Mitochondrial Dysfunction In Rats Research Articles

Hesperitin prevents non-alcoholic steatohepatitis by modulating mitochondrial dynamics and mitophagy via the AMPKα-Drp1/PINK1-Parkin signaling pathway

Non-alcoholic fatty liver disease (NAFLD) is becoming a global public health burden, yet effective therapeutic strategies are notably lacking. NAFLD development may be mediated by mitochondrial dysfunction, according to new research. Producing mitochondrial regulators from plant-based substances to treat mitochondrial dysfunction is an appealing approach to treating NAFLD. Hesperetin (HES) is a flavonoid that is found naturally and is a member of the flavanone family. This study aims to clarify the mechanism of HES in preventing NAFLD which is caused by a high-fat diet (HFD). Serum and liver biochemical parameters, liver histology, lipid profiles, and mitochondrial function were evaluated in HFD-induced NAFLD Sprague-Dawley (SD) rats. HES treatment significantly reduced body weight gain, liver weight, and the liver index, while also improving hepatic steatosis, lipid metabolism disorders, and mitochondrial dysfunction in rats with NAFLD. The mechanism was investigated and confirmed using western blot and real-time quantitative polymerase chain reaction (RT-qPCR). We showed that in the liver of NAFLD rats, HES decreased the expression of dynamic-related protein 1 (Drp1), phosphorylated Drp1 at serine-616 (Drp1-pS616) and induced phosphorylated Drp1 at serine-637 (Drp1-pS637), PTEN-induced kinase 1 (PINK1), and E3 Ubiquitin-Protein Ligase Parkin (Parkin) via an AMP-activated protein kinase alpha (AMPKα)-dependent mechanism. Moreover, HES increased the expression of the mitochondrial fusion proteins mitofusin-2 (Mfn2) and optic atrophy 1 (Opa1) while suppressing the expression of fission protein 1 (Fis1). In this work, we identify a unique mechanism by which HES prevents NAFLD from developing. HES may be an attractive potential therapeutic agent to cure NAFLD.

Retraction Note to: Ocimum basilicum attenuates ethidium bromide-induced cognitive deficits and pre-frontal cortical neuroinflammation, astrogliosis and mitochondrial dysfunction in rats.

Retraction Note to: Ocimum basilicum attenuates ethidium bromide-induced cognitive deficits and pre-frontal cortical neuroinflammation, astrogliosis and mitochondrial dysfunction in rats.

Effects of Allanblackia floribunda stem-bark Extracts on Oxidative stress and Mitochondrial Dysfunction in Rats Exposed to Crude Oil

The development of degenerative diseases has been linked to oxidative stress and mitochondrial dysfunction. Additionally, it has been demonstrated that the changes caused by crude oil exposure contribute to the onset of degenerative diseases. There is little or no information on the anti-degeneration properties of Allanblackia floribunda. This study was carried out to investigate brain mitochondrial tissues exposed to crude oil and the effects of A. floribunda as a preventive and therapeutic intervention against oxidative stress and mitochondrial dysfunction. Twenty-five Wistar rats were divided into five groups: the control group received distilled water, the second group received ethanol extracts of A. floribunda, the third group received crude oil (5 mL/kg), the fourth and fifth groups received crude oil and A. floribunda extract concurrently (200 and 400 mg/kg, respectively). The results showed that crude oil treatment caused a significant increase in brain mitochondrial MDA levels and induced significant alterations in brain mitochondrial antioxidant enzyme activities compared with control. Treatment with the extract alone revealed a significant increase in protein carbonyl, conjugated dienes, and ATPases compared with crude oil-treated rats. This indicates that A. floribunda inhibited crude oil-induced mitochondrial lipid peroxidation and improved ATPase and antioxidant status in the rat brain mitochondria, which further suggests that A. floribunda possesses potential and may efficiently inhibit crude oil-induced oxidative damage and improve mitochondrial functions.

Resveratrol protects renal damages induced by periodontitis via preventing mitochondrial dysfunction in rats.

Periodontitis is closely associated with kidney disease and reactive oxygen species (ROS) involvement. Mitochondria are the primary source of both endogenous ROS and renal energy. We investigated whether resveratrol (RSV) prevents renal injury and mitochondrial dysfunction in periodontitis rats. Thirty male Wistar rats were divided into control, experimental periodontitis (Ep) and Ep-RSV groups. To induce periodontitis, a steel ligature was placed on the cervix of the bilateral first maxillary molars. RSV (50mg/kg/day) to the Ep-RSV group and vehicle to the Ep and control groups were gavaged. After 8weeks, alveolar bone loss, pocket depth, gingival blood index and tooth mobility were assessed. Oxidative stress parameters, mitochondrial structure, mitochondrial membrane potential (MMP), mitochondrial ROS, adenosine triphosphate (ATP), sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) were analysed in renal. Renal function and histology were also evaluated. Compared with the control group, the Ep group showed renal structural destruction, elevated oxidative stress levels, mitochondrial structure destruction, MMP loss, mitochondrial ROS accumulation, ATP reduction, and decreased SIRT1 and PGC-1α levels. RSV prevented these destruction (p<0.05). However, there was no significant impairment in renal function (p>0.05). Periodontitis induces mitochondrial dysfunction in renal tissues. Resveratrol exerts a preventive effect on periodontitis-induced kidney injury by preventing mitochondrial dysfunction.

Low-dose bisphenol S exposure induces hypospermatogenesis and mitochondrial dysfunction in rats: A possible implication of StAR protein

A wide variety of environmental chemicals/xenobiotics including bisphenol A (BPA) has been shown to cause male reproductive dysfunctions and infertility. Recently, bisphenol S (BPS) replaces BPA, in several products, including foodstuffs, under the BPA-free label. However, several studies have raised inquietude about the potential adverse effects of BPS. The present study was conducted to evaluate sperm parameters, biochemical parameters, mitochondrial function, and histopathological patterns after post-lactation BPS exposure at a low dose. Male rats (21 days old) were exposed to water containing BPS at 50 μg/L in drinking water for 10 weeks. Results showed no significant alteration in the gonadosomatic index (GSI) and relative reproductive organs weight. However, a significant reduction in epididymal sperm parameters (number, viability, and mobility) with morphological abnormalities were observed in the BPS group compared to control. An increase of malondialdehyde (MDA) level accompanied by antioxidant defense alteration particularly, in glutathione peroxidase activity, as well as a defective mitochondrial function were observed in testicular tissues of BPS treated rats. More importantly, in histopathological diagnosis, BPS treatment induces hypospermatogenesis and alteration in Sertoli cells. In silico docking studies illustrated BPS binds with steroidogenic acute regulatory (StAR) protein thereby affecting the transport of cholesterol into mitochondria resulting in decreased steroidogenesis. These results reflect a reprotoxic effect of BPS vould potentially lead to fertility reduction, in sexually maturity age. We highlighted that post-lactation exposure to BPS, equivalent in humans to the period covering childhood and adolescent stages, disrupt male reproduction function.

Kynurenic Acid and Its Synthetic Derivatives Protect Against Sepsis-Associated Neutrophil Activation and Brain Mitochondrial Dysfunction in Rats.

Background and AimsThe systemic host response in sepsis is frequently accompanied by central nervous system (CNS) dysfunction. Evidence suggests that excessive formation of neutrophil extracellular traps (NETs) can increase the permeability of the blood–brain barrier (BBB) and that the evolving mitochondrial damage may contribute to the pathogenesis of sepsis-associated encephalopathy. Kynurenic acid (KYNA), a metabolite of tryptophan catabolism, exerts pleiotropic cell-protective effects under pro-inflammatory conditions. Our aim was to investigate whether exogenous KYNA or its synthetic analogues SZR-72 and SZR-104 affect BBB permeability secondary to NET formation and influence cerebral mitochondrial disturbances in a clinically relevant rodent model of intraabdominal sepsis.MethodsSprague–Dawley rats were subjected to fecal peritonitis (0.6 g kg-1 ip) or a sham operation. Septic animals were treated with saline or KYNA, SZR-72 or SZR-104 (160 µmol kg-1 each ip) 16h and 22h after induction. Invasive monitoring was performed on anesthetized animals to evaluate respiratory, cardiovascular, renal, hepatic and metabolic parameters to calculate rat organ failure assessment (ROFA) scores. NET components (citrullinated histone H3 (CitH3); myeloperoxidase (MPO)) and the NET inducer IL-1β, as well as IL-6 and a brain injury marker (S100B) were detected from plasma samples. After 24h, leukocyte infiltration (tissue MPO) and mitochondrial complex I- and II-linked (CI–CII) oxidative phosphorylation (OXPHOS) were evaluated. In a separate series, Evans Blue extravasation and the edema index were used to assess BBB permeability in the same regions.ResultsSepsis was characterized by significantly elevated ROFA scores, while the increased BBB permeability and plasma S100B levels demonstrated brain damage. Plasma levels of CitH3, MPO and IL-1β were elevated in sepsis but were ameliorated by KYNA and its synthetic analogues. The sepsis-induced deterioration in tissue CI–CII-linked OXPHOS and BBB parameters as well as the increase in tissue MPO content were positively affected by KYNA/KYNA analogues.ConclusionThis study is the first to report that KYNA and KYNA analogues are potential neuroprotective agents in experimental sepsis. The proposed mechanistic steps involve reduced peripheral NET formation, lowered BBB permeability changes and alleviation of mitochondrial dysfunction in the CNS.

C60 Fullerene Reduces 3-Nitropropionic Acid-Induced Oxidative Stress Disorders and Mitochondrial Dysfunction in Rats by Modulation of p53, Bcl-2 and Nrf2 Targeted Proteins.

C60 fullerene as a potent free radical scavenger and antioxidant could be a beneficial means for neurodegenerative disease prevention or cure. The aim of the study was to define the effects of C60 administration on mitochondrial dysfunction and oxidative stress disorders in a 3-nitropropionic acid (3-NPA)-induced rat model of Huntington’s disease. Animals received 3-NPA (30 mg/kg i.p.) once a day for 3 consecutive days. C60 was applied at a dose of 0.5 mg/kg of body weight, i.p. daily over 5 days before (C60 pre-treatment) and after 3-NPA exposure (C60 post-treatment). Oxidative stress biomarkers, the activity of respiratory chain enzymes, the level of antioxidant defense, and pro- and antiapoptotic markers were analyzed in the brain and skeletal muscle mitochondria. The nuclear and cytosol Nrf2 protein expression, protein level of MnSOD, γ-glutamate-cysteine ligase (γ-GCLC), and glutathione-S-transferase (GSTP) as Nrf2 targets were evaluated. Our results indicated that C60 can prevent 3-NPA-induced mitochondrial dysfunction through the restoring of mitochondrial complexes’ enzyme activity, ROS scavenging, modulating of pro/antioxidant balance and GSH/GSSG ratio, as well as inhibition of mitochondria-dependent apoptosis through the limitation of p53 mitochondrial translocation and increase in Bcl-2 protein expression. C60 improved mitochondrial protection by strengthening the endogenous glutathione system via glutathione biosynthesis by up-regulating Nrf2 nuclear accumulation as well as GCLC and GSTP protein level.

A metabolomics approach to investigate the proceedings of mitochondrial dysfunction in rats from prediabetes to diabetes.

BackgroundDiabetes mellitus (DM) is a leading cause of preventable cardiovascular disease, but the metabolic changes from prediabetes to diabetes have not been fully clarified. This study implemented a metabolomics profiling platform to investigate the variations of metabolites and to elucidate their global profiling from metabolic syndrome to DM. Methods: Male Sprague-Dawley rats (n = 44) were divided into four groups. Three groups were separately fed with a normal diet, a high-fructose diet (HF), or a high-fat (HL) diet while one group was treated with streptozotocin. The HF and HL diet were meant to induce insulin resistance, obesity, and dyslipidemia, which known to induce DM. Results: The most significant metabolic variations in the DM group’s urine samples were the reduced release of citric acid cycle intermediates, the increase in acylcarnitines, and the decrease in urea excretion, all of which indicated energy metabolism abnormalities and mitochondrial dysfunction. Overall, the metabolic analysis revealed tryptophan metabolic pathway variations in the prediabetic phase, even though the mitochondrial function remains unaffected. Conclusion: This study show that widespread methylations and impaired tryptophan metabolism occur in metabolic syndrome and are then followed by a decline in citric acid cycle intermediates, indicating mitochondrial dysfunction in diabetes.

Proteomics and transcriptomics jointly identify the key role of oxidative phosphorylation in fluoride-induced myocardial mitochondrial dysfunction in rats

The regulation of mitochondrial function, which is dominated by oxidative phosphorylation (OXPHOs), is important in fluoride induced cardiovascular disease. Based on the previous study of fluoride-induced mitochondrial structure and membrane potential abnormalities, this study integrated ITRAQ protein quantification and RNA-Seq methods to analyze the sequencing data of rat myocardial tissue under fluoride exposure (0, 30, 60 and 90 mg/L). A total of 22 differentially expressed genes associated with the OXPHOs pathway were screened by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) co-enrichment analysis, and were localizated by Interaction Network and calculated inter-genes and inter-omics correlations by Pearson correlation. In general, fluoride exposure can down-regulate genes related OXPHOs, particularly affecting the assembly of the complex I including Ndufa10, resulting in abnormal mitochondrial ATP synthesis and reduced myocardial energy supply. Most importantly, this study shows that the enriched information from the proteomics can explain the change process of energy production, but the specific molecules involved in energy supply cannot be obtained via transcriptomics information alone. Based on the results of transcriptional and protein analysis, our findings contribute to an innovative understanding of the pathways and molecular changes of myocardial injury induced by fluorosis.

Saturated fatty acid‐enriched diet exacerbate hepatic mitochondrial dysfunction in rats subjected to maternal protein restriction

The nutritional transition that the western population has undergone is increasingly associated with chronic metabolic diseases. In this context, dietary factors has been linked to oxidative stress, making the body vulnerable to mitochondrial dysfunction and reactive oxygen species. In this work, we evaluated the impact of a saturated fatty acid‐enriched diet in the post‐weaning offspring subjected to maternal protein restriction on the liver mitochondrial bioenergetics. Wistar rats were mated and during gestation and lactation, mothers received control diets (NP, normal protein content 17%) or low protein (LP, 8% protein). After weaning, rats received either NL (normolipidic) or HL (+59% SFA) diets up to 90 days of life. It was verified that all respiratory states of hepatic mitochondria showed a reduction in the LP group subjected to the post‐weaning HL diet (LP‐HL), basal state (−43.7%), state 3 (−37.3%), state 4 (−32.1%) and uncoupled state (−60.4%). Similarly, respiratory control was significantly lower (p&lt;0.01). This group also presented greater mitochondrial swelling compared to controls (p&lt;0.01), potentiated after Ca2+ addition (p &lt;0,01) and prevented in the presence of EGTA (calcium chelator) (p&lt;0.001); and cyclosporin A (mitochondrial permeability transition pore inhibitor) (p&lt;0.0001). These effects were associated to increased liver protein and lipid peroxidation and reduced anti‐oxidant enzymes activities in the LP group fed HL diet after weaning. Additionaly, it was observed increase in PGC‐1α and VDAC and decrease in Tfam gene expressions compared to LP‐NL (p&lt;0.05). Our data suggest that SFA‐enriched HFD induces mitochondrial dysfunction associated with oxidative stress, greater expression of VDAC that may potentiate the opening of the mitochondrial permeability transition pore, and lower mitochondrial biogenesis in the liver of adults rats, with major effects in animals previously submitted to maternal protein restriction.Support or Funding InformationThis study was supported by FACEPE (Brazil), CNPq (Brazil) and CAPES/COFECUB (Brazil/France).

Ocimum basilicum attenuates ethidium bromide-induced cognitive deficits and pre-frontal cortical neuroinflammation, astrogliosis and mitochondrial dysfunction in rats.

Multiple sclerosis (MS) is a chronic neurodegenerative disorder with clinical symptoms of neuroinflammation and demyelination in the central nervous system. Recently, herbal medicines are clinically effective against MS as the current disease-modifying drugs have limited effectiveness. Hence, the present study evaluated the therapeutic potential of Ocimum basilicum essential oil (OB) in ethidium bromide (EB)-induced cognitive deficits in the male rats. Further, the effect of OB (50, 100 and 200μL/kg) was evaluated on EB-induced neuroinflammation, astrogliosis and mitochondrial dysfunction in the pre-frontal cortex (PFC) of the animals. The EB was injected through bilateral intracerebroventricular route into hippocampus to induce MS-like manifestations in the rats. OB (100 and 200μL/kg) and Ursolic acid (UA) significantly reduced the EB-induced cognitive deficits in Morris water maze and Y-maze test paradigms. OB (100 and 200μL/kg) and UA significantly attenuated the EB-induced neuroinflammation in terms of increase in the levels of pro-inflammatory cytokines (TNF-alpha and IL-6) in the rat PFC. Further, OB (100 and 200μL/kg) and UA significantly attenuated the EB-induced astrogliosis in terms of increase in the levels of GFAP (Glial fibrillary acidic protein) and Iba-1 (Ionized calcium binding adaptor molecule-1) in the rat PFC. In addition, OB (100 and 200μL/kg) and UA significantly attenuated the EB-induced decrease in the mitochondrial function, integrity, respiratory control rate and ADP/O in the PFC of the rodents. Moreover, OB (100 and 200μL/kg) and UA significantly reduced the EB-induced mitochondria-dependent apoptosis in the PFC of the rat. Hence, it can be presumed that OB could be a potential alternative drug candidate in the pharmacotherapy of MS.

Betulin attenuated liver damage by prevention of hepatic mitochondrial dysfunction in rats with alcoholic steatohepatitis.

Betulin, a pentacyclic triterpene, possesses antioxidant, anti-inflammatory and hepatoprotective properties. The aim of this study was to evaluate the impact of liver mitochondria in hepatoprotection of betulin using a rat model of alcoholic steatohepatitis induced by ethanol administration (4g/kg, intragastric) for 8weeks. The treatment with betulin (50 and 100mg/kg b.w., intragastric) during this period attenuated the histological signs of steatohepatitis and lowered the serum and liver triglyceride contents, as well as the serum activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Betulin (100mg/kg) decreased the liver/body weight ratio and inhibited the increase in the serum levels of TNFα, IL-1β, TGFβ, and hyaluronic acid, demonstrating hepatoprotective, anti-inflammatory, and antifibrotic potential. Betulin also inhibited the formation of superoxide anions in mitochondria and the end-products of lipid peroxidation in liver tissue, the amount of which was significantly increased in ethanol-treated rats. The disturbances in mitochondrial respiration, uncoupling of oxidative phosphorylation and decreasing of mitochondrial complex I, II, and IV activities in rats with steatohepatitis, were reverted by betulin administration. The increased susceptibility of mitochondria to Ca2+-induced permeability transition pore formation in the hepatitis group was improved in rats treated with betulin. In conclusion, betulin, having antioxidant properties, exerts a beneficial effect in the rat model of alcoholic steatohepatitis via prevention of liver mitochondria dysfunction, which may be attributed to the inhibition of mitochondrial permeability transition.

Guanosine protects against Ca2+-induced mitochondrial dysfunction in rats

Mitochondria play an important role in cell life and in the regulation of cell death. In addition, mitochondrial dysfunction contributes to a wide range of neuropathologies. The nucleoside Guanosine (GUO) is an endogenous molecule, presenting antioxidant properties, possibly due to its direct scavenging ability and/or from its capacity to activate the antioxidant defense system. GUO demonstrate a neuroprotective effect due to the modulation of the glutamatergic system and maintenance of the redox system. Thus, considering the few studies focused on the direct effects of GUO on mitochondrial bioenergetics, we designed a study to evaluate the in vitro effects of GUO on rat mitochondrial function, as well as against Ca2+-induced impairment. Our results indicate that GUO prevented mitochondrial dysfunction induced by Ca2+ misbalance, once GUO was able to reduce mitochondrial swelling in the presence of Ca2+, as well as ROS production and hydrogen peroxide levels, and to increase manganese superoxide dismutase activity, oxidative phosphorylation and tricarboxylic acid cycle activities. Our study indicates for the first time that GUO could direct prevent the mitochondrial damage induced by Ca2+ and that these effects were not related to its scavenging properties. Our data indicates that GUO could be included as a new pharmacological strategy for diseases linked to mitochondrial dysfunction.

The Effect of the Primula Veris Solid Herbal Extract on the Development of Oxidative Stress and the Functional State of Cardiomyocyte Mitochondria of Rats with Experimental Chronic Heart Failure

Experimental chronic heart failure (CHF), caused by intraperitoneal administration of L-isoproterenol (2.5 mg/kg twice a day for 21 days), promotes uncoupling of respiration and oxidative phosphorylation in rat cardiac mitochondria. The rate of mitochondrial oxygen consumption in the metabolic state V3 by Chance in animals with CHF decreased by 53.3% (p < 0.05) with malate (as an oxidation substrate feeding complex I of the electron transport chain (ETC)), by 70.6% (p < 0.05) with succinate (complex II substrate) and by 63.6% (p < 0.05) when malate and succinate were added simultaneously. The respiratory control ratio (RCR) of mitochondria from CHF rats demonstrated a significant decrease for complex I substrate (2.3-fold), complex II substrate (2.5-fold) and 2.6-fold in the case of simultaneous addition of complex I and II substrates and 2.6 times as compared to cardiac mitochondria of intact animals. Mitochondrial dysfunction in experimental CHF is evidently associated with the development of oxidative stress: the malondialdehyde (MDA) content in the group of CHF rats was higher by 54.7% (p < 0.05), as compared with intact animals. The activity of superoxide dismutase (SOD) and catalase was lower by 17.5% (p < 0.05), and by 18.4%, respectively, than in the intact group. Administration of the Primula veris solid herbal extract (PVSHE) attenuated the development of mitochondrial dysfunction in rats with experimental CHF as evidenced by an increase in the V3 respiration using complex I (77.2%; p < 0.05), complex II (114.6%; p < 0.05) substrates and a 1.7- and 2-fold increase in the RCR value (p < 0.05) determined versus negative control with complex I and complex II substrates, respectively. Under these conditions the MDA concentration was lower by 15.7% (p < 0.05), while SOD activity was higher by 56.3% (p < 0.05).

Improved neuroprotective effect of resveratrol nanoparticles as evinced by abrogation of rotenone-induced behavioral deficits and oxidative and mitochondrial dysfunctions in rat model of Parkinson's disease.

The objective of the present study was to evaluate the protective effect of resveratrol nanoparticles (NRSV) against rotenone-induced neurodegeneration in rats. NRSV were prepared by temperature-controlled antisolvent precipitation method and characterized for its particle size, shape, and dissolution properties. Moreover, NRSV effects compared with the free resveratrol (RSV). Animals were divided into four groups: (I) control, (II) rotenone (2mg/kg s.c.), (III) RSV (40mg/kg, p.o.) + rotenone, and (IV) NRSV (40mg/kg, p.o.) + rotenone. Animals received treatments 30min before rotenone administration for a period of 35days. Behavioral quantifications were done using rota rod test and rearing behavior after 24h of last dose. Animals were euthanized, and mid brains were isolated for the estimation of tricarboxylic acid cycle enzymes, oxidative measures (lipid peroxidation (LPO), glutathione (GSH), and catalase), and complex-I activity. In addition, histopathological studies were also performed. Our results showed that chronic rotenone treatment causes motor deficits, decreased rearing behavior, mitochondrial dysfunction, and oxidative stress. Furthermore, histological analysis demonstrated neuronal degeneration in rotenone-treated rats. An important finding of the present study was NRSV showed comparatively better efficacy than the RSV treatment in attenuating the rotenone-induced Parkinson's like behavioral alterations, biochemical and histological changes, oxidative stress, and mitochondrial dysfunction in rats.

A perspective of mitochondrial dysfunction in rats treated with silver and titanium nanoparticles (AgNPs and TiNPs)

Nanotechnology is a growing branch of science that deals with the development of structural features bearing at least one dimension in the nano range. More specifically, nanomaterials are defined as objects with dimensions that range from 1 to 100 nm, which give rise to interesting properties. In particular, silver and titanium nanoparticles (AgNPs and TiNPs, respectively) are known for their biological and biomedical properties and are often used in consumer products such as cosmetics, food additives, kitchen utensils, and toys. This situation has increased environmental and occupational exposure to AgNPs and TiNPs, which has placed demand for the risk assessment of NPs. Indeed, the same properties that make nanomaterials so attractive could also prove deleterious to biological systems. Of particular concern is the effect of NPs on mitochondria because these organelles play an essential role in cellular homeostasis. In this scenario, this work aimed to study how AgNPs and TiNPs interact with the mitochondrial respiration chain and to analyze how this interaction interferes in the bioenergetics and oxidative state of the organelles after sub-chronic exposure. Mitochondria were exposed to the NPs by gavage treatment for 21 days to check whether co-exposure of the organelles to the two types of NPs elicited any mitochondrion-NP interaction. More specifically, male Wistar rats were randomly assigned to four groups. Groups I, II, III, and IV received mineral oil, TiNPs (100 μg/kg/day), AgNPs (100 μg/kg/day), and TiNPs + AgNPs (100 μg/kg/day), respectively, by gavage. The liver was immediately removed, and the mitochondria were isolated and used within 3 h. Exposure of mitochondria to TiNPs + AgNPs lowered the respiratory control ratio, causing an uncoupling effect in the oxidative phosphorylation system. Moreover, both types of NPs induced mitochondrial swelling. Extended exposure of mitochondria to the NPs maintained increased ROS levels and depleted the endogenous antioxidant system. The AgNPs and TiNPs acted synergistically—the intensity of the toxic effect on the mitochondrial redox state was more significant in the presence of both types of NPs. These findings imply that the action of the NPs on mitochondria underlie NP toxicity, so future application of NPs requires special attention.

Pkcδ Activation is Involved in ROS-Mediated Mitochondrial Dysfunction and Apoptosis in Cardiomyocytes Exposed to Advanced Glycation End Products (Ages).

Diabetic patients exhibit serum AGE accumulation, which is associated with reactive oxygen species (ROS) production and diabetic cardiomyopathy. ROS-induced PKCδ activation is linked to mitochondrial dysfunction in human cells. However, the role of PKCδ in cardiac and mitochondrial dysfunction caused by AGE in diabetes is still unclear. AGE-BSA-treated cardiac cells showed dose- and time-dependent cell apoptosis, ROS generation, and selective PKCδ activation, which were reversed by NAC and rotenone. Similar tendency was also observed in diabetic and obese animal hearts. Furthermore, enhanced apoptosis and reduced survival signaling by AGE-BSA or PKCδ-WT transfection were reversed by kinase-deficient (KD) of PKCδ transfection or PKCδ inhibitor, respectively, indicating that AGE-BSA-induced cardiomyocyte death is PKCδ-dependent. Increased levels of mitochondrial mass as well as mitochondrial fission by AGE-BSA or PKCδ activator were reduced by rottlerin, siPKCδ or KD transfection, indicating that the AGE-BSA-induced mitochondrial damage is PKCδ-dependent. Using super-resolution microscopy, we confirmed that PKCδ colocalized with mitochondria. Interestingly, the mitochondrial functional analysis by Seahorse XF-24 flux analyzer showed similar results. Our findings indicated that cardiac PKCδ activation mediates AGE-BSA-induced cardiomyocyte apoptosis via ROS production and may play a key role in the development of cardiac mitochondrial dysfunction in rats with diabetes and obesity.

Influence of the dense extract from herb of Primula veris L. On the oxidative stress development and the functional state of the cardiomyocytes mitochondria of rats with experimental chronic heart failure

Experimental chronic heart failure (CHF), caused by administration of L-isoproterenol (2.5 mg/kg twice a day intraperitoneally for 21 days), promotes uncoupling of respiration and oxidative phosphorylation. The rate of mitochondrial oxygen consumption in the metabolic state V3 by Chance in animals with CHF decreased by 53.3% (p<0.05) with malate using (as an oxidation substrate feeding сomplex I of the electron transport chain (ETC)), by 70.6% (p<0.05) with succinate using (сomplex II substrate) and by 63.6% (p<0.05) when malate and succinate were added simultaneously. The respiratory control ratio significantly decreased 2.3 times for сomplex I, 2.5 for сomplex II, and 2.6 times for the simultaneous operation of two respiratory chain complexes in mitochondria of CHF rats compared to intact animals. Mitochondrial dysfunction in experimental CHF is evidently due to the development of oxidative stress. It was revealed that the content of malonic dialdehyde (MDA) in the group of rats with experimental CHF was higher by 54.7% (p<0.05), as compared with intact animals. The activity of superoxide dismutase (SOD) and catalase was lower by 17.5% (p<0.05), and by 18.4%, respectively than in the intact group. The dense extract from herba of Primula veris L. (DEHPV) 30 mg/kg limits the development of mitochondrial dysfunction in rats with experimental CHF, as evidenced by an increase in the role of V3 respiration for the first and second respiratory chain complexes in 1.7 (p<0.05) and 2.0 times (p<0.05), respectively, the ratio of respiratory control (RCR) - 1.7 times (p<0.05) for сomplex I and 2 times (p<0.05) for сomplex II compared with the negative control. The concentration of MDA was by 15.7% (p<0.05), lower and the activity of SOD was by 56.3% (p<0.05) higher.

Correction of free radical processes and Mitochondrial dysfunction in rats poisoned by sodium nitrite and tobacco smoke, mildronate preparation

Introduction. According to the WHO, smoking takes the second place in the list of reasons that cause premature death of people. The interest in clarifying the mechanisms of action on the organism of nitrites and nitrates and the links of the pathogenesis of gemic hypoxia, which thus arises, is due to their widespread use in industry, agriculture and medicine. Therefore, the study of the combined effects of several xenobiotics on the body is feasible and relevant.The aimof the study –to investigate the effectiveness of using antihydroxant Mildronate and its influence on the oxidative processes in the body of rats of different ages infected with sodium nitrite on the background of 45 days of tobacco intoxication.Research methods. Under the conditions of damage to rats of different ages, sodium nitrite on the background of tobacco intoxication was determined in the blood of the content of methemoglobin (MetHb) in reaction with acetone cyanadirin and carboxyhemoglobin (HbCO) in reaction with hexacyanone (III) potassium. The activity of lipoperoxidation processes was assessed by the content of TBА – active products (TBА – AP) in the serum of blood, lungs and myocardium of experimental animals. The evaluation of the functioning of the bioenergetic processes was carried out using the activity of succinate dehydrogenase (SAD), which was studied by the reaction of reduction of potassium ferricyanide, which solution has a yellow color, to colorless ferrocyanide of potassium succinate by the action of EDA and cytochrome oxidase (CO) by the oxidation reaction of dimethyl-n-phenylenediamine.Results and Discussion. It has been established that the defeat of rats of different age groups by sodium nitrite (24 and 72 h before the end of the experiment) on the background of 45 days intoxication with tobacco smoke leads to the activation of free radical oxidation processes, indicating an increase in the content of methemoglobin in the blood of affected animals and TBА-AP in serum of blood, lungs and myocardium after poisoning. At the same time in the blood the content of carboxyhemoglobin increases. In the body, there is a mixed hypoxia (hemitic and circulatory), which leads to disturbances in the functioning of the mitochondrial oxidation chain. The most susceptible to the activity of toxicotoxins were immature animals, and in older animals there was a significant change in the activity of mitochondrial enzymes in the myocardium after the injury, which was more pronounced in comparison with other age groups of rats. In order to correct the revealed violations, a drug of metabolic action with antihypoxant properties of mildronate was used, which positively influenced the activity of lipoperoxidation processes and the activity of mitochondrial enzymes under hypoxia conditions.Conclusions. The obtained results indicate the expediency of inclusion of mildronate in the complex treatment of poisonings of different genesis.

Effect of emulsified isoflurane post-conditioning on mitochondrial function during lung ischemia-reperfusion in rats: an in vitro experiment

Objective To evaluate the effect of emulsified isoflurane post-conditioning on the mitochondrial function during lung ischemia-reperfusion (I/R) in rats in an in vitro experiment. Methods Twenty-four SPF healthy male Sprague-Dawley rats, weighing 250-300 g, were used in the study.After the animals were anesthetized, the lungs were removed, connected to the perfusion system and then divided into 4 groups (n=6 each) using a random number table: control group (group C), group I/R, emulsified isoflurane post-conditioning group (group EI) and intralipid post-conditioning group (group IL). After 20 min of equilibration, the lungs were continuously perfused for 105 min in group C, and the lungs were subjected to 45 min ischemia followed by 60 min reperfusion to establish the model of lung I/R injury in the other three groups.During the reperfusion period, the common perfusate was used in group I/R, the perfusate containing 1.68 mmol/L emulsified isoflurane was used in group EI, and the equal volume of perfusate containing 30% intralipid was used in group IL.At the end of the equilibration (T0), immediately after beginning of reperfusion (T1) and at 30 and 60 min of reperfusion (T2, 3), the arterial oxygen partial pressure (PaO2), airway resistance, pulmonary compliance and tidal volume (VT) were recorded.The right upper lobe of the lung was removed at T3 for determination of wet to dry weight ratio (W/D ratio). The right middle lobe of the lung was removed at T3 for pathologic examination with light microscope.The contents of reactive oxygen species (ROS), NAD+ and ATP in lung tissues were detected. Results Compared with group C, the PaO2, pulmonary compliance and VT were significantly decreased, and the airway resistance was increased at T1-3, and the W/D ratio and ROS content were increased, and NAD+ and ATP contents were decreased at T3 in I/R, EI and IL groups (P<0.05). Compared with I/R and IL groups, the PaO2, pulmonary compliance and VT were significantly increased, and the airway resistance was decreased at T2, 3, and the W/D ratio and ROS content were decreased, and NAD+ and ATP contents were increased at T3 in group EI (P<0.05). The pathologic changes of lungs were significantly attenuated in group EI as compared with group I/R. Conclusion The mechanism by which emulsified isoflurane post-conditioning attenuates lung I/R injury is related to decrease in mitochondrial dysfunction in rats in an in vitro experiment. Key words: Isoflurane; Fat emulsions, intravenous; Reperfusion injury; Lung; Mitochondrial; Ischemia post-conditioning