Liver, pancreas and biliary tract enhanced lipoperoxidation products in pure pancreatic juice: evidence for organ-specific oxidative stress in chronic pancreatitis

Circulating Biomarkers Involved in the Development of and Progression to Chronic Pancreatitis-A Literature Review

Chronic pancreatitis (CP) is the end-stage of continuous inflammation and fibrosis in the pancreas evolving from acute- to recurrent acute-, early, and, finally, end-stage CP. Currently, prevention is the only way to reduce disease burden. In this setting, early detection is of great importance. Due to the anatomy and risks associated with direct sampling from pancreatic tissue, most of our information on the human pancreas arises from circulating biomarkers thought to be involved in pancreatic pathophysiology or injury. The present review provides the status of circulating biomarkers involved in the development of and progression to CP.

Lipid (per) oxidation in mitochondria: an emerging target in the ageing process?

Lipids are essential for physiological processes such as maintaining membrane integrity, providing a source of energy and acting as signalling molecules to control processes including cell proliferation, metabolism, inflammation and apoptosis. Disruption of lipid homeostasis can promote pathological changes that contribute towards biological ageing and age-related diseases. Several age-related diseases have been associated with altered lipid metabolism and an elevation in highly damaging lipid peroxidation products; the latter has been ascribed, at least in part, to mitochondrial dysfunction and elevated ROS formation. In addition, senescent cells, which are known to contribute significantly to age-related pathologies, are also associated with impaired mitochondrial function and changes in lipid metabolism. Therapeutic targeting of dysfunctional mitochondrial and pathological lipid metabolism is an emerging strategy for alleviating their negative impact during ageing and the progression to age-related diseases. Such therapies could include the use of drugs that prevent mitochondrial uncoupling, inhibit inflammatory lipid synthesis, modulate lipid transport or storage, reduce mitochondrial oxidative stress and eliminate senescent cells from tissues. In this review, we provide an overview of lipid structure and function, with emphasis on mitochondrial lipids and their potential for therapeutic targeting during ageing and age-related disease.

Role of methionine containing antioxidant combination in the management of pain in chronic pancreatitis: a systematic review and meta-analysis

BACKGROUND

Pain in CP results from inflammation and neuroimmune alterations that are associated with oxidative stress, among other mechanisms. This is marked by depletion of antioxidant defenses including methionine, which is a donor of methyl moieties that maintains the acinar transsulfuration pathway. We performed a systematic review and meta-analysis of trials evaluating methionine-containing antioxidants in CP.

PATIENT AND METHODS

Literature search was conducted in Medline/Pubmed, EMBASE, and Cochrane databases. Systematic review and meta-analysis was performed per PRISMA guidelines. Main study outcome was pain relief. GRADE system was used for quality assessment. Heterogeneity was assessed by the Q and I(2) measures; publication bias by Egger's test. Random-effect model (DerSimonian and Laird) was used if there was heterogeneity.

RESULTS

Eight studies (n = 411) were identified that used methionine-containing antioxidants. The study duration ranged from 10 wks to 12 months. All studies used methionine, organic selenium, ascorbate, beta-carotene and alpha-tocoferol. Four studies (including two RCTs) that reported change in pain scores were metaanalyzed. Though overall effect [standardized difference in means (95% CI)] on pain score reduction was -0.95 (-1.738 to -0.160) (z = -2.36; p = 0.018), the significance was lost when the two RCTs were meta-analyzed. RCTs that reported the number of pain free patients had a statistically significant overall effect of -3.204 (p = 0.001). Though more patients on methionine containing antioxidants had adverse events, majority of them were mild.

CONCLUSION

Methionine containing antioxidants appear to result in pain reduction in a significant proportion of CP patients. Further randomized controlled trials with homogeneous outcome measures are needed.

Antioxidant status and oxidative stress markers in pancreatic cancer and chronic pancreatitis

OBJECTIVES

Oxidative stress has been implicated in the pathogenesis of chronic pancreatitis (CP) and pancreatic cancer (PC). The study aim was to assess the oxidative stress markers and antioxidant defense system in patients with CP and those with PC.

METHODS

Activities of superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase 1 (GPX1), glutathione reductase (GR), arylesterase (PON1-A) and lactonase (PON1-L) activities of paraoxonase 1 (PON1) and concentrations of reduced glutathione, conjugated dienes in low-density lipoprotein (CD/LDL) and oxidized LDL (ox-LDL/LDL) were assessed in 50 PC and 50 CP patients and 50 age and sex-matched controls.

RESULTS

Comparison of PC and CP groups to controls found the following changes: glutathione peroxidase 1 (GPX1) (-20.2%, -25.5%; P < 0.001), glutathione reductase (GR) (-9.5%, -11.9%; P < 0.05), SOD1 (+22.9%; P < 0.01), CAT (-10.6%; P < 0.05), PON1-A (-34.3%, -16.0%; P < 0.001), PON1-L (-44.2%; -17.0%; P < 0.01), conjugated dienes in LDL (CD/LDL) (+20%, +33.3%; P < 0.05) and ox-LDL/LDL (+42.2%, +14.4%; P < 0.05). The patients with PC had changed activities and levels of SOD1 (+24.2%), CAT (-10.4); P < 0.01), PON1-A (-21.7%), PON1-L (-32.9%), and ox-LDL/LDL (+24.3%); (all P < 0.01) compared with the patients with CP.

CONCLUSIONS

Reduced antioxidant defense system capacity and increased markers of oxidative stress were found in PC and CP. PON1-L and CAT activities, along with ox-LDL/LDL levels, were the independent factors differentiating the patients with PC from the patients with CP.

Intake patterns of food nutrients and other substances associated with chronic pancreatitis

BACKGROUND/OBJECTIVES

While alcohol is considered the most common aetiological factor for chronic pancreatitis, the intake of various nutrient and other substances is thought to act as cofactors in the pathogenesis of the disease due to modulation of oxidative stress. This study examined incident cases of acute pancreatitis to determine the dietary and other intakes that characterize those harbouring underlying chronic pancreatitis.

METHODS

Cases of acute pancreatitis presenting to a single institution were prospectively recruited (n = 153). The presence of chronic pancreatitis was defined by a composite of clinical, biochemical and radiological criteria. Information was obtained on the intake of dietary macro- and micronutrients, coffee, tobacco and alcohol in the period just prior to the acute exacerbation. Univariate and multivariate analyses of association were undertaken. Principal components analysis (PCA) was employed to elicit patterns of intake.

RESULTS

After adjustment for key demographic variables, no individual nutrient or other substance showed a significant association with chronic pancreatitis. However, following PCA there emerged a significant positive association with a so-called "stimulant" intake pattern and a negative association with a so-called "nutritive" pattern.

CONCLUSIONS

Preceding an acute exacerbation, patients with underlying chronic pancreatitis are more likely to substitute food-based intake for combinations of other substances, such as tobacco and coffee. This finding may have application in the clinical setting as part of a chronic disease management protocol.

Lipidomic profiling of serum and pancreatic fluid in chronic pancreatitis

OBJECTIVES

Oxidative stress is intimately involved in the pathogenesis of chronic pancreatitis (CP), and its quantification may represent a useful biomarker. The aim was to determine whether oxidized fatty acid (OxFA) levels in serum and/or pancreatic fluid are elevated in CP.

METHODS

Patients evaluated for abdominal pain were classified into 3 groups (controls, mild CP, and severe CP). Serum and secretin-stimulated pancreatic fluid samples were stored under conditions to minimize artificial oxidation. Ten arachidonic and linoleic acid oxidation products were simultaneously measured using liquid chromatography-electrospray ionization-tandem mass spectrometry.

RESULTS

Most OxFAs were significantly elevated in the serum of patients with mild and severe CP compared to controls and correlated with structural features on endoscopic ultrasound. For example, the mean (SD) ratio of serum 13-HODE to its precursor linoleic acid was 0.03 (0.004) in controls, 0.06 (0.02) in mild CP, and 0.10 (0.04) in severe CP (analysis of variance, P = 0.004) and had a strong correlation with endoscopic ultrasound features (Spearman r = 0.84, P < 0.001). In the pancreatic fluid, statistically significant increases of OxFA products were observed in mild CP compared to controls.

CONCLUSIONS

Oxidized fatty acid products are increased in the serum and pancreatic fluid of patients with CP, suggesting a potential role as biomarkers.

ABBREVIATIONS

AA - arachidonic acidANOVA - analysis of varianceAP - acute pancreatitisCP - chronic pancreatitisePFT - endoscopic pancreatic function testEUS - endoscopic ultrasoundHPLC - high-pressure liquid chromatographyHETE - hydroxy-eicosatetranoic acidHODE - hydroxy-octadecadienoic acidLA - linoleic acidLC-ESI-MS/MS - liquid chromatography-electrospray ionization-tandem mass spectrometryM - molarOxFA - oxidized fatty acidsPFT - pancreatic function test.

Antioxidants and chronic pancreatitis: theory of oxidative stress and trials of antioxidant therapy

Chronic pancreatitis (CP) is an inflammatory disease characterized by the progressive destruction of pancreatic tissue and resulting in pancreatic exocrine and endocrine insufficiency. Increased oxidative stress has been implicated as a potential mechanism in its etiology and pathology. A number of studies have demonstrated that CP patients have a compromised antioxidant status, which may be a contributing factor to the enhanced oxidative state associated with the disease. Nutrition is an essential consideration in the treatment of CP, especially since diet is a source of several antioxidants and cofactors required for the production of cellular antioxidant enzymes. Many CP patients have an inadequate intake of macro and micronutrients because of abdominal pain and discomfort, which often increase postprandially and discourage eating. Exocrine insufficiency leads to further complications by preventing adequate digestion and absorption of ingested food, thus causing even greater deficiencies and impairment of antioxidant status. The aims of this article are to review the oxidative stress model of CP and to examine the evidence for nutrition, and, particularly, antioxidants, in the treatment of CP.

Chronic pancreatitis

Chronic pancreatitis is a progressive fibroinflammatory disease that exists in large-duct (often with intraductal calculi) or small-duct form. In many patients this disease results from a complex mix of environmental (eg, alcohol, cigarettes, and occupational chemicals) and genetic factors (eg, mutation in a trypsin-controlling gene or the cystic fibrosis transmembrane conductance regulator); a few patients have hereditary or autoimmune disease. Pain in the form of recurrent attacks of pancreatitis (representing paralysis of apical exocytosis in acinar cells) or constant and disabling pain is usually the main symptom. Management of the pain is mainly empirical, involving potent analgesics, duct drainage by endoscopic or surgical means, and partial or total pancreatectomy. However, steroids rapidly reduce symptoms in patients with autoimmune pancreatitis, and micronutrient therapy to correct electrophilic stress is emerging as a promising treatment in the other patients. Steatorrhoea, diabetes, local complications, and psychosocial issues associated with the disease are additional therapeutic challenges.

Hydrogen sulfide, nitric oxide and a molecular mass 66 u substance in the exhaled breath of chronic pancreatitis patients

BACKGROUND/AIMS

Human exhaled breath contains many molecules either present as gases or occurring in a soluble form in the vapor of the breath. This study was designed to evaluate the substances present in the exhaled breath of chronic pancreatitis (CP) patients.

SUBJECTS

Thirty-one consecutive CP patients (11 with exocrine insufficiency) and 31 healthy subjects (HS) were studied.

METHODS

Ninety-eight different substances were analyzed using a mass spectrometer on a breath sample from all subjects and on each respective ambient air sample.

RESULTS

H(2)S, NO and a substance having a molecular mass of 66 u (M66) were those which had significantly higher concentrations in CP patients than in HS after adjustment for the ambient air; the estimated increases attributable to the disease were 14% (p = 0.040) for H(2)S, 84% (p = 0.006) for M66 and 50% (p = 0.033) for NO, but the three volatile compounds showed poor diagnostic accuracy in differentiating CP patients from HS (AUC-ROC: 0.664, 0.715, and 0.602 for H(2)S, M66, and NO, respectively). Finally, no significant differences of H(2)S, M66, and NO were found between patients with and without alcoholic pancreatitis as well as between patients with and without pancreatic insufficiency.

CONCLUSIONS

Exhaled breath analysis can rapidly and easily assess the presence of volatile compounds (H(2)S, NO and a substance having a molecular mass of 66 u) which may have properties capable of explaining, at least in part, the pathogenesis of CP.

Assessment of oxidative stress in chronic pancreatitis patients

AIM: To assess the levels of antioxidant capacity and oxidative damage in blood of chronic pancreatitis (CP) patients in comparison with those in healthy control subjects, by using several different analytical techniques.

METHODS: Thirty-five CP patients and 35 healthy control subjects were investigated prospectively with respect to plasma levels of thiols, ferric reducing ability of plasma (FRAP, i.e. antioxidant capacity), levels of protein carbonyls and thiobarbituric acid reactive substances (TBARS). Additionally, we evaluated the production of reactive oxygen species (ROS) in whole blood.

RESULTS: The antioxidative thiols including cysteine, cysteinylglycine and glutathione were significantly lower in CP patients. In addition, the non-enzymatic antioxidant capacity was significantly lower in CP patients, which correlated with the amount of oxidative protein (protein carbonyls) and the extent of lipid damage (TBARS), both were significantly higher in CP patients. The ROS production in whole blood after stimulation with phorbol 12-myritate 13-acetaat, demonstrated a strong tendency to produce more ROS in CP patients.

CONCLUSION: Oxidative stress may contribute to the pathogenesis of chronic pancreatitis by decreasing antioxidant capacity and increasing oxidative damage in CP patients may be a rationale for intervention with antioxidant therapy.

Nitric oxide/redox-based signalling as a therapeutic target for penile disorders

Oxidative and/or nitrosative stress is implicated in the pathogeneses of assorted penile disorders of clinical significance, notably erectile dysfunction, priapism and penile fibrosis. It is becoming increasingly recognised that the generation and activity of reactive oxygen and nitrogen species in the penis influence vascular homeostasis of this organ, with adverse effects exerted at cellular and molecular levels. Furthermore, these elements may interact with molecular signalling pathways operating in the penis, modulating their functional roles. This interaction in particular suggests that by accessing molecular targets associated with oxidative/nitrosative stress in the penis, new pharmacotherapeutic approaches may be developed to promote normal erectile ability and preserve erectile tissue health. This notion pertains to, but also extends beyond, interventions which predictably target components of the nitric oxide-based signal transduction pathway for the on-demand treatment of erectile dysfunction. The next line of pharmaceuticals for disorders of the penis, in general, may well spawn from an integrative understanding of the complex regulatory interactions influenced by, as well as influencing nitric oxide signalling in this organ.

Clinical implications of oxidative stress and antioxidant therapy

Oxidative stress occurs when there is an imbalance between generation of reactive oxygen species and inadequate antioxidant defense systems. Oxidative stress can cause cell damage either directly or through altering signaling pathways. Oxidative stress is a unifying mechanism of injury in many types of disease processes, including gastrointestinal diseases. For example, in alcoholic liver disease, reactive oxygen species have been detected through direct spin-trapping techniques and through indirect markers, such as products of lipid peroxidation. A host of antioxidants have protected against liver injury in animal models of alcoholic liver disease. Similarly, in inflammatory bowel disease, oxidative stress has been postulated to play a role in disease initiation and progression, and antioxidant therapy, such as green tea polyphenols and gene therapy with superoxide dismutase, has a markedly attenuated disease. Downregulation of specific detoxification genes may play a role in the pathogenesis of inflammatory bowel disease, especially in ulcerative colitis. Oxidative stress is postulated to play a sustaining role in acute and chronic pancreatitis. Antioxidant supplementation has been used with some success in the treatment of chronic pancreatitis. This review covers recent findings related to oxidative stress in liver disease, inflammatory bowel disease, and pancreatitis.

Especies reactivas de oxígeno en las enfermedades inflamatorias del páncreas: ¿una posible diana terapéutica?

Chronic and acute pancreatitis can be understood as distinct stages of an inflammatory spectrum in the pancreas. Although its pathogenesis is not well defined, oxidative stress seems to be clearly involved in its development. During acute pancreatitis, there is an extraordinary and rapid formation of reactive oxygen species that leads to the extinction of pancreatic antioxidant reserves, causes direct tissue damage and activates oxidative cellular mediators, giving rise to the lesion. However, classical antioxidants have not been shown to have clear benefits in patients with acute pancreatitis. Chronic pancreatitis seems to be the result of a recurrent lesion and defective repair, leading to pancreatic atrophy and fibrosis. In this process, oxidative stress is an efficient stimulus to maintain pancreatic stellar cells active, the fibrogenic motor of chronic pancreatitis. Although antioxidant supplements relieve abdominal pain in these patients, the direction of future antioxidant therapies lies in identifying oxidative mechanisms with the potential for intervention.

Paraoxonase 1-192Q Allele is a Risk Factor for Idiopathic Chronic Pancreatitis

BACKGROUND

The cause of chronic pancreatitis (CP) remains unknown. However, oxidative stress might play a role since recent animal studies have demonstrated that oxygen-free radicals contribute to the pathogenesis of experimental pancreatitis. Human serum paraoxonase (PON1) is an antioxidant enzyme that protects against cellular damage from oxidative stress. Genetic variations resulting in variable activity rates of this enzyme, are of toxicological and physiological importance.

AIM

We investigated whether genetic polymorphisms of the PON1 gene modify the risk for CP.

MATERIALS AND METHODS

DNA samples were obtained from 236 adult CP patients of hereditary (n = 23), alcoholic (n = 137), or idiopathic (n = 76) origin. DNA from 113 healthy controls and from 93 alcoholic controls were analyzed for comparison. Patients and controls were all of Caucasian origin. Genetic polymorphisms (L55M and Q192R) in PON1 were determined by PCR, followed by restriction fragment length polymorphism analyses in all subjects.

RESULTS

The frequencies of the PON1-55 alleles did not differ between CP patients and healthy controls. However, the PON1-192Q allele was significantly more common in idiopathic CP patients (OR : 1.5, 95% CI 1.02, 2.5) compared with healthy controls.

CONCLUSIONS

These data suggest that the PON1-192Q allele, resulting in partly deficient antioxidant and detoxification activity of this enzyme, might be a risk factor for idiopathic CP in Caucasians.

Oxidative damage during chagasic cardiomyopathy development: role of mitochondrial oxidant release and inefficient antioxidant defense

In this study, we evaluated the oxidant status and antioxidant defense capabilities of the heart during the course of Trypanosoma cruzi infection and disease development in a murine model system. Our data show that the extent of protein carbonylation and lipid peroxidation is increased in the heart, but not the skeletal muscle, of infected mice. The level of oxidative injury biomarkers in the myocardium consistently increased with chronic disease severity. The antioxidant defense constituted by catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GSR), and reduced glutathione was increased in murine heart and skeletal tissue in response to the stress of T. cruzi infection. After the initial burst, CAT, GPx, and GSR remained unresponsive to the severity of chronic tissue damage in chagasic hearts. The cardiac level of Mn(2+) superoxide dismutase (MnSOD) was diminished in chagasic mice. Our data suggest that the host responds to acute injuries by activating antioxidant defenses that are of sufficient magnitude to scavenge the reactive oxidants in skeletal tissue. The myocardia of infected mice, however, sustain increased oxidative injuries with disease progression. We surmise that MnSOD deficiencies, resulting in the increased release of mitochondrial free radicals, lead to sustained oxidative stress that exceeds the cardiac antioxidant defense capacity and contribute to persistent oxidative damage in chagasic myocardium.