• The Korean Journal of Pharmacology
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• v.21 no.1
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• pp.12-26
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• 1985

The generation of $O^{-}_{2}{\cdot}$ and its toxic effects were studied with rat brain mitochondria. The production of $O^{-}_{2}{\cdot}$ from mitochondria in the presence of succinate and antimycin was demonstrated by SOD-inhibitable reduction of NBT. Although succinate can support the $O^{-}_{2}{\cdot}$ formation, the highest rate needs antimycin indicating that blockade of electron flow in the respiratory chain augments the univalent reduction of molecular oxygen. Under this condition, $H_2O_2$ was also observed to be produced. But its formation appears to be derived from the dismutation of the primary product, $O^{-}_{2}{\cdot}$ since the rate of $H_2O_2$ production was markedly decreased by NBT and ferricytochrome c. The $O^{-}_{2}{\cdot}$ and $H_2O_2$ produced were able to cause toxic actions to mitochondrial and extra-mitochondrial components as shown by lipid peroxidation of mitochondrial membrane, and inactivation and lysis of isocitrate dehydrogenase and erythrocytes added to the medium, respectively. In all the toxic actions observed, $Fe^{++}$ was required. It appears that in the toxic actions $OH{\cdot}$ generated from the iron-catalyzed Haber-Weiss reaction acts as a mediator. This was supported by the finding that mitochondria in the presence of succinate and antimycin produced ethylene from methional, and $Fe^{++}$ added increased the ethylene production. The observed toxic actions of mitochondrial $O^{-}_{2}{\cdot}$ may provide evidence supporting a potential role of mitochondria as a source of oxygen radicals to cause tissue damage.

• BMB Reports
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• v.37 no.2
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• pp.239-245
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• 2004

We have previously demonstrated that the redox reactant pyruvate prevents apoptosis in the oxidant model of bovine pulmonary artery endothelial cells (BPAEC), and that the anti-apoptotic mechanism of pyruvate is mediated in part via the mitochondrial matrix compartment. However, cytosolic mechanisms for the cytoprotective feature of pyruvate remain to be elucidated. This study investigated the pyruvate protection against endothelial cytotoxicity when the glycolysis inhibitor 2-deoxy-D-glucose (2DG) was applied to BPAEC. Millimolar 2DG blocked the cellular glucose uptake in a concentration- and time-dependent manner with >85% inhibition at $\geq$5 mM within 24 h. The addition of 2DG evoked BPAEC cytotoxicity with a substantial increase in lipid peroxidation and a marked decrease in intracellular total glutathione. Exogenous pyruvate partially prevented the 2DG-induced cell damage with increasing viability of BPAEC by 25-30%, and the total glutathione was also modestly increased. In contrast, 10 mM L-lactate, as a cytosolic reductant, had no effect on the cytotoxicity and lipid peroxidation that are evoked by 2DG. These results suggest that 2DG toxicity may be a consequence of the diminished potential of glutathione antioxidant, which was partially restored by exogenous pyruvate but not L-lactate. Therefore, pyruvate qualifies as a cytoprotective agent for strategies that attenuate the metabolic dysfunction of the endothelium, and cellular glucose oxidation is required for the functioning of the cytosolic glutathione/NADPH redox system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.376-383
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• 1988

The effect of dietary methionine level on lipid peroxidation of rats was studied. Rats were fed vitamin E- selenium- deficient diet or diet supplemented with various levels (0.3, 0.6, 0.9%) of methionine. In rat fed MF diet, body weight gain and feed efficiency ratio were decreased compared with those of control rats, but reversed by supplementation with 0.3 and 0.6% methionine. Lipid peroxide levels in plasma and hepatic mitochondrial fraction of MF group rats were significantly higher than those of control rats. However, supplementation with 0.6% methionine modified this increment. GSH-Px activity was decrased to varying degrees in erythrocyte and hepatic mitochondrial fraction from rats fed MF diet. Methionine supplementation did not affect induction of this enzyme activity. Examination of hepatocytes by electronmicroscopy showed that Influence of vitamin E, selenium, and methionine deficiency was mainly characterized by lipid droplets, swollen mitochondria and microvilli destruction. Supplementation with various levels of dietary methionine modified these changes to some extent. The results of this experiment indicated that MF diet causes significant change in lipid peroxide level, GSH-Px activity and morphology of rats which these changes may lessen by supplementation with 0.6% methionine.

• Journal of Life Science
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• v.27 no.5
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• pp.517-523
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• 2017

This study was to investigate the role of antioxidants on the characteristics of arsenite-damaged boar semen. Collected sperm was diluted with semen extender, and $100{\mu}M$ arsenite was used for sperm damage. Then melatonin, silymarin, curcumin, and vitamin E were applied for 3, 6, and 9 hr in arsenite-treated boar sperm. Sperm characteristics were then analyzed for motility, plasma membrane integrity, mitochondrial activity, and lipid peroxidation. In the results, sperm motility (control, $77.3{\pm}1.8%$) was decreased by arsenite ($33.3{\pm}1.5%$), while the antioxidant treatment groups (100 nM melatonin, $55.8{\pm}3.4%$; $2{\mu}M$ silymarin, $48.8{pm}3.4%$; $10{\mu}M$ curcumin, $53.9{\pm}2.8%$; and $500{\mu}M$ vitamin E, $54.5{\pm}3.1%$) showed increases compared to the arsenite group (p<0.05). $100{\mu}M$ arsenite decreased the sperm plasma membrane integrity ($24.5{\pm}1.6%$) and mitochondrial activity ($58.2{\pm}2.6%$), and increased lipid peroxidation ($5.3{\pm}0.2%$) at 3 hr (p<0.05). However, arsenite-treated samples with 100 nM melatonin, $2{\mu}M$ silymarin, $10{\mu}M$ curcumin, and $500{\mu}M$ vitamin E increased the plasma membrane integrity and mitochondria activity, and decreased lipid peroxidation compared to the arsenite-treated samples. In summary, arsenite may induce sperm damage and oxidation stress, while antioxidants such as melatonin, silymarin, curcumin, and vitamin E are useful for maintaining sperm characteristics. Therefore, antioxidants can protect sperm against damage by arsenite in fresh boar semen.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.438-445
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• 2008

Dodam formula (Dodam) has been used for neurodegenerative disease in Oriental medicine. Dodam is capable of protecting diverse kinds of cells from damage caused by a variety of toxic stimuli. In the present study, we investigated the underlying protective mechanism of Dodam on rotenone-induced cytotoxicity in rat neuroblastoma Neuro-2A cells. Treatment with Neuro-2A cells with rotenone caused the loss of cell viability, and condensation and fragmentation of nuclei, which was associated with the elevation of ROS level, and lipid peroxidation, the increase in Bax/Bcl-2 ratio. Rotenone induced mitochondrial dysfunction characterized by mitochondrial membrane potential loss and cytochrome-c release. These phenotypes induced by rotenone were reversed by pretreatment with Dodam. Our results suggested that major features of rotenone-induced neurotoxicity are partially mediated by mitochondrial dysfunction and oxidative stress, and that Dodam markedly protects Neuro-2A cells from oxidative injury. These data indicated that Dodam might provide a useful therapeutic strategy in treatment of the neurodegenerative diseases caused by oxidative injuries.

• Development and Reproduction
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• v.23 no.1
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• pp.11-19
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• 2019

The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or methyl-beta-cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p<0.05). Mitochondrial activity, morphological abnormality, ROS and LPO levels in ALA+BSA or MBCD groups were no significant difference compared with ALA, BSA and MBCD treatment groups. On the other hand, plasma and acrosomal membrane intact, and sperm motility in ALA+MBCD group were higher than single treatment groups (p<0.05), whereas ALA+BSA did not differ. Our findings indicate that carrier proteins such as BSA and MBCD could improve the effect of ALA during cryopreservation of boar sperm, and treatment of ALA with carrier proteins enhance membrane integrity, mitochondrial activity through reduction of ROS-induced LPO.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.165-177
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• 1995

Dissociated cell cultures from rat embryonic ventral mesencephalon were used to evaluate the mechanisms of $MPP^+$ neurotoxicity. The cells were treated with MPTP or $MPP^+$ and the viability of the cells was assessed biochemically; tyrosine hydroxylase (TH) immunoreactivity, protein, intracellular ATP and lactate content and lipid peroxidation. Also the generation of the intracellular oxidants was measured after loading 2', 7‘-dichlorofluorescin diacetate to the cells. When cultures were exposed to 0.1 mM $MPP^+$, at 2 hour incubation lactate was significantly accumulated in the cells and then the intracellular ATP content and TH immunoreactivity were decreased dose- and time-dependently. But, malondialdehyde as an index for lipid peroxidation was not changed even though the generation of the intracellular oxidants was stimulated by the addition of $MPP^+$. On the other hand, 1 mM MPTP significantly reduced the TH immunoreactivity at 24 hour exposure without any change in the intracellular A TP, lactate and MDA content until 6 hour exposure. And also MPTP inhibited the generation of the intracellular oxidants from control cells and $MPP^+$ exposed cells. These results indicate that cytotoxicity of $MPP^+$ is mediated by inhibiting the mitochondrial energy metabolism rather than generating the intracellular oxidants. And MPTP would have direct action in addition to conveting to the toxic metabolite, $MPP^+$ to exert the toxicity on the dopaminergic neurons.

• Herbal Formula Science
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• v.11 no.2
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• pp.135-146
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• 2003

Objectives : Wolguk-whan has been used as a prescription of natural drug for the treatment of stress digestive system disease. Recently, we reported that Wolguk-whan methnol extract (WGWM) exerted a significant protective effect against oxidative damage to the liver of ICR mice. This study was purposed to investigate the effects of Wolguk-whan water extract (WGWW) on liver injury induced by oxidative stress. Methods : In order to investigate the effects of WGWW on acute liver injury, ICR mice were pretreated with WGWW for 6days, starved for 24hrs, and administerated acetamirtophen(500mg/kg, i.p.). In the liver homogenates, lipid peroxide and glutathione(GSH) levels were measured. In addition, activities of hepatic enzyme, such as catalase, glutathione peroxidase(GSH-Px), glutathione S-transferase(GST) were measured in the hepatic mitochondrial and cytosolic fractions. Results : In vivo administeration of WGWW showed effective inhibition of acetaminophen induced lipid peroxidation, and showed elevations of GSH level, catalase, GSH-Px, GST activities. Conclusions : These results suggested that WGWW might suppress the formation of oxidative metabolites, and prevent acetaminophen induced hepatotoxicity.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.436-441
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• 2009

The final bio-metabolites of lipid peroxidation (LPO) such as 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) have been suggested to mediate the oxidative stress-linked pathological incidences. Natural phytochemicals such as polyphenolic compounds in green tea have been known in preventing the LPO induced cellular growth inhibition and apoptosis. We investigated that green tea ethanol extracts (GTE) inhibit LPO-induced apoptosis in ECV 304 cells. GTE had time- or dose-dependent anti-apoptotic effects as evidenced by changes in cell morphology, MTT assay, DNA fragmentation, LPO production, and the Western blotting for apoptotic expression. In the 4-HNE-induced apoptosis model, GTE $10-20{\mu}g/mL$ decreased cell death through decreasing LPO production. GTE protected 4-HNE induced apoptosis, as evidence with down regulation of mitochondrial signaling such as cytochrome C and caspase-3 activity. GTE increased bcl2, survival signaling protein, compared to 4-HNE alone within 6 hr incubation. Since polyphenols in GTE are effective antioxidants in endothelial ECV 304 cells, we suggested that natural polyphenols might be anti-atherosclerotic.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.631-640
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• 1999

The present study investigated the stimulatory effects of iron (or ascorbate) on cyclosporine-induced kidney mitochondrial damage. Damaging effect of $50\;{\mu}M$ cyclosporine plus $20\;{\mu}M\;Fe^{2+}$ on mitochondrial lipids and proteins of rat kidney and hyaluronic acid was greater than the summation of oxidizing action of each compound alone, except sulfhydryl oxidation. Cyclosporine and $100\;{\mu}M$ ascorbate showed an enhanced damaging effect on lipids but not on proteins. The peroxidative action of cyclosporine on lipids was enhanced with increasing concentrations of $Fe^{2+}.$ Ferric ion $(20\;{\mu}M)$ also interacted with cyclosporine to stimulate lipid peroxidation. Damaging action of cyclosporine on mitochondrial lipids was enhanced by ascorbate $(100\;{\mu}M\;and\;1\;mM)$. Iron chelators, DTPA and EDTA, attenuated carbonyl formation induced by cyclosporine plus ascorbate. Cyclosporine $(100\;{\mu}M)$ and $50\;{\mu}M\;Fe^{2+}$ $(or\;100\;{\mu}M\;ascorbate)$ synergistically stimulated degradation of $2-{\alpha}$ deoxyribose. Cyclosporine $(1\;to\;100\;{\mu}M)$ reduced ferric ion in a dose dependent manner, which is much less than ascorbate action. Addition of $Fe^{2+}$ caused a change in absorbance spectrum of cyclosporine in $230{\sim}350$ nm of wavelengths. The results show that cyclosporine plus iron (or ascorbate) exerts an enhanced damaging effect on kidney mitochondria. Iron and ascorbate appear to promote the nephrotoxicity induced by cyclosporine.