The intensity of free radical processes and chaperone activity in the saliva of patients with type 2 diabetes

Introduction

Saliva is a clinically informative biological fluid that contains many biomarkers, allowing multiple analyses to be performed.

Aim

The objectives of this study were the assessment of the serum and saliva levels of biochemical parameters and intensity of free radical processes in T2DM patients and the identification of the correlation between certain criteria.

Methods

This case-control study included 40 T2DM patients, which were compared with 40 healthy individuals. The levels of glucose, cholesterol triglycerides, total protein, diene conjugates, and chaperone activity were measured using the spectrophotometric method. The concentration of 8-oxo-2'-deoxyguanosine was assessed by competitive enzyme-linked immunosorbent assay.

Results

It was established that the progression of diabetes led to an increase in glucose in saliva. The content of 8-oxo-2'-deoxyguanosine and conjugated dienes increased in serum and this increase was associated with the level of glucose and glycated hemoglobin. The level of protein and chaperone activity increased in the saliva of patients with T2DM compared with the control. The correlation analysis revealed a relationship between total protein concentration and conjugated dienes and between chaperone activity and conjugated dienes in saliva.

Conclusions

According to the results of the analysis, the pathological changes in DM affected the salivary glands and their secretions. The obtained results allowed us to recommend using saliva as an alternative to blood for the diagnosis and monitoring of T2DM treatments since it is readily available and quickly responds to changes in metabolism in the body.

Inflammation is associated with impairment of oxidative status, carbohydrate and lipid metabolism in type 2 diabetes complicated by non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is accompanied by inflammation and impairment of the lipid metabolism. In addition, NAFLD is one of the major complications of type 2 diabetes associated with oxidative stress. Based on this, we evaluated the tumour necrosis factor alpha (TNF-α), nuclear factor κB (NF-κB), oxidative status rates, and analysed its correlation with carbohydrate and lipid metabolism in patients with NAFLD and type 2 diabetes.

METHODS

A case-control study included 63 participants with NAFLD developing in patients with type 2 diabetes, and 65 healthy volunteers with a normal complete blood count and blood biochemical profile. The following parameters and states were assessed during the study: glycaemia, insulin resistance, lipid levels, liver tests, intensity of free radical induced oxidation, antioxidant enzymes, TNF-α and NF-κB level.

RESULTS

Free radical induced oxidation was significantly elevated (p<0.001), total antioxidant activity was significantly decreased (p<0.001) and associated with insulin resistance (p=0.019) and lipid metabolism shifts (p<0.05) in patients with NAFLD and type 2 diabetes. Such patients had showed impaired functioning of antioxidant system (p<0.001), inhibition of NADPH-generating enzymes activity (p<0.001), increased levels of TNF-α (p<0.001) and NF-κB (p=0.019) correlated with the severity of hyperglycaemia (p<0.05), concentration of reduced glutathione (p=0.005) and total cholesterol (p=0.016).

CONCLUSIONS

The increase of free radical induced oxidation, TNF-α and NF-κB levels, and depletion of the antioxidant system seems to be the key factors of the development of NAFLD in patients with type 2 diabetes.

[Effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on the intensity of free radical processes and the activity of oxidative metabolism enzymes under toxic liver injury in rats]

The effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on markers of hepatocytes cytolysis (aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transpeptidase), parameters reflecting the state of oxidative status (intensity of biochemical luminescence and the content of diene conjugates), and the activity of oxidative metabolism enzymes (aconitate hydratase, glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) was studied in rats with CCl4-induced liver injury. The results obtained in the course of the work demonstrated the ability of the test compound to reduce the severity of oxidative stress and liver cells damage, as well as to change the activity of aconitate hydratase and NADP-generating enzymes in the direction of control values. 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline was more effective in normalizing CCl4-induced changes of the analyzed parameters that Carsil used as a reference compound. The tendency to normalize the state of oxidative status and enzyme activity of oxidative metabolism can attributed to hepatoprotective and antioxidant properties of the tested compound.

[The effect of biguanide derivatives on oxidative stress in rats with hyperglycemia]

The effect of the synthetic biguanide derivatives N-[imino(1-piperidinyl)methyl]guanidine (NIPMG) and 1,3-dimethyl-5-[(carbamimidamidomethanimidoil) amino]benzoyl-1,3dicarboxylate (DCB) on the degree of proteins oxidative modification (POM) and the DNA fragmentation, the content of the lipid peroxidation primary products - conjugated dienes (CD), and the activity of glutathione antioxidant system in the liver and heart of rats with experimental hyperglycemia was investigated. Administration of the biguanides (15.0 mg/kg) to hypoglycemic rats promoted reduction of the free radical processes intensity in the studied tissues. Data about CD and POM level changes in hyperglycemic rats treated by NIPMG and DKB correlate with the results of DNA fragmentation degree evaluation. At the same time, the activity of antioxidant enzymes (glutathione peroxidase and glutathione reductase), and the reduced glutathione content in the liver and heart of rats changed toward control values. For metformin, which was used as a comparison drug, changes in the studied parameters in the same direction were also found. These results indicate the ability of the tested biguanide derivatives to exhibit a positive regulatory effect on free radical homeostasis, reducing the degree of oxidative stress at this pathology.

Effects of N-[Imino(1-Piperidinyl)Methyl] Guanidine on the Intensity of Free Radical Processes, Aconitase Activity, and Citrate Level in the Tissues of Rats with Experimental Type 2 Diabetes Mellitus

Effects of a synthetic biguanide derivative N-[imino(1-piperidinyl)methyl] guanidine (NIPMG) on free radical homeostasis, aconitase activity, and citrate concentration were studied in the liver and blood serum of rats with type 2 diabetes mellitus. Analysis of biochemiluminescence parameters showed that administration of this agent (10 mg/kg body weight) to animals with diabetes reduced the intensity of free radical processes in study tissues relative to the increased values in untreated diabetic animals. Under these conditions, aconitase activity, a principal target of ROS effects, and citrate level in the liver and blood serum of rats approached the control levels. The results show that NIPMG can positively regulate free radical homeostasis and reduce the intensity of oxidative stress in type 2 diabetes mellitus, which was accompanied by normalization of the studied parameters.

Effects of Melatonin-Aided Therapy on the Glutathione Antioxidant System Activity and Liver Protection

Acute hepatitis results from oxidative stress triggered by hepatotoxic drugs causing liver injury and the activation of caspases cascade. The glutathione antioxidant system protects against reactive oxygen species and mitigates development of these processes. The effectiveness of silymarin, a polyphenolic flavonoid, essenthiale, composed of phosphatidyl choline, and melaxen, a melatonin-correcting drug, as hepatoprotectors has been investigated. The variation of 6-sulfatoxymelatonin (aMT6s), resulting from the biotransformation of melatonin, and GSH has been measured. The activities of caspase-1 and caspase-3, glutathione antioxidant system, and NADPH-generating enzymes were determined. The aMT6s decreases in patients with drug hepatitis and recovers with administration of mexalen. GSH increased in the presence of the studied hepatoprotectors. Pathologically activated caspase-1 and caspase-3 decreased their activities in the presence of hepatoprotectors with melaxen showing the highest effect. The positive effect of melatonin appears to be related to the suppression of decompensation of the glutathione antioxidant system functions, recovery of liver redox status, and the attenuation of inhibition of the NADPH supply.

Effect of N-[Imino(4-morpholyl)methyl]guanidine on the oxidative status in rats with toxic hepatitis

The hepatoprotective and antioxidant properties of a synthetic biguanide N-[imino(4-morpholyl)methyl]guanidine (IMMG) were prognosticated by the method of computer prediction. Administration of IMMG was accompanied by a decrease in serum transaminase activity in rats with toxic hepatitis, which reflects inhibition of hepatocyte cytolysis. IMMG treatment was followed by a decrease in biochemiluminescence parameters reflecting the intensity of free radical oxidation. We revealed an increase in activity of aconitase, which was reduced during toxic hepatitis. The content of citrate in the liver and serum was returned to normal under these conditions. IMMG also increased activities of superoxide dismutase and catalase and total antioxidant activity in rat liver. Our results suggest that the hepatoprotective effect of IMMG is associated with its antioxidant activity.