The evaluation of lipid peroxidation and adenosine deaminase activity in patients with Behçet's disease

Evaluation of the gastroprotective and ulcer healing properties by Fridericia chica (Bonpl.) L.G. Lohmann hydroethanolic extract of leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Fridericia chica (Bonpl.) L.G. Lohmann (Bignoniaceae), is a climber native to Brazil, found in all Brazilian biomes. It is mostly known in Brazil as "carajiru," and home medicines made from the leaves have been used to cure disorders including stomach ulcers and other gastrointestinal disorders.

AIM OF THE STUDY

The objective of the study was to investigate the F. chica hydroethanolic extract of leaves (HEFc) preventative and curative antiulcer gastrointestinal efficacy as well as the mechanisms of action using in vivo rodent models.

MATERIALS AND METHODS

F. chica was collected in the municipality of Juína, Mato Grosso, and its leaves were used to prepare the extract by maceration technique (70% hydroethanol in the 1:10 ratio, w/v) to obtain the HEFc. The chromatographic analysis of HEFc was carried out by High Performance Liquid Chromatography-Photo Diode Array-Electrospray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS)- LCQ Fleet™ system. To determine the potential antiulcer potential of HEFc (1, 5 and 20 mg/kg, p.o.), the gastroprotective activity was assessed in various animal models of stomach ulcers caused by acidified ethanol, water constraint stress, indomethacin, (acute), and acid acetic (chronic). Additionally, the prokinetic properties of the HEFC were assessed in mice. The gastroprotective underlying mechanisms were evaluated by the histopathological analysis and determination of gastric secretion (volume, free and total acidity), gastric barrier mucus, activation of PGs, NO, K ⁺_ATP channels, α₂-adrenoceptor, antioxidant activity (GSH, MPO and MDA), NO and mucosal cytokines (TNF-α, IL-1β, and IL-10) levels.

RESULTS

The chemical composition of HEFc was analyzed and apigenin, scutellarin, and carajurone were identified. HEFc (1, 5 and 20 mg/kg) showed effect against acute ulcers induced by HCl/EtOH with a reduction in the ulcerated area of 64.41% (p < 0.001), 54.23% (p < 0.01), 38.71% (p < 0.01), respectively. In the indomethacin experiment, there was no change in the doses tested, whereas in the water immersion restraint stress ulcer there was a reduction of lesions at doses of 1, 5, and 20 mg/kg by 80.34% (p < 0.001), 68.46% (p < 0.01) and 52.04% (p < 0.01). HEFc increased the mucus production at doses of 1 and 20 mg/kg in 28.14% (p < 0.05) and 38.36% (p < 0.01), respectively. In the pyloric ligation-induced model of gastric ulceration, the HEFc decreased the total acidity in all doses by 54.23%, 65.08%, and 44.40% (p < 0.05) and gastric secretory volume in 38.47% at dose of 1 mg/kg (p < 0,05) and increased the free acidity at the dose of 5 mg/kg by 11.86% (p < 0.05). The administration of EHFc (1 mg/kg) showed a gastroprotective effect possibly by stimulating the release of prostaglandins and activating K⁺_ATP channels and α_2-adrenoreceptors. Also, the gastroprotective effect of HEFc involved an increase in CAT and GSH activities, and a reduction in MPO activity and MDA levels. In the chronic gastric ulcer model, the HEFc (1, 5 and 20 mg/kg) decreased the ulcerated area significantly (p < 0.001) at all doses by 71.37%, 91.00%, and 93.46%, respectively. In the histological analysis, HEFc promoted the healing of gastric lesions by stimulating the formation of granulation tissue and consequently epithelialization. On the other hand, regarding the effect of HEFc on gastric emptying and intestinal transit, it was observed that the extract did not alter gastric emptying, but there was an increase in intestinal transit at the dose of 1 mg/kg (p < 0.01).

CONCLUSION

These outcomes confirmed the advantages of Fridericia chica leaves for the treatment of stomach ulcers, which are well-known. HEFc was discovered to have antiulcer characteristics through multitarget pathways, which might be related to an increase in stomach defense mechanisms and a decrease in defensive factor. HEFc can be regarded as a potential new antiulcer herbal remedy because of its antiulcer properties, which may be attributed to the mixture of flavonoids, apigenin, scutellarin and carajurone.

Identification and Functional Characterization of Adenosine Deaminase in Mucor circinelloides: A Novel Potential Regulator of Nitrogen Utilization and Lipid Biosynthesis

Adenosine deaminase (ADA) is an enzyme distributed in a wide variety of organisms that cleaves adenosine into inosine. Since inosine plays an important role in nitrogen metabolism, ADA may have a critical function in the regulation of fatty acid synthesis. However, the role of ADA in oleaginous fungi has not been reported so far. Therefore, in this study, we identified one ada gene encoding ADA (with ID scaffold0027.9) in the high lipid-producing fungus, Mucor circinelloides WJ11, and investigated its role in cell growth, lipid production, and nitrogen metabolism by overexpressing and knockout of this gene. The results showed that knockout of the ada altered the efficiency of nitrogen consumption, which led to a 20% increment in the lipid content (25% of cell dry weight) of the engineered strain, while overexpression of the ada showed no significant differences compared with the control strain at the final growth stage; however, interestingly, it increased lipid accumulation at the early growth stage. Additionally, transcriptional analysis was conducted by RT-qPCR and our findings indicated that the deletion of ada activated the committed steps of lipid biosynthesis involved in acetyl-CoA carboxylase (acc1 gene), cytosolic malic acid enzyme (cme1 gene), and fatty acid synthases (fas1 gene), while it suppressed the expression of AMP-activated protein kinase (ampk α1 and ampk β genes), which plays a role in lipolysis, whereas the ada-overexpressed strain displayed reverse trends. Conclusively, this work unraveled a novel role of ADA in governing lipid biosynthesis and nitrogen metabolism in the oleaginous fungus, M. circinelloides.

Skin Mucus as a Relevant Low-Invasive Biological Matrix for the Measurement of an Acute Stress Response in Rainbow Trout (Oncorhynchus mykiss)

Skin mucus is a non-lethal and low-invasive matrix appropriate to assess fish welfare as it contributes to their defence against external aggressions and reflects changes in fish health status. However, more information on the response of this matrix to specific stressors is needed. In this study, rainbow trout (Oncorhynchus mykiss) specimens were subjected to an acute stress by air exposure and sampled after 1, 6, and 24 h post-stress. Blood and skin mucus were collected, and a battery of biochemical biomarkers were measured in both matrices. Cortisol and glucose values showed the expected classical stress response in plasma, increasing after the acute stress. The same pattern was observed in skin mucus, corroborating previous data in fish, and allowing us to confirm that skin mucus can be a useful complementary matrix for stress assessment in fish. The results showed sensitivity to hypoxic stress in skin mucus for cortisol, glucose, alkaline phosphatase (ALP), aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine kinase (CK), and calcium. From the 15 parameters evaluated, 12 did not show statistically significant changes between plasma and mucus; therefore, using skin mucus cannot replace the use of plasma. Finally, the principal component analysis in skin mucus revealed a complete separation between the two experimental groups, being ALP, AST, glucose, cortisol, and CK, the biomarkers that contributed the most to this separation.

The association between serum adenosine deaminase levels and Graves' disease

BACKGROUND

Adenosine deaminase (ADA) is essential for the differentiation and maturation of lymphocytes, while lymphocytes infiltration in thyroid tissue is a vital pathological feature of Graves' disease (GD). The aim of the present study was to compare the concentration of ADA between healthy controls (HC) and patients with GD, and evaluate the association between ADA and GD.

METHODS

A total of 112 GD patients and 77 matched HC were enrolled in this study. Each participant was examined for thyroid hormones and autoantibodies, ADA concentration, and thyroid ultrasonography.

RESULTS

Serum ADA levels in GD patients were significantly higher than that in HC subgroup (P < 0.001). In GD patients, serum ADA levels were positively associated with serum-free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), thyroid-stimulating hormone receptor antibody (TRAb) levels, and total thyroid gland volume (thyroid VolT) and negatively associated with serum thyroid-stimulating hormone receptor (TSH) levels (all P < 0.05). There were no similar correlations in the HC subgroup. Multiple linear regression analysis suggested that serum TSH, FT3, and ADA levels played an important role in serum TRAb levels.

CONCLUSIONS

Our results demonstrated that serum ADA levels were closely associated with GD.

Analytical validation of an automated assay for the measurement of adenosine deaminase (ADA) and its isoenzymes in saliva and a pilot evaluation of their changes in patients with SARS-CoV-2 infection

OBJECTIVES

The aim of the present study was to validate a commercially available automated assay for the measurement of total adenosine deaminase (tADA) and its isoenzymes (ADA1 and ADA2) in saliva in a fast and accurate way, and evaluate the possible changes of these analytes in individuals with SARS-CoV-2 infection.

METHODS

The validation, in addition to the evaluation of precision and accuracy, included the analysis of the effects of the main procedures that are currently being used for SARS-CoV-2 inactivation in saliva and a pilot study to evaluate the possible changes in salivary tADA and isoenzymes in individuals infected with SARS-CoV-2.

RESULTS

The automated assay proved to be accurate and precise, with intra- and inter-assay coefficients of variation below 8.2%, linearity under dilution linear regression with R² close to 1, and recovery percentage between 80 and 120% in all cases. This assay was affected when the sample is treated with heat or SDS for virus inactivation but tolerated Triton X-100 and NP-40. Individuals with SARS-CoV-2 infection (n=71) and who recovered from infection (n=11) had higher mean values of activity of tADA and its isoenzymes than healthy individuals (n=35).

CONCLUSIONS

tADA and its isoenzymes ADA1 and ADA2 can be measured accurately and precisely in saliva samples in a rapid, economical, and reproducible way and can be analyzed after chemical inactivation with Triton X-100 and NP-40. Besides, the changes observed in tADA and isoenzymes in individuals with COVID-19 open the possibility of their potential use as non-invasive biomarkers in this disease.

Characterization of total adenosine deaminase activity (ADA) and its isoenzymes in saliva and serum in health and inflammatory conditions in four different species: an analytical and clinical validation pilot study

Background

Measurement of adenosine deaminase (ADA) can provide information about cell-mediated immunity. This report’s objective was to study the enzymatic activity of total ADA (tADA) and its isoenzymes ADA1 and ADA2 in canine, equine, porcine, and bovine serum and saliva and their changes in different inflammatory situations in each species. Besides, an automated method for ADA2 measurement was developed and validated.

Results

tADA was present in serum and saliva of healthy animals of the four species. Erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) concentration of 0.47 mM was needed for ADA1 inhibition in canine and porcine samples (serum and saliva) and bovine saliva, whereas for equine saliva 0.94 mM was needed. ADA2 activity was not detected in bovine serum and was very low or absent in equine serum and bovine saliva. An automated procedure to measure ADA2 consisting of adding EHNA to a commercial reagent for tADA measurement provided repetitive (coefficients of variation < 8.8% in serum and < 10% in saliva) and accurate (linearity of serial sample dilutions with R² > 0.90) results, being equivalent to a manual incubation of the sample with EHNA at a similar concentration. Salivary tADA, as well as ADA1 and ADA2, were higher in dogs with leishmaniosis, horses with acute abdominal disease and pigs with lameness than in healthy animals. tADA and isoenzymes in saliva showed a positive significant correlation with serum ferritin in dogs (r = 0.602, P < 0.01; r = 0.555, P < 0.05; and r = 0.632, P < 0.01; respectively for tADA, ADA1 and ADA2) and serum C-reactive protein in pigs (r = 0.700, P < 0.01, for both tADA and ADA1; r = 0.770, P < 0.001, for ADA2), whereas salivary ADA2 significantly correlated with serum amyloid A in horses (r = 0.649, P < 0.01). In cows, salivary tADA and ADA1 significantly increased after calving, correlating with total white blood cell count (r = 0.487, P < 0.05, for both tADA and ADA1).

Conclusions

The activity of total ADA and its different isoenzymes, can be measured in serum and saliva of dogs, horses, pigs and cows by a simple and fast procedure described in this report. When measured in saliva, these analytes correlated with other biomarkers of inflammation and it could potentially be used as a biomarkers of inflammation and immune activation in the species of this study.

Hypothyroidism and hyperthyroidism change ectoenzyme activity in rat platelets

The purinergic system has an important role in the regulation of vascular functions. The interference of thyroid hormones in this system and in cardiovascular events has been studied in recent years. However, the mechanisms involved in vascular, purinergic, and oxidative changes in thyroid disorders are not completely understood. Therefore, the present study aimed to assess purinergic enzyme activity in platelets from rats with hypothyroidism and hyperthyroidism induced, respectively, by continuous exposure to methimazole (MMI) at 20 mg/100 mL or L-thyroxine at 1.2 mg/100 mL in drinking water for 1 month. Results showed that rats exposed to L-thyroxine had a significant decrease in NTPDase activity, wherein ATP hydrolysis was 53% lower and ADP hydrolysis was 40% lower. Moreover, ecto-5'-nucleotidase activity was decreased in both groups, by 39% in the hypothyroidism group and by 52% in the hyperthyroidism group. On the other hand, adenosine deaminase (ADA) activity was increased in hyperthyroidism (75%), and nucleotide pyrophosphatase/phosphodiesterase (NPP) activity was increased in animals with hypothyroidism (127%) and those with hyperthyroidism (128%). Our findings suggest that changes in purinergic enzyme and purine levels could contribute to the undesirable effects of thyroid disturbances. Moreover, oxidative stress and, in particular, a high level of ROS production, showed a causal relation with changes in ectonucleotidase activity and nucleotide and nucleoside levels.

Influence of different sample preparation strategies on the proteomic identification of stress biomarkers in porcine saliva

Background

The influence of two different sample treatments comprising the enrichment of glycoproteins by boronic acid and dynamic range compression by hexapeptide libraries, on the detection of stress markers in saliva of pigs was evaluated in this study. For this purpose, saliva samples collected before and after the application of an acute stress model consisting of nasal restraining in pigs were processed without any treatment and with the two different treatments mentioned above. Protein separation by two-dimensional gel electrophoresis (2-DE) followed by identification of proteins using MALDI-TOF/TOF mass spectrometry (MS) was used as proteomic technique.

Results

The application of each of the two different sample treatment protocols allowed the identification of unique proteins that could be potential salivary acute stress markers in pigs: lipocalin 1, protein S100-A8 and immunoglobulin M by enrichment of glycoproteins; protein S100-A9, double headed protease inhibitor submandibular gland, and haemoglobin by dynamic range compression; and protein S100-A12 by both protocols. Salivary lipocalin, prolactin inducible protein, light chain of immunoglobulins, adenosine deaminase and carbonic anhydrase VI were identified as potential markers in untreated saliva as well as one of the other treatments.

Conclusion

The use of different procedures allowed the detection of different potential stress markers. Although from a practical point of view, the use of saliva without further treatment as well as the enrichment of glycoproteins are less expensive and easy to do procedures.

Adenosine deaminase activity in pig saliva: analytical validation of two spectrophotometric assays

We validated 2 assays for the measurement of adenosine deaminase (ADA) activity in the saliva of pigs: the Giusti-Galanti manual method (ADA-GG) and a commercial automated assay (Diazyme Laboratories; ADA-D). Intra-assay coefficients of variation (CVs) were <7 and 9%, and interassay CVs were <12 and 5%, for ADA-GG and ADA-D, respectively. Accuracy was measured by 2 methods: recovery and linearity-under-dilution. Recovery was 82.4-106.8% for ADA-GG, and 92.8-107.9% for ADA-D. Serial dilutions showed R² > 0.95 and 0.99 for ADA-GG and ADA-D, respectively. Linear regression between the methods gave R² = 0.997 ( p < 0.0001), and a Bland-Altman plot showed a proportional bias of 112 IU/L (95% confidence interval of -99 to 322 IU/L) for ADA-D. No significant differences were observed between the results obtained by either method in saliva or serum. ADA activity was much higher in porcine saliva than in serum. Salivary ADA activity was significantly higher in lame pigs compared to healthy animals. However, serum ADA activity was significantly lower in lame pigs.

Post-thyroidectomy hypothyroidism increases the expression and activity of ectonucleotidases in platelets: Possible involvement of reactive oxygen species

Signaling mediated by purines is a widespread mechanism of cell-cell communication related to vasomotor responses and the control of platelet function in the vascular system. However, little is known about the involvement of this signaling as well as the role of reactive oxygen species (ROS) in the development of hypothyroidism. Therefore, the present study investigates changes in the purinergic system, including enzyme activities and expression in platelets, and oxidative profiles in patients with post-thyroidectomy hypothyroidism. The nucleoside triphosphate diphosphohydrolase 1 (NTPDase/CD39) expression in patients increased by 40%, and the adenosine triphosphate (ATP) or adenosine diphosphate (ADP) hydrolyzing activity increased by 82% and 70%, respectively. The activities of ecto-5´-nucleotidase and adenosine deaminase (ADA) also significantly enhanced (39% and 52%, respectively), which correlates with a 45% decrease in adenosine concentration. Furthermore, these patients demonstrated an increased production of ROS (42%), thiobarbituric acid reactive substances (TBARS) (115%), carbonyl protein (30%) and a decreased glutathione S-transferase (GST) activity (20%). This study demonstrates that hypothyroidism interferes with adenine nucleoside and nucleotide hydrolysis and this is correlated with oxidative stress, which might be responsible for the increase in ADA activity. This increase causes rapid adenosine deamination, which can generate a decrease in their concentration in the systemic circulation, which can be associated with the development of vascular complications.

Serum prolidase enzyme activity and oxidative status in patients with Behçet's disease

OBJECTIVES

To assess serum prolidase enzyme activity and oxidative stress in patients with Behçet's disease (BD).

METHODS

The study population consisted of BD patients (n = 42) and healthy participants (n = 29). BD patients were classified as active (n = 18) or inactive (n = 24) according to disease activity. Serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and malondialdehyde (MDA) levels were measured.

RESULTS

In BD patients with active disease, serum prolidase activity was significantly higher compared with the inactive and control participants. Serum prolidase activity was also significantly higher in all BD patients in comparison with controls. Serum prolidase activity was also positively correlated with OSI, C-reactive protein, and active BD. MDA, TOS, and OSI levels were all significantly higher in the BD group when compared with the healthy control participants. Serum TAS levels were significantly lower in BD patients in comparison with healthy controls.

CONCLUSION

High prolidase activity may indicate critical biological activities relevant to pathological events in BD, and this activity may be a biological indicator of disease. Further studies are needed to verify these findings.

Effects of thyroid hormone analogue and a leukotrienes pathway-blocker on renal ischemia/reperfusion injury in mice

BACKGROUND

Acute renal failure (ARF) is an important clinical problem with a high mortality and morbidity. One of the primary causes of ARF is ischemia/reperfusion (I/R). Inflammatory process and oxidative stress are thought to be the major mechanisms causing I/R. MK-886 is a potent inhibitor of leukotrienes biosynthesis which may have anti-inflammatory and antioxidant effects through inhibition of polymorphonuclear leukocytes (PMNs) infiltration into renal tissues. 3, 5-diiodothyropropionic acid (DITPA) have evidences of improving effects on I/R in heart through modulation of cellular signaling in response to ischemic stress. The objective of present study was to assess the effects of MK-886 and DITPA on renal I/R injury.

METHODS

A total of 24 Adult males of Swiss albino mice were randomized to four groups: I/R group (n = 6), mice underwent 30 minute bilateral renal ischemia and 48 hr reperfusion. Sham group (n = 6), mice underwent same anesthetic and surgical procedures except for ischemia induction. MK-886-treated group: (n = 6), I/R + MK-886 (6 mg/kg) by intraperitoneal injection. DITPA-treated group: (n = 6), I/R + DITPA (3.75 mg/kg) by intraperitoneal injection.After the end of reperfusion phase mice were sacrificed, blood samples were collected directly from the heart for determination of serum TNF-a, IL-6, urea and Creatinine. Both kidney were excised, the right one homogenized for oxidative stress parameters (MDA and GSH) measurements and the left kidney fixed in formalin for histological examination.

RESULTS

Serum TNF-α, IL-6, urea and Creatinine, kidney MDA levels and scores of histopathological changes were significantly (P < 0.05) elevated in I/R group as compared with that of sham group. Kidney GSH level was significantly (P < 0.05) decreased in I/R group as compared with that of sham group. MK-886 treated group has significantly (P < 0.05) lowered levels of all study parameters except for GSH level which was significantly (P < 0.05) higher as compared with that of I/R group. DITPA caused non-significant (P > 0.05) changes in levels of all study parameters as compared with that of I/R group.

CONCLUSION

The results of the present study show that MK-886 significantly ameliorated kidney damage that resulted from I/R. For DITPA, as its administration might not be successful, administration using a different protocol may give different effects on I/R.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

Serum adenosine deaminase activity in patients with systemic lupus erythematosus: a study based on ADA1 and ADA2 isoenzymes pattern

Adenosine deaminase (ADA) plays a crucial role in the development and maintenance of normal immune system. So, any immunological imbalances could associate with its altered activity in serum. This study evaluated the activity of total ADA and its isoenzymes in serum of 45 patients with systemic lupus erythematosus (SLE). Included were 23 patients with active SLE, 22 during the inactive phase of the disease, and 45 healthy subjects. Our results provided evidence that the significantly elevated total ADA activity in serum of SLE patients is correlated mainly with the increased ADA2 level. The highest mean ADA2 activity during the relapse phase of the disease could be an indication to the macrophages, the main source of ADA2. It might be concluded that ADA and its isoenzymes analysis in serum of patients could be used as a useful and non-invasive diagnostic tool in evaluation of SLE active phase and the disease severity.

Oxidative stress impairs endothelial nitric oxide levels in Behçets' disease

BACKGROUND

Behçet's disease (BD) is an inflammatory vasculitis. Endogenous nitric oxide (NO), produced by endothelial cells, has pleiotropic effects such as vasodilatator, antiplatelet, antiproliferative. Reactive oxygen species (ROS) are produced at sites of endothelial inflammation. ROS target polyunsaturated lipids, which results in malondialdehyde (MDA) production.

OBJECTIVE

The aim was to investigate the oxidative stress in BD patients by measuring MDA and total antioxidant status (TAS) levels and to establish a possible relationship with respect to NO levels regarding disease activity.

MATERIALS AND METHODS

55 BD patients (30 active/25 inactive) and 20 healthy volunteers were included in the study. Blood samples were drawn following an overnight fasting. TAS and MDA levels were determined spectrophotometrically. Serum nitrite (NO(2-)) and nitrate (NO(3-)) levels were measured to estimate NO production. Data were expressed as mean ± SD.

RESULTS

TAS levels were significantly lower in BD patients than the controls (1.19 ± 0.34 vs. 3.29 ± 0.89 mmol/L). In the active BD group, MDA levels (0.36 ± 0.19 nmol/mL) were significantly higher than both the inactive BD group (0.25 ± 0.18 nmol/mL) and controls (0.18 ± 0.41 nmol/mL). NO levels were significantly lower in the active group compared to the inactive group (18.0 ± 2.80 vs. 19.40 ± 2.70 µmol/L). MDA levels correlated negatively with NO levels in the active group.

CONCLUSION

Decreased NO levels mediated by increased oxidative stress significantly contribute to endothelial dysfunction observed in BD.

An in vitro comparison of a new vinyl chalcogenide and sodium selenate on adenosine deaminase activity of human leukocytes

Selenium (Se) is a dietary essential trace element with important biological roles. Sodium selenate (Na(2)SeO(4)) is an inorganic Se compound used in human and animal nutrition that acts as precursor for selenoprotein synthesis. The organoselenium 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C(21)H(2)HOSe) is an α,β-unsaturated ketone functionalized vinyl chalcogenide that has been found as a potential tool in organic synthesis. Adenosine deaminase (ADA) is an important enzyme in the degradation of adenine nucleotides. In this study, we investigated the in vitro effects of both Se compounds on ADA activity and cell viability in leukocyte suspension (LS) of healthy donors (n=12). We first observed an inhibition of ADA activity using 0.1 μM of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one, and an increase in cellular viability when 30 μM were used. However, we did not observe alterations in the presence of sodium selenate. Moreover, both Se compounds did not alter lactate dehydrogenase activity and thiobarbituric acid reactive substance levels. These results suggest that the inhibition of ADA activity caused by α,β-unsaturated ketone may affect the adenosine levels in LS and modulate cell viability, attenuating conditions that involve the activation of the immune system.

Therapeutic benefit of pentostatin in severe IL-10-/- colitis

BACKGROUND

Pentostatin, an adenosine deaminase (ADA) inhibitor, is a purine antimetabolite used for the treatment of leukemias. ADA inhibition blunts expansion of proliferating lymphocytes and increases adenosine release, a potent anti-inflammatory molecule. Human inflammatory bowel disease (IBD) is driven by expansion of effector T cells (T(eff)) that overwhelm reulatory T cells (T(reg)) and propagate innate immune reponses. Here we study the therapeutic benefits of ADA inhibition to impair T(eff) cell expansion and reduce inflammatory cytokine release in IL-10-deficient (IL-10-/-) mice.

METHODS

Colitis was induced in IL-10-/- mice by administering piroxicam for two weeks. Mice were treated with daily pentostatin or phosphate-buffered saline for 1 week and effects on tissue inflammation, lymphocyte numbers and cytokine production examined.

RESULTS

Pentostatin reduced inflammation by >50% and nearly normalized serum amyloid A levels. Lymphocyte expansions in the colon and mesenteric lymph node (MLN) (3.5-fold and >5-fold respectively) dropped by >50-90%. Pro-inflammatory factors in the colon and MLN (IL-1beta, IFN-gamma, IL-6, CXCL10, TNF) dropped whereas FoxP3 and TGF-beta were unchanged. Reductions in cytokine production from equivalent numbers of T cells from pentostatin-treated mice after in vitro (36h) or in vivo (3h) activation suggested anti-inflammatory effects of pentostatin independent of lymphodepletion contributed to its therapeutic benefit. Analysis of mucosal lymphocyte subsets suggested pentostatin reduced numbers of effector CD4+ CD69+ T cells, while sparing CD4+ CD62L+ T cells.

CONCLUSIONS

Pentostatin dosages that avoid severe lymphocyte depletion effectively treat colitis by impairing T(eff) cell expansion and reducing pro-inflammatory cytokine production while preserving regulatory T(reg) populations and function.

Serum adenosine deaminase levels in pancreatic diseases

BACKGROUND

Adenosine deaminase (ADA) is found in most tissues including the pancreas. Its role in inflammation and malignancy has been studied experimentally. To date, serum ADA levels in pancreatic diseases have not been studied before.

AIM

To assess the levels of ADA in patients with pancreatitis and cancer of the pancreas.

METHODOLOGY

Serum levels of ADA were investigated in 14 cases with acute pancreatitis (mean age 46 years; male/female 5/9), 38 with chronic pancreatitis (mean age 46 years; male/female 25/13), 21 with cancer of the pancreas (mean age 67 years; male/female 11/10), and 21 healthy controls (mean age 40 years; male/female 11/10). The ADA levels were also compared among patients with pancreatic cancer with regard to tumor size and localization and the presence of metastases. Correlation analysis between ADA and CA 19.9 was also performed.

RESULTS

Serum ADA levels were 12.66 (9.54-20.72), 12.51 (8.88-26.64), 15.36 (10.20-21.05) and 9.39 (6.58-11.84) U/l in patients with acute pancreatitis, chronic pancreatitis, pancreatic cancer, and healthy controls, respectively. Serum ADA levels were significantly higher in acute and chronic pancreatitis, and pancreatic cancer patients compared to the control group (p < 0.05). Pancreatic cancer patients had significantly higher serum ADA levels when compared with acute and chronic pancreatitis cases (p < 0.05). The serum ADA levels were comparable according to tumor size and location and the presence of metastases. There was a linear correlation between serum ADA and CA 19-9 levels (p = 0.027, r = 0.552).

CONCLUSIONS

Our data suggest that the ADA enzyme may play a role in inflammatory diseases of the pancreas. Serum ADA levels increase in pancreatic disorders especially in pancreatic cancer. It may be a serum marker for the diagnosis of pancreatic cancer.

The usefulness of adenosine deaminase in the diagnosis of tuberculous pericarditis

The objective of this study was to evaluate the adenosine deaminase (ADA) activity usefulness in the diagnosis of tuberculous pericarditis (TP), comparing its value with pericardial effusions (PE) caused by other pericardial diseases. A retrospective case-control study was conducted with nine cases of TP and 39 other than TP diseases (12 neoplastic, 11 septic and 16 unknown origin). Every patient included in this study had PE samples submitted to ADA activity measures and microbiological analysis, and then had pericardial tissue samples submitted to microbiological and histopathological examination. Considering the value of 40 U/L as the cut-off for the diagnosis of TP, the specificity and sensitivity were respectively of 72% and 89%. The specificity of ADA activity for the TP was best applied in the differential diagnosis from PE of unknown origin. The present study demonstrates the clinical value of the measurement of ADA activity in PE in the diagnosis of TP.

Oxidative stress in patients with Behcet's disease: I correlation with severity and clinical parameters

The study was designed to investigate the possible correlation between some oxidative stress parameters in Behcet's disease and the clinical manifestations of the disease as well as the possible correlation with the disease severity. Seventy-six patients diagnosed according to the International Study Group criteria for Behcet's disease were included in the study. Sixty patients had mild-to-moderate disease and 16 patients had severe disease. Sixty matched control subjects were also included. After a full history and examination from each subject, 10 mL blood was drawn from each for analysis. Serum malondialdehyde, glutathione, ceruloplasmin, copper and zinc levels were determined. Patients with Behcet's disease showed increased levels of serum malondialdehyde and copper while glutathione and zinc levels were decreased. Comparison between these parameters in patients with mild-to-moderate disease with those with severe disease showed only that serum zinc levels were lower in severe Behcet's disease. Serum malondialdehyde levels were found to be significantly positively correlated with oral ulcer size, duration and frequency. Glutathione levels were found to be inversely correlated with the clinical manifestation index and all oral ulcer parameters. Zinc levels were found to be inversely correlated with the clinical manifestation index and pathergy test positivity grades. Copper levels were found to be positively correlated with oral ulcer number. Although the parameters of oxidative stress did not show correlation with disease severity, they were correlated with the disease manifestations. This points out the importance of oxidative stress in Behcet's disease.

Oxidant/antioxidant status in men with Behçet’s disease

Behçet's disease (BD) is a chronic, progressive disorder that affects many systems of the body including the eye. The aim of this study was to assess whether the increase in oxidative stress in the affected tissues is reflected by lipid peroxidation and to check for alterations in antioxidants and antioxidant enzyme activities in patients with BD. Erythrocyte antioxidant potential (AOP), glutathione (GSH) and GSH-dependent enzymes (glutathione peroxidase (GSH-Px), glutathione reductase (GRD) and glutathione-S-transferase (GST), catalase (CAT), Cu-Zn superoxide dismutase (Cu-Zn SOD) activities, malondialdehyde (MDA) and some trace elements (zinc, Zn; copper, Cu; manganese, Mn) levels in men with BD. Erythrocyte CAT, GSH-Px activities, MDA, GSH, AOP and serum Zn values were significantly lower in patients with BD than in the control group. However, erythrocyte Cu-Zn SOD, GRD activities, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) and Cu values were significantly higher in patients with BD than in the control group, but GST activity and serum Mn values were unchanged. In conclusion, our results confirm the presence of oxidative stress in patients with BD and suggest that the severity of BD may arise from impaired antioxidant mechanisms. Therapy with antioxidants may lead to the increase in the antioxidant defense system and thus improvement in clinical symptoms.

Oral zinc sulfate in the treatment of Behcet's disease: A double blind cross-over study

This was a randomized, controlled, double-blind trial of zinc sulfate in the treatment of Behcet's disease. Patients with Behcet's disease were recruited in this study between November 2001 and February 2003. A clinical manifestations index (CMI) was calculated for each patient. Serum zinc was estimated in all patients both at the beginning and monthly throughout the trial. Serum zinc levels were estimated from 30 healthy normal subjects matched for age and sex as a control group. Patients were randomly allocated to receive either 100 mg zinc sulfate or identical placebo tablet three times daily in a double-blind manner. After 3 months of starting treatment, patients were crossed over, that is, patients on placebo received zinc sulfate and vice versa. Mean serum zinc level in Behcet's disease patients was statistically significantly lower than mean serum zinc levels in healthy the control. In group A (started with zinc sulfate), the mean CMI started to decline directly after the first month of therapy with zinc sulfate to significantly lower levels. After shifting to placebo treatment in the fourth month, the mean of CMI started to rise again gradually but remained significantly lower than levels before therapy for the fourth and fifth months. In group B (started with placebo), the mean of CMI remained high for the first 3 months. After crossing over to zinc sulfate in the fourth month, the mean of CMI started to decrease after the fourth month. An inverse correlation between CMI and serum zinc level was found. No side-effects were seen in either group. In conclusion, zinc sulfate was found to be a good option in the treatment of Behcet's disease.

Serum and erythrocyte adenosine deaminase activities in patients with Behçet's disease

OBJECTIVES

Adenosine deaminase (ADA) is a non-specific marker of the activation of the T cell, which has an important role in the etiology of Behçet's disease (BD). The purpose of this study was to investigate the determination of ADA activity as an index of T-lymphocyte function in BD, which is known to have an T-cell-mediated immune response.

MATERIALS AND METHODS

Adenosine deaminase activities in both serum and erythrocytes were measured in 23 untreated patients with BD and in 20 healthy controls. The patients with BD were divided into two groups: active (n = 10) and inactive (n = 13).

RESULTS

When compared with the control group, serum ADA activity was high (P < 0.01) and erythrocyte ADA activity was significantly low (P < 0.01) in BD. Serum ADA activity of active BD was higher than that of inactive BD (P < 0.01), but erythrocyte ADA activity was found to be lower in active BD than inactive BD (P < 0.01).

COMMENT

These findings may provide an additional benefit for the diagnosis of BD and sub-typing of active and inactive BD.

Adenosine deaminase enzyme levels, their relation with disease activity, and the effect of colchicine on adenosine deaminase levels in patients with Behçet's disease

Behçet's disease (BD) is a systemic vasculitis. Although its clinical characteristics are well defined, the etiology and immune pathogenesis are not clear yet. Neutrophilic vasculitis, which is a consequence of immunological events, is suggested as the underlying pathophysiological mechanism. Adenosine deaminase (ADA) is a non-specific marker of T-lymphocyte activation. A total of 75 patients with BD (45 women and 30 men) and 25 age-matched and gender-matched healthy control volunteers (13 women and 12 men) were included in this study. BD patients were divided into three groups according to their clinical findings: inactive BD patients (group 1, n=25); active BD patients under colchicine treatment (group 2, n=25); and active BD patients without colchicine treatment (group 3, n=25). Plasma ADA (p-ADA) levels of all BD patients and the control group were measured and compared. The relationship between p-ADA levels and disease activity, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels was evaluated and correlated. Patients with BD had significantly higher p-ADA levels (20.6+/-6.3 U/l) than control subjects (12.8+/-1.8 U/l; P<0.001). The p-ADA levels of patients with active BD were significantly (for each, P<0.05) higher than those of inactive BD patients or controls. On the other hand, the difference was not significant (P>0.05) between active patients with or without colchicine use. In addition, there were significantly positive correlations between p-ADA, ESR and CRP levels in patients with BD (for each, P<0.05). However, disease duration or haemoglobin levels were not relevant. ADA level may be a valuable and supportive indicator of disease activity and is not affected by colchicine therapy in BD.

Increased advanced oxidation protein products in Behçet's disease: a new activity marker?

BACKGROUND

Behçet's disease (BD) is a chronic inflammatory disease with unknown pathogenesis. As various functions of neutrophils in peripheral blood, such as chemotaxis, phagocytosis and generation of reactive oxygen species (ROS) increase in BD, ROS-mediated oxidative stress related to neutrophil activation may have an important role in the pathogenesis of BD.

OBJECTIVES

To investigate the importance of neutrophil activation as the main source of oxidative stress through protein oxidation in the pathogenesis of BD, and also to investigate whether one of the products of protein oxidation, advanced oxidation protein products (AOPP), may be used as an activity marker for BD.

METHODS

Patients with BD (n = 49), at active and inactive stages, with or without evidence of uveitis, and healthy volunteers (n = 40) were entered into the study. A full blood count, peripheral blood smears, routine biochemical analyses, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) measurements were performed in all patients preceding the study. Plasma myeloperoxidase (MPO) activity, representing neutrophil activation, and biomarkers of oxidative stress reflecting protein oxidation, such as levels of AOPP and thiol, were measured spectrophotometrically. Statistical comparisons were made using Mann-Whitney U-tests, Student's t-tests, anova/post-anova tests and correlation analyses.

RESULTS

In all patients, the results of full blood count, peripheral blood smears and routine biochemical analyses were in the normal range, but mean values of CRP and ESR were higher than laboratory reference values. Plasma MPO activity and AOPP levels were found to be higher and thiol values lower in the total patient group and individual subgroups than in controls. Patients with active BD had significantly higher MPO and AOPP levels and lower thiol levels than patients with inactive BD. There was no difference between uveitis-positive and uveitis-negative subgroups in MPO and thiol levels, but AOPP levels were lower in the latter group. Patients with active BD +/- uveitis were shown to have increased MPO and AOPP but decreased thiol levels in comparison with the inactive BD, uveitis-negative subgroup. There were strong positive correlations between ESR and CRP, ESR and MPO, ESR and thiol, ESR and AOPP, CRP and MPO, CRP and AOPP, MPO and AOPP, and thiol and AOPP levels in patients with BD.

CONCLUSIONS

Based on this first study, in which MPO-mediated AOPP formation has been demonstrated, it may be suggested that activated neutrophils may play an important role in the pathogenesis of BD and that chlorinated oxidants of neutrophil origin may lead to oxidative stress, notably protein oxidation. Therefore, AOPP may be a useful marker for monitoring the progress and the severity of the disease activity.

Comparison of Serum Nitric Oxide, Malondialdehyde Levels, and Antioxidant Enzyme Activities in Behçet’s Disease with and without Ocular Disease

OBJECTIVE

The pathogenesis of Behçet's disease (BD) may be related to excessive production of reactive oxygen species, activated neutrophils, and T lymphocytes. The goal of this prospective study was to investigate whether there is any relationship among the oxidant/antioxidant system and nitric oxide (NO) and malondialdehyde (MDA) levels in patients with BD and its subtypes: complete Behçet's disease (CBD) and incomplete Behçet's disease (ICBD), with or without ocular disease.

METHODS

Thirty-two patients and 26 age- and sex-matched healthy control subjects were evaluated for NO and MDA levels and antioxidant enzyme activities. The patients with BD were divided into two subgroups: those with and without ocular disease. Twelve patients with CBD and 4 patients with ICBD had ocular disease. The serum NO level was determined by Griess reaction. The MDA level was detected by thiobarbituric acid reaction. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum were analyzed with spectrophotometric methods.

RESULTS

Increased MDA levels but decreased GSH-Px activities in plasma were observed in BD patients with all subtypes, as compared with controls. Concerning the presence of ocular disease and the subtype (CBD or ICBD) compared with each other, there were no significant differences in MDA or NO serum levels and SOD or GSH-Px enzyme activities.

CONCLUSIONS

Serum NO levels and SOD enzyme activities were not significantly changed in patients with BD and its subtypes; however, a remarkable decrease of GSH-Px enzyme activity and increase of MDA levels were found.

Hyperhomocysteinemia in patients with Behçet’s disease: is it due to inflammation or therapy?

Considerable discrepancies exist in the literature with respect to plasma total homocysteine (tHcy) levels in Behçet's disease (BD). The aim of this study was to evaluate tHcy concentrations in these patients. Thirty-two patients with BD and 20 age- and body mass index-matched healthy volunteers were enrolled. Plasma tHcy concentrations were significantly higher, while vitamin B12 and folate levels were significantly lower in patients with thrombosis and eye involvement than those without. C-reactive protein levels also correlated significantly in a negative manner with vitamin B12 and folate but positively with tHcy. In conclusion, increased use or accelerated catabolism of folate and vitamin B12 due to chronic inflammation and moderately increased tHcy concentrations related with deficiency of these cofactors, and immunosuppressive drug administration might be potential threats of vascular disease in BD.

Involvement of oxidative and nitrosative stress in promoting retinal vasculitis in patients with Eales' disease

OBJECTIVES

Eales' disease (ED) is an idiopathic retinal vasculitis condition, which affects retina of young adult males. The histopathological hallmark in ED is the adhesion of leukocytes to the endothelium and the infiltration of these cells into the retinal parenchyma. Phagocyte generated free radicals have been implicated in mediating tissue damage associated with various inflammatory vasculopathies. In the present study, we have investigated the possible role of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in causing retinal tissue damage in ED.

DESIGN AND METHODS

35 patients with ED and 20 healthy control subjects were included in the study. Monocytes (MC) were separated from peripheral blood of the respective study participants. Inducible nitric oxide synthase (iNOS) protein expression was assessed using Western blot and 3 nitrotyrosine (3NTYR) by reversed phase high performance liquid chromatography (RP HPLC). Thiobarbituric acid reactive substances (TBARS) were determined by measuring malondialdehyde (MDA) formed. Superoxide dismutase (SOD) activity was assayed based on the ability of SOD to inhibit auto-oxidation of epinephrine. Iron, copper and zinc content were determined using Atomic Absorption Spectrophotometer. Immunolocalization of iNOS and 3NTYR was performed on the surgically excised epiretinal membranes (ERM) from patients with ED.

RESULTS

There was a significant increase in the expression of iNOS, as well as 3NTYR accumulation, diminished SOD activity, elevated lipid peroxides, iron, copper and decreased zinc content in the MC of patients with ED when compared with healthy control subjects. The elevated levels of ROS and RNS products correlated with diminished antioxidant status in patients with ED. Strong immunoreactivity for iNOS and 3NTYR was observed in inflammatory cells and endothelial cells in ERM obtained from patients with ED.

CONCLUSIONS

Our findings from this study clearly reveal the involvement of RNS and ROS in the development of retinal vasculitis in ED. Based on our present study and earlier studies we confirm the role of free radicals in mediating retinal tissue damage in ED. Hence we believe selective inhibition of iNOS or supplementation with antioxidants vitamin E and C might be beneficial in controlling retinal vasculitis in patients with ED.

Effects of vitamin E supplementation on blood antioxidants levels in patients with Behçet's disease

Behçet's disease (BD) is known for many years, yet its etiology remains unknown. In BD, the increased production of reactive oxygen species from activated neutrophils may reduce concentrations of antioxidant vitamins and enzymes in plasma and red blood cells (RBC). Vitamin E is an important fat soluble antioxidant and its role on antioxidant parameters of BD is unclear. The study was undertaken to evaluate the role of vitamin E on lipid peroxidation (MDA) levels, antioxidant vitamin and enzyme concentrations in plasma and RBC in patients with BD. There were three groups i.e., control, patient and treatment groups with twenty-five subjects in each. Nonsmoking patients with BD, patient group, was compared with an equal number of healthy control subjects (control group). Blood samples were taken from both control and patient groups and then oral vitamin E was daily supplemented to the patients with BD for six weeks (treated group). At the end of six weeks, blood was taken from the treated group once more. RBC and plasma MDA levels, serum neopterin, complement system (C(3) and C(4)), ASO, CRP, rheumatoid factor, plasma lipoprotein (a), total cholesterol concentrations and erythrocyte sedimentation rate were higher in the patient group than in the control group, but they were lower in the treatment group than in the patient group. While vitamins A, E and beta-carotene concentrations in plasma, catalase, glutathione peroxidase activities and reduced glutathione levels in RBC and plasma were lower in patient group than in the controls, they were found to be higher in the treatment group than in the patient group. These results provide some evidence for a potential role of increased lipid peroxidation and decreased enzymatic and non enzymatic antioxidants in BD by its inflammatory character and vitamin E which may strengthen the antioxidant defense system, and may contribute to the treatment of BD.

The activities of serum adenosine deaminase and xanthine oxidase enzymes in Behcet's disease

BACKGROUND

Adenosine deaminase (AD) and xanthine oxidase (XO) are enzymes of purine catabolism that catalyze the conversion of adenosine to inosine, deoxyadenosine to deoxyinosine, hypoxanthine to xanthine and xanthine to uric acid, respectively. AD is known to be an important enzyme in the maturation and function of T lymphocytes. The aim of this prospective study was to evaluate whether there are changes in serum AD activity as an index of T lymphocyte function in Behcet's disease (BD) which is known as having T cell-mediated immune response.

METHODS

A total of 32 patients and 26 sex- and age-matched healthy control subjects were analysed for AD and XO activities. The patients with BD were divided into two subgroups: BD with and without eye lesions. Twelve patients with complete BD and four patients with incomplete BD had eye complications. AD and XO activities in serum were measured with spectrophotometric methods.

RESULTS

There was a remarkable increase in AD activity and moderate increase in XO in patients with BD compared to controls indicating T cell activation and increased maturation. Serum AD activity of complete BD was higher than that of incomplete BD. There was no difference in XO activity between the subgroups of BD. Significant positive correlation was found between AD and XO in BD, although there was no correlation in control group.

CONCLUSIONS

The results indicate that increased AD and XO activities may provide an additional benefit for the diagnosis of BD and subtyping of the disease as having eye complication or not and complete and incomplete BD. Further studies are needed to bring to light the exact mechanism of AD and XO activity elevation.

Superoxide dismutase activity and glutathione system in erythrocytes of men with Behchet's disease

In order to clarify whether erythrocyte superoxide dismutase (SOD) activity and glutathione system including reduced glutathione (GSH), glutathione peroxidase (G-Px), glutathione reductase (G-Red), glutathione S-transferase (GST) are impaired in men with Behchet's disease (BD) at the first diagnosed time, erythrocyte SOD activity, GSH level, activities of G-Px, G-Red and GST were determined in men with new diagnosed BD. Erythrocyte GSH level, G-Px and G-Red activities were found to be lower, SOD activity was found to be higher in the patients as compared the controls. There was no significant difference between patients and controls for GST activity. Significant positive correlations between GSH and G-Px, GSH and G-Red; significant negative correlations between GSH and SOD, G-Px and SOD, G-Red and SOD were determined. It was concluded that erythrocyte SOD activity and glutathione system are altered in men with new diagnosed BD. It was concluded that these alterations may be a contributory factor for tissue damage associated with BD.