• Proceedings of the PSK Conference
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• 2003.04a
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• pp.229.2-230
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• 2003

Among the aldehydes derived from lipid peroxidation, 4-hydroxynonenal (HNE) that can be produced from arachidonic acids. linoleic acids, or their hydroperoxides in relatively large amounts in response to oxidative insult. Therefore, HNE might be an important mediator of Oxidative stress-induced apoptosis. To study the hypothesis that HNE may induce apoptosis, we estimated cytotoxicity of HNE on YPEN-1 rat prostatic endothelial cells. (omitted)

• Toxicological Research
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• v.27 no.1
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• pp.1-6
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• 2011

Lipid peroxidation is a free radical oxidation of polyunsaturated fatty acids such as linoleic acid or arachidonic acid. This process has been related with various pathologies and disease status mainly because of the oxidation products formed during the process. The oxidation products include reactive aldehydes such as malondialdehyde and 4-hydroxynonenal. These reactive aldehydes can form adducts with DNAs and proteins, leading to the alterations in their functions to cause various diseases. This review will provide a short summary on the implication of lipid peroxidation on cancer, atherosclerosis, and neurodegeneration as well as chemical and biochemical mechanisms by which these adducts affect the pathological conditions. In addition, select examples will be presented where antioxidants were used to counteract oxidative damage caused by lipid peroxidation. At the end, isoprostanes are discussed as a gold standard for the assessment of oxidative damages.

• Journal of Life Science
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• v.26 no.2
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• pp.226-233
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• 2016

Vascular smooth muscle cell (VSMC) apoptosis has been identified in various vascular diseases, including atherosclerosis and restenosis after angioplasty, and has been known to precipitate atherosclerotic plaque instability and rupture. Oxysterols are known as inducers of apoptosis in VSMC, and 7-ketocholesterol (7KC) is the major nonenzymically formed oxysterol in atherosclerotic lesions. The precise mechanism underlying VSMC apoptosis is still poorly understood. In this study, we investigated whether 7KC causes apoptosis, and characterized its apoptotic mechanisms in primary cultured rat aortic VSMC. Cell viability was assessed by MTT assay and trypan blue assay. Apoptosis was assessed by flow cytometry, immunofluorescence, immunoprecipitation, and Western blot analyses. 7KC markedly decreased the VSMC viability in a time- and concentration-dependent manner, and increased the production of 4-hydroxynonenal (HNE), a major end-product of lipid peroxidation, which also decreased the VSMC viability. Pretreatment with 2,4-dinitrophenylhydrazine, a well-known reagent of lipid peroxidation-derived aldehydes, significantly restored the 7KC-decreased viability of VSMC. Furthermore, HNE, as well as 7KC, reduced the level of total Akt, a major mediator of cell survival. The 7KC-decreased level of total Akt was significantly restored by pretreatments with 2,4-dinitrophenylhydrazine and N-acetylcysteine. Lactacystin, a proteasome inhibitor, protected VSMC against apoptosis and Akt degradation, but did not inhibit HNE production. In the immunoprecipitation assay, 7KC increased HNE-modified Akt. From the results, it seems that, in atherosclerotic lesions, 7KC induces HNE production in VSMC, and this HNE binds to Akt, proceeding to proteasomal degradation of Akt, through which mechanism the atherosclerotic plaque instability may be facilitated.

• Journal of Life Science
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• v.27 no.3
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• pp.310-317
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• 2017

Mammalian cells control cellular homeostasis using a variety of defensive enzymes in order to combat against environmental oxidants and electrophiles. NF-E2-related factor-2 (NRF2) is a transcription factor that, in response to an exposure to oxidative stress, translocates into the nucleus and modulates the inducible expression of various phase II cytoprotective enzymes by binding to the antioxidant response element (ARE). In the present study, we have acquired 400 ethanol extracts of traditional medicinal plants and attempted to find out possible extract(s) that can increase the NRF2/ARE-dependent gene expression in human keratinocytes. As a result, we have identified that ethanol extracts of Rheum undulatum and Inula japonica strongly activated the ARE-dependent luciferase activity in HaCaT- ARE-luciferase cells. Exposure of ethanol extracts of Rheum undulatum and Inula japonica increased the viability and activated transcription and translation of NRF2-dependent phase II cytoprotective enzymes in HaCaT cells, such as heme oxygenase-1 (HO-1) and NAD[P]H:quinone oxidorecutase-1 (NQO1). In addition, ethanol extracts of Rheum undulatum and Inula japonica suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced generation of intracellular reactive oxygen species (ROS), thereby inhibiting the formation of 8-hydroxyguanosine (8-OHG) and 4-hydroxynonenal (4-HNE) in HaCaT cells. Together, our results demonstrate that ethanol extracts of Rheum undulatum and Inula japonica exert anti-oxidant effects via the induction of NRF2/ARE-dependent gene expression in human keratinocytes.

• Biomolecules & Therapeutics
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• v.24 no.6
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• pp.604-609
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• 2016

5-fluorouracil (5-FU) is a chemotherapeutic agent commonly used for treatment of solid tumors, including colorectal cancer. However, chemoresistance against 5-fluorouracil (5-FU) often limits its success for chemotherapy and, therefore, finding out appropriate adjuvant(s) that might overcome chemoresistance against 5-FU bears a significant importance. In the present study, we have found that ${\alpha}$-mangostin can sensitize 5-FU-resistant SNUC5/5-FUR colon cancer cells to apoptosis. Exposure of ${\alpha}$-mangostin induced significant DNA damages and increased the intracellular 8-hydroxyguanosine (8-OH-G) and 4-hydroxynonenal (4-HNE) levels in SNUC5 and SNUC5/5-FUR cells. Western blot analysis illustrated that ${\alpha}$-mangostin-induced apoptosis was mediated by the activation of the extrinsic and intrinsic pathways in SNUC5/5-FUR cells. In particular, we observed that Fas receptor (FasR) level was lower in SNUC5/5-FUR cells, compared with SNUC5 cells and that silencing FasR attenuated ${\alpha}$-mangostin-mediated apoptosis in SNUC5/5-FUR cells. Together, our study illustrates that ${\alpha}$-mangostin might be an efficient apoptosis sensitizer that can overcome chemoresistance against 5-FU by activating apoptosis pathway.

• The Korea Journal of Herbology
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• v.31 no.1
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• pp.77-82
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• 2016

Objectives : The study was designed to observe the effect of Polygalae Radix Preparata Cum Glycyrrhizae Radix on 4-Hydroxynonenal (4-HNE)-induced apoptosis in PC-12 cell.Methods : A cytotoxic test on Polygalae Radix Preparata Cum Glycyrrhizae Radix (PG) was conducted and another MTT assay was conducted to observe the cytoprotective effect against 4-HNE that cause oxidative stress. In addition, in order to observe the expression of Bax, Bcl-2, Caspase-3 and TNF-α protein involved with apoptosis, western blot was conducted.Results : The groups treated with 25 ㎍, 50 ㎍ and 100 ㎍ of PG water extract had no toxicity for PC-12 cell. The groups treated with 25 ㎍, 50 ㎍ and 100 ㎍ of PG water extract showed a significant increase of cell survival rate in comparison with the control group injected by only 4-HNE. The groups treated with 25 ㎍ and 50 ㎍ of PG water extract showed a significant supression on increase of Bax protein expression in the control group. The group treated with 100 ㎍ of PG water extract showed a significant promotion on decrease of Bcl-2 protein expression in the control group. The group treated with 50 ㎍ of PG water extract showed a significant supression on increase of Caspase-3 protein expression in the control group. The group treated with 25 ㎍ of PG water extract showed a significant supression on increase of TNF-α protein expression in the control group.Conclusions : These results suggest that Polygalae Radix Preparata Cum Glycyrrhizae Radix is effective in reducing apoptosis by 4-HNE-dameged cell.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.20-26
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• 2014

Obesity is an epidemic disease characterized by an increased inflammatory state and chronic oxidative stress with high levels of pro-inflammatory cytokines and lipid peroxidation. Moreover, obesity alters cholesterol metabolism with increases in low-density lipoprotein (LDL) cholesterols and triglycerides and decreases in high-density lipoprotein (HDL) cholesterols. It has been shown that mulberry leaf and fruit ameliorated hyperglycemic and hyperlipidemic conditions in obese and diabetic subjects. We hypothesized that supplementation with mulberry leaf combined with mulberry fruit (MLFE) ameliorate cholesterol transfer proteins accompanied by reduction of oxidative stress in the high fat diet induced obesity. Mice were fed control diet (CON) or high fat diet (HF) for 9 weeks. After obesity was induced, the mice were administered either the HF or the HF with combination of equal amount of mulberry leaf and fruit extract (MLFE) at 500mg/kg/day by gavage for 12 weeks. MLFE treatment ameliorated HF induced oxidative stress demonstrated by 4-hydroxynonenal (4-HNE) and modulated the expression of 2 key proteins involved in cholesterol transfer such as scavenger receptor class B type 1 (SR-B1) and ATP-binding cassette transporter A1 (ABCA1) in the HF treated animals. This effect was mainly noted in liver tissue rather than in cutaneous tissue. Collectively, this study demonstrated that MLFE treatment has beneficial effects on the modulation of high fat diet-induced oxidative stress and on the regulation of cholesterol transporters. These results suggest that MLFE might be a beneficial substance for conventional therapies to treat obesity and its complications.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.589-601
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• 2023

Purpose: Baicalein, a natural flavone found in herbs, exhibits diverse biological activities. Nonalcoholic steatohepatitis (NASH) is an irreversible condition often associated with a poor prognosis. This study aimed to evaluate the effects of baicalein on the development of NASH in mice. Methods: Male C57BL/6J mice were randomly divided into four groups. Three groups were fed a methionine-choline-deficient (MCD) diet to induce NASH and were simultaneously treated with baicalein (at doses of 50 and 100 mg/kg) or vehicle only (sodium carboxymethylcellulose) through oral gavage for 4 weeks. The control group was fed a methionine-choline-sufficient (MCS) diet without the administration of baicalein. Results: The baicalein treatment significantly reduced serum levels of alanine aminotransferase and aspartate aminotransferase, suggestive of reduced liver damage. Histological analysis revealed a marked decrease in nonalcoholic fatty liver activity scores induced by the MCD diet in the mice. Similarly, baicalein treatment at both doses significantly attenuated the degree of hepatic fibrosis, as examined by Sirius red staining, and hepatocellular death, as examined by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Baicalein treatment attenuated MCD-diet-induced lipid peroxidation, as evidenced by lower levels of hepatic malondialdehyde and 4-hydroxynonenal, demonstrating a reduction in oxidative stress resulting from lipid peroxidation. Moreover, baicalein treatment suppressed hepatic protein levels of 12-lipoxygenase (12-Lox) induced by the MCD diet. In contrast, baicalein enhanced the activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. Additionally, baicalein treatment significantly reduced hepatic non-heme iron concentrations and hepatic ferritin protein levels in mice fed an MCD diet. Conclusion: To summarize, baicalein treatment suppresses hepatic lipid peroxidation, 12-Lox expression, and iron accumulation, all of which are associated with the attenuation of NASH progression.

• Herbal Formula Science
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• v.25 no.3
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• pp.363-374
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• 2017

Dried fruits of Schizandra chinensis Baillon, Fructus Schisandrae, have been widely used for many years to prevent and treat various diseases in Asian countries including Korea and Russia. It has recently been reported that extracts of Fructus Schisandrae are effective for controlling muscle and skeletal diseases. In this study, we investigated the efficacy of ethanol extract of Fructus Schisandrae (EEFS) on apoptosis and inflammatory response in gastrocnemius muscle of dexamethasone-induced catabolic muscle atrophy mice as part of natural substance discovery and functional analysis for improving muscle function. According to the results of this study, EEFS supplementation attenuated body weight gains and suppressed calf thickness loss in dexamethasone-induced muscle atrophic mice. Gastrocnemius muscle immunohistochemistry showed that expression of caspase-3 and poly(ADP-ribose) polymerase, which are representative apoptotic markers, was markedly increased in dexamethasone control mice; however, their expression was effectively reduced in the EEFS-fed mice. EEFS supplementation also prevented dexamethasone-induced increases in immunoreactivity of muscle fibers for myostatin, an important negative regulator of skeletal muscle mass. In addition, EEFS significantly normalized the increased numbers of nitrotyrosine, 4-hydroxynonenal and inducible nitric oxide synthase-positive muscle fibers compared to that found in dexamethasone control mice. These results suggest that EEFS protects dexamethasone-induced muscular atrophy by decreasing apoptosis and inflammatory responses, and EEFS is more likely to be developed as a muscle strengthening agent.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.105-115
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• 2015

Background: Alcoholic steatosis is the earliest and most common liver disease, and may precede the onset of more severe forms of liver injury. Methods: The effect of Korean Red Ginseng extract (RGE) was tested in two murine models of ethanol (EtOH)-feeding and EtOH-treated hepatocytes. Results: Blood biochemistry analysis demonstrated that RGE treatment improved liver function. Histopathology and measurement of hepatic triglyceride content verified the ability of RGE to inhibit fat accumulation. Consistent with this, RGE administration downregulated hepatic lipogenic gene induction and restored hepatic lipolytic gene repression by EtOH. The role of oxidative stress in the pathogenesis of alcoholic liver diseases is well established. Treatment with RGE attenuated EtOH-induced cytochrome P450 2E1, 4-hydroxynonenal, and nitrotyrosine levels. Alcohol consumption also decreased phosphorylation of adenosine monophosphate-activated protein kinase, which was restored by RGE. Moreover, RGE markedly inhibited fat accumulation in EtOH-treated hepatocytes, which correlated with a decrease in sterol regulatory element-binding protein-1 and a commensurate increase in sirtuin 1 and peroxisome proliferator-activated receptor-a expression. Interestingly, the ginsenosides Rb2 and Rd, but not Rb1, significantly inhibited fat accumulation in hepatocytes. Conclusion: These results demonstrate that RGE and its ginsenoside components inhibit alcoholic steatosis and liver injury by adenosine monophosphate-activated protein kinase/sirtuin 1 activation both in vivo and in vitro, suggesting that RGE may have a potential to treat alcoholic liver disease.