Introduction: There has been demonstrated that pharmaceutical effect of epigallocatechin-3-gallate (EGCG), a polyphenol, which is found in green tea (Camellia sinensis), is implemented through the activation of Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2).The importance of Keap1 / Nrf2 / antioxidant response element (ARE) system is determined by the fact that the state of NF-κB- and АР-1-associated pathways depends on its activity. Recent studies have demonstrated the property of quercetin to suppress ubiquitin-dependent proteolysis of complex of NF-κB and its inhibitory protein IκB. All this provides preconditions to eliminate the potentiality of NF-κB-dependent expression of the number of genes of pro-oxidant and pro-inflammatory proteins. However, co-effect produced by quercetin and EGCG on the oxidative nitrosative stress markers in the periodontal tissues is still unclear. The aim: To investigate the co-effect produced by quercetin and an inducer of the Keap1 / Nrf2 / ARE epigallocatechin-3-gallate on markers of oxidative-nitrosative stress in rats’ periodontium under the systemic and local administration of Salmonella typhi lipopolysaccharide (LPS). Materials and methods: The studies were conducted on 30 white rats of the Wistar line, divided into 5 groups: the 1st included intact animals, the 2nd was made up of animals after their exposure to combined systemic and local LPS administration, the 3rd and 4th groups included animals, which were given injections with water-soluble form of quercetin (corvitin) and EGCG respectively, and the 5th group involved rats, which were injected with co-administered corvitin and EGCG. The formation of superoxide anion radical (.О-2 ) was evaluated by a test with nitro blue tetrazolium using spectrophotometry of the periodontal soft tissue homogenate. The total activity of NO-synthase and concentration of peroxynitrite in the homogenate of the soft components of periodontium were evaluated spectrophotometrically. Results: Co-effect produced by corvitin and EGCG under systemic and local LPS administration is accompanied with reduced О-2 production by NADPH-dependent electron transport chains (microsomal and NOS) by 20.0 % (p<0.05) compared with values for the animals received separate corvitin during the experiment. .О-2 generation by the mitochondrial respiratory chain yielded to comparable data of the 3rd and 4th groups by 27.6 % (p<0.01) and 23.8 % (p<0.05) respectively. No differences were found between the groups exposed to combined or separate action of the above mentioned agents in the experiment when assessing О-2 generation by leukocyte NADPH-oxidase. Combined effect of corvitin and EGCG during systemic and local LSP administration showed the decrease in NOS activity and peroxynitrite concentration in periodontal tissues by 53.3 % (p<0.001) and 27.0 % (p<0.02) compared with the findings in the 3rd group, and by 42.0 % (p<0.01) and 22.3 % (p<0.01) in the 4th group. Conclusions: the co-administration of water-soluble form of quercetin and epigallocatechin-3-gallate under systemic and local introducing of lipopolysaccharide Salmonella typhi has been proven to be more effective means for preventing and correcting oxidative-nitrosative stress in the periodontal tissues than this occurs at separate administration of each of the polyphenols.

The aim: To investigate the effects of bioflavonoids (curcumin, epigallocatechin-3-gallate and quercetin) on nitro-oxidative stress and the functions of submandibular SGs in rats under alcohol exposure during SIR. Materials and methods: The studies were conducted on 35 rats of the Wistar line weighing 205-220 g, divided into 5 groups of seven animals in each: the 1st group, control group I, included animals receiving isotonic sodium chloride solution intragastrically twice a day; the 2nd group, control group II, included rats exposed to alcohol (in a dose of 24 mg/kg intragastrically through gavage a twice a day) for last 2 weeks during lipopolysaccharide (LPS)-induced SIR; the rats of the 3rd, 4th and 5th groups exposed to alcohol during LPS-induced SIR, which also received bioflavonoids. The bioflavonoids (“Sigma-Aldrich, Inc.”, USA) were as following: curcumin (in a daily dose of 200 mg/kg), epigallocatechin-3-gallate (in a daily dose of 40 mg/kg), and quercetin (in a daily dose of 200 mg/kg), respectively. SIR was induced by intraperitoneal administration of Salmonella typhi LPS (during the first week a dose of 0.4 μg/kg of body weight was administered 3 times a week; during the next 7 weeks of the experiment rats received 0.4 μg/kg of body weight once a week. The formation of superoxide anion radical (О2 -), activity of NO-synthase – total (NOS), its constitutive and inducible isoforms (cNOS, iNOS), and concentration of peroxynitrites and S-nitrosothiols were evaluated spectrophotometrically. To assess the functional status of submandibular SGs in their homogenate we determined α-amylase activity (spectrophotometrically) and the aquaporin-5 concentration (by enzyme-linked immunosorbent assay). through gav-age with orogastric cannul. Results: When applying bioflavonoids under the conditions of alcohol administration during SIR, NADH-induced .О2 - production decreased and yielded to the result in the control group II by 36.8% under administering curcumin, by 34.5% under administering epigallocatechin-3-gallate, and by 41.3% under administering quercetin. The total NOS activity in SGs tissues was inferior by 42.8% to the relevant data in the control group II (under curcumin administration), by 33.7% (under epigallocatechin-3-gallate administration) and by 46.6% (under quercetin administration); and the iNOS activity decreased by 47.0, 38.3 and 52.0%, respectively. Under the administration of bioflavonoids peroxynitrites concentration in the submandibular SGs tissues was inferior to the control group II by 35.6% (under curcumin administration), by 37.4% (under epigallocatechin-3-gallate administration), and by 39.3% (under quercetin administration); the content of S-nitrosothiols was lower by 34.5, 31.1 and 35.3%, respectively. The administration of bioflavonoids led to the changes in α-amylase activity in the submandibular SGs tissues: its values exceeded the relevant data in the control group II by 40.4% (under curcumin administration), by 38.2% (under epigallocatechin-3-gallate administration), and by 34.1% (under quercetin administration); under those conditions aquaporin-5 concentration grew in 2.66, 2.61 and 2.55 times, respectively. Conclusions: The use of bioflavonoids (curcumin, epigallocatechin-3-gallate, and quercetin) under the combined administration of 40% ethanol solution and LPS considerably limits the development of nitro-oxidative stress in the tissues of the submandibular SGs. The administration of the bioflavonoids increases the level of cNOS coupling, and improves the functional status of the submandibular SGs under the combined administration of alcohol and LPS enhancing the activity of α-amylase and concentration of aquaporin-5.

The aim: To investigate the effect of water-soluble form of quercetin on the indices reflecting the progression of oxidative-nitrosative stress in the cerebral tissues and the periodontium of rats after experimental TBI. Materials and methods: The studies were conducted on 30 white rats of the Wistar line weighing 180-220 g, divided into 3 groups: the 1st group included pseudo-injured animals (subjected to ether anaesthesia, fixation without TBI modeling), the 2nd group included the animals exposed to modeled moderate TBI, the 3rd group involved the rats, which were given injections with water-soluble form of quercetin (corvitin, “Borshchahivskiy CPP”, Ukraine) intraperitoneally in a daily dose of 10 mg/kg recalculated for quercetin for 7 days following the TBI modeling. The formation of superoxide radical anion (.О2 -), activity of NO-synthase – total (NOS), its constitutive and inducible isoforms (cNOS, iNOS) – and concentration of peroxynitrite were evaluated spectrophotometrically. The level of lipid peroxidation (LPO) in the tissues was evaluated by the formationof a stained trimethine complex during the reaction of tiobarbituric acid (TBA). The activity of the antioxidant system was assessed by increasing in the concentration of TBA active products during 1.5 hour incubation in iron-ascorbate buffer solution, as well as by the activity of antioxidant enzymes – superoxide dismutase (SOD) and catalase. Results: The use of quercetin under the experimental conditions significantly reduced the О2 - generation by NADPH- and NADH-dependent electron transport chains by 30.2 and 35.0% (in the cerebral hemispheres) and by 23.5 and 32.5% (in the soft periodontal tissues), respectively, compared to the findings in the 2nd group. The production of this radical by leukocyte NADPH oxidase in these organs was inferior to the value of the 2nd group by 39.3 and 29.9%. We revealed that the use of quercetin in the experimental conditions probably reduced the activity of NOS, including iNOS, by 38.2 and 45.3% (in the cerebral hemispheres) and by 53.5 and 66.9% (in the soft periodontal tissues), respectively, compared with the findings in the 2nd group. Under these conditions, the cNOS activity went up by 50.0% and doubled, the peroxynitrite content was lower by 19.5 and 32.1% than that in the 2nd group. The administration of quercetin in the experimental conditions significantly reduced the concentration of TBA-active products in the homogenate of cerebral hemispheres and soft periodontal tissues. The development of decompensated LPO is also confirmed by a decrease in the activity of SOD and catalase. Conclusions: on the 7th day after modeling moderate TBI in rats the signs of oxidative-nitrosative stress are found not only in locus morbi (in the tissue of the cerebral hemisphere), but also in distant organs (periodontal tissues). Applying of water-soluble form of quercetin significantly reduces signs of oxidative-nitrosative stress in the tissue of the cerebral hemisphere of rats, as well as in periodontal tissues on the 7th day after moderate TBI modeling.

Influence de l'intoxication combinée nitrate-fluorure sur les troubles tissulaires conjonctifs dans la muqueuse gastrique des rats Introduction. Certaines régions d'Europe et d'Ukraine présentent une concentration élevée de fluorures dans les eaux potables. Une agriculture très développée peut entraîner une concentration accrue de nitrates dans les eaux souterraines et les eaux potables. Par conséquent, leur consommation excessive combinée avec de la nourriture et de l'eau n'est pas exclue. Le but de l'étude est de déterminer l'influence de l'intoxication combinée au fluorure de nitrate sur la concentration de différentes fractions de glycosaminoglycanes (GAG) et la concentration de L-hydroxyproline dans la muqueuse gastrique de rats. Matériaux et méthodes. Les intoxications chroniques ont été induites par une injection intragastrique de fluorure de sodium à une dose de 10 mg / kg, de nitrate de sodium à une dose de 500 mg / kg et de leur association pendant 30 jours. La concentration en GAG a été déterminée par la méthode au carbazole. Pour évaluer les concentrations de différentes fractions de GAG, nous avons utilisé une méthode de précipitation différentielle à l'éthanol. Pour l'estimation de la concentration en L-hydroxyproline, nous avons ABSTRACT Introduction. Certain regions in Europe and Ukraine have high concentration of fluorides in drinking waters. Highly developed agriculture can result in increased concentration of nitrates in ground and drinking waters. Therefore, their combined excessive intake with food and water is not excluded. The objective of the study was to determine the influence of combined nitrate-fluoride intoxication on concentration of different fractions of glycosaminoglycans (GAG) and L-hydroxyproline concentration in gastric mucosa of rats. Materials and methods. Chronic intoxications were induced by intragastric injection of sodium fluoride in a dose of 10 mg/kg, sodium nitrate in a dose of 500 mg/kg and their combination during 30 days. Concentration of GAG was determined by carbazole method. To evaluate concentrations of different fractions of GAG we used the method of differential precipitation with ethanol. For L-Hydroxyproline concentration estimation, we used Hydroxyproline Colorimetric Assay Kit (BioVision K555-100). Results. The total concentration of GAG decreases during chronic fluoride and nitrate intoxications, but increases during combined intoxication. Concentration of Heparin/Heparan GAG fraction and Keratan/Dermatan GAG fraction drops during

The purpose of this study is to investigate the effects of bioflavonoids, epigallocatechin-3-gallate (EGCG) and quercetin, on the production of reactive oxygen and nitrogen species in the liver of rats under round-the-clock light exposure with an intensity of 1500 lux for 30 days while being kept on carbohydrate-lipid diet (20% fructose solution and appropriate food) for 60 days. In the liver tissues, the rate of the superoxide anion production by NADPH-dependent electron transport chains (microsomal monooxygenases and constitutive uncoupled NO synthases) increased by 1.93 times, by the mitochondrial respiratory chain by 1.89 times, and it was doubled by leukocyte NADPH-oxidase. The total activity of NO synthase was increased by 2.35 times, the activity of its inducible isoform increased by 2.57 times, and the concentration of alkali and alkaline earth metals peroxynitrites elevated by 1.68 times. Administration of bioflavonoids-epigallocatechin-3-gallate and quercetinsignificantly restrained the rate of superoxide anion production in the liver tissues by microsomal monooxygenases and NO synthase by 39.1 and 40.1%, by the mitochondrial respiratory chain by 37.2 and 34.4%, by leukocyte NADPH-oxidase by 35.0 and 32.1%, respectively. Epigallocatechin-3-gallate and quercetin inhibited the total activity of NO-synthase by 46.7 and 36.2%, the activity of its inducible isoform by 49.6 and 39,0%, increased the activity of the constitutive isoenzyme NO-synthase by 2.9 times and its coupling index by 4.5 and 4.7 times. Additionally, administration of these bioflavonoids lowered the concentration of peroxynitrites of alkali and alkaline earth metals by 30.5 and 34.3% compared to the respective values obtained in the group of rats, which did not receive the bioflavonoids, but were exposed to light and carbohydrate-lipid-rich diet. We suggest that epigallocatechin3-gallate and quercetin in the above experimental conditions are effective means to restrain the formation of reactive oxygen and nitrogen species in the liver tissue.