Parameters of Oxidative Stress and Activity of Antioxidant Enzymes in the Saliva of Patients with Type 1 Diabetes Mellitus.

Glucose concentration in the saliva is increased in type 1 diabetes mellitus. This parameter directly correlates with markers of the disease in the blood serum. Increased concentration of 8-oxo-2'-deoxyguanosine (8-OHdG) and diene conjugates, markers of oxidative stress, and reduced activities of superoxide dismutase and catalase were also observed in this pathology. Correlation analysis revealed a strong positive correlation between glucose concentration and the levels of oxidative stress markers and a negative correlation between activity of antioxidant enzymes and glucose concentration. The results indicate that the level of 8-OHdG, diene conjugates, and superoxide dismutase and catalase activities can serve as diagnostic markers of pathophysiological changes in the body in type 1 diabetes mellitus.

1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline exerts a neuroprotective effect and normalises redox homeostasis in a rat model of cerebral ischemia/reperfusion.

Ischemia is one of the main etiological factors of stroke and is associated with the development of energy deficiency, oxidative stress, and inflammation. An abrupt restoration of blood flow, called reperfusion, can worsen the effects of ischemia. In our study, we assessed the neuroprotective potential of 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline (BHDQ) in cerebral ischemia/reperfusion (CIR) in rats. Wistar rats, divided into 4 groups were used in the study: sham-operated animals; animals with CIR caused by occlusion of the common carotid arteries and subsequent removal of the occlusions; rats treated with BHDQ at a dose of 50 mg/kg in the presence of pathology; sham-operated animals treated with BHDQ. The analysis of the state of energy metabolism in the brain, the level of the S100B protein and the histological assessment of the brain tissue were carried out. The antioxidant potential of BHDQ was assessed by measuring biochemiluminescence parameters, analysing the level of 8-isoprostane, products of lipid and protein oxidation, concentration of α-tocopherol and citrate, and aconitate hydratase activity during CIR in rats. A study of the effect of BHDQ on the regulation of the enzymatic antioxidant system and the inflammatory processes was performed. We demonstrated that BHDQ has a neuroprotective effect in CIR, reducing histopathological changes in the brain, normalizing pyruvate and lactate concentrations, and the transcripts level of Hif-1α gene. The positive effect of BHDQ was probably due to its antioxidant and anti-inflammatory activity, manifested in a decrease in the parameters of the oxidative stress, decreased mRNA of proinflammatory cytokines and NF-κB factor genes. In addition, BHDQ reduced the load on antioxidant protection enzymes, contributing to a change in their activities, decreased the level of antioxidant gene transcripts and expression of Nrf2 and Foxo1 factors toward control. Thus, BHDQ exhibited a neuroprotective effect due to a decrease in the level of oxidative stress and inflammation and the normalization of redox homeostasis on CIR in rats.

Neuroprotective effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline mediated via regulation of antioxidant system and inhibition of inflammation and apoptosis in a rat model of cerebral ischemia/reperfusion.

The aim of the study was the assessment of the neuroprotective potential of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline (DHQ) and its effect on inflammation, apoptosis, and transcriptional regulation of the antioxidant system in cerebral ischemia/reperfusion (CIR) in rats. The CIR rat model was constructed using the bilateral common carotid artery occlusion followed by reoxygenation. DHQ was administered at a dose of 50 mg/kg for three days. Histological staining was performed using hematoxylin and eosin. The level of S100B protein, 8-hydroxy-2-deoxyguanosine, and 8-isoprostane was assessed using an enzyme immunoassay. The intensity of apoptosis was assessed based on the activity of caspases and DNA fragmentation. The activity of enzymes was measured spectrophotometrically, the level of gene transcripts was assessed by real-time PCR. DHQ reduced the histopathological changes and normalized levels of S100B, lactate, pyruvate, and HIF-1 mRNA in the CIR rat model. In addition, DHQ decreased the oxidative stress markers in animals with a pathology. The tested compound also inhibited inflammation by decreasing the activity of myeloperoxidase, expression of interleukins and Nfkb2. DHQ-treated rats with CIR showed decreased caspase activity, DNA fragmentation, and AIF expression. DHQ changed activity of antioxidant enzymes to the control values, decreased the expression of Cat, Gsr, and Nfe2l2, which was overexpressed in CIR, and activated the expression of Sod1, Gpx1, Gsta2, and Foxo1. DHQ showed a neuroprotective effect on CIR in rats. The neuroprotective effect involve mechanisms such as the inhibition of oxidative stress, leading to a reduction in the inflammatory response and apoptosis and the modulation of the antioxidant defense components.

[The effect of the biologically active additive epiphamine on antioxidant and NADPH-generating enzymes activity under experimental cerebral ischemia/reperfusion in rats]. / Vozdeistvie BAD épifamin na aktivnost' antioksidantnykh i NADPH-generiruiushchikh fermentov pri éksperimental'noi ishemii/reperfuzii golovnogo mozga u krys.

The effect of biologically active additive with immunomodulator properties epiphamine on the activity of antioxidant (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase) and NADPH-generating (glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) enzymes has been investigated at experimental cerebral ischemia/reperfusion in rats. The results obtained indicate epiphamine-induced changes of these enzymes activities towards control values. Changes in the content of lactate, a marker of the pathology development, have also been found in experimental animals under ischemia and epiphamine administration caused changes similar to those observed in the case of enzyme activities studied. In most cases, the changes were dose-dependent. Thus, epiphamine can be of considerable interest from the point of view of metabolic changes pharmacological correction at the development of the pathology accompanied by oxidative stress.

[Effect of melaxen on free radical processes intensity and some antioxidant enzymes activity in rats liver and blood serum under type 2 diabetes mellitus].

The effect of melaxen on free radical processes and activity of superoxide dismutase and catalase in rats with type 2 diabetes mellitus (T2DM) has been investigated. It was established that melaxen administration to diabetic rats caused a decrease of the intensity of free radical processes as evidenced a decrease of the lipid peroxidation primary products content and biochemiluminescence parameters. The activity of the antioxidant enzymes changed towards normal values. These effects were probably induced by the correction of the melatonin level at the result of the melaxen action.

Activity of the glutathione antioxidant system and NADPH-generating enzymes in blood serum of rats with type 2 diabetes mellitus after administration of melatonin-correcting drugs.

We studied the effects of epifamin and melaxen on serum content of reduced glutathione and activities of glutathione peroxidase, glutathione reductase, and NADPH-generating enzymes (glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase) in rats with type 2 diabetes mellitus. The concentration of reduced glutathione was decreased in rats with this disease (by 1.8 times), but increased after treatment with epifamin and melaxen (by 1.6 and 1.7 times, respectively). Activities of glutathione peroxidase, glutathione reductase, and NADPH-generating enzymes returned to the control level. Correction of melatonin concentration after treatment with the test drugs was probably followed by inhibition of free radical processes. The observed changes were accompanied by normalization of activity of the glutathione antioxidant system and NADPH-generating enzymes required for normal function of this system.

Intensity of Free Radical Processes in Rat Liver under Type 2 Diabetes and Introduction of Epifamin.

The effect of epifamin on free radical processes, the activity of caspase-1 and -3, aconitate hydratase and citrate content in rat's liver at experimentally induced type 2 diabetes mellitus (T2DM) was studied. The action of epifamin at T2DM leads to a decrease in biochemiluminescence parameters, characterizing the intensity of free radical processes, and changes in aconitase activity and citrate level towards the control. Activities of caspase-1 and caspase-3 in the tissue decreased by a factor of 2.4 and 1.6 in comparison with the levels at the disease. Apparently, epifamin-mediated correction of the level of melatonin, providing a significant antioxidant effect, promotes positive action on the free radical homeostasis.

[Stability of biocatalysts on the basis of carrageenan-immobilized Escherichia coli during continuous synthesis of L-malic acid]. / Stabil'nost' biokatalizatorov na osnove immobilizovannykh v karraginan kletok Escherichia coli v protsesse nepreryvnogo sinteza L-iablochnoi kisloty.

Continuous enzymatic synthesis of L-malic acid from potassium fumarate in packed-bed flow reactors was investigated. Carrageenan-immobilized Escherichia coli cells were used as a biocatalyst. The operational stability of the biocatalyst fumarase activity was studied, and conditions for preserving high activity of the biocatalyst were determined.

[The effect of composition and ionic strength of external solution on the aspartate-ammonia lyase and fumarate hydratase activity in Escherichia coli cells]. / Vliianie sostava i ionnoi sily vneshnego rastvora na aktivnost' aspartat-ammiak-liazy i fumarat-gidratazy v kletkakh Esherichia coli.

It was found that the nonspecific effect of ionic strength of the external solution on the enzymatic activity of E. coli cells consists in rapid changes in the permeability of cell membranes interacting with the substrate. This effect depends on the initial substrate concentration, i.e., ionic strength of the external solution, and is maintained for some time as the substrate concentration decreases. Chloramphenicol, a protein synthesis inhibitor, and sodium azide, a respiration inhibitor (300 micrograms/ml and 200 microM, respectively) do not change the enzymatic activity of E. coli cells during the synthesis of L-aspartic and L-malic acids from fumaric acid. The kinetic equations of L-aspartate and L-malate synthesis are described by equations of zero and intermediate (between zero and first) order, respectively.

[Enzymatic synthesis of L-malic acid from fumaric acid using immobilized Escherichia coli cells]. / Enzimaticheskii sintez L-iablochnoi kisloty iz fumarovoi s pomoshch'iu immobilizovannykh kletok Escherichia coli.

Optimal conditions were chosen for cultivation of Escherichia coli 85 cells with a rather high fumarate-hydratase activity on a cheap medium containing no edible raw material. An active biocatalyst for the synthesis of L-malic acid from fumaric acid was obtained based on E. coli 85 cells immobilized in carrageenan. The enzymatic synthesis of L-malic acid from potassium fumarate was kinetically studied and optimized. Some thermodynamic parameters of fumaric acid hydration into malic acid were determined. A technique for assaying the reaction mixture was developed that involved high performance liquid chromatography.

[Aspartase activity and the stability of Escherichia coli cells immobilized in different carrageenan samples]. / Aspartaznaia aktivnost' i stabil'nost' kletok Escherichia coli, immobilizovannykh v razlichnye obraztsy karraginana.

The cells of Escherichia coli 85 immobilized in carrageenan from various sources were being studied for the aspartase activity and stability. These properties of the resultant preparations which display a relatively high and stable biocatalytic activity were shown to be almost independent of the raw material from which carrageenan was obtained and of the degree of its purification.

[Comparison of the aspartase activity and its stability in Escherichia coli cells immobilized on polyacrylamide gel and carrageenan]. / Sravnenie aspartaznoi aktivinosti i ee stabil'nosti u kletok Escherichia coli, immobilizovannykh v poliakrilamidnyi gel' i karraginan.

The conditions for immobilization of Escherichia coli cells (Soviet strain 85) on the natural polysaccharide carrier carrageenan (Soviet-made) were investigated and kinetic regularities of the aspartase reaction catalysed by immobilized in carrageenan cells of E. coli 85 were established. The conditions for retaining a high aspartase activity and stability of biocatalysts based on the E. coli 85 cells immobilized in PAAG and carrageenan were determined using full-loaded tanks for continuous synthesis of L-aspartic acid. The time-stable aspartase activity of the biocatalyst can be increased by treating the beads of the catalyst with bifunctional reagents (hexamethylenediamine, glutaraldehyde), the most active catalyst for the biotechnological synthesis of L-aspartic acid being obtained when carrageenan is used.