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Selenium (Se) has anti-inflammatory and antioxidant properties and is necessary for the development and normal function of the central nervous system. This study was aimed to compare the in vitro effects of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C21H2HOSe; organoselenium) and sodium selenate (inorganic Se) on adenosine deaminase (ADA) activity, cell viability, lipid peroxidation, scavenger of nitric oxide (NO) and nonprotein thiols (NP-SH) content in the cerebral cortex slices of the young rats. A decrease in ADA activity was observed when the slices were exposed to organoselenium at the concentrations of 1, 10 and 30 µM. The same compound showed higher scavenger capacity of NO than the inorganic compound. Inorganic Se was able to protect against sodium nitroprusside-induced oxidative damage and increased the NP-SH content. Both the compounds displayed distinctive antioxidant capacities and were not cytotoxic for the cerebral cortex slices in the conditions tested. These findings are likely to be related to immunomodulatory and antioxidant properties of this compound.

Methylmercury (MeHg) is an organic form of mercury with toxic effects in multiple organs. The aim of the present investigation was to evaluate the in vivo effects of MeHg (1 and 4 mg/kg) given orally for seven consecutive days on adenosine deaminase (ADA), n-acetyl-β-D-glucosaminidase (NAG) and ecto-nucleoside triphosphate phosphohydrolase (NTPDase) activities, and on lipid peroxidation in hippocampus, cerebral cortex, kidney and liver of suckling rat pups. The results showed that NAG activity and lipid peroxidation levels increased in the kidney in both treatments, whereas urinary NAG activity increased only in the 1 mg/kg treatment. Despite the fact that the lipid peroxidation increased in both cerebral cortex and hippocampus, the latter appeared to be more vulnerable to MeHg exposure as it also had an increase in ADA activity. Thus, although dietary MeHg modified renal cell function, it did not alter histological features in suckling rat pups. The results of our investigation are of significant importance because they demonstrated responses to exposition to low doses of MeHg in target organs during the development of the rat. Especially the kidney was affected by the oral exposure to MeHg, suggesting the vulnerability of this organ at this stage of development. Moreover, the urinary NAG may provide important data that could serve as basis for risk assessment purposes following MeHg exposure.

Syzygium cumini (Sc) have been intensively studied in the last years due its beneficial effects including anti-diabetic and anti-inflammatory potential. Thus, the aim of this study was to evaluate the effect of aqueous seed extract of Sc (ASc) in the activity of enzymes involved in lymphocyte functions. To perform this study, we isolated lymphocytes from healthy donors. Lymphocytes were exposed to 10, 30, and 100 mg/mL of ASc during 4 and 6 h and adenosine deaminase (ADA), dipeptidyl peptidase IV (DPP-IV), and acetylcholinesterase (AChE) activities as well as CD26 expression and cellular viability were evaluated. ASc inhibited the ADA and DPP-IV activities without alteration in the CD26 expression (DPP-IV protein). No alterations were observed in the AChE activity or in the cell viability. These results indicate that the inhibition of the DPP-IV and ADA activities was dependent on the time of exposition to ASc. We suggest that ASc exhibits immunomodulatory properties probably via the pathway of DPP-IV-ADA complex, contributing to the understanding of these proceedings in the purinergic signaling.

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.

The study was undertaken to evaluate changes in the activity of adenosine deaminase (ADA) in brains of rats infected by Trypanosoma evansi. Each rat was intraperitoneally infected with 10(6) trypomastigotes either suspended in fresh (group A; n = 13) and cryopreserved blood (group B; n = 13). Thirteen animals were used as control (group C). ADA activity was estimated in the cerebellum, cerebral cortex, striatum and hippocampus. No differences (P0.05) in ADA activity were observed in the cerebellum between infected and non-infected animals. Significant (P0.05) reductions in ADA activity occurred in cerebral cortex in acutely (day 4 post-infection; PI) and chronically (day 20 PI) infected rats. ADA activity was significantly (P0.05) decreased in the hippocampus in acutely infected rats, but significantly (P0.05) increased in the chronically infected rats. Significant (P0.05) reductions in ADA activity occurred in the striatum of chronically infected rats. Parasites could be found in peripheral blood and brain tissue through microscopic examination and PCR assay, respectively, in acutely and chronically infected rats. The reduction of ADA activity in the brain was associated with high levels of parasitemia and anemia in acute infections. Alterations in ADA activity of the brain in T. evansi-infected rats may have implications for pathogenesis of the disease.

Diabetes mellitus, a chronic metabolic disorder, has assumed epidemic proportions and its long-term complications can have devastating consequences. The oxidative stress in diabetes was greatly increased due to prolonged exposure to hyperglycemia and impairment of oxidant/antioxidant equilibrium. Syzygium cumini is being widely used to treat diabetes by the traditional practitioners over many centuries. Adenosine deaminase (ADA) and 5′-Nucleotidase (5′NT) are enzymes of purine nucleoside metabolism that play an important role in the regulation of adenosine (Ado) levels. In this study, we investigated the effect of Syzygium cumini aqueous leaves extract (ASc) on ADA and 5′NT activities and on parameters of oxidative stress under in vitro conditions, using platelets of patients with Type 2 diabetes mellitus. Platelet-Rich Plasma (PRP) was assayed by ADA, 5′NT, Catalase (CAT), Superoxide Dismutase (SOD) activities and Thiobarbituric acid reactive substances (TBARS) levels. We observed that ADA, 5′NT activities and TBARS levels were significantly higher when compared to the control group, and ASc (100 and 200 µg/mL) prevented these effects. Our study demonstrates that ASc was able to remove oxidant species generated in diabetic conditions and modulates in the Ado levels. Then, ASc may promote a compensatory response in platelet function, improving the susceptibility-induced by the diabetes mellitus.

Adenosine deaminase (ADA) is involved in purine metabolism and plays a significant role in the immune system. The focus of this investigation was to examine the effects of low concentrations of organic mercury on ADA activity in human leukocytes and to investigate the relationship between these effects and cell death. We have examined the protective potential effects of Allium sativum extract (GaE) against Methylmercury (MeHg)-induced cytotoxic effects on human leucocytes under in vitro conditions. MeHg (0.05-10 microM) significantly decreased leukocyte viability (58.97% for MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) and 51.67% for Alamar Blue (AB) and this decrease was positively correlated to the MeHg-induced inhibition of ADA activity. N-acetylcysteine (NAC) and GaE prevented both the MeHg-induced cytotoxic effects on leukocytes according to MTT and AB assays and the effects on the ADA activity. The present results suggest that the protective effects of GaE against MeHg-induced leukocyte damage is related to the removal of oxidant species generated in the presence of MeHg due to the antioxidant efficacy of garlic constituents. It is important to point out that the intense presence of ADA in Leukocyte suspension (LS) highlights the relevant effects in the immune system and in vitro cytotoxicity of MeHg exposure.

Syzigium cumini (L.) Skeels from the Myrtaceae family is among the most common medicinal plants used to treat diabetes in Brazil. Leaves, fruits, and barks of S. cumini have been used for their hypoglycemic activity. Adenosine deaminase (ADA) is an important enzyme that plays a relevant role in purine and DNA metabolism, immune responses, and peptidase activity. ADA is suggested to be an important enzyme for modulating the bioactivity of insulin, but its clinical significance in diabetes mellitus (DM) has not yet been proven. In this study, we examined the effect of aqueous leaf extracts of S. cumini (L.) (ASC) on ADA activity of hyperglycemic subjects and the activity of total ADA, and its isoenzymes in serum and erythrocytes. The present study indicates that: (i) the ADA activity in hyperglycemic serum was higher than normoglycemic serum and ADA activity was higher when the blood glucose level was more elevated; (ii) ASC (60-1000 microg/mL) in vitro caused a concentration-dependent inhibition of total ADA activity and a decrease in the blood glucose level in serum; (iii) ADA1 and 2 were reduced both in erythrocytes and in hyperglycemic serum. These results suggest that the decrease of ADA activity provoked by ASC may contribute to control adenosine levels and the antioxidant defense system of red cells and could be related to the complex ADA/DPP-IV-CD26 and the properties of dipeptidyl peptidase IV (DPP-IV) inhibitors which serve as important regulators of blood glucose.

Hypoxia ischemia (HI) is a common cause of damage in the fetal and neonatal brain. Lifelong disabilities such as cerebral palsy, epilepsy, behavioral and learning disorders are some of the consequences of brain injury acquired in the perinatal periods. Inflammation and formation of free radicals appear to play key roles in neonatal HI. The aim of this study was to describe the chronological sequence of adenosine deaminase (ADA) activity, the oxidative damage changes and astrocyte response using the classic model of neonatal HI. We observed an increase in the activity of ADA and lipid peroxidation in the cerebral cortex 8 days after neonatal HI. This was accompanied by a GFAP-positive, and the degree of brain damage was determined histochemically by hematoxylin-eosin (HE). Taking into account the important anti-inflammatory role of adenosine, ADA may provide an efficient means for scavenging cell-surrounding adenosine and play an important part in subsequent events of neonatal HI in association with GFAP reactive gliosis. The present investigation showed that neonatal HI causes the increase of free radicals and significant damage in the cerebral cortex. The increase in ADA activity may reflect the activation of the immune system caused by HI because the morphological analysis exhibited a lymphocytic infiltration.

The relation between adenine nucleotides and cancer has already been described in literature. Considering that the enzymes ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) act together to control nucleotide levels, we aimed to investigate the role of these enzymes in prostate cancer (PCa). E-NPP and ADA activities were determined in serum and platelets of PCa patients and controls. We also verified the influence of the Gleason score, bone metastasis and treatment in the enzyme activities. Platelets and serum E-NPP activity increased, whereas ADA activity in serum decreased in PCa patients. In addition, Gleason score, metastasis and treatment influenced E-NPP and ADA activities. We may propose that E-NPP and ADA are involved in the development of PCa. Moreover, E-NPP and ADA activities are modified in PCa patients with distinct Gleason score, with bone metastasis, as well as in patients under treatment.

Immune response and inflammation were suggested to play certain roles in the development and complications of type 2 diabetes mellitus. The main objective of this study was to investigate the CD26 expression and its relationship with adenosine deaminase (ADA), dipeptidyl peptidase IV (DPP-IV), γ-glutamyltransferase (GGT), and N-acetyl-β-glucosaminidase (NAG) activities in lymphocytes of type 2 diabetics (T2DM) patients. These parameters were assessed in 25 T2DM patients and 20 control subjects. We observed a decrease in CD26 expression and a significant increase in the ADA activity in T2DM patients when compared with control subjects. There were no differences between activities of DPP-IV, NAG, and GGT in lymphocytes of T2DM patients and control subjects. Meanwhile, a significant negative correlation was observed between CD26 expression and DPP-IV activity in lymphocytes of T2DM patients. Moreover, a positive correlation was found between DPPIV and ADA activities. The results suggest that the reduction of CD26 expression may be associated in the regulation of DPP-IV in T2DM patients.

The aim of the present study was to investigate the effects of Syzygium cumini leaf extract (ASc), on Adenosine deaminase (ADA) and Acetylcholinesterase (AChE) activities, and also on oxidative stress parameters in erythrocytes hemolysates (RBCs) and erythrocytes membranes (ghosts) from type 2 diabetics patients (Type 2 DM) under in vitro conditions. Non protein thiol groups (NP-SH), AChE, Catalase (CAT) and Superoxide Dismutase (SOD) activities were measure in RBCs. Further, ADA activity, Thiobarbituric Acid-Reactive Substances (TBARS) levels and protein thiol groups (P-SH) were estimated in ghosts. Also, P-SH and Vitamin C (VIT C) were measure in plasma sample. The results demonstrated that ADA and AChE activities, besides TBARS levels were higher in erythrocytes of Type 2 DM, while SOD activity and NP-SH levels were decreased when compared to control group. ASc, in vitro, reduced ADA and AChE activities and some parameters of oxidative stress. Furthermore, we observed correlations between VIT C and P-SH levels, ADA activity and P-SH levels, as well as NP-SH and TBARS levels in diabetics. The results suggest that ASc in vitro is able to promote the reduction of inflammation and oxidative stress parameters, and act against biochemical changes occurring in Diabetes mellitus (DM).

SUMMARYIn Trypanosoma evansi infections changes in the haemogram are commonly observed, and the enzyme adenosine deaminase (ADA) plays an important role in the production and differentiation of blood cells. Thus, the aim of this study was to evaluate the activity of ADA in serum, erythrocytes and lymphocytes of rats infected with T. evansi compared to non-infected rats. Thirty adult rats were used, divided into 3 uniform groups. The animals in groups A and B were infected intraperitoneally with 2×106 trypomastigotes/rat. Rodents from group C (control group), were not-infected. Blood collection was performed on days 4 and 20 post-infection (p.i.) in order to obtain acute and chronic infection stages of disease. The blood was used to assess the activity of ADA. In the blood, reduced haematocrit and increased lymphocytes were correlated with ADA activity in erythrocytes and lymphocytes. We observed reduction of ADA activity in serum and erythrocytes in rats infected with T. evansi compared to non-infected rats (PT. evansi.

The extracellular nucleotides, ATP and ADP, as well as the nucleoside adenosine have been implicated in a great number of pathologic and physiological functions. However, extracellular adenine nucleotide levels are controlled by a complex cell surface-located group of enzymes called ectonucleotidases. We evaluated activities of enzymes that hydrolyze adenine nucleotides and nucleosides in platelets from patients with ischemic heart disease (IHD).Sixty IHD patients were selected for the study. The activities of ectonucleoside triphosphate diphosphohydrolase (NTPDase, CD39), ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP), ecto-5'-nucleotidase and adenosine deaminase (ADA) were studied in isolated platelets of these patients, as well as the platelet aggregation and NTPDase expression.The results show that NTPDase, ecto-5'-nucleotidase, E-NPP activities and NTPDase expression were increased in platelets of IHD patients when compared with the control group (p0.05). On the other hand, ADA activity and platelet aggregation were decreased in IHD patients, when compared with the control group (p0.05).The pathological condition in IHD generates alterations in ectonucleotidase activities as a compensatory organic response to thrombotic events that occur in IHD.

Background Multiple sclerosis (MS) is a demyelinating neurological disease, which is presumed to be a consequence of infiltrating lymphocytes that are autoreactive to myelin proteins. ATP and adenosine contribute to fine-tuning immune responses and NTPDase (CD39) and adenosine deaminase (ADA) are important enzymes in the control of the extracellular levels of these molecules at the site of inflammation. We evaluated the activity and expression of NTPDase and adenosine deaminase (ADA) activity in lymphocytes from patients with the relapsing–remitting form of MS (RRMS). Methods This study involved 22 patients with RRMS and 22 healthy subjects as a control group. The lymphocytes were isolated from blood and separated on Ficoll density gradients and after isolation the NTPDase and ADA activities were determined. Results The NTPDase activity and expression were increased in lymphocytes from RRMS patients when compared with the control group (p

Multiple sclerosis (MS) is the most common chronic disabling neurological disease in young adults. Alterations in platelet function have been observed in MS; however, the mechanism and the relevance of this blood cell disorder with regard to MS pathogenesis are not yet understood. The aim of this study was to evaluate activities of ectonucleoside thiphosphate diphosphohydrolase (NTPDase, CD39), ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP), 5′-nucleotidase and adenosine deaminase (ADA) in platelets from patients with the relapsing–remitting form of MS (RRMS), as well as to analyze platelet aggregation and expression of NTPDase. The results obtained show that NTPDase, 5′-nucleotidase, E-NPP and ADA activities were decreased in platelets of RRMS patients when compared with the control group (p < 0.05). In addition, NTPDase expression in platelets was also decreased in these patients (p < 0.05); however, no differences were observed in platelet aggregation between RRMS patients and the control group. Our results suggest that the alterations in NTPDase, E-NPP, 5′-nucleotidase and ADA may have contributed to the alterations in platelet function in MS by altering the levels of nucleotides and nucleosides in the circulation.