Syzygium cumini is more effective in preventing the increase of erythrocytic ADA activity than phenolic compounds under hyperglycemic conditions in vitro

Syzygium cumini (S. cumini) is a plant known for its antidiabetic properties. The aim of this study was to evaluate the effect of Sc aqueous leaf extract (ASc) on adenosine deaminase (ADA) activity in erythrocytes (RBCs) exposed to high glucose concentrations (30 mM) in vitro. We also investigated the effects of the main phenolic compounds found in ASc (gallic acid, rutin, and chlorogenic acid) and the effects of insulin, caffeine, and dipyridamole, which are substances involved in the adenosine metabolism, on ADA activity in vitro. Blood samples were obtained from healthy volunteers and a suspension of RBCs was used for the determination of ADA activity. The results showed that: (1) the effect of ASc on ADA activity was more significant than the combination of phenolic compounds; (2) insulin, caffeine, or dipyridamole prevented high glucose increase of ADA activity at doses as low as 50 μU/mL, 25 μM, and 1 μM, respectively; (3) the inhibitory effect caused by ASc on erythrocyte ADA activity remained practically the same after the combination of the extract with insulin or caffeine; (4) when RBCs were exposed to ASc plus dipyridamole, this chemical attenuated the effect of ASc on ADA activity, suggesting an antagonism or a competition with ASc by the same site of action. Therefore, ASc was more effective in preventing the increase in ADA activity than phenolic compounds, suggesting that ASc may collaborate to improve endothelial dysfunction, antioxidant, anti-inflammatory, and antithrombotic properties of adenosine by affecting its metabolism. The results of this study help to provide evidence of the empirically supported benefits of the use of S. cumini in diabetes

Syzygium cumini is more effective in preventing the increase of erythrocytic ADA activity than phenolic compounds under hyperglycemic conditions in vitro.

Syzygium cumini (S. cumini) is a plant known for its antidiabetic properties. The aim of this study was to evaluate the effect of Sc aqueous leaf extract (ASc) on adenosine deaminase (ADA) activity in erythrocytes (RBCs) exposed to high glucose concentrations (30 mM) in vitro. We also investigated the effects of the main phenolic compounds found in ASc (gallic acid, rutin, and chlorogenic acid) and the effects of insulin, caffeine, and dipyridamole, which are substances involved in the adenosine metabolism, on ADA activity in vitro. Blood samples were obtained from healthy volunteers and a suspension of RBCs was used for the determination of ADA activity. The results showed that: (1) the effect of ASc on ADA activity was more significant than the combination of phenolic compounds; (2) insulin, caffeine, or dipyridamole prevented high glucose increase of ADA activity at doses as low as 50 µU/mL, 25 µM, and 1 µM, respectively; (3) the inhibitory effect caused by ASc on erythrocyte ADA activity remained practically the same after the combination of the extract with insulin or caffeine; (4) when RBCs were exposed to ASc plus dipyridamole, this chemical attenuated the effect of ASc on ADA activity, suggesting an antagonism or a competition with ASc by the same site of action. Therefore, ASc was more effective in preventing the increase in ADA activity than phenolic compounds, suggesting that ASc may collaborate to improve endothelial dysfunction, antioxidant, anti-inflammatory, and antithrombotic properties of adenosine by affecting its metabolism. The results of this study help to provide evidence of the empirically supported benefits of the use of S. cumini in diabetes.

Butyrylcholinesterase and γ-glutamyltransferase activities and oxidative stress markers are altered in metabolic syndrome, but are not affected by body mass index.

Metabolic syndrome (MetS) leads to changes in enzymatic activities, oxidative and inflammatory parameters. Adenosine deaminase (ADA), dipeptidyl peptidase IV (DPP-IV), butyrylcholinesterase (BuChE) and γ-glutamyltransferase (γ-GT) activities, C-reactive protein (hsCRP) and nitric oxide levels (NOx), as well as oxidative stress markers were analyzed in 39 subjects with MetS and 48 controls. Also, the influence of body mass index (BMI) and anthropometric measurements were evaluated. Disturbances in antioxidant defenses and higher γ-GT and BuChE activities, NOx and hsCRP levels were observed in subjects with MetS. These findings remained associated with MetS after adjustment for BMI, except for hsCRP. ADA was correlated with age, insulin levels and HOMA-IR index in MetS. DPP-IV and total cholesterol (TC), BuChE activity and TC, and VIT C and hsCRP levels also were correlated. The analyzed parameters may reflect the inflammatory state of the MetS, and could contribute to prevention and control of various aspects of this syndrome.

Exposição aguda ao Metilmercúrio em ratos em desenvolvimento: mini-revisão / Acute exposition of developing rats to Methylmercury: a mini-review

Mercúrio (Hg) está presente no ambiente em três diferentes formas químicas: elementar (Hg0), inorgânico e orgânico, sendo que a sua distribuição, toxicidade e metabolismo são dependentes de sua forma química. A exposição oral ao consumo de peixes e alimentos contaminados é a principal forma de exposição humana ao metilmercúrio (MeHg), um poluente ambiental que é absorvido por ingestão, inalação e através da pele. O MeHg é um potente neurotóxico, especialmente para o cérebro em desenvolvimento. Neste estudo, foram examinados os principais efeitos da exposição ao MeHg durante o desenvolvimento salientando os mecanismos bioquímicos envolvidos nestes processos. Também foram apresentados recentes resultados sobre o uso de extratos de plantas medicinais que atenuaram os efeitos adversos deste metal. Deste modo, estes dados reforçam a toxicidade do MeHg durante o desenvolvimento e sugerem possíveis caminhos para futuras intervenções terapêuticas.

Mercury (Hg) is present in the environment in three different chemical forms: elemental, inorganic and organic Hg. The distribution, toxicity and metabolism of Hg are linked to its chemical form. The oral exposition following fish and food contaminated is the main route of contamination of humans to the methilmercury (MeHg), an environmental pollutant which is absorbed by ingestion, inhalation and through the skin. MeHg is a strong neurotoxic molecule, especially for the developing brain. In this study, the main effects of the MeHg exposition and the biochemical parameters involved in this process were examined. The results of the use of plant extracts which attenuate the adverse effects of this metal are also presented here. Therefore, these data reinforce the MeHg toxicity during the development and suggest alternative ways for future therapeutic approaches.

Lymphocytic enzymes and lipid peroxidation in patients with metabolic syndrome.

OBJECTIVES: Metabolic syndrome (MetS) is considered a state of chronic inflammation. This study aimed to ascertain selected parameters of purinergic and cholinergic systems related to glucose metabolism and inflammation, as well as (γ)-glutamyltransferase (GGT) and N-acetyl-b-glucosaminidase (NAG) activities and lipoperoxidation in lymphocytes of patients with MetS. DESIGN AND METHODS: The adenosine deaminase (ADA), dipeptidyl peptidase IV (DPP-IV), acetylcholinesterase (AChE), GGT and NAG activities, as well as thiobarbituric acid reactive substances (TBARS) levels were investigated in lymphocytes of patients with MetS (n=38) and healthy volunteers (n=41). We also evaluated the insulin levels, anthropometric measurements and routine biochemical analyses. RESULTS: ADA (p<0.05), DPP-IV and AChE (p<0.0001) activities were higher in patients with MetS when compared to the control group. Furthermore, we observed correlations between ADA and DPP-IV activities (p=0.0002; r=0.5945), TBARS levels and ADA (p=0.0021; r=0.5172) and DPP-IV activities (p=0.0022; r=0.5010). CONCLUSIONS: Our findings showed that MetS might cause tissue distress that disturbed lymphocytic ADA, DPP-IV and AChE activities in response to inflammatory stimuli. These alterations evidence clinical abnormalities, since these enzymatic systems are able to regulate several aspects of adipose tissue function and inflammatory state of MetS and could be used successfully both for preventing and for halting the progression of MetS.

Hypertension strengthens δ-ALA-D activity inhibition and increases it reactivation index in type 2 diabetic patients.

AIMS: To assess the effect of hypertension on δ-aminolevulinate dehydratase (δ-ALA-D) activity of type 2 diabetic patients (T2DM). METHODS: δ-ALA-D activity and reactivation index, as well as markers of oxidative stress, biochemical and anthropometrics parameters were determined in T2DM (n=23), type 2 diabetic patients with hypertension (T2DM/HT) (n=30) and controls (n=30). RESULTS: T2DM/HT presented a greater inhibition of δ-ALA-D activity, a higher reactivation index (p<0.05) and a greater depletion of plasma protein thiol groups (P-SH) when compared to T2DM. Moreover, δ-ALA-D activity was positively associated with SH groups and negatively associated with serum protein carbonyl (PC) while its reactivation index was negatively associated with SH groups and positively associated with PC. CONCLUSIONS: These results point out that there is a possible interference of hypertension on the mechanism of the δ-ALA-D activity suggesting that this condition aggravated the oxidative stress of diabetes mellitus.

δ-Aminolevulinate dehydratase activity in type 2 diabetic patients and its association with lipid profile and oxidative stress.

OBJECTIVES: To investigate the activity of δ-Aminolevulinate dehydratase (δ-ALA-D) and its possible relationship with oxidative status, lipid profile, body mass index (BMI) in type 2 diabetics (DM2) patients. DESIGN AND METHODS: δ-ALA-D activity and reactivation index, as well as markers of oxidative stress and biochemical and anthropometrics parameters were determined in DM2 patients (n = 63) and controls (n = 63). RESULTS: There was a decreased δ-ALA-D activity and a higher reactivation index (p<0.05) in DM2 patients besides an elevated level of oxidative stress. Disturbances on lipid profile were related to the enzymatic activity and BMI also was correlated with oxidative level in DM2 patients (p<0.05). CONCLUSION: There is an association between oxidative stress, abnormalities on lipid profile, distribution of body fat and δ-ALA-D activity inhibition as well as the enzyme is more oxidized in the DM2 suggesting that it would be a good biomarker for assessing prejudice in chronic metabolic processes.

Syzygium cumini extract decrease adenosine deaminase, 5'nucleotidase activities and oxidative damage in platelets of diabetic patients.

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.