• Clinical and Experimental Reproductive Medicine
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• v.50 no.1
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• pp.26-33
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• 2023

Objective: Human exposure to multiple xenobiotics, over various developmental windows, results in adverse health effects arising from these concomitant exposures. Humans are widely exposed to bisphenol A, and acetaminophen is the most commonly used over-the-counter drug worldwide. Bisphenol A is a well-recognized male reproductive toxicant, and increasing evidence suggests that acetaminophen is also detrimental to the male reproductive system. The recent recognition of male reproductive system dysfunction in conditions of suboptimal reproductive outcomes makes it crucial to investigate the contributions of toxicant exposures to infertility and sub-fertility. We aimed to identify toxicity in the male reproductive system at the mitochondrial level in response to co-exposure to bisphenol A and acetaminophen, and we investigated whether melatonin ameliorated this toxicity. Methods: Male Wistar rats were divided into six groups (n=10 each): a control group and groups that received melatonin, bisphenol A, acetaminophen, bisphenol A and acetaminophen, and bisphenol A and acetaminophen with melatonin treatment. Results: Significantly higher lipid peroxidation was observed in the testicular mitochondria and sperm in the treatment groups than in the control group. Levels of glutathione and the activities of catalase, glutathione peroxidase, glutathione reductase, and manganese superoxide dismutase decreased significantly in response to the toxicant treatments. Likewise, the toxicant treatments significantly decreased the sperm count and motility, while significantly increasing sperm mortality. Melatonin mitigated the adverse effects of bisphenol A and acetaminophen. Conclusion: Co-exposure to bisphenol A and acetaminophen elevated oxidative stress in the testicular mitochondria, and this effect was alleviated by melatonin.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.517-521
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• 2013

Background Diabetes is characterized by chronic hyperglycemia, which can increase reactive oxygen species (ROS) production by the mitochondrial electron transport chain. The formation of ROS induces oxidative stress and activates oxidative damage-inducing genes in cells. No research has been published on oxidative damage-related extracellular superoxide dismutase (EC-SOD) protein levels in human diabetic skin. We investigated the expression of EC-SOD in diabetic skin compared with normal skin tissue in vivo. Methods The expression of EC-SOD protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was also carried out to confirm the EC-SOD expression level in the 6 diabetic skin tissue samples. Results The western blotting showed significantly lower EC-SOD protein expression in the diabetic skin tissue than in the normal tissue. Immunohistochemical examination of EC-SOD protein expression supported the western blotting analysis. Conclusions Diabetic skin tissues express a relatively small amount of EC-SOD protein and may not be protected against oxidative stress. We believe that EC-SOD is related to the altered metabolic state in diabetic skin, which elevates ROS production.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.108-111
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• 2003

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by a progressive loss of dopaminergic neurons in the substantia nigra. While its precise etiology is unknown, such factors as oxidative stress, impairment of mitochondrial respiration, excitotoxicity and inflammation may play roles in its pathogenesis. Although the role of apoptosis in the process of dopaminergic neuronal death has been highlighted in studies using postmortem brains and experimental models of PD, other evidence implicates both apoptosis and non-apoptotic death in PD. (omitted)

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.145-151
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• 2019

Methamphetamine (METH) acts strongly on the nervous system and damages neurons and is known to cause neurodegenerative diseases such as Alzheimer's and Parkinson's. Flavonoids, polyphenolic compounds present in green tea, red wine and several fruits exhibit antioxidant properties that protect neurons from oxidative damage and promote neuronal survival. Especially, epicatechin (EC) is a powerful flavonoid with antibacterial, antiviral, antitumor and antimutagenic effects as well as antioxidant effects. We therefore investigated whether EC could prevent METH-induced neurotoxicity using HT22 hippocampal neuronal cells. EC reduced METH-induced cell death of HT22 cells. In addition, we observed that EC abrogated the activation of ERK, p38 and inhibited the expression of CHOP and DR4. EC also reduced METH-induced ROS accumulation and MMP. These results suggest that EC may protect HT22 hippocampal neurons against METH-induced cell death by reducing ER stress and mitochondrial damage.

• Anatomy and Cell Biology
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• v.56 no.1
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• pp.16-24
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• 2023

Endothelial cells (EC) are the anatomical boundaries between the intravascular and extravascular space. Damage to ECs is catastrophic and induces endothelial cell dysfunction. The pathogenesis is multifactorial and involves dysregulation in the signaling pathways, membrane lipids ratio disturbance, cell-cell adhesion disturbance, unfolded protein response, lysosomal and mitochondrial stress, autophagy dysregulation, and oxidative stress. Autophagy is a lysosomal-dependent turnover of intracellular components. Autophagy was recognized early in the pathogenesis of endothelial dysfunction. Autophagy is a remarkable patho (physiological) process in the cell homeostasis regulation including EC. Regulation of autophagy rate is disease-dependent and impaired with aging. Up-regulation of autophagy induces endothelial cell regeneration/differentiation and improves the function of impaired ones. The paper scrutinizes the molecular mechanisms and triggers of EC dysregulation and current perspectives for future therapeutic strategies by autophagy targeting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.409-417
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• 1991

To investigate effects of chronic alcohol consumption and tocopherol on lipid peroxidation and mitochondrial respiration 48 male rats of Sprague-Dawley strain were divided into 4 groups. Each group received for 3 weeks one of 4 experimental diets: tocopherol deficient control (TDC), tocopherol deficient-ethanol (TDE), tocopherol-supplemented control (TSC) and tocopherol-supplemented-ethanol (TSE). Composition of the diets was based on the Lieber and Decarli liquid diet and $\alpha$-tocopherol was supplemented at the level of 30mg/liter of diet, and ethanol supplied 36kcal%. TDC and TSC were pair-fed to TDE and TSE, respectively. Increase of body weight of tocopherol deficient-ethanol group was the lowest and the effect was diminished with tocopherol supplementation. Respiration of liver mitochondria was depressed in ethanol-administered groups and the effect became larger with tocopherol deficiency. Hepatic lipid peroxide level was not influenced by ethanol, but hepatic tocopherol content decreased with ethanol treatment. The result indicated that, although lipid perroxide level was unchanged with chronic ethanol consumption, oxidative stress exists in tissues of rate administered ethanol and may be relieved by tocopherol supplementation.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.41-47
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• 2019

The apoptotic effects of shikonin (5,8-dihydroxy-2-[(1R)-1-hydroxy-4-methylpent-3-enyl]naphthalene-1,4-dione) on the human colon cancer cell line SNU-407 were investigated in this study. Shikonin showed dose-dependent cytotoxic activity against SNU-407 cells, with an estimated $IC_{50}$ value of $3{\mu}M$ after 48 h of treatment. Shikonin induced apoptosis, as evidenced by apoptotic body formation, sub-G_1$ phase cells, and DNA fragmentation. Shikonin induced apoptotic cell death by activating mitogen-activated protein kinase family members, and the apoptotic process was mediated by the activation of endoplasmic reticulum (ER) stress, leading to activation of the $PERK/elF2{\alpha}/CHOP$ apoptotic pathway, and mitochondrial $Ca^{2+}$ accumulation. Shikonin increased mitochondrial membrane depolarization and altered the levels of apoptosis-related proteins, with a decrease in B cell lymphoma (Bcl)-2 and an increase in Bcl-2-associated X protein, and subsequently, increased expression of cleaved forms of caspase-9 and -3. Taken together, we suggest that these mechanisms, including MAPK signaling and the ER- and mitochondria-mediated pathways, may underlie shikonin-induced apoptosis related to its anticancer effect.

• Nutrition Research and Practice
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• v.15 no.1
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• pp.12-25
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• 2021

BACKGROUND/OBJECTIVES: The study was conducted to investigate the efficacy of the combination treatment of phytochemical resveratrol and the anticancer drug docetaxel (DTX) on prostate carcinoma LNCaP cells, including factors related to detailed cell death mechanisms. MATERIALS/METHODS: Using 2-dimensional monolayer and 3-dimensional spheroid culture systems, we examined the effects of resveratrol and DTX on cell viability, reactive oxygen species (ROS) levels, mitochondrial membrane potential, apoptosis, and necroptosis by MTT, flow cytometry, and Western blotting. RESULTS: At concentrations not toxic to normal human prostate epithelial cells, resveratrol effectively decreased the viability of LNCaP cells depending on concentration and time. The combination treatment of resveratrol and DTX exhibited synergistic inhibitory effects on cell growth, demonstrated by an increase in the sub-G0/G1 peak, Annexin V-phycoerythrin positive cell fraction, ROS, mitochondrial dysfunction, and DNA damage response as well as concurrent activation of apoptosis and necroptosis. Apoptosis and necroptosis were rescued by pretreatment with ROS scavenger N-acetylcysteine. CONCLUSIONS: We report resveratrol as an adjuvant drug candidate for improving the outcome of treatment in DTX therapy. Although the underlying mechanisms of necroptosis should be investigated comprehensively, targeting apoptosis and necroptosis simultaneously in the treatment of cancer can be a useful strategy for the development of promising drug candidates.

• Herbal Formula Science
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• v.31 no.2
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• pp.111-124
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• 2023

Objectives : Oxidative stress is an important cause of many diseases including liver injury. Therefore, adequate regulation of oxidative stress plays a pivotal role in maintaining liver function. Until recently, there has been no studies on the hepatoprotective effect of Samchulgeonbi-tang (SCGBT). Therefore, the hepatoprotective effect of SCGBT was investigated in HepG2 cells. In this study, oxidative stress was induced by arachidonic acid (AA) and iron. Methods : To analyze the hepatoprotective effects of SCGBT against oxidative stress induced by AA + iron, the cell viability, apoptosis-related proteins and intracellular ROS, glutathione (GSH), and mitochondrial membrane permeability (MMP) were measured. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) transcription activation and expressions of Nrf2 target gene were analyzed through immunoblot analysis. Results : SCGBT increased the cell viability from AA + iron - induced cell death and inhibited apoptosis by regulating apoptosis related proteins. SCGBT protected cells by inhibiting ROS production, GSH depletion, and MMP degradation against AA + iron induced oxidative stress. Furthermore, Nrf2 activation was increased by SCGBT, and the Nrf2 target genes were also activated by SCGBT. Conclusions : These results suggest that the SCGBT has a hepatocyte protection effect and antioxidant effect from AA + iron induced oxidative stress.

• Interdisciplinary Bio Central
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• v.1 no.2
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• pp.7.1-7.7
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• 2009

"To be, or not to be?" This question is not only Hamlet's agony but also the dilemma of mitochondria in a cancer cell. Cancer cells have a high glycolysis rate even in the presence of oxygen. This feature of cancer cells is known as the Warburg effect, named for the first scientist to observe it, Otto Warburg, who assumed that because of mitochondrial malfunction, cancer cells had to depend on anaerobic glycolysis to generate ATP. It was demonstrated, however, that cancer cells with intact mitochondria also showed evidence of the Warburg effect. Thus, an alternative explanation was proposed: the Warburg effect helps cancer cells harness additional ATP to meet the high energy demand required for their extraordinary growth while providing a basic building block of metabolites for their proliferation. A third view suggests that the Warburg effect is a defense mechanism, protecting cancer cells from the higher than usual oxidative environment in which they survive. Interestingly, the latter view does not conflict with the high-energy production view, as increased glucose metabolism enables cancer cells to produce larger amounts of both antioxidants to fight oxidative stress and ATP and metabolites for growth. The combination of these two different hypotheses may explain the Warburg effect, but critical questions at the mechanistic level remain to be explored. Cancer shows complex and multi-faceted behaviors. Previously, there has been no overall plan or systematic approach to integrate and interpret the complex signaling in cancer cells. A new paradigm of collaboration and a well-designed systemic approach will supply answers to fill the gaps in current cancer knowledge and will accelerate the discovery of the connections behind the Warburg mystery. An integrated understanding of cancer complexity and tumorigenesis is necessary to expand the frontiers of cancer cell biology.