• Herbal Formula Science
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• v.26 no.4
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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.

• Food Science and Preservation
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• v.24 no.1
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• pp.107-115
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• 2017

The aim of this study was to investigate the hepatoprotecive effect of silk protein hydrolysates (SDH), which was prepared by acid hydrolysis, in rats. SDH itself did not exhibit any cytotoxic effect on hepatic tissues. SDH showed a protective effect on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity and liver damage. SDH effectively reduced AST (aspartate aminotransferase) and ALT (alanine aminotransferase), which are biomarkers for liver damage, in a dose-dependent manner. Malondialdehyde (MDA), a lipid peroxidation product, was significantly reduced by SDH. A high dose of SDH (2 g/kg) reduced t-BHP-induced MDA production by 40%. Glutathione (GSH), which is an endogenous antioxidant molecule, was effectively increased by SDH treatment. GSH content was enhanced by around 2.5-fold, compared with t-BHP control, upon SDH (2 g/kg) treatment. Lactate dehydrogenase (LDH), which is an enzyme released by cell cytotoxicity, was greatly increased by t-BHP, but significantly decreased by SDH treatment. Furthermore, hematoxylin and eosin (H&E) staining showed that SDH suppressed t-BHP-induced lesions in liver tissue. Taken together, SDH might be used as a protective agent against liver damage.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.887-890
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• 2005

To evaluate the hepatoprotective activity of lactic acid bacteria, their effects on tert-butylperoxide (t-BHP)-induced hepatotoxicity in mice were measured. When lactic acid bacteria at doses of 0.5 and 2 g (wet weight)/kg were orally administered to mice with t-BHP-induced liver injury, these bacteria significantly inhibited the increase of plasma alanine aminotransferase and aspartate aminotransferase activities by $17-57\%$ and $57-66\%$ of the t-BHP control group, respectively. However, these lactic acid bacteria did not protect cytotoxicity induced by t-BHP against HepG2 cells. The inhibitory effects of these lactic acid bacteria at a dose of 15 g/kg were comparable with that of diphenyl dimethyl bicarboxylate at a dose of 0.2 g/kg, which has been used as a commercial hepatoprotective agent. Among these lactic acid Jacteria, Bifidobacterium longum HY8001 exhibited the most potent hepatoprotective effect. These orally administered lactic acid bacteria inhibited liver lipid peroxidation on t-BHP-induced hepatotoxicity of mice. We suggest that lactic acid bacteria may be an effective agent against liver injury.

• YAKHAK HOEJI
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• v.49 no.6
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• pp.443-448
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• 2005

Diosgenin (25 (R) - spirost-5-en-3$\beta$ -ol) was oxidized with 2,3-dichloro -5,6-dicyano-1,4-benzoquinone to form 25(R)-1,4,6-spirostatrien-3-one (1) as rigid cyclic $\alpha$,$\beta$-unsaturated carbonyl compound. This compound was reacted with $H_{2}O_{2}$, m-chloroperoxybenzoic acid (mCPBA), NaOCl in the presence with (R,R)- or (S,S)-Jacobsen catalyst, tert-butyl-hydroperoxide (TBHP) in Mo$(CO)_{6}$, and in VO $(acac)_{2}$ catalyst, respectively, 25(R) -1,4,6-spirostatrien -3-one (1) was reduced with $NaBH_{4}$ L-Selectride, $LiAIH_{4}$,$BH_{3}$ $\cdot$$(CH_{3})_{2}S$, Superhydride, Red-Al, and lithium tri-tert-butoxyaluminium hydride. And 25(R)-4,6-spirostadien-3$\beta$-ol (4) was treated with $H_{2}O_{2}$, mCPBA, TBHP in D - (-) - and L-(+)-diisopropyltar-trate and $Ti(OiPr)_{4}$ condition (Sharpless asymmetric epoxidation), TBHP in $Mo(CO)_{6}$, and in $VO(acac)_{2}$ catalyst, respectively.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1381-1385
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• 2006

Cobalt (cyclam) complex has been successfully immobilized onto SBA-15, and proven to be an active catalyst for the epoxidation of styrene with tert-butyl hydroperoxide as a terminal oxidant. The selectivity for styrene oxide was observed to be up to 66% with 40% styrene conversion after 12h reaction time. The reversible redox cycle between Co(III) and Co(II) couple which was supposed to play key role during the epoxidation reaction was supported by a cyclic voltametry analysis. The textural properties of the catalyst was characterized by XRD, N2 adsorption-desorption, and TEM analysis.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.53-60
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• 2005

Objectives : This study was carried out to determine if Dendrobii Herba have protective effect against cell injury induced by various toxic agents in rat kidney slices. Water(DWe) and methanol(DMe) extracts were prepared for this experiment. Methods : Cell injury was estimated by measuring lactate dehydrogenase(LDH). Lipid peroxidation was examined by measuring malondialdehyde, a product of lipid peroxidation. Results : DMe prevented the LDH release by $CCl_4$, menadione, tert-butyl hydroperoxide and mercury treatment in vitro in kidney slices, but DWe prevented the LDH release by $CCl_4$ and mercury. DMe also prevented reduction in GSH and lipid peroxidation induced by $CCl_4$ and mercury. Conclusion : Thus, DMe may have more powerful efficacy on anti-oxidative effects when compared with DWe. And further studies have to be followed concerned with extraction of Dendrobii Herba and its change of effects.

• Journal of Life Science
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• v.10 no.5
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• pp.475-483
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• 2000

Normally, aerobic cells are protected from the damage of free radicals by antioxidative enzymes such as catalase, superoxide dismutase (SOD), glutathione (GSH) peroxidase and GSH-S-transferase. In this study, we have investigate the effect of egg yolk protein hydrolysates on antioxidative activity and the activity of antioxidative enzyme in cultured hepatocytes (Chang). Without the pretreatment with hydrolysate, about 50% of the hepatocytes were killed within 2h by 225$\mu$M tert-butyl hydroperoxide (t-BHP). By contrast, fewer than 20% of the 5 K hydrolysate (permeate from 5 kDa membrane and not passed through 1 kDa membrane)-pretreated hepatocytes were killed by the same concentrations of t-BHP. In addition, the activities of catalase, GSH peroxidase and GSH-transferase were significantly increasing with the treatment of 5 K hydrolysate. These results suggest that 5 K hydrolysate exerts antioxidative effect by increasing activity of antioxidative enzymes.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.944-946
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• 2004

Phytochemical investigation of the aqueous extract of ~he roots of Agrimania pilosa Ledeb. (Rosaceae), as guided by hepatoprotective activity in vitro, furnished two isocoumarins, agri-monolide (1) and agrimonolide 6-O-$\beta$-D-glucoside (3), and (＋)-catechin (2). Compound 1 showed hepatoprotective effects on both tacrine-induced cytotoxicity in human liver-derived Hep G2 cells and tert-butyl hydroperoxide-induced cytotoxicity in rat primary hepatocytes with EC$_{50}$ values of 88.2$\pm$2.8 and 37.7$\pm$1.6 $\mu$M, respectively.y.

• Natural Product Sciences
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• v.12 no.3
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• pp.134-137
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• 2006

Four lignan compounds including gomisin J (1), schizandrin (2), gomisin A (3), and angeloyl gomisin H (4) have been isolated from the MeOH extract of Schizandra chinensis fruits. The evaluation for protective effect of compounds 1-4 against tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in hippocampal HT22 cell line was conducted. Compound 1 showed significant protective effect with an $EC_{50}$ value of $43.3{\pm}2.3\;{\mu}M$, whereas compounds 2-4 were inactive. Trolox, one of the well-known antioxidant, used as a positive control, and also showed protective effect with an $EC_{50}$ value of $213.8{\pm}8.4\;{\mu}M$. These results suggest that compound 1 may possess the neuroprotective activity against oxidant-induced cellular injuries.

• Biomedical Science Letters
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• v.20 no.2
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• pp.56-61
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• 2014

This study attempted to confirm the antioxidative potential of luteolin against tert-butyl hydroperoxide (t-BHP) induced oxidative damage and to investigate its molecular mechanism related to glutathione (GSH)-dependent enzymes in HepG2 cells. Treatment with luteolin resulted in attenuation of t-BHP induced generation of reactive oxygen species (ROS) and oxidative stress-mediated cell death. In addition, accelerated expression of GSH-dependent antioxidative enzymes, glutathione peroxidase (GPx) and glutathione reductase (GR), and heme oxygenase (HO)-1, as well as strengthened GSH content was induced by treatment with luteolin, which was in accordance with increased nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), a transcription factor for phase 2 enzymes, in a dose-dependent manner. These results suggest that the cytoprotective potential of luteolin against oxidative damage can be attributed to fortified GSH-mediated antioxidative pathway and HO-1 expression through regulation of Nrf2 in HepG2 cells.