with better response to therapy might be of importance in the understanding of the successful immune response and in the future of combination therapy to HCV infection.

AIMS

The authors delivered a review on the immunology of HCV infection and characterized the cause of impaired cellular immune response in chronic HCV infection. Natural killer (NK) cell activity, perforin and the inhibitory CD81 HCV co-receptor expression, and Th1/Th2 cytokine production of the monocytes and lymphocytes have been investigated.

PATIENTS AND METHODS

42 patients with chronic hepatitis C, out of them 25 being on interferon (PEG-IFN) + ribavirin (RBV) therapy, 12 sustained virological responders, 26 HCV carriers with normal transaminase values and 22 healthy controls were studied. NK cell activity, perforin and CD81 expression, the IFNgamma, TNFalpha, IL-2 (Th1) and IL-4, IL-6, IL-10 (Th2) production of LPS stimulated monocytes and PMA + ionomycine stimulated lymphocytes were measured by flow-cytometry.

RESULTS

In patients with chronic hepatitis C we demonstrated decreased NK cell activity associated with increased CD81 expression. The perforin expression of lymphocytes was also impaired in HCV patients. The pretreatment capacity of the macrophages to produce TNFalpha was predictive for sustained virological response. This increased TNFalpha production of the monocytes counteracted the observed impaired Th1 type cytokine production of the lymphocytes. IL-10 and IL-4 production showed positive correlation with HCV RNA levels, and negative correlation with histological activity index was noted. PEG-IFN + RBV treatment increased NK activity, perforin expression, Th1 type cytokine production of thr lymphocytes and downregulated CD81 expression inducing effective cellular immune response against HCV. The author's results provide further data to understand the causes of impaired cellular immune response in chronic HCV hepatitis and may be useful in the developement of immunotherapy as an adjunctive treatment to cure patients with chronic hepatitis C.

Effect of special Hungarian probiotic kefir on faecal microflora

AIM: To investigate the effect of a four-week consumption of a special Hungarian probiotic agent (Biofir^®) on the faecal microflora in human healthy subjects.

METHODS: The effect of Biofir^® with 10⁶/cm³ initial germs on the faecal microflora was studied in 120 healthy volunteers (71 females, 49 males). The traditional Russian type kefir was used as control. The various germ groups and pH values were determined in wk 2, 4 and 6.

RESULTS: The number of all microbes increased during the 4-week probiotic treatment. The number of microbes increased 4.3-fold in the control group and 6.8-fold in Biofir-treated group. The probiotic kefir caused multiplication of the probiotic flora, meanwhile the undesired bacteria multiplied in the control group. No significant change of pH values of the faeces was found in both groups.

CONCLUSION: The Hungarian probiotic kefir (Biofir^®) is capable of promoting multiplication of probiotic bacterial flora in the large bowel.

Changes of plasma fasting carnitine ester profile in patients with ulcerative colitis

AIM: To determine the plasma carnitine ester profile in adult patients with ulcerative culitis (UC) and compared with healthy control subjects.

METHOD: Using ESI triple quadrupole tandem mass spectrometry, the carnitine ester profile was measured in 44 patients with UC and 44 age- and sex-matched healthy controls.

RESULTS: There was no significant difference in the fasting free carnitine level between the patients with UC and the healthy controls. The fasting propionyl- (0.331 ± 0.019 vs 0.392 ± 0.017 μmol/L), butyryl- (0.219 ± 0.014 vs 0.265 ± 0.012), and isovalerylcarnitine (0.111 ± 0.008 vs 0.134 ± 0.008) levels were decreased in the UC patients. By contrast, the level of octanoyl- (0.147 ± 0.009 vs 0.114 ± 0.008), decanoyl- (0.180 ± 0.012 vs 0.137 ± 0.008), myristoyl- (0.048 ± 0.003 vs 0.039 ± 0.003), palmitoyl- (0.128 ± 0.006 vs 0.109 ± 0.004), palmitoleyl- (0.042 ± 0.003 vs 0.031 ± 0.002) and oleylcarnitine (0.183 ± 0.007 vs 0.163 ± 0.007; P < 0.05 in all comparisons) were increased in the patients with UC.

CONCLUSION: Our data suggest selective involvement of the carnitine esters in UC patients, probably due to their altered metabolism.

Gastroprotection induced by capsaicin in healthy human subjects

AIM: To evaluate the gastro-protective effect of capsaicin against the ethanol- and indomethacin (IND)-induced gastric mucosal damage in healthy human subjects.

METHODS: The effects of small doses (1-8 μg/mL, 100 mL) of capsaicin on the gastric acid secretion basal acid output (BAO) and its electrolyte concentration, gastric transmucosal potential difference (GTPD), ethanol- (5 mL 300 mL/L i.g.) and IND- (3×25 mg/d) induced gastric mucosal damage were tested in a randomized, prospective study of 84 healthy human subjects. The possible role of desensitization of capsaicin-sensitive afferents was tested by repeated exposures and during a prolonged treatment.

RESULTS: Intragastric application of capsaicin decreased the BAO and enhanced “non-parietal” component (GTPD) in a dose-dependent manner. The decrease of GTPD evoked by ethanol was inhibited by the capsaicin application, which was reproducible. Gastric microbleeding induced by IND was inhibited by co-administration with capsaicin, but was not influenced by two weeks pretreatment with a daily capsaicin dose of 3×400 μg i.g.

CONCLUSION: Capsaicin in low concentration range protects against gastric injuries induced by ethanol or IND, which is attributed to stimulation of the sensory nerve endings.

Dual role of endogenous nitric oxide in development of dextran sodium sulfate-induced colitis in rats

The role of nitric oxide (NO) in the etiology of ulcerative colitis is controversial with reports of the improvement and aggravation of colonic lesions by inducible NO synthase (iNOS) inhibitors. In the present study, we compared the effect of the selective iNOS inhibitor aminoguanidine and the nonselective NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) on a dextran sulfate sodium (DSS)-induced model of colitis in rats. Experimental colitis was induced by a 3% DSS-solution added to drinking water for 7 days. Aminoguanidine (5 approximately 20 mg/kg) and L-NAME (10 mg/kg) were administered p.o. twice daily for the first 3 days, the last 3 days or all 6 days of DSS treatment. Body weight and severity of colitis (diarrhea, bloody feces) were observed over a period of 7 days. DSS treatment resulted in severe colonic lesions, accompanied by diarrhea, bloody feces, decrease of body weight and colon shortening. All of the parameters investigated improved significantly with aminoguanidine treatment at 20 mg/kg for 6 days or the last 3 days of DSS-treatment, but L-NAME did not significantly affect the colitis during these periods. When L-NAME or aminoguanidine was given in the first 3 days of DSS treatment, the colonic lesions were slightly aggravated by L-NAME but not affected by aminoguanidine. The expression of iNOS mRNA was observed from the 3(rd) day of DSS treatment. These results suggested that endogenous NO exerts a biphasic influence on DSS-induced colitis, depending on the NOS isoenzyme; a beneficial effect of NO derived from constitutive NOS and a detrimental effect of NO produced by iNOS in the development of colitis.

Protective effect of lactulose on dextran sulfate sodium-induced colonic inflammation in rats

Promising results have recently been obtained with pre- and probiotic therapy in ulcerative colitis (UC). The prebiotic potential of lactulose is well established, but it has not yet been investigated in experimental colitis models. The purpose of the study was to examine the effect of lactulose on an UC model induced by 3% dextran sulfate sodium (DSS) solution added to drinking water for 7 days in male Wistar rats. Lactulose (300-1000 mg/kg) or 5-aminosalicylic acid (5-ASA; 150 mg/kg) was administered orally twice daily for 6 days. Colonic ulceration area, colon length, body weight changes, diarrhea/bloody feces, colonic mucosal myeloperoxidase activity (MPO), thiobarbituric acid reactive substances (TBARS), and histology were examined. Treatment of animals with DSS for 7 days resulted in severe colonic lesions accompanied by diarrhea, bloody feces, a decrese in body weight, shortening of the colon length, and an increase in MPO activity as well as TBARS, compared to normal rats. Lactulose treatment ameliorated DSS-induced colitis in a dose-dependent manner, and at 1000 mg/kg all of the parameters examined, except TBARS, were shown to improve significantly as compared to controls. Daily administration of 5-ASA also significantly reduced the severity of colonic lesions following DSS treatment. These results demonstrated the protective effect of lactulose in this rat colitis model and suggested that the background of this lactulose effect may be due to alterations of colonic microflora.

[Viral co-infections in hepatitis C: HBV, HBV-C/HGV and TTV studies]

BACKGROUND/AIMS

The prevalence of co-infections with hepatitis B virus (HBV) and novel hepatitis viruses GBV-C (Hepatitis G virus, HGV) and TT virus (TTV) in chronic hepatitis C (HCV) infection has been studied. In patients with chronic hepatitis C and in asymptomatic healthy HCV carriers, the influence of these agents on the course of HCV infection was assessed.

METHODS

a total of 110 HCV-positive individuals, among them 77 patients with chronic hepatitis C--50 of them treated with interferon (IFN)--and 33 HCV carriers with normal alanine aminotransferase have been investigated. HBV-DNA, HGV RNA and TTV DNA were detected by PCR, to determine HBsAg and anti-HBc ELISA technic has been used.

RESULTS

In the healthy population, the prevalence of anti-HCV was 0.3%, HBsAg 0.09%, anti-HBc 2.5%, HGV RNA 8.0% and TTV DNA 18.5%, respectively. In chronic hepatitis C HBsAg (accompanied with HBV-DNA) occurred in 1.29%, anti-HBc 25.97%, HGV RNA in 9.09% and TTV DNA in 40.25% of cases. In IFN-treated patients with sustained remission, the frequency of TTV was 20% vs. 45.7% found in non-responders. Among asymptomatic HCV-carriers, the prevalence of anti-HBc was 27.27%, HGV RNA 9.09% and TTV DNA 75.7% respectively.

CONCLUSIONS

Neither previous HBV infection, nor HGV RNA and TTV DNA had apparent effect on the course of chronic HCV infection. TTV was detected with the lowest frequency in persons with sustained remission due to IFN, suggesting antiviral effect of IFN on TTV.

Hemochromatosis (HFE) gene mutations and hepatitis C virus infection as risk factors for porphyria cutanea tarda in Hungarian patients

AIM

It is not clear whether the mutations in hemochromatosis (HFE) gene and hepatitis C virus (HCV) infection act independently in the pathogenesis of porphyria cutanea tarda (PCT). The prevalence of both risk factors varies greatly in different parts of the world. PCT patients from Hungary were evaluated to assess both factors.

METHODS

The prevalence of C282Y and H63D mutations in the HFE gene was determined in 50 PCT patients and compared with the reported control frequencies. Furthermore, the presence of HCV infection was determined and related to the patients' HFE gene status.

RESULTS

The C282Y mutation was found in 8/50 cases (three homozygotes and five heterozygotes), with an 11% allele frequency (vs. 3.8% control) (P<0.05). Seventeen patients were heterozygous, one was homozygous for the H63D mutation, allele frequency 19%, which did not differ significantly from the reported control prevalence of 12.3%. Twenty-two patients (44%) were HCV-RNA positive; six out of them were heterozygous for H63D mutation, one only for the C282Y mutation and one was compound heterozygous for both mutations.

CONCLUSION

HCV infection and HFE C282Y mutation may probably be independent predisposing factors for development of PCT in Hungarian patients.

[Chromium (III)-ion enhances the utilization of glucose in type-2 diabetes mellitus]

INTRODUCTION

The prevalence of the type 2 diabetes mellitus is still growing. Although the occurrence of insulin resistance is quite frequent in the whole population, diabetes not always develops because for a time the compensating mechanism avoids it. In a frequent variation of type-2 diabetes the disease is not the result of an alteration in the insulin receptor or the glucose transporter, but a genetically determined defect of the postreceptorial intracellular signaling mechanism plays a role in its occurrence. There have been investigations for decades to find out more about the role of chromium (III) ions in glucose metabolism and in the prevention of type-2 diabetes. It has also been investigated if chromium substitution can prevent or treat those forms of diabetes where chromium deficiency is suspected to be in the background of the disorder.

AIM

The aim of our present investigation is to test the role of chromium (III) compounds in glucose metabolism that are known from literature. The authors examined the effect of oral chromium supplementation on antidiabetic treatment. Chromium supplementation was applied for 6 months.

METHODS

Before, through and after the investigation changes in the patient's carbohydrate and lipid metabolism were followed by laboratory tests.

RESULTS

At the end of our examination the cholesterin level significantly, the HbA1c level close to the significant value decreased. Due to their results the authors presume that chromium (III) compounds may be effective in the treatment of patients' with decreased glucose tolerance or type-2 diabetes mellitus as a supplement to their therapy.

[Activation of the nuclear factor kappa B--key role in oncogenesis? Chronic hepatitis C virus infection and lymphomagenesis]

INTRODUCTION

Hepatitis C virus (HCV) infection may have an etiopathogenic role in development of B-cell non-Hodgkin lymphoma (NHL). Antiapoptotic effect of the HCV may display via activation of nuclear factor kappa B (NF-kappa B) transcription factor and can lead to development of carcinoma.

AIMS

1. Activated NF-kappa B was examined in peripheral blood lymphocytes of patients with HCV infection or NHL, and HCV positive B-cell NHL. 2. NF-kappa B was detected in liver biopsies of patients with HCV positive hepatocellular carcinoma (HCC) and in lymphnodes of patients with HCV positive NHL.

PATIENTS AND METHODS

1. Fifteen patients with chronic HCV infection, 13 patients with B-cell NHL (among them 4 HCV positive) and 10 healthy subjects were examined for the activity of NF-kappa B using electrophoretic mobility shift assay (EMSA). 2. Immunohistochemistry was performed in 8 liver biopsies from HCV positive patients and 2 HCC patients (1 HCV positive and 1 HCV negative) and 2 B-cell NHL patients (1 HCV positive and 1 HCV negative).

RESULTS

1. In the HCV negative control samples there was no shift detected, but we found NF-kappa B specific oligonucleotide-protein complexes in the lymphocyte extracts from all HCV positive patients and 10/13 (76.92%) in B-cell NHL. 2. NF-kappa B was detectable in 7/8 cases in liver biopsies from HCV positive patients. Strong reaction was detected in nuclei in HCV positive HCC and NHL patients (no reaction in HCV negative biopsies).

CONCLUSIONS

NF-kappa B activation was justified in both diseases, which can connect the development of both HCV infection and B-cell NHL. This factor activation may have role in hepato- and lymphomagenesis.

Expanded parietal cell pool in transgenic mice unable to synthesize histamine

BACKGROUND

The histidine decarboxylase enzyme (HDC) is responsible for the synthesis of histamine in mammals. Histidine decarboxylase-deficient (HDC-/-) mice have recently been developed by targeted mutation of the HDC gene.

METHODS

The impact of prolonged histamine deficiency was studied on gastric morphology (by immunohistochemistry and morphometry), gastric acid secretion (by a wash-through method for basal gastric acid secretion and by pylorus ligation for stimulated gastric acid secretion) and gastrin levels (by radioimmunoassay) in homozygous HDC-/- mice kept on a low-histamine diet.

RESULTS

A double maximal gastric acid secretory response was found in knockouts after exogenous histamine administration. In contrast, the gastric acid secretion was significantly reduced after gastrinergic and cholinergic stimulation in the absence of histamine. The oxynthic gland area of HDC-/- mice was thickened with an increased parietal cell count compared to wild types. Substantially elevated serum and antral tissue gastrin levels of HDC-/- mice could be possible indications of both an expanded parietal cell mass and/or an increased histamine-induced maximal gastric acid secretory capacity of this genotype.

CONCLUSIONS

These data suggest that not enough compensatory mechanisms develop in HDC-/- mice during a prolonged low-histamine diet to maintain/restore normal gastric acid secretion. An expanded parietal cell pool was also demonstrated in HDC-/- mice kept on a low-histamine diet, probably caused by a trophic effect of sustained hypergastrinaemia. The HDC-/- strain is a suitable model for studying the effects of achlorhydria and consequent hypergastrinaemia as an approach to human conditions such as atrophic gastritis or long-term antisecretory therapies.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results

INTRODUCTION

Esomeprazole, the first proton pump inhibitor to be developed as an optical isomer, has demonstrated more effective healing vs. omeprazole and lansoprazole in patients with reflux oesophagitis (RO). However, RO recurs in a high proportion (approximately 80%) of these patients within 12 months of initial therapy, highlighting the importance of maintenance treatment. Previous studies have shown esomeprazole to be effective as maintenance therapy in healed RO patients.

AIM

This study was conducted to compare esomeprazole 20 mg once daily (o.d.) with lansoprazole 15 mg o.d. for the prevention of recurrence of RO.

METHODS

1391 patients with endoscopically verified RO (LA classification) were enrolled in this randomized, double-blind, parallel-group, multicentre trial. During the initial healing phase of the study, all patients received 4-8 weeks' open treatment with esomeprazole 40 mg: 1236 healed (identified by endoscopy at 4 and 8 weeks) and symptom-free (i.e. no heartburn or acid regurgitation) patients were randomized to 6 months' maintenance treatment with esomeprazole 20 mg o.d. or lansoprazole 15 mg o.d. Time to relapse (relapse of RO and/or discontinuation due to symptom recurrence) was analysed using a log-rank test.

RESULTS

Esomeprazole maintained a significantly higher proportion of patients in remission than lansoprazole over the 6-month course of treatment (P < 0.0001, intention-to-treat analysis). After 6 months' treatment, 83% of esomeprazole recipients were in remission compared with 74% of lansoprazole recipients (life-table estimates). Esomeprazole gave a longer time to relapse than lansoprazole irrespective of baseline LA Grade, significantly so for baseline LA Grades B, C and D (P < 0.05 for each comparison). Significantly more patients were free from heartburn in the esomeprazole group compared with the lansoprazole group at 1, 3 and 6 months (P < 0.05). Significant differences at 6 months between esomeprazole 20 mg o.d. and lansoprazole 15 mg o.d. were also observed for control of epigastric pain and acid regurgitation (P < 0.05 and P < 0.001, respectively). Both treatment regimens were well tolerated.

CONCLUSION

Esomeprazole 20 mg o.d. is a more effective maintenance treatment than lansoprazole 15 mg o.d. for symptom-free patients with healed RO.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results

AIM

To compare the efficacy of esomeprazole, 20 mg once daily, vs. lansoprazole, 15 mg once daily, for the maintenance treatment of patients with healed reflux oesophagitis.

METHODS

During the initial open healing phase, 1391 patients with endoscopically verified reflux oesophagitis and a history of heartburn, with or without acid regurgitation, received esomeprazole 40 mg for 4-8 weeks. Patients who were healed (identified by endoscopy at 4 or 8 weeks) and symptom free were then randomized to receive 6 months of treatment with esomeprazole, 20 mg once daily, or lansoprazole, 15 mg once daily.

RESULTS

Esomeprazole, 20 mg once daily, maintained a significantly higher proportion of patients in remission than lansoprazole, 15 mg once daily, over 6 months [83% (95% CI, 80-86%) of esomeprazole recipients compared with 74% (95% CI, 70-78%) of lansoprazole recipients; P < 0.0001; life table estimates]. When data were analysed according to baseline Los Angeles grade classification, esomeprazole, 20 mg once daily, achieved consistently higher remission rates across all grades of disease severity, whereas the efficacy of lansoprazole decreased to a greater extent with increasing severity of reflux oesophagitis.

CONCLUSION

Esomeprazole, 20 mg once daily, is more effective than lansoprazole, 15 mg once daily, in maintaining remission in patients with healed reflux oesophagitis.

[Investigation of the gene locus in autosomal polycystic kidney disease in a 21 year old female patient with congenital hepatic fibrosis and polycystic liver]

BACKGROUND

Congenital hepatic fibrosis is an uncommon cause of portal hypertension in childhood or the early adolescence, usually presented with hepatomegaly and bleeding from esophageal varices. Despite the hepatomegaly and the fibrotic reconstruction of the liver the liver function tests are usually normal. In most cases it is associated with cystic disease of the kidneys. Congenital hepatic fibrosis is a constant feature of autosomal recessive polycystic kidney disease.

CASE

The authors report on the case of a female patient with polycystic kidneys and polycystic liver. The symptoms of portal hypertension presented in the age of 20, on the basis of liver biopsy congenital hepatic fibrosis was diagnosed.

AIMS

The authors intended to investigate whether there is genetic alteration as common etiology behind the rare association of congenital hepatic fibrosis confirmed in the adolescence and the polycystic disease of the liver and the kidneys. The clinical manifestation raised the possibility of autosomal recessive polycystic kidney disease. Segregation of microsatellite markers for autosomal recessive polycystic kidney disease gene locus 6p21.1-p12 was examined in the affected family to assess the possible role of theis gene.

RESULTS

Four out of the 6 polymorphic microsatellite markers were informative, indicating that the autosomal recessive polycystic kidney disease may be responsible for the development of the rare association of the lesions of the liver and the kidneys in authors' patient.

Decrease in CD3-negative-CD8dim(+) and Vdelta2/Vgamma9 TcR+ peripheral blood lymphocyte counts, low perforin expression and the impairment of natural killer cell activity is associated with chronic hepatitis C virus infection

BACKGROUND/AIMS

As chronic hepatitis C virus (HCV) infection is associated with impaired natural killer (NK) cell cytotoxicity, we examined the phenotypes and perforin expression of peripheral blood lymphocytes, as well as the effect of interferon-alpha2b (IFN-alpha2b) therapy.

METHODS

Thirty-three patients had chronic hepatitis C, and of them 12 had been on IFN-alpha2b treatment. Eleven individuals had been treated earlier with IFN-alpha2b and completely cured, and eight were HCV carriers with persistently normal serum alanine aminotransferase. Three-colour flow cytometry was used to measure the percentage of CD3(+/-)CD8+, CD3+CD4+, gammadeltaTcR+, Vdelta2 TcR+, Vgamma9 TcR+, Vdelta1 TcR+, CD3-CD16+, CD3-CD56+, CD19+ and perforin-positive cells. NK cell activity was assessed by single cell cytotoxic and flow cytometric assay.

RESULTS

Patients with chronic hepatitis C showed an impaired NK cytotoxicity, decreased percentage of CD3-negative-CD8dim-positive (NK subtype) and Vgamma9/Vdelta2 TcR+ as well as perforin-positive T lymphocytes, compared to controls and to those who were cured from HCV infection. IFN-alpha2b increased NK cell cytotoxicity and the percentage of perforin-positive lymphocytes.

CONCLUSIONS

Our findings suggest that in chronic HCV infection a decreased percentage of CD3(-)CD8+, Vgamma9/Vdelta2 TcR+ and perforin-positive T cells and simultaneous decreased peripheral NK activity may contribute to the impaired cellular immune response and the chronicity of the disease.

[Hepatitis C and immunoglobulin heavy-chain gene rearrangement]

Hepatitis C virus (HCV) has cytopathogenic effect not only on hepatocytes, however on salivary glands, monocytes of peripheral blood and lymphoid cells, may explain the systemic manifestations of the infection. HCV activates B and T-cells, modifies the immune response, causes lymphoproliferation, leading the development of B-cell non-Hodgkin's lymphoma (NHL). In the majority of B-cell NHLs immunoglobulin heavy chain (IgH) and light chain (IgL) genes are rearranged and expressed on cell surface in the early stage of the ontogenesis. The analyses of IgH rearrangement prove the clonality of lymphoproliferative disorders giving a powerful approach to the B-cell origin identification of cell proliferation.

PATIENTS AND METHODS

IgH gene rearrangements were examined from the sera of 57 chronic HCV infected patients and 11 HCV-positive cryoglobulinemic patients as well.

RESULTS

Cryoglobulinemia was detected in 20% of all chronic hepatitis C virus infected patients and IgH rearrangement was observed in 10.29% (7/68), 4/7 patients (57.14%) suffered from cryoglobulinemia.

CONCLUSIONS

These results support the hypothesis that IgH gene rearrangement in HCV positive patients can indicate the lymphoproliferative disorder in the HCV infection released B-cell proliferation and lymphoma development.

[Prevalence of Leiden mutation in various gastrointestinal disorders]

Molecular biological examinations have been carried out by the authors from 1995 in patients with different haemostasis, very recently these types of the studies were done in patients with different gastrointestinal (Helicobacter pylori-induced gastritis, hepatitis C infection, ileitis terminalis, ulcerative colitis, colon polyposis and adenocarcinoma in polyps) disorders.

AIM, PATIENTS, METHOD

The Leiden mutation was detected by polymerase chain reaction (PCR) in 1354 healthy persons and patients with different GI disorders.

RESULTS

The results of Leiden prevalence in patients with different gastrointestinal disorders were compared to those obtained in patients with venous thrombosis and familiar thrombophilia. The authors indicated that the prevalence of heterozygous Leiden positive persons was 5.9% in healthy (n = 87) and blood donors (n = 600). The prevalence of heterozygous Leiden mutation was 27% in patents who under went venous thrombosis (n = 300; P < 0.001), 38% in patients with familial thrombophilia (n = 116; P < 0.001). The prevalence of Leiden mutation was 0 in patients with Helicobacter pylori-induced gastritis (n = 24), 8% in hepatitis C infections (n = 75), 14.28% in Crohn's disease, (n = 49; P < 0.01), 27.5% in ulcerative colitis (n = 35; P < 0.001), 44% in colon polyposis (n = 59; P < 0.001) and 55% in situ adenocarcinomas (in polyposis) (n = 9; P < 0.001).

CONCLUSION

The presented results suggest that the Leiden mutation is involved in patients with different inflammatory bowel disease, colon polyposis, as one of the suggested genetic factors.

[Gene therapy in liver diseases]

The basic principles of gene therapy, ex vivo and in vivo gene transfers and various vectors have been reviewed first in the paper. Then the models for clinical application are shown, including the recent results of experimental studies, with special regard to the treatment of liver diseases and amongst them hepatocellular carcinoma. Gene therapy is still in preclinical stage. Due to the ongoing intensive genetic studies and if the existing problems being resolved in this field, we can predict that the early years of this millennium gene therapy will be a useful modality in the clinical hepatology as well.

[Genetic aspects of liver diseases]

Genetic factors play a privotal role in the pathogenesis of several liver diseases. A review is devoted to discussing the genetics of autoimmune hepatitis, chronic viral hepatitis B and C, cholestatic and alcoholic liver diseases, UDP-glucuronyl transferase deficiency, alpha, antitripsin deficiency, hereditary haemochromatosis, Wilson's disease and hepatocellular carcinoma.

Mechanisms of action of retinoids in gastrointestinal mucosal protection in animals, human healthy subjects and patients

Retinoids prevent chemically induced gastric mucosal damage without inhibiting gastric acid secretion ("nutritional gastric cytoprotection"). The gastroprotective effects of retinoids do not depend on 1) vitamin A activity; 2) number of unsaturated double bonds; 3) the presence of a characteristic chemical structure of their terminal components; however, they depend on 1) intact vagal nerve and 2) adrenals in experimental animals. The gastric cytoprotective effect of retinoids produces a dose-dependent inhibition of ATP-transformation into ADP. It also increases the transformation of ATP into cAMP. Other features of these gastric cytoprotective effects of retinoids include: 1) The retinoid-induced gastric mucosal protection differs from that of PGs; 2) The cAMP is an intracellular signal in the development of gastric mucosal damage produced by chemicals (e.g., ethanol, HCl, indomethacin) and in the protection of gastric mucosa induced by retinoids (but not by PGs); 3) The gastric mucosal protection induced by retinoids and gastric mucosal permeability can be separated in time. The existence of gastric mucosal protection can be demonstrated in healthy persons (against indomethacin treatment), in patients with gastric ulcer (GU) and duodenal ulcer (DU) without any inhibition of gastric acid secretion. The serum levels of vitamin A and zeaxanthin were significantly decreased in patients with chronic gastrointestinal (GI) inflammatory diseases (e.g., terminal ileitis, ulcerative colitis), colorectal polyposis, and different (e.g., esophageal, gastric, pancreatic, hepatocellular and colorectal) malignant diseases. The serum levels of vitamin A provitamins were unchanged and their GI mucosal protective effects do not depend on vitamin A activity.

CONCLUSIONS

1) Abundant experimental and human observations clearly proved the defensive role of retinoids in the GI tract; 2) There is a correlation between the a) scavenger properties of retinoids vs. intact vagal nerve; b) scavenging properties vs. intact adrenals. 3) The GI mucosal protective effect of retinoids is correlated with biochemical changes in the GI mucosa.

Four response stages of capsaicin-sensitive primary afferent neurons to capsaicin and its analog: gastric acid secretion, gastric mucosal damage and protection

Capsaicin is the active component of red hot peppers, which modifies specifically the capsaicin-sensitive sensory afferent nerves. The action of capsaicin is an initial short-lasting stimulation, which is followed by desensitization to capsaicin itself, and to other stimuli of afferent sensory nerves. Four response stages of capsaicin-sensitive primary afferents exist to capsaicin, depending on the dose and duration of exposure to the drug. These are excitation, a sensory blocking effect, long-term selective neurotoxic impairment, and irreversible cell destruction. The possible roles of four stages of capsaicin-sensitive primary afferents can be evaluated in relation to gastric acid secretion, and to the details of the defensive side of gastric mucosa against different chemicals, physical agents, drugs and other pathological stress. Capsaicin inhibited the gastric acid secretion in pylorus-ligated rats when it was given intragastrically at a dose of 0.4-1.8 microg/kg. Small doses of capsaicin (up to 800 microg, i.g.) produced a dose-dependent inhibition (ID50 = 400 microg), and its inhibitory effect was exerted for 1 h in healthy human subjects. While a small dose (5 microg/kg) of capsaicin caused inhibition, a high dose (50-100 mg/kg) enhanced the gastric mucosal lesions productivity by causing hyperacidity in pylorus-ligated animals. Capsaicin and its analog inhibited the development of different chemically induced gastric mucosal damage in various experimental models if they were given intragastric doses (microg/kg). The final effects of capsaicin depend on the dosage and timing. The different effects are excitation, a sensory-blocking effect, long-term selective neurotoxic impairment and irreversible cell destruction.

Atropine-induced gastrointestinal cytoprotection dependences to the intact of vagal nerve against indomethacin-induced gastrointestinal mucosal and microvascular damage in rats

The non-steroidal antiinflammatory drugs, such as an indomethacin (IND), cause mucosal ulceration and increase the mucosal vascular permeability in the gastrointestinal (GI) tract. Some exogenous agents, e.g. the atropine, can protect the GI mucosa against these ulcerogenic effects. The gastrointestinal functions and mucosal protection, however, are regulated by the vagal nerve. The aims of this study was to examine the dependence of atropine-induced GI cytoprotection to the vagal innervation against the development of IND-caused ulcers and microvascular damage in the mucosa of stomach and small intestine in rats.

METHODS

the observations were carried out on CFY-strain rats. The mucosal damage was produced by subcutaneous administration of IND in a 20 mg/kg dose 24 h prior to the killing of animals at the same time as the start of atropine-application, which was given in a small dose (0.1 mg/kg) every 5 h. The subdiaphragmatic bilateral surgical vagotomy was done 24 h before the experiment. The vascular permeability, indicated by the microvascular endothel damage, was measured by the appearance and concentration of intravenously administered Evans blue into the GI mucosa. The number and severity of mucosal lesions and the Evans blue content of mucosa were determined in the stomach and small intestine.

RESULTS

(1) The IND caused mucosal ulcers and Evans blue extravasation into the mucosa of the stomach and small intestine. (2) The IND-induced mucosal ulceration and vascular permeability significantly decreased after atropine-administration in the same parts of GI tract. (3) The extent of cytoprotective effect of atropine against the IND was decreased after bilateral surgical vagotomy.

CONCLUSIONS

(1) The IND causes microvascular endothel damage in the stomach and small intestinal. (2) The atropine has a cytoprotective effect in the stomach and small intestine against the aggressive effects of IND without decrease of gastric acid secretion. (3) The intact vagal nerve is necessary to the function of cytoprotective mechanisms of atropine against the IND.

Changes of serum carotenoids in patients with esophageal, gastric, hepatocellular, pancreatic and colorectal cancer

The serum levels of carotenoids (vitamin A, lutein, zeaxanthin, alfa- and beta cryptoxanthin, alfa- and beta-carotene) were measured in healthy persons (n=40) and in 98 patients with different malignant gastrointestinal diseases (44 patients with colon adenocarcinoma, 21 with gastric cancer, 15 with hepatocellular adenocarcinoma, 10 patients with pancreas adenocarcinoma and eight patients with esophagus cancer). The serum levels of carotenoids were measured with high-pressure liquid chromatography. The sera of the patients were taken at the time of the diagnosis.

RESULTS

the measurements indicated that (1) the serum level of vitamin A and zeaxanthin were significantly lower in all of these groups (except of pancreas adenocarcinoma), but the extent of the A decrease was different in the patients with different types of gastrointestinal malignancy. The serum level of vitamin A was in the healthy subjects 2.072+/-0.332 mmol/l and in the case of gastrointestinal malignancies was 0.77+/-0.14 mmol/l (P<0.001) The serum level of zeaxanthin was in the healthy subjects 0.143+/-0.057 mmol/l and at the malignancies was 0.042+/-0.014 mmol/l (P<0.01). (2) There were no significant differences in the serum levels of other carotenoids in the checked groups. (3) The serum level of cholesterol, total protein, albumin and haemoglobin were in the normal range in these patients. These results indicate that the carotenoids may be responsible nutritional factors (as nutritional scavengers) in the development of different malignant diseases. This supposed role in the carcinogenesis does not depend fully on the vitamin A activity.

Multimodality treatment resulting in long-term survival in hepatocellular carcinoma

The early detection and complex therapy of the hepatocellular carcinoma (HCC) is one of the most seasonable questions of the gastroenterology-oncology, because of the increasing prevalence of the primary liver cancer. The course of the hepatocellular carcinoma is rapid, untreated patients rarely live over 5-6 months. Combination of different treatment modalities in HCC can offer the best chances for survival. If possible, a surgical resection should be the primary procedure, followed by adjuvant cytostatic treatment and chemoembolisation. The authors report three cases with HCC with extremely long survival. The long-term survival achieved by multimodality therapy, as presented in these cases, seems to justify aggressive therapeutical approaches in HCC. It has been concluded, that early detection and complex, aggressive multimodality treatment--even repeated liver resections and surgical elimination of duplex distant metastases--can result in long-term survival with a good quality of life.