Hydroperoxide Levels Research Articles

Effects of α-Lipoic Acid, Carnosine, and Thiamine Supplementation in Obese Patients with Type 2 Diabetes Mellitus: A Randomized, Double-Blind Study.

Type 2 diabetes mellitus (T2DM) is evolving to an epidemic of the modern world. T2DM is associated with a number of pathological complications, including cardiovascular disease that is mostly promoted by the increased oxidative stress in type 2 diabetic patients. We performed a randomized double-blind placebo-controlled trial to investigate the effectiveness of an individualized oral supplementation with α-lipoic acid (ALA), carnosine, and thiamine. For that purpose, 82 obese type 2 diabetic patients were randomly assigned to 2 groups, and were either supplemented daily with 7 mg ALA/kg body weight, 6 mg carnosine/kg body weight, and 1 mg thiamine/kg body weight or placebo for 8 weeks. An array of biochemical tests including the estimation of oxidative stress and platelet aggregation were performed at baseline and at follow-up. Moreover, the antiplatelet activity of each of the supplement's components was determined ex vivo at human and washed rabbit platelets. Glucose and HbA1c levels were significantly reduced after supplementation (135.7 ± 19.5 mg/dL vs. 126.5 ± 16.8 mg/dL and 8.3% ± 0.3% vs. 6.03% ± 0.58%, respectively, P < .05); however, insulin was significantly increased (3.6 ± 0.7 μIU/mL vs. 6.8 ± 0.2 μIU/mL, P < .05). The patients treated with the supplement recorded higher follow-up values for HOMA-IR and HOMA-β, and a significant drop in serum hydroperoxide level. Only ALA inhibited platelets aggregation ex vivo through ADP, platelet activating factor, arachidonic acid, epinephrine, collagen, and thrombin pathways. Daily supplementation with an individualized ALA, carnosine, and thiamine supplement effectively reduced glucose concentration in type 2 diabetic patients, probably by increasing insulin production from the pancreas. In addition to that, the reduction of oxidative stress and inhibition of platelet aggregation could potentially provide greater cardiovascular protection. Further studies are needed to fine-tune the supplementation dose-response effects in T2DM patients.

Oxidative Status in Different Areas of the Cerebral Cortex of Wistar Rats during Focal Ischemia and Its Modulation with Carnosine.

Oxidative status was assessed in different areas of the cerebral cortex of male Wistar rats under normal condition and during permanent 24-h focal ischemia. In intact animals, the level of lipid hydroperoxides in the frontal lobes of both hemispheres was by 36% higher than in other cortical areas, while total antioxidant activity was by 25% higher than in other areas. During ischemia, changes in oxidative status were localized only in the ischemic focus and penumbra zone and did not involve other cortical areas. We demonstrated for the first time a neuroprotective effect of therapeutic administration of carnosine in low doses (50 mg/kg) on parameters of the oxidative status under conditions of focal ischemia comparable to its effect of high doses (500 mg/kg) as well as its local effect in the penumbra zone. A dose-dependent effect of carnosine on antioxidant activity in the penumbra zone during ischemia was also demonstrated. These findings confirm effectiveness of not only preventive carnosine administration, but also its application in the postischemic period of the stroke.

High Dimension Biological Analysis of Carbon Nanotube Toxicity

The toxic effects of multi-walled carbon nanotubes (MWCNTs) are associated with intracellular oxidative processes related to generation of reactive oxygen species (ROS). This is enhanced by metallic impurities that can be mobilized from the carbon nanotubes to the surrounding biological microenvironment. Aiming at identifying the effects of exposure to purified and unpurified MWCNTs on different biological targets immunological, biochemical, gene expression and biological pathway analyses were carried out on samples from healthy humans and in vitro models. The MWCNTs with higher amount of metallic impurities caused a 1.8-fold increase in lipid hydroperoxide levels, while the number of mature T lymphocytes with reduced potential underwent a more than 3-fold increase, as compared to the purified MWCNTs. Whole genome transcriptomics in lung epithelium cells (A549) and keratinocytes (HaCaT) showed that gene expression is significantly modulated after exposure to purified and unpurified MWCNTs. 48-hour exposure resulted in approximately 500 genes expressed differentially in the case of MWCNTs with different levels of impurities. Similar results were found when we analyzed the data isolating the 25 genes involved in the molecular pathway associated to oxidative stress. The persistence of the induction of genes driving chemokine and cytokine-signaling-mediated inflammation showed the importance of the inflammatory effects of MWCNTs, and in particular the unpurified ones. Pathway analysis showed significant modulation of genes related to the NFkB pathway, after exposure to unpurified MWCNTs, as a result of oxidative stress induction. This may cause a perturbation of the IL-6 pathway that aims to regulate inflammatory processes and compensate apoptotic changes. Overall observed immunological responses related to MWCNT exposure are considered the result of the synergistic effect of systemic (mediated by cells of the exposure routes) and local inflammation (blood cells).

Supplementation of scopoletin improves insulin sensitivity by attenuating the derangements of insulin signaling through AMPK.

Scopoletin (SPL), a phenolic coumarin, is reported to regulate glucose metabolism. This study is initiated to substantiate the action of SPL on the regulation of insulin signaling in insulin resistant RIN5f cells and high fat, high fructose diet (HFFD)-fed rat model. Adult male Sprague Dawley rats were fed HFFD for 45days to induce type 2 diabetes and then treated or untreated with SPL for the next 45days. The levels of glucose, insulin, lipid profile, oxidative stress markers along with insulin signaling and AMPK protein expressions were examined at the end of 90days. SPL lowered the levels of plasma glucose, insulin, and lipids which were increased in HFFD-fed rats. HFFD intake suppressed the activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase; however, they were reversed by SPL supplementation, which reduced TBARS, lipid hydroperoxide, and protein carbonyl levels both in plasma and pancreas. SPL supplementation significantly activated insulin receptor substrate 1 (IRS1), phosphatidyl inositol 3-kinase (PI3K), and protein kinase B (Akt) phosphorylation which was suppressed in HFFD rats due to lipotoxicity. Moreover, SPL significantly activated AMPK and enhanced the association of IRS1-PI3K-Akt compared to the control group. The results revealed that SPL alleviated T2D induced by HFFD by escalating the antioxidant levels and through insulin signaling regulation. We conclude that SPL can improve insulin signaling through AMPK, thereby confirming the role of SPL as an AMPK activator.

Enhancing the Cancer Cell Growth Inhibitory Effects of Table Grape Anthocyanins.

Chemical components of grapes are good for our health and have been shown to lower risk for certain cancers. Their beneficial health effects could also be enhanced by consuming other molecules that improve their bioavailability.

Cell growth potential drives ferroptosis susceptibility in rhabdomyosarcoma and myoblast cell lines.

Ferroptosis is a programmed form of iron-dependent cell death caused by lipid hydroperoxide accumulation, which can be prevented by glutathione peroxidase 4 (GPx4) activity. Here we investigated the effects of ferroptosis inducers called erastin and RSL3, which act by glutathione depletion and GPx4 inactivation, respectively, on muscle-derived cell lines of embryonal and alveolar rhabdomyosarcoma (RMS), and mouse normal skeletal C2C12 myoblasts. Myogenic lines were exposed to stepwise increasing concentrations of ferroptosis inducers either alone or in combination with iron supplementation, iron chelating agents (bathophenanthrolinedisulfonic acid, BPS), antioxidant molecules (glutathione, N-acetylcysteine), lipid peroxidation inhibitors (ferrostatin-1), and chemotherapeutic agents (doxorubicin and actinomycin D). Drug susceptibility was quantified by measuring cell viability, proliferation and differentiation via neutral red assay, crystal violet assay and Giemsa staining, respectively. The detection of lipid hydroperoxide and protein levels was performed by immunofluorescence and Western blot analysis, respectively. Erastin and RSL3 increased lipid hydroperoxide levels preferentially in the embryonal U57810 and myoblast C2C12 lines, leading to ferroptosis that was accentuated by iron supplementation or prevented by co-treatment with BPS, glutathione, N-acetylcysteine and ferrostatin-1. The inhibition of extracellular regulated kinases (ERK) pathway prevented ferroptosis in U57810 and C2C12 cells, whereas its increased activation in the embryonal RD cells mediated by caveolin-1 (Cav-1) overexpression led to augmented ferroptosis susceptibility. Finally, we observed the combination of erastin or RSL3 with chemotherapeutic doxorubicin and actinomycin D agents to be effective in increasing cell death in all RMS lines. Erastin and RSL3 triggerferroptosis in highly proliferatingmyogenic lines through a ERK pathway-dependent fashion.

Lavatera critica controls systemic insulin resistance by ameliorating adipose tissue inflammation and oxidative stress using bioactive compounds identified by GC–MS

BackgroundLavatera critica, a leafy green herb, is reported to have many pharmacological activities; but, the improvement of insulin sensitivity against the high gram-fat diet (HGFD)-caused insulin resistance (IR) has not yet been studied. ObjectiveThis study evaluated the role of Lavatera critica leaf extract (LCE) in systemic insulin resistance through the alleviation of adipose tissue inflammation and oxidative damage in HGFD fed mice. MethodsThe mice were fed with HGFD for 10 weeks and the diet was supplemented with LCE each day for the next five weeks. Body weight, food intake, leptin, blood glucose, insulin, insulin resistance, and pro- and anti-inflammatory genes expression were assessed on day 106. ResultsThe HGFD control mice displayed markedly elevated adipose tissue inflammation, oxidative stress, insulin inactivity, and hyperglycemia. Administration of LCE in the HGFD mice, especially a dose of 100 mg/kg, lowered the body weight, food intake, plasma leptin, plasma glucose, plasma insulin, insulin resistance, and increased the food efficacy ratio when compared with the HGFD control mice. The oral glucose tolerance test (OGTT) revealed that LCE prevented further increase in the circulating levels after the glucose load. LCE-treated mice demonstrated a marked suppression of pro-inflammatory cytokines mRNA expression. On the other hand, the mice showed a higher anti-inflammatory genes mRNA expression in the adipose tissue. In addition, LCE treatment improved the oxidative damage as evidenced by the reduced levels of lipid hydroperoxides and thiobarbituric acid reactive substances coupled with the increased antioxidants (superoxide dismutase, total glutathione, glutathione/glutathione disulfide ratio and glutathione peroxidase) in the adipose tissue, plasma and erythrocytes. Gas chromatography-mass spectrometry analysis of the bioactive compounds revealed the presence of 9, 12, 15-octadecatrienoic acid, vitamin E, phytol, hexadecanoic acid, benzenepropanoic acid, and stigmasterol. ConclusionsThese findings prove that LCE improves the insulin-sensitizing activity in the mouse model of HGFD-caused IR, probably due to the amelioration of adipose tissue inflammation and oxidative damage. Hence, the LCE could serve as a useful anti-diabetic agent.

Choroid plexus glutathione peroxidases are instrumental in protecting the brain fluid environment from hydroperoxides during postnatal development.

Hydrogen peroxide, released at low physiological concentration, is involved in different cell signaling pathways during brain development. When released at supraphysiological concentrations in brain fluids following an inflammatory, hypoxic, or toxic stress, it can initiate lipid peroxidation, protein, and nucleic acid damage and contribute to long-term neurological impairment associated with perinatal diseases. We found high glutathione peroxidase and glutathione reductase enzymatic activities in both lateral and fourth ventricle choroid plexus tissue isolated from developing rats, in comparison to the cerebral cortex and liver. Consistent with these, a high protein expression of glutathione peroxidases 1 and 4 was observed in choroid plexus epithelial cells, which form the blood-cerebrospinal fluid barrier. Live choroid plexuses isolated from newborn rats were highly efficient in detoxifying H2O2 from mock cerebrospinal fluid, illustrating the capacity of the choroid plexuses to control H2O2 concentration in the ventricular system of the brain. We used a differentiated cellular model of the blood-cerebrospinal fluid barrier coupled to kinetic and inhibition analyses to show that glutathione peroxidases are more potent than catalase to detoxify extracellular H2O2 at concentrations up to 250 µM. The choroidal cells also formed an enzymatic barrier preventing blood-borne hydroperoxides to reach the cerebrospinal fluid. These data point out the choroid plexuses as key structures in the control of hydroperoxide levels in the cerebral fluid environment during development, at a time when the protective glial cell network is still immature. Glutathione peroxidases are the main effectors of this choroidal hydroperoxide inactivation.

ANTI-CATARACT ACTIVITY OF GARCINIA INDICA AGAINST NAPHTHALENE-INDUCED CATARACT IN RATS

Objective: The objective of this study is to investigate the anti-cataract activity of the aqueous extract of Garcinia indica (AGI) fruit rinds on naphthalene-induced cataract using rats.Methods: Anti-cataract activity of AGI was evaluated using naphthalene model. Rats were divided into five groups (n=6 in each). Naphthalene solution was prepared by dissolving naphthalene in warm corn oil and administered at the dose of 0.5 g/kg/day p.o. for first 3 days and 1 g/kg/day p.o. thereafter for the induction of cataract. Group I normal control received corn oil 5 ml/kg/day. Group II cataract control received naphthalene solution. Group III received Vitamin E 50 mg/kg/day p.o., and Groups IV and V received AGI 200 mg/kg/day p.o and 400 mg/kg/day p.o., respectively, along with the naphthalene solution for 28 days. At the end of the treatment, levels of malondialdehyde, lipid hydroperoxides (LH), carbonyl and sulfhydryl content, and enzymatic and non-enzymatic antioxidants in lens homogenate were measured.Results: Administration of naphthalene produced a mature cataract and an increase in the opacity index. A significant increase in LH and protein carbonyl content while decrease in protein SH content and antioxidant enzymes was found in naphthalene control group as compared to normal control group. Simultaneous administration of AGI and naphthalene delayed the onset and maturation of cataract.Conclusion: The present investigation suggests that AGI protected the lens against naphthalene-induced oxidative damage which might be responsible for delaying the progression of cataract.

Oxidative Stress in Spinocerebellar Ataxia Type 7 Is Associated with Disease Severity.

Spinocerebellar ataxia type 7 is a neurodegenerative inherited disease caused by a CAG expansion in the coding region of the ATXN7 gene, which results in the synthesis of polyglutamine-containing ataxin-7. Expression of mutant ataxin-7 disturbs different cell processes, including transcriptional regulation, protein conformation and clearance, autophagy, and glutamate transport; however, mechanisms underlying neurodegeneration in SCA7 are still unknown. Implication of oxidative stress in the pathogenesis of various neurodegenerative diseases, including polyglutamine disorders, has recently emerged. We perform a cross-sectional study to determine for the first time pheripheral levels of different oxidative stress markers in 29 SCA7 patients and 28 age- and sex-matched healthy subjects. Patients with SCA7 exhibit oxidative damage to lipids (high levels of lipid hydroperoxides and malondialdehyde) and proteins (elevated levels of advanced oxidation protein products and protein carbonyls). Furthermore, SCA7 patients showed enhanced activity of various anti-oxidant enzymes (glutathione reductase, glutathione peroxidase, and paraoxonase) as well as increased total anti-oxidant capacity, which suggest that activation of the antioxidant defense system might occur to counteract oxidant damage. Strikingly, we found positive correlation between some altered oxidative stress markers and disease severity, as determined by different clinical scales, with early-onset patients showing a more severe disturbance of the redox system than adult-onset patients. In summay, our results suggest that oxidative stress might contribute to SCA7 pathogenesis. Furthermore, oxidative stress biomarkers that were found relevant to SCA7 in this study could be useful to follow disease progression and monitor therapeutic intervention.

Spondias mombin supplementation attenuated cardiac remodelling process induced by tobacco smoke.

The objective of this study was to investigate the influence of Spondias mombin (SM) supplementation on the cardiac remodelling process induced by exposure to tobacco smoke (ETS) in rats. Male Wistar rats were divided into 4 groups: group C (control, n = 20) comprised animals not exposed to cigarette smoke and received standard chow; group ETS (n = 20) comprised animals exposed to cigarette smoke and received standard chow; group ETS100 (n = 20) received standard chow supplemented with 100 mg/kg body weight/d of SM; and group ETS250 (n = 20) received standard chow supplemented with 250 mg/kg body weight/d of SM. The observation period was 2 months. The ETS animals had higher values of left cardiac chamber diameters and of left ventricular mass index. SM supplementation attenuated these changes. In addition, the myocyte cross‐sectional area (CSA) was lower in group C compared with the ETS groups; however, the ETS250 group had lower values of CSA compared with the ETS group. The ETS group also showed higher cardiac levels of lipid hydroperoxide (LH) compared with group C; and, groups ETS100 and ETS250 had lower concentrations of LH compared with the ETS group. Regarding energy metabolism, SM supplementation decreased glycolysis and increased the β‐oxidation and the oxidative phosphorylation. There were no differences in the expression of Nrf‐2, SIRT‐1, NF‐κB, interferon‐gamma and interleukin 10. In conclusion, our results suggest that ETS induced the cardiac remodelling process. In addition, SM supplementation attenuated this process, along with oxidative stress reduction and energy metabolism modulation.

Chemical profile and pharmacological effects of the resin and essential oil from Bursera slechtendalii: A medicinal “copal tree” of southern Mexico

This study reports on the volatile profile and pharmacological activities of the essential oil and resin from Bursera slechtendalii, an aromatic medicinal tree commercialized in southern Mexico. The essential oil contained 25 volatiles including p-cymen-8-ol (25.4–35.7%), n-hexyl hexanoate (6.8–17.6%) and n-octyl hexanoate (7.6–14.8%), whereas the crystallized resin contained 14 volatiles, including n-octyl acetate (29.6–34.2%), limonene (15.8–18.7%) and n-octyl butyrate (12.6–17-6%). The inhalation of vapors from the resin and essential oil caused a significant anxiolytic-like effect (p < .01) in ICR mice after 20 min of exposure at a dose of 50–150 mg L−1. The prolonged inhalation of the essential oil (for 40 days, for 15 min, twice a day) produced a significant decrease (p < .01) in total cholesterol and LDL-c content as well as an increase of HDL-c levels in the same murine model. Interestingly, levels of hepatic lipid hydroperoxide decreased, whereas the hepatic activity of superoxide dismutase and glutathione peroxidase was significantly enhanced (P < .05). The detection of p-cymen-8-ol and n-octyl acetate in the plasma of mice strongly suggests their bioavailability and possible role in the biological activities described herein. Also, both the resin and essential oil from B. slechtendalii, as well as their main volatiles, showed a potent repellence activity against Aedes aegypti (p < .01).

Interlaboratory evaluation of methods to quantify skin‐sensitizing hydroperoxides of limonene and linalool (II): Analysis in cosmetic bases

AbstractThe fragrant terpenes limonene and linalool can form skin‐sensitizing hydroperoxides (HPs) upon prolonged exposure to air. Sources of exposure of consumers to sensitizing doses of HPs have not been identified, and it is not clear whether fragranced products are a relevant source. Previously this question was addressed via analytical studies on fine fragrances; however, linalool and limonene are widely used in different consumer products, especially in other leave‐on toiletries. Hence, analytical methods also need to be able to detect potential HPs in more complex consumer product matrices. Here we applied different simple extraction methods and a toolbox of analytical methods to creams and lotions. Blinded samples of a commercial skin cream and a body lotion were spiked with four different HPs at different doses. Five laboratories analysed the samples with a method based on HP reduction in the sample, followed by Extrelut® NT extraction and GC‐MS to quantify the formed alcohols. This method found an average recovery of spiked levels of 80–105%, with a relative standard deviation between laboratories of 11–25% in samples spiked with 100–200 μg g−1. Quantification was also possible in samples spiked with 20–50 μg mL−1, with a relative standard deviation between laboratories of 11–38%. Thus, this method can indirectly detect low levels of HPs in complex bases. In parallel, the same samples were analysed with three LC‐based methods directly detecting the parent HPs: LC coupled with chemiluminescence, LC‐Q‐TOF‐MS, and LC‐orbitrap‐MS. On average, the different analytes were detected with a recovery of 80–143%. No HPs were detected in the non‐spiked products, despite the fact that they do contain linalool and limonene. Results of these studies indicate that consumer exposure can now be studied routinely in different product types as the required methods are ready for roll‐out.

Protein-lipid co-oxidation in emulsions stabilized by microwave-treated and conventional thermal-treated faba bean proteins.

The course of protein–lipid co‐oxidation was investigated in oil‐in‐water emulsions stabilized with proteins extracted from microwave‐treated (MWT) and conventional thermal‐treated (CTT) faba beans stored at 37°C for 7 days. Emulsions prepared with proteins from untreated (UT) faba beans and soy protein isolate (SP) were monitored for comparison. Lipid oxidation was detected through formation of primary and secondary oxidation products while protein oxidation was examined via tryptophan fluorescence degradation in interface and aqueous phase. Oxidation of proteins was more emphasized in the interfacial layers of MWT, CTT, and SP emulsions than in UT emulsions due to the prominence of radical chain‐driven co‐oxidation mechanism while lipoxygenase (LOX) activity in UT and MWT emulsions resulted in high amounts of hydroperoxides and abundance in lipid oxidation volatiles. Conventional thermal treatment provided better oxidative stability than microwave treatment reflected in lower levels of hydroperoxides and relative lack of diversity in lipid volatiles. Among detected volatiles, formation of ketones was more distinguished in MWT, CTT, and SP emulsions while UT emulsions contained a more diverse range of alkenals and alkanals. Ketones are known to form mainly through radical recombination reactions which combined with the results of protein oxidation supports that radical transfer reactions between proteins and lipids were the driving force behind oxidation in MWT, CTT, and SP emulsions. Treatments of faba beans resulted in increased oxidative stability of emulsified lipids and lower degradation of aqueous phase proteins.

Developmental toxicity of dibutyl phthalate and citrate ester plasticizers in Xenopus laevis embryos

Citrate esters have been considered as alternatives to phthalate plasticizers. Being considered to have low toxicity in mammals, their toxicological information for aquatic animals remains poorly understood. We examined the developmental toxicity of citrate esters including tributyl O-acetylcitrate (ATBC), triethyl 2-acetylcitrate (ATEC), and trihexyl O-acetylcitrate (ATHC) together with dibutyl phthalate (DBP) based on the frog embryo teratogenesis assay-Xenopus (FETAX). ATBC has the lowest 96 h LC50 and 96 h EC50 values. In RT-qPCR, the ratio of bax and bcl-2 mRNA was significantly increased by DBP, but not by ATBC, ATEC and ATHC. DNA fragmentation was obvious in DBP-treated tadpoles, but not in those treated with ATBC and ATEC, whereas ATHC caused necrotic DNA degradation. Lipid hydroperoxide levels in tadpoles were significantly increased by DBP and ATHC, but not by ATBC and ATEC, suggesting that induction of oxidative stress by DBP and ATHC in embryos. In tadpoles with head abnormalities, basihyal bone, ceratohyal bone and Meckel's cartilage were frequently missed together with reduction in branchial gill bones. Col2a1 mRNA in the head of tadpoles was significantly decreased by low concentration of DBP, ATHC, and high concentration of ATEC. In stage 25 embryos FoxN3 mRNA, a master regulator for differentiation of neural crest cells to chondrocytes in head, was significantly decreased by DBP and ATHC, but not by ATBC and ATEC. In conclusion, ATEC was recommended as the alternative to phthalate plasticizer having the lowest developmental toxicity in amphibian embryos.

Operation of the Permeability Transition Pore in Rat Heart Mitochondria in Aging

The functioning of the mitochondrial permeability transition pore (mPTP) is involved in the mechanism of programmed cell death and mitochondrial dysfunction observed with aging. In this work, the functional state of heart mitochondria isolated from young (mature and 2–3-month-old) and old (20–22-month-old) rats under conditions of mPTP opening was studied. In the mitochondria of old rats, the rates of Ca2+ and TPP+ absorption decreased by 40 and 42%, respectively, the threshold concentration of Ca2+ decreased by 20%, and the swelling rate of mitochondria from old animals was by 40% higher than that of mitochondria from young ones. In the heart mitochondria of old animals, the content and production of reactive oxygen species (ROS) varied, the superoxide anion content was increased, and the level of hydroperoxide (H2O2) increased at a threshold calcium concentration. Electron microscopy revealed a decrease in the number of cristae in mitochondria of the rat heart during aging. To study the potential role of proteins modulating the mPTP functioning, the content of 2',3'-cyclonucleotide-3'-phosphodiesterase (CNPase) and translocator protein (TSPO) in the heart mitochondria of rats of different ages was measured. A significant age-related decrease in the level of CNPase and an increase in the amount of TSPO were detected. The role of these proteins in mitochondrial dysfunction observed during aging is discussed.

CORRECTION OF PROCESSES OF LIPID PEROXIDATION AND ENDOGENIC TOXICITY WITH EXTRACT OF GERANIUM PALUSTRE HERB AS A DENTAL FILM IN CONDITIONS OF EXPERIMENTAL STOMATITIS

The development of stomatitis is characterized by the appearance of oxidative stress, which is marked by an increase in the intensity of peroxide lipid oxidation processes, resulting in metabolic disturbance in oral mucosa. As a result, toxic substances accumulate and endogenic toxicity develops. Thus, correction of pathological processes in the oral mucosa with antioxidant medication enables to optimize the intensity of inflammation, shorten the period of catabolic phase and accelerate the regeneration. Extract of Geranium palustre herb as a dental film was used to reduce the intensity of processes of lipid peroxidation and endogenous intoxication. This treatment method enables to release an active substance from the drug locally and to provide optimal therapeutic effect. The efficacy of the experimental medication was studied in the dynamics of experimental ulcerative stomatitis development in rabbits. The experimental model of ulcerative stomatitis in animals was induced with a burn method. For the experiment, the animals were divided into 2 groups: control group, where treatment was not performed, and experimental group, where animals were treated by applying a dental film with Geranium palustre extract. The monitoring was conducted on the 3rd, 5th, 7th and 10th days of the experiment, which are key stages of healing.&#x0D; During these periods, blood was taken under anesthesia from the auricular vein of each experimental animal. Dynamics of prooxidant processes was detected by the level of lipid hydroperoxides and malondialdehyde, and the level of endogenic toxicity by the content of middle molecules. Statistic processing of the obtained results of investigation was performed using personal computer with installed proper software package StatSoft Statistica 10. Reliable difference was considered р&lt;0.05.&#x0D; It has been shown that extract of Geranium palustre herb, as a dental film, has antioxidant properties, which are effectively reducing the intensity of lipid peroxidation processes. It should be mentioned that the content of lipid hydroperoxides and final product of lipid peroxidation processes – malondialdehyde – in experimental animals’ blood was statistically lower in all periods of investigation than in control group, where treatment was not performed. The obtained results show that higher inhibiting effect of experimental medication is marked during the final stage of lipid peroxide oxidation than during the initial stage.&#x0D; As the result showed, the development of endogenic toxicity was observed in both groups and the highest indices were recorded at the peak of the inflammatory process on the third day of the experiment. Dynamics of middle molecules content shows that application of Geranium palustre extract, as a dental film, decreases this index during all investigated periods and reduces intoxication level in experimental animals.&#x0D; Thus, application of dental film in stomatitis treatment enables to release medication directly into the damaged area, which significantly increases therapeutic effect of biologically active substances of Geranium palustre phytocomplex, and rapid absorption of the film in the oral cavity provides easy use. Considering efficacy, non-toxicity and availability of the investigated medication, the expediency of its application in dental practice for the treatment of stomatitis and other inflammatory diseases of the oral mucosa may be considered.

СРАВНИТЕЛЬНАЯ ЭФФЕКТИВНОСТЬ СИНТЕТИЧЕСКОГО И ПРИРОДНОГО АНТИОКСИДАНТОВ ПРИ ТОКСИЧЕСКОМ ПОВРЕЖДЕНИИ ПЕЧЕНИ ЧЕТЫРЕХХЛОРИСТЫМ УГЛЕРОДОМ

Currently there is an active search for medicines increasing the stability of liver to pathological effects, reinforcing its neutralizing function, promoting its functional recovery after various injuries, including poisoning by industrial poisons. Therefore, the study of opportunities to reduce toxic liver damage by carbon tetrachloride introduction of synthetic and natural antioxidants is of interest. In experimental conditions the possibility to correct free radical lipid oxidation of rats’ organism membranes was studied with the introduction of the succinate containing drug called Reamberin (Polysan, St.Petersburg) and licorice syrup. The animals were divided into 4 groups and each of them had 10 rats: the group with intact animals which were held in standard conditions of vivarium; the control group in which rats were given carbon tetrachloride during 3 days daily; the experimental group in which before the introduction of carbon tetrachloride animals had a daily intra-abdominal intake of the Reamberin in a dose of 100 mg/kg (20 ml/kg); the experimental group in which before the introduction of carbon tetrachloride animals had a daily oral intake of the licorice syrup in a dose of 5 ml/kg. It was found out that in the blood and in the liver of experimental animals an introduction of carbon tetrachloride during 3 days contributes to the increase of lipid hydroperoxides level (by 24-43%), of diene conjugate (by 19-47%), and of malonic dialdehyde (by 61-81%) against the decrease of antioxidant system activity in the blood of intact animals. The introduction of the succinate containing drug to rats in the conditions of oxidative stress contributes to the decrease in the blood and in the liver of lipid hydroperoxides by 13-26%, of diene conjugates by 11-28%, and of malonic dialdehyde by 30-34% in comparison with the rats of the control group. Adding of the licorice syrup to rats contributes to the reliable decrease in the blood and in the liver of lipid hydroperoxides by 6-23%, of diene conjugates by 9-24%, and of malonic dialdehyde by 25-30% in comparison with the rats of the control group. While analyzing the effect of the antioxidants on the activity of the components of antioxidant system it was shown that the level of ceruloplasmin in the blood and in the liver of animals was reliably higher by 10-47%, of vitamin E by 13-42% in comparison with the same parameters of the rats of the control group. So, the application of the synthetic and natural antioxidants in the conditions of introduction of carbon tetrachloride of the organism of animals under experiment leads to the stabilization of the processes of peroxidation against the increase of antioxidant system activity.

Vitamins C and K3: A Powerful Redox System for Sensitizing Leukemia Lymphocytes to Everolimus and Barasertib

Recent studies provided convincing evidence for the anticancer activity of combined application of vitamin C and pro-vitamin K3 (menadione). The molecular pathways underlying this process are still not well established. The present study aimed to investigate the effect of the combination of vitamin C plus pro-vitamin K3 on the redox status of leukemia and normal lymphocytes, as well as their sensitizing effect for a variety of anticancer drugs. Cytotoxicity of the substances was analyzed by trypan blue staining and automated counting of live and dead cells. Apoptosis was analyzed by fluorescein isothiocyanate-annexin V test. Oxidative stress was evaluated by the intracellular levels of reactive oxygen and nitrogen species and protein-carbonyl products. Combined administration of 300 μM vitamin C plus 3 μM pro-vitamin K3 reduced the viability of leukemia lymphocytes by ~20%, but did not influence the viability of normal lymphocytes. All combinations of anticancer drug plus vitamins C and K3 were characterized by synergistic cytotoxicity towards Jurkat cells, compared to cells treated with drug alone for 24 h. In the case of barasertib and everolimus, this synergistic cytotoxicity increased within 72 hours. It was accompanied by strong induction of apoptosis, but a reduction of level of hydroperoxides and moderately increased protein-carbonyl products in leukemia cells. Leukemia lymphocytes were more sensitive to combined administration of anticancer drug (everolimus or barasertib) plus vitamins C and K3, compared to normal lymphocytes. The combination of vitamin C plus K3 seems to be a powerful redox system that could specifically influence redox homeostasis of leukemia cells and sensitize them to conventional chemotherapy.

Antihypertensive and antioxidant effects of protocatechuic acid in deoxycorticosterone acetate-salt hypertensive rats

Protocatechuic acid (PCA) is a natural antioxidant with beneficial cardiovascular properties. In this study, the effect of supplementation with PCA was investigated in deoxycorticosterone acetate (DOCA)-salt hypertension. Male Wistar rats received DOCA (25 mg/kg, s.c.) twice weekly and 1% NaCl in drinking water and simultaneously treated with PCA (50, 100 and 200 mg/kg, p.o.) for 4 weeks. Systolic blood pressure (SBP) was detected using tail-cuff method. Electrolytes including Na+, K+ and chloride, catalase activity, glutathione, total antioxidant capacity, malondialdehyde (MDA) and hydroperoxides concentration were measured in serum samples. Body and organs weight, water intake and, kidney and heart histopathology were also evaluated. Administration of PCA reversed the changes caused by DOCA-salt approximately at all doses. At the lowest dose, PCA significantly decreased SBP (132.5 ± 4.0 vs 152.3 ± 4.5 mmHg, P < .05), serum sodium (138.5 ± 1.52 vs 141 ± 1.50, P < .05) and chloride level (101.6 ± 1.47 vs 110 ± 1.39, P < .01) and raised serum potassium level (3.8 ± 0.09 vs 3.1 ± 0.17, P < .05) compared with DOCA-salt hypertensive rats. PCA increased serum catalase activity, total antioxidant capacity and glutathione concentration and reduced MDA and hydroperoxides levels. PCA also improved organ weight changes, reduced water intake and moderately prevented histopathological changes of kidney and heart upon DOCA-salt administration. The present study indicates the antihypertensive and antioxidant effects of PCA against DOCA-salt hypertension.