• Herbal Formula Science
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• 제26권4호
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• pp.329-340
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• 2018

Objectives : In Traditional Korean medicine, Daucus carota L. has been used for treating dyspepsia, diarrhea, dysentery and cough. Recent pharmacognosic evidence showed D. carota has anti-oxidant, anti-cancer, anti-fungal, and hypotensive effects. Present study investigated hepato-protective effect of D. carota ethanol extract (DCE) against oxidative stress in HepG2 cells. Methods : After HepG2 cells were pretreated with different concentrations of DCE, the cells were exposed to tert-butyl hydroperoxide (tBHP) for inducing oxidative stress. Cell viability, hydrogen peroxide production, glutathione concentration, and mitochondrial membrane potentials were measured to explore hepato-protective effect of DCE. Phosphorylation of AMP-activated protein kinase (AMPK) and effect of compound C on cell viability were determined to investigate the role of AMPK on DCE-mediated cytoprotection. Results : DCE significantly decreased the tBHP-mediated cytotoxicity in a concentration dependent manner and reduced the changes on apoptosis-related proteins by tBHP in HepG2 cells. In addition, DCE significantly prevented hydrogen peroxide production, glutathione depletion, and mitochondrial membrane impairment induced by tBHP. Treatment with DCE increased phosphorylation of AMPK, and the DCE-mediated cytoprotection was abolished by pretreatment with compound C. Conclusions : These results demonstrate that DCE can protect hepatocytes from oxidative stress through activation of AMPK.

• BMB Reports
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• 제52권3호
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• pp.190-195
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• 2019

Acetaminophen (APAP) overdose can cause hepatotoxicity by inducing mitochondrial damage and subsequent necrosis in hepatocytes. Sirtuin2 (Sirt2) is an $NAD^+$-dependent deacetylase that regulates several biological processes, including hepatic gluconeogenesis, as well as inflammatory pathways. We show that APAP decreases the expression of Sirt2. Moreover, the ablation of Sirt2 attenuates APAP-induced liver injuries, such as oxidative stress and mitochondrial damage in hepatocytes. We found that Sirt2 deficiency alleviates the APAP-mediated endoplasmic reticulum (ER) stress and phosphorylation of the p70 ribosomal S6 kinase 1 (S6K1). Moreover, Sirt2 interacts with and deacetylates S6K1, followed by S6K1 phosphorylation induction. This study elucidates the molecular mechanisms underlying the protective role of Sirt2 inactivation in APAP-induced liver injuries.

• The Journal of Internal Korean Medicine
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• 제43권3호
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• pp.344-362
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• 2022

Objective: In this study, the antioxidant activity of Ojayeonjong-hwan extracts was compared, and the following results were obtained. Methods: For hydrothermal and ethanol extracts, DPPH free radical and ABTS cationic radical erasing activity and reducing power using the FRAP method were compared, and the association between the antioxidant power of each extract and total phenol content was investigated. Significant results were obtained through in vitro apoptosis analysis through FFITC staining, mitochondrial membrane potential analysis, and ROS level measurement using C2C12 myoblastoma. Results: 1. In a comparison of DPPH free radical and ABTS cationic radical scavenging activity, water, and 70% ethanol extracts of Ojayeonjong-hwan (WEO and EEO) showed superior radical scavenging ability. 2. In the results of reducing power using the FRAP method, WEO and EEO showed antioxidant activity, which was shown to be dependent on the total phenol content contained in the extracts. 3. In comparison to the protective effect against H₂O₂-induced oxidative stress in C2C12 myoblasts, water extracts had no significant effect, but 70% ethanol extracts inhibited H₂O₂-mediated cytotoxicity in a concentration-dependent manner. 4. The cytotoxic protective effect of EEO against oxidative stress in C2C12 myoblasts was correlated with its inhibitory effects on H₂O₂-induced apoptosis and cell-cycle arrest. 5. In H₂O₂-treated C2C12 myoblasts, the apoptosis inhibitory effects of EEO were associated with the suppression of mitochondrial dysfunction and DNA damage. 6. The protective effects of EEO against H₂O₂-induced oxidative stress in C2C12 myoblasts were directly related to the inhibition of ROS generation. Conclusions: Ojayeonjong-hwan extracts all have protective potential against oxidative stress.

• Journal of Ginseng Research
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• 제47권2호
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• pp.311-318
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• 2023

Background: The beneficial effects of compound K (CK) on different chronic diseases have been shown to be at least related to antioxidant action. Nevertheless, since its antioxidant activity in human retinal pigment epithelial (RPE) cells is still unknown, here we investigated whether CK alleviates oxidative stress-stimulated damage in RPE ARPE-19 cells. Methods: The cytoprotective consequence of CK in hydrogen peroxide (H₂O₂)-treated cells was evaluated by cell viability, DNA damage, and apoptosis assays. Fluorescence analysis and immunoblotting were performed to investigate the inhibitory action of CK on reactive oxygen species (ROS) production and mitochondrial dysfunction. Results: H₂O₂-promoted cytotoxicity, oxidative stress, DNA damage, mitochondrial impairment, and apoptosis were significantly attenuated by CK in ARPE-19 cells. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation level and its shuttling to the nucleus were increased, which was correlated with upregulated activation of heme oxygenase-1 (HO-1). However, zinc protoporphyrin, a blocker of HO-1, significantly abrogated the preventive action of CK in H₂O₂-treated ARPE-19 cells. Conclusion: This study indicates that activation of Nrf2/HO-1 signaling by CK plays an important role in rescuing ARPE-19 cells from oxidative cellular damage.

• Biomedical Science Letters
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• 제28권4호
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• pp.237-246
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• 2022

Ischemia-reperfusion results in excess reactive oxygen species (ROS) that affect myocardial cell damage. ROS production inhibition is effectively proposed in treating cardiovascular diseases including myocardial hypertrophy. Studies have shown that oxidizing cultured cells in in vitro experiments gradually decreases the permeability of mitochondrial membranes time- and concentration-dependent, resulting in increased mitochondrial membrane damage due to secondary ROS production and cardiolipin loss. However, recent studies have shown that 5-iodo-6-amino-1,2-benzopyrone (INH₂BP), an anticancer and antiviral drug, inhibited peroxynitrite-induced cell damage in in vitro and alleviated partial or overall inflammation in animal experiments. Therefore, in this paper, we studied the preventive effect of INH₂BP on H9c2 cells derived from mouse heart damaged by oxidative stress using 700 μM of hydrogen peroxide. As a result of oxidative stress to H9c2 cells by hydrogen peroxide whether the treatment of INH₂BP or not, hydrogen peroxide caused serious damage in H9c2 cells. These results were confirmed with cell viability and Hoechst 33342 assays. And this damage was through cell death. However, it was confirmed that H9c2 cells pretreated with INH₂BP significantly reduced cell death by hydrogen peroxide. In addition, measurements with DCF-DA assay to determine whether ROS is produced in H9c2 cells treated with only hydrogen peroxide produced ROS significantly, but H9c2 cells pretreated with INH₂BP significantly reduced ROS production by hydrogen peroxide. Taken together, it is believed that INH₂BP can be useful for the prevention and treatment of cardiovascular diseases induced through oxidative stress such as heart damage caused by ischemia/reperfusion.

• Molecules and Cells
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• 제46권11호
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• pp.655-663
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• 2023

Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.

• Journal of Korean Biological Nursing Science
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• 제26권2호
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• pp.99-110
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• 2024

Purpose: This study reviewed the pathophysiological mechanisms of cellular aging caused by psychological stress and aimed to establish a biobehavioral theoretical framework for nursing interventions to promote autonomic balance based on these mechanisms. Methods: A comprehensive literature review was conducted. Results: A review of the literature showed that the stress response increases the secretion of catecholamines and glucocorticoids, resulting in a greater allostatic load. This load induces inflammatory reactions and oxidative stress, shortening telomere length and damaging mitochondrial DNA, which can lead to cellular aging. Based on this mechanism, a biobehavioral theoretical framework for nursing interventions was established. This framework focuses on delaying or inhibiting the cellular aging process by acting on the stress response stage and improving autonomic balance. Conclusion: According to the proposed biobehavioral theoretical framework, stress-relieving nursing interventions may act on the mechanism of cellular aging caused by stress responses. We believe that this framework could expand our understanding of the biobehavioral aspects of stress and would facilitate efforts to use biomarkers to evaluate the effectiveness of stress-related nursing interventions at the cellular level.

• Journal of Life Science
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• 제27권11호
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• pp.1349-1356
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• 2017

Potassium channel openers (KCOs) produce physiological and pharmacological defense mechanisms against cell injuries caused by oxidative stress of diverse origins. Openings of mitochondrial and plasmalemmal $K^+$ channels are involved in the defense mechanisms. This study tested whether NS 1619, an opener of large-conductance BK channels, has a similar beneficial influence on the pigment epithelial cells of retinas. The human retinal pigment epithelial cell line ARPE-19 was exposed to $H_2O_2$-induced oxidative stress in the absence and presence of NS 1619. The degrees of the cells' injuries were assessed by analyzing the cells' trypan-blue exclusion abilities and TUNEL staining. NS 1619 produced remarkable protections against cell injuries caused by $H_2O_2$. It prevented apoptotic and necrotic cell deaths. The protective effect of NS 1619 was significantly diminished when the cells were treated with NS 1619 in combination with the BK channel-blocker paxilline. NS 1619 significantly ameliorated cellular ATP deprivations in $H_2O_2$-treated cells. It helped mitochondria preserve their functional integrity, which was estimated by their MTT reduction abilities and mitochondrial membrane potential. In conclusion, it was suggested that NS 1619 had a beneficial effect on mitochondria in regards to preserving their functional integrity under oxidative stress, and it produces defense mechanisms against oxidant-induced cell injuries in ARPE-19 cells.

• Animal Bioscience
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• 제35권10호
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• The Korean Journal of Physiology and Pharmacology
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• 제21권5호
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• pp.531-546
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• 2017

Activation of Toll-like receptor-4 (TLR-4) in articular chondrocytes increases the catabolic compartment and leads to matrix degradation during the development of osteoarthritis. In this study, we determined the proteomic and genomic alterations in human chondrocytes during lipopolysaccharide (LPS)-induced inflammation to elucidate the underlying mechanisms and consequences of TLR-4 activation. Human chondrocytes were cultured with LPS for 12, 24, and 36 h to induce TLR-4 activation. The TLR-4-induced inflammatory response was confirmed by real-time PCR analysis of increased interleukin-1 beta ($IL-1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor alpha ($TNF-{\alpha}$) expression levels. In TLR-4-activated chondrocytes, proteomic changes were determined by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-mass spectroscopy analysis, and genomic changes were determined by microarray and gene ontology analyses. Proteomics analysis identified 26 proteins with significantly altered expression levels; these proteins were related to the cytoskeleton and oxidative stress responses. Gene ontology analysis indicated that LPS treatment altered specific functional pathways including 'chemotaxis', 'hematopoietic organ development', 'positive regulation of cell proliferation', and 'regulation of cytokine biosynthetic process'. Nine of the 26 identified proteins displayed the same increased expression patterns in both proteomics and genomics analyses. Western blot analysis confirmed the LPS-induced increases in expression levels of lamin A/C and annexins 4/5/6. In conclusion, this study identified the time-dependent genomic, proteomic, and functional pathway alterations that occur in chondrocytes during LPS-induced TLR-4 activation. These results provide valuable new insights into the underlying mechanisms that control the development and progression of osteoarthritis.