Rat Liver Mitochondria Research Articles

Alkyl esters of 7-hydroxycoumarin-3-carboxylic acid as potent tissue-specific uncouplers of oxidative phosphorylation: Involvement of ATP/ADP translocase in mitochondrial uncoupling

An impressive body of evidence has been accumulated now on sound beneficial effects of mitochondrial uncouplers in struggling with the most dangerous pathologies such as cancer, infective diseases, neurodegeneration and obesity. To increase their efficacy while gaining further insight in the mechanism of the uncoupling action has been remaining a challenge. Encouraged by our previous promising results on lipophilic derivatives of 7-hydroxycoumarin-4-acetic acid (UB-4 esters), here, we use a 7-hydroxycoumarin-3-carboxylic acid scaffold to synthesize a new series of 7-hydroxycoumarin (umbelliferone, UB)-derived uncouplers of oxidative phosphorylation – alkyl esters of umbelliferone-3-carboxylic acid (UB-3 esters) with varying carbon chain length. Compared to the UB-4 derivatives, UB-3 esters proved to be stronger uncouplers: the most effective of them caused a pronounced increase in the respiration rate of isolated rat heart mitochondria (RHM) at submicromolar concentrations. Both of these series of UB derivatives exhibited a striking difference between their uncoupling patterns in mitochondria isolated from liver and heart or kidney, namely: a pronounced but transient decrease in membrane potential, followed by its recovery, was observed after the addition of these compounds to isolated rat liver mitochondria (RLM), while the depolarization of RHM and rat kidney mitochondria (RKM) was rather stable under the same conditions. Interestingly, partial reversal of this depolarization in RHM and RKM was caused by carboxyatractyloside, an inhibitor of ATP/ADP translocase, thereby pointing to the involvement of this mitochondrial membrane protein in the uncoupling activity of both UB-3 and UB-4 esters. The fast membrane potential recovery in RLM uncoupled by the addition of the UB esters was apparently associated with hydrolysis of these compounds, catalyzed by mitochondrial aldehyde dehydrogenase (ALDH2), being in high abundance in liver compared to other tissues. Protonophoric properties of the UB derivatives in isolated mitochondria were confirmed by measurements of RHM swelling in the presence of potassium acetate. In model bilayer lipid membranes (liposomes), proton-carrying activity of UB-3 esters was demonstrated by measuring fluorescence response of the pH-dependent dye pyranine. Electrophysiological experiments on identified neurons from Lymnaea stagnalis demonstrated low neurotoxicity of UB-3 esters. Resazurin-based cell viability assay showed low toxicity of UB-3 esters to HEK293 cells and primary human fibroblasts. Thus, the present results enable us to consider UB-3 esters as effective tissue-specific protonophoric mitochondrial uncouplers.

Inhibition of respiratory complex I by 6-ketocholestanol: Relevance to recoupling action in mitochondria

6-Ketocholestanol (kCh) is known as a mitochondrial recoupler, i.e. it abolishes uncoupling of mitochondria by such potent agents as carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and 3,5-di(tert-butyl)-4-hydroxybenzylidenemalononitril (SF6847) [Starkov et al., 1997]. Here, we report data on the kCh-induced inhibition of both NADH-oxidase and NADH-ubiquinone oxidoreductase activities of the respiratory complex I in bovine heart submitochondrial particles (SMP). Based on the absence of such inhibition with hexaammineruthenium (III) (HAR) as the complex I electron acceptor, the kCh effect could be associated with the ubiquinone-binding centre of this respiratory enzyme. In isolated rat liver mitochondria (RLM), kCh inhibited oxygen consumption with the glutamate/malate, substrates of NAD-linked dehydrogenases, while no inhibition of RLM respiration was observed with succinate, in agreement with the absence of the kCh effect on the succinate oxidase activity in SMP. Three kCh analogs (cholesterol, 6α-hydroxycholesterol, and 5α,6α-epoxycholesterol) exhibited no effect on the NADH oxidase activities in both SMP and RLM. Importantly, the kCh analogs were ineffective in the recoupling of RLM treated with CCCP or SF6847. Therefore, interaction of kCh with the complex I may be involved in the kCh-mediated mitochondrial recoupling.

Proteins oxidative modification and antioxidant enzymes activity in the liver mitochondria of rats under laser irradiation and administration of ω-3 polyunsaturated fatty acids

Proteins oxidative modification and antioxidant enzymes activity in the liver mitochondria of rats under laser irradiation and administration of ω-3 polyunsaturated fatty acids

Alkyl esters of umbelliferone-4-acetic acid as protonophores in bilayer lipid membranes and ALDH2-dependent soft uncouplers in rat liver mitochondria

A great variety of coumarin-related compounds, both natural and synthetic, being often brightly fluorescent, have shown themselves beneficial in medicine for both therapeutic and imaging purposes. Here, in search for effective uncouplers of oxidative phosphorylation, we synthesized a series of 7-hydroxycoumarin (umbelliferone, UB) derivatives combining rather high membrane affinity with the presence of a hydroxyl group deprotonable at physiological pH - alkyl esters of umbelliferone-4-acetic acid (UB-4 esters) differing in alkyl chain length. Addition of UB-4 esters to isolated rat liver mitochondria (RLM) resulted in their rapid depolarization, unexpectedly followed by membrane potential recovery on a minute time scale. According to TLC and HPLC data, incubation of RLM with UB-4 esters caused their hydrolysis, which led to disappearance of the uncoupling activity (recoupling). Both mitochondrial recoupling and hydrolysis of UB-4 esters were suppressed by inhibitors of mitochondrial aldehyde dehydrogenase (ALDH2), disulfiram and daidzin, thus pointing to the involvement of this enzyme in the recoupling of RLM incubated with UB-4 esters. The protonophoric mechanism of mitochondrial uncoupling by UB-4 esters was proved in experiments with artificial bilayer lipid membranes (BLM): these compounds induced proton-selective electrical current across planar BLM and caused dissipation of pH gradient on liposomes. UB-4 esters showed antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Mycobacterium smegmatis.

Role of Mitochondrial Cytochrome P450 2E1 in Healthy and Diseased Liver.

Cytochrome P450 2E1 (CYP2E1) is pivotal in hepatotoxicity induced by alcohol abuse and different xenobiotics. In this setting, CYP2E1 generates reactive metabolites inducing oxidative stress, mitochondrial dysfunction and cell death. In addition, this enzyme appears to play a role in the progression of obesity-related fatty liver to nonalcoholic steatohepatitis. Indeed, increased CYP2E1 activity in nonalcoholic fatty liver disease (NAFLD) is deemed to induce reactive oxygen species overproduction, which in turn triggers oxidative stress, necroinflammation and fibrosis. In 1997, Avadhani’s group reported for the first time the presence of CYP2E1 in rat liver mitochondria, and subsequent investigations by other groups confirmed that mitochondrial CYP2E1 (mtCYP2E1) could be found in different experimental models. In this review, we first recall the main features of CYP2E1 including its role in the biotransformation of endogenous and exogenous molecules, the regulation of its expression and activity and its involvement in different liver diseases. Then, we present the current knowledge on the physiological role of mtCYP2E1, its contribution to xenobiotic biotransformation as well as the mechanism and regulation of CYP2E1 targeting to mitochondria. Finally, we discuss experimental investigations suggesting that mtCYP2E1 could have a role in alcohol-associated liver disease, xenobiotic-induced hepatotoxicity and NAFLD.

Ethyl acetate extract of Terminalia arjuna bark shows antioxidant activity and protects against oxidative stress in rat liver mitochondria

The antioxidant properties of Terminalia arjuna (TA) bark have been identified in this present study. The antioxidant properties of ethyl acetate extract of TA bark were established by DPPH radical scavenging activity, reducing power, H2O2 scavenging activity, scavenging activity of hydroxyl radical, superoxide radical, and nitric oxide radical. This present study also showed the protective effects of ethyl acetate extract against copper-ascorbate-induced oxidative stress in rat liver mitochondria in vitro. The ethyl acetate extract of TA barkaltered the content of reduced glutathione (GSH), levels of lipid-peroxidation (LPO), and protein carbonylation (PCO) (P<0.001) against copper-ascorbate treated rat liver mitochondria, in vitro. Thus, the results indicate that the ethyl acetate extract of TA bark can be considered as a therapeutic agent in the future.

Effect of diterpene alkaloids on lipid peroxidation in mitochondria

In this article, the antioxidant activity of some alkaloids lipid peroxidation (LPO) in rat liver mitochondria has been studied. It has been established that diterpenoid alkaloids: 1-О-benzoylnapelline, napelline and songorine have a protective effect on mitochondria, reducing the damaging effect of Fe2+/ascorbate and the release of malondialdehyde (MDA) into the secondary products of peroxidation. The effect of alkaloids napelline, 1-O-benzoylnapelline and songorine on the processes of MDA formation in rat liver mitochondria in vitro has been studied.Where in at 200 мM concentrations, 1-О-benzoylnapelline inhibited the formation of MDA by 95 %, and the alkaloids napelline and songorine at this concentration inhibited the formation of MDA by 54 and 44 %. From the data obtained, it can be shown that 1-О-benzoylnapelline strongly inhibits the formation of MDA compared to songorine and napelline.

STUDY OF THE FLAVONOID COMPOSITION AND BIOLOGICAL ACTIVITY OF HAWTHORN`S LEAVES CRATAEGUS PONTICA

The results of studies of the content of polyphenolic compounds and their antioxidant activity in the Pontic hawthorn plant Crataegus pontica K.Koch., growing in the mountainous regions of the Tashkent region of the Republic of Uzbekistan are presented. The collection of raw materials took place in the spring at the beginning of October 2019 and at the end of April 2020. The conditions for the isolation of polyphenolic compounds were selected under various conditions. It was shown that the optimal content of polyphenols is extracted with 70% acetone, followed by fractionation of the aqueous residue with ethyl acetate and precipitation with hexane. It was shown that in the plants harvested in spring, the amount of polyphenols was 4.28%, and the collected volume was 2.6%, of the air-dry mass of the raw material. Chromatographic methods (BC and TLC) revealed that the composition of plant leaves collected in spring contains more polyphenols than those collected in autumn. This plant contains compounds belonging to the class of flavonols, phenolic acids and flavan-3-ols. Polyphenols were identified by rutin, quercetin, quercetin-3-O-β-galactoside, catechin, and gallic acid by BC and TLC methods.
 The antioxidant activity of the sum of polyphenolic compounds was studied in the model of lipid peroxidation (LPO) in rat liver mitochondria. It was found that polyphenols have a protective effect on mitochondria, a reduced damaging effect of Fe2+ / ascorbate and antioxidant activity depends on the concentration of the studied polyphenolic substances. The introduction of rutin into the incubation medium in 5 μM medium inhibits LPO processes by 32.0%, and at 10 μM – by 85.9% and in 20 μM – by 96.8%, compared with the control.

Carbenoxolon Is Capable to Regulate the Mitochondrial Permeability Transition Pore Opening in Chronic Alcohol Intoxication.

Background: carbenoxolone, which is a derivative of glyceretic acid, is actively used in pharmacology for the treatment of diseases of various etiologies. In addition, we have shown carbenoxolone as an effective inducer of mitochondrial permeability transition pore in rat brain and liver mitochondria. Methods: in the course of this work, comparative studies were carried out on the effect of carbenoxolone on the parameters of mPTP functioning in mitochondria isolated from the liver of control and alcoholic rats. Results: within the framework of this work, it was found that carbenoxolone significantly increased its effect in the liver mitochondria of rats with chronic intoxication. In particular, this was expressed in a reduction in the lag phase, a decrease in the threshold calcium concentration required to open a pore, an acceleration of high-amplitude cyclosporin-sensitive swelling of mitochondria, as well as an increase in the effect of carbenoxolone on the level of mitochondrial membrane-bound proteins. Thus, as a result of the studies carried out, it was shown that carbenoxolone is involved in the development/modulation of alcohol tolerance and dependence in rats.

Self-assembled magnetic polymeric micelles for delivery of quercetin: Toxicity evaluation on isolated rat liver mitochondria

Multifunctional nanocarriers as a promising platform could provide numerous opportunities in the field of drug delivery. Drug carriers loaded with both magnetic nanoparticles (MNPs) and therapeutic agents would allow the combination of chemotherapy with the possibility of monitoring or controlling the distribution of the nano vehicles in the body which may improve the effectiveness of the therapy. Furthermore, by applying these strategies, triggering drug release and/or synergistic hyperthermia treatment are also reachable. This study aimed to explore the potential of the quercetin (QUR) loaded magnetic nano-micelles for improving drug bioavailability while reducing the drug adverse effects. The bio-safety of developed QUR loaded magnetic nano-micelles (QMNMs) were conducted via mitochondrial toxicity using isolated rat liver mitochondria including glutathione (GSH), malondialdehyde (MDA), and the ferric reducing ability of plasma (FRAP). QMNMs with a mean particle size of 85 nm (PDI value of 0.269) and great physical stability were produced. Also, TEM images indicated that the prepared QMNMs were semi-spherical in shape. These findings also showed that the constructed QMNMs, as a pH-sensitive drug delivery system, exhibited a stable and high rate of QUR release under mildly acidic conditions pH (5.3) compared to neutral pH (7.4). The most striking result to emerge from the data is that an investigation of various mitochondrial functional parameters revealed that both QMNMs and QUR have no specific mitochondrial toxicity. Altogether, these results offer overwhelming evidence for the bio-safety of QMNMs and might be used as an effective drug delivery system for targeting and stimuli-responsive QUR delivery.

A study on the interaction of the amyloid fibrils of α-synuclein and hen egg white lysozyme with biological membranes

Alpha-synuclein (α-syn) aggregation and mitochondrial dysfunction are considered as two of the main factors associated with Parkinson's disease (PD). In the present investigation, the effectiveness of the amyloid fibrils obtained from α-syn with those of hen egg white lysozyme (HEWL), as disease-related and-unrelated proteins, to damage rat brain and rat liver mitochondria have been investigated. This was extended by looking at SH-SY5Y human neuroblastoma cells and erythrocytes, thereby investigating the significance of structural characteristics of amyloid fibrils related to their interactions with biomembranes obtained from various sources. Results presented clearly demonstrate substantial differences in the response of tested biomembranes to toxicity induced by α-syn/HEWL amyloid fibrils, highlighting a structure-function relationship. We found that fibrillar aggregates of α-syn, but not HEWL, caused a significant increase in mitochondrial ROS, loss of membrane potential, and mitochondrial swelling, in a dose-dependent manner. Toxicity was found to be more pronounced in brain mitochondria, as compared to liver mitochondria. For SH-SY5Y cells and erythrocytes, however, both α-syn and HEWL amyloid fibrils showed the capacity to induce toxicity. Taken together, these results may suggest selective toxicity of α-syn amyloid fibrils to mitochondria mediated likely by their direct interaction with the outer mitochondrial membrane, indicating a correlation between specific structural characteristics of α-syn fibrils and an organelle strongly implicated in PD pathology.

Palmitoyl-CoA effect on cytochrome c release, a key process of apoptosis, from liver mitochondria of rat with sucrose diet-induced obesity

Cytochrome c (cyt-c) release from the mitochondria to the cytosol is a key process in the initiation of hepatocyte apoptosis involved in the progression of non-alcoholic fatty liver disease (NAFLD) to fibrosis, cirrhosis and hepatocellular carcinoma. Hepatocyte apoptosis may be related to lipotoxicity due to the accumulation of palmitic acid and palmitoyl-CoA (Pal-CoA). Therefore, the aim of this study is to examine whether Pal-CoA induces cyt-c release from liver mitochondria of sucrose-fed rat (SF). Pal-CoA-induced cyt-c release was sensitive to cyclosporine A indicating the involvement of the mitochondrial membrane permeability transition (mMPT). In addition, cyt-c release from SF mitochondria remains significantly lower than C mitochondria despite the increased rate of H2O2 generation in SF mitochondria. The decreased cyt-c release from SF may be also related to the increased proportion of the palmitic acid-enriched cardiolipin, due to the high availibilty of palmitic acid in SF liver. The enrichment of cardiolipin molecular species with palmitic acid makes cardiolipin more resistant to peroxidation, a mechanism involved in the dissociation of cyt-c from mitochondrial inner membrane. These results suggest that Pal-CoA may participate in the progression of NAFLD to more severe disease through mechanisms involving cyt-c release and mMPT, a key process of apoptosis.

Lovastatin attenuates glyoxal-induced toxicity on rat liver mitochondria.

Alpha-dicarbonyls such as glyoxal (GO) trigger mitochondrial dysfunction resulting in the development of different diabetic complications. The present study investigated the effects of lovastatin against GO-induced toxicity on rat liver mitochondria. The rat liver mitochondria (0.5 mg protein/mL) were treated with various concentrations of lovastatin (1, 5, 10 µM) at 37°C for 30 min and then exposed to GO (3 mM) at 37°C for 30 min. Oxidative stress markers including MDA, reactive oxygen species (ROS), glutathione (GSH) and protein carbonylation (PC) level were measured. Mitochondrial complex II activity and mitochondrial membrane potential (MMP) were assessed for evaluating mitochondrial function. Glyoxal significantly increased the level of ROS, PC and MDA. This effect was associated with the reduction of MMP, complex II activity and GSH content. Pre-treatment with lovastatin potentially reversed GO-induced mitochondrial toxicity. These results suggest that lovastatin have a protective effect against GO-induced toxicity in isolated rat liver mitochondria.

Stigmasterol isolated from the chloroform fraction of Adenopus breviflorus Benth fruit induces mitochondrial-dependent apoptosis in rat liver.

Decoction of Adenopus breviflorus fruit is used in folkloric medicine for treating dysmenorrhea and gonorrhea. Phytochemicals from A.breviflorus may be potent in inducing mitochondrial-dependent apoptosis via the opening of the mitochondrial permeability transition (MPT) pore. Therefore, this study investigated the in vitro effects of stigmasterol isolated from the chloroform fraction of A.breviflorus (CFAB) and also the increasing concentration of CFAB on the opening of rat liver mitochondrial permeability transition (MPT) pore. Fractionation of CFAB on column chromatography yielded a needle-like crystal which structure was elucidated by standard spectroscopic techniques. The effects of stigmasterol and CFAB on MPT pore opening were assayed spectrophotometrically. Also, the effect of CFAB on mitochondrial ATPase (mATPase) activity and cytochrome c (Cyt c) release were determined. Stigmasterol isolated from CFAB induced MPT pore opening significantly (p<0.05) when compared withthe control. Similarly, CFAB significantly (p<0.05) induced MPT pore opening in rat liver mitochondria in a concentration-dependent manner in the presence and absence of the triggering agent- calcium ion. Furthermore, the increasing concentration of CFAB significantly (p<0.05) stimulated mitochondrial ATPase (mATPase) activity and Cyt c release in a concentration-dependent manner. The study showed that stigmasterol isolated from the chloroform fraction of A.breviflorus is a potent inducer of mitochondrial-dependent apoptosis. Also, the study further revealed that CFAB possesses potent bioactive compounds which can induce the mitochondrial-dependent apoptosis through the opening of the mitochondrial permeability transition pore, activation of mitochondrial ATPase (mATPase) activity and cytochrome c release.

Improving pollutants environmental risk assessment using a multi model toxicity determination with in vitro, bacterial, animal and plant model systems: The case of the herbicide alachlor

Several environmental pollutants, including pesticides, herbicides and persistent organic pollutants play an important role in the development of chronic diseases. However, most studies have examined environmental pollutants toxicity in target organisms or using a specific toxicological test, losing the real effect throughout the ecosystem. In this sense an integrative environmental risk of pollutants assessment, using different model organisms is necessary to predict the real impact in the ecosystem and implications for target and non-target organisms.The objective of this study was to use alachlor, a chloroacetanilide herbicide responsible for chronic toxicity, to understand its impact in target and non-target organisms and at different levels of biological organization by using several model organisms, including membranes of dipalmitoylphosphatidylcholine (DPPC), rat liver mitochondria, bacterial (Bacillus stearothermophilus), plant (Lemna gibba) and mammalian cell lines (HeLa and neuro2a).Our results demonstrated that alachlor strongly interacted with membranes of DPPC and interfered with mitochondrial bioenergetics by reducing the respiratory control ratio and the transmembrane potential. Moreover, alachlor also decreased the growth of B. stearothermophilus and its respiratory activity, as well as decreased the viability of both mammalian cell lines. The values of TC50 increased in the following order: Lemna gibba < neuro2a < HeLa cells < Bacillus stearothermophilus. Together, the results suggest that biological membranes constitute a putative target for the toxic action of this lipophilic herbicide and point out the risks of its dissemination on environment, compromising ecosystem equilibrium and human health.

Influence of 2-Ethyl-6-Methyl-3-Hydroxypyridine on the Functional State of Rat Liver Mitochondria In Vitro

The influence of 2-ethyl-6-methyl-3-hydroxypyridine hydrochloride on the in vitro free-radical oxidation and respiration of intact rat liver mitochondria was studied. The drug used at a concentration within the pharmacokinetic range had a modulating effect on lipid peroxidation and oxidative modification of mitochondrial proteins. Emoxypine hydrochloride caused transient accumulation of lipid peroxidation products at relatively high concentrations in the incubation mixture (~10–3 M) and redistribution of free-radical oxidation substrates in favor of proteins with a gradual restriction of oxidative phosphorylation, a decrease in affinity of the respiratory chain to ADP, and an impaired intactness of mitochondrial structures reaching the most significant values at emoxypine hydrochloride concentrations of 10–8 and 10–9 M.

Effect of Methyltriclosan on the Functioning of Isolated Rat Liver Mitochondria and Permeability of Liposomal Membranes

Effect of Methyltriclosan on the Functioning of Isolated Rat Liver Mitochondria and Permeability of Liposomal Membranes

The Mitochondrial Carnitine Acyl-carnitine Carrier (SLC25A20): Molecular Mechanisms of Transport, Role in Redox Sensing and Interaction with Drugs.

The SLC25A20 transporter, also known as carnitine acyl-carnitine carrier (CAC), catalyzes the transport of short, medium and long carbon chain acyl-carnitines across the mitochondrial inner membrane in exchange for carnitine. The 30-year story of the protein responsible for this function started with its purification from rat liver mitochondria. Even though its 3D structure is not yet available, CAC is one of the most deeply characterized transport proteins of the inner mitochondrial membrane. Other than functional, kinetic and mechanistic data, post-translational modifications regulating the transport activity of CAC have been revealed. CAC interactions with drugs or xenobiotics relevant to human health and toxicology and the response of the carrier function to dietary compounds have been discovered. Exploiting combined approaches of site-directed mutagenesis with chemical targeting and bioinformatics, a large set of data on structure/function relationships have been obtained, giving novel information on the molecular mechanism of the transport catalyzed by this protein.

Benefits of Morinda citrifolia L. Fruit Extract on Methotrexate Induced Mitochondrial Toxicity – An In Vivo Study in Rat Liver Mitochondria.

Mitochondrial dysfunction has been implicated in the etiology of many drug-induced toxicities. Methotrexate (MTX), an antimetabolite and one of the folic acid antagonists, has widely been used to treat a variety of disorders such as cancer and several autoimmune disorders. It induces oxidative stress which results in many of its ill effects on different target and non-target organs, altering different metabolic pathways and interfering mitochondrial bioenergetics. Here, in our study, we have assessed the toxicity of methotrexate on rat liver mitochondria and its modulation by Morinda citrifolia L. (Noni) fruit extract. MTX significantly affects mitochondrial function, and activity of important mitochondrial enzymes such as Succinate dehydrogenase (SDH), Malate dehydrogenase (MDH) and NADH dehydrogenase. Reduced Cytochrome C – oxidase activity and Reduced glutathione (GSH) levels in MTX treated group (p&lt;0.001) was also observed. An increase in the activity of calcium dependent ATPase (Ca2+ dependent ATPase) was observed along with increase in lipid peroxidation (lpx), and significant decrease in mitochondrial protein in MTX treated groups. Liver mitochondria of animals administered with Noni extract did not show any toxicity and combination of aqueous Noni fruit extract and methotrexate showed amelioration of toxicity as compared to methotrexate alone. Our study suggests that Noni can have significant protective effect on liver injury induced by MTX. Nutraceutical supplement like antioxidants found in edible plants such as Noni may be a safe and effective way of alleviating the liver toxicity. Hence, we propose that combination of Noni and methotrexate can be potentially safer combination in cancer therapy.

The Effects of CeO2 Nanoparticles (CeNPs) on Oxidative Stress Biomarkers of Rat Liver Mitochondria: An In vitro Study

Background:: In recent years, the applications of nanoparticles have received a great attention due to their industrial and biomedical applications, while their beneficial effects suffer from controversial results at clinical stages. Objective:: In the current study, cytotoxicity of cerium oxide (CeNP) nanoparticles (100 nm) were evaluated using mitochondria derived from wistar rat's liver. Methods:: Isolated mitochondria from rat’s liver were divided into 7 groups including group 1 as control and group 2 to 7 as treatment group with different doses of CeNP (5, 10, 50, 100, 250 and 500 mg/ml, respectively), for 24, 48 and 72 h. After exposure, oxidative stress biomarkers such as total antioxidant capacity (TAC), lipid peroxidation (LPO), total thiol groups (TTG), catalase activity (CAT) and mitochondrial viability, were determined in isolated rat liver mitochondria. Results:: Results have shown that CeNPs increase TAC, TTG, CAT, LPO and viability of mitochondria in various exposure times and confirm antioxidant properties of CeNPs in mithocondria while mitochondria is a main source for the generation of reactive oxygen species (ROS). Conclusion:: CeNPs trigger a wide range of biological responses that vary from cytotoxic to cytoprotective.