• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1331-1338
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• 2010

This study was designed to investigate the potentially protective effects of Curcuma longa Linn. extract (CLE) on carbon tetrachloride ($CCl_4$)-induced hepatotoxicity in rats. Male Sprague-Dawley rats were pretreated with 50 or 100mg/kg of CLE or 100mg/kg of butylated hydroxytoluene(BHT) for 14 days before $CCl_4$ administration. In addition, the CLE control group was pretreated with 100mg/kg CLE for only 14 days. Three hours after the final treatment, a single dose of $CCl_4$ (20mg/kg) was administrated intraperitoneally to each group. After the completion of this phase of the experiment, food and water were removed 12 h prior to the next step. The rats were then anesthetized by urethane and their blood and liver were collected. It was observed that the aspartate aminotransferase and alanine aminotransferase activities of the serum, and the hepatic malondialdehyde levels had significantly decreased in the CLE group when compared with the $CCl_4$-treated group. The antioxidant activities, such as superoxide dismutase, catalase, and glutathione peroxidase activities, in addition to glutathione content, had increased considerably in the CLE group compared with the $CCl_4$-treated group. Phase II detoxifying enzymes, such as glutathione S-transferase, were found to have significantly increased in the CLE group as opposed to the $CCl_4$-treated group. The content of Nrf2 was determined by Western blot analysis. Pretreated CLE increased the level of nuclear translocated Nrf2, and the Nrf2 then increased the activity of the antioxidant and phase II detoxifying enzymes. These results indicate that CLE has protective effects against $CCl_4$-induced hepatotoxicity in rats, via activities of antioxidant and phase II detoxifying enzymes, and through the activation of nuclear translocated Nrf2.

• BMB Reports
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• v.39 no.5
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• pp.479-491
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• 2006

Heme oxygenase (HO), the rate limiting enzyme in the breakdown of heme into carbon monoxide (CO), iron and bilirubin, has recently received overwhelming research attention. To date three mammalian HO isozymes have been identified, and the only inducible form is HO-1 while HO-2 and HO-3 are constitutively expressed. Advances in unveiling signal transduction network indicate that a battery of redox-sensitive transcription factors, such as activator protein-1 (AP-1), nuclear factor-kappa B (NF-${\kappa}B$) and nuclear factor E2-related factor-2 (Nrf2), and their upstream kinases including mitogen-activated protein kinases play an important regulatory role in HO-1 gene induction. The products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression contributes to protection against liver damage induced by several chemical compounds such as acetaminophen, carbon tetrachloride and heavy metals, suggesting HO-1 induction as an important cellular endeavor for hepatoprotection. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect against chemically-induced liver injury as well as hepatocarcinogenesis.

• Journal of Life Science
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• v.23 no.8
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• pp.1057-1063
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• 2013

Citri Pericarpium is one of the most commonly used traditional herbal medicines in Korea, China, and Japan. Its extracts have many properties including the treatment of indigestion and inflammatory respiratory syndromes such as bronchitis and asthma. However, the underlying molecular mechanisms of anti-cancer activity and molecular targets are not fully understood. In this work, we investigated the anti-proliferative activity of Citri Pericapium (EMCP) methanol extract on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death using U937 human leukemia cells in vitro. EMCP treatment decreased cell proliferation in a dose-dependent manner following an increase of the sub-G1 phase, the down-regulation of Bax proteins, the activation of caspases, the degradation of poly (ADP-ribose) polymerase proteins (PARP), and the induction of ROS generation. However, the quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the EMCP-induced apoptosis effects. In addition, heme oxygenase-1 expression also recovered by inhibiting the nuclear translocation of phosphorylated NF-E2-related factor 2. Taken together, our data indicate that ROS are involved as key mediators in the early molecular events in the EMCP-induced apoptotic pathway.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.170-176
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• 2014

In this study, the anti-oxidative and anti-inflammatory activities of Euptelea pleiosperma ethanol extract (EPEE) were evaluated using in vitro assays and cell culture model systems. EPEE possessed a more potent scavenging activity against 1,1-diphenyl-2-picryl hydrazyl than the ascorbic acid used as a positive control. EPEE effectively suppressed lipopolysaccharide (LPS), in addition to hydrogen peroxide induced reactive oxygen species on RAW 264.7 cells. Furthermore, EPEE induced the expression of the anti-oxidative enzyme heme oxygenase 1 (HO-1) and its upstream transcription factor, nuclear factor-E2-related factor 2 (Nrf2), dose and time dependently. The modulation of HO-1 and Nrf2 expression might be regulated by mitogen-activated protein kinases and phosphatidyl inositol 3 kinase/Akt as their upstream signaling pathways. On the other hand, EPEE inhibited LPS induced nitric oxide (NO) formation without cytotoxicity. Suppression of NO formation was the result of the down regulation of inducible NO synthase (iNOS) by EPEE. Suppression of NO and iNOS by EPEE may be modulated by their upstream transcription factor, nuclear factor ${\kappa}B$, and AP-1 pathways. Taken together, these results provide important new insights into E. pleiosperma, namely that it possesses anti-oxidative and anti-inflammatory activities, indicating that it could be utilized as a promising material in the field of nutraceuticals.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.120-125
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• 2009

Alaria esculenta is a brown seaweed found in the Arctic. This study investigated the protective effect of A. esculenta extract (AEE) against oxidant-mediated injury and its mode of action in RAW264.7 macrophages. The methyl thiazolyl tetrazolium (MTT) assay showed that $H_2O_2$ treatment reduced cell viability, whereas AEE protected cells from $H_2O_2$-mediated cytotoxicity in a dose-dependent manner. Because heme oxygenase-1 (HO-1) is known to protect cells against oxidative damage, we investigated the effect of AEE on HO-1 gene expression and HO enzyme activity. The protective effect of AEE against $H_2O_2$-induced injury was correlated with increased HO enzyme activity. AEE also induced HO-1 mRNA and protein expression, as determined RT-PCR and Western blotting, respectively. To characterize the mechanisms by which AEE induces HO-1 gene expression, we examined the effect of AEE on the nuclear translocation of NF-E2-related factor-2 (Nrf2) and Akt phosphorylation. AEE treatment activated upstream signaling for HO-1 gene expression, including the nuclear translocation of Nrf2 and Akt phosphorylation. Collectively, these results suggest that AEE has anti-oxidant activity that is mediated, at least in part, via the activation of Nrf2 and Akt and the subsequent induction of HO-1 gene expression.

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.230-236
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• 2009

Acrolein, a known toxin in cigarette smoke, is the most abundant electrophilic $\alpha$, $\beta$-unsaturated aldehyde to which humans are exposed in a variety of environmental pollutants, and is also product of lipid peroxidation. Increased unsaturated aldehyde levels and reduced antioxidant status plays a major role in the pathogenesis of various diseases such as diabetes, Alzheimer's and atherosclerosis. The findings reported here show that low concentrations of acrolein induce heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophages. HO-1 induction by acrolein and signal pathways was measured using reverse transcription-polymerase chain reaction, Western blot and immunofluorescence staining analyses. Inhibition of extracellular signal-regulated kinase activity significantly attenuated the induction of HO-1 protein by acrolein, while suppression of Jun N-terminal kinase and p38 activity did not affect induction of HO-1 expression. Moreover, rottlerin, an inhibitor of protein kinase $\delta$, suppressed the upregulation of HO-1 protein production, possibly involving the interaction of NF-E2-related factor 2 (Nrf2), which has a key role as a HO-1 transcription factor. Acrolein elevated the nuclear translocation of Nrf2 in nuclear extraction. The results suggest that RAW 264.7 may protect against acrolein-mediated cellular damage via the upregulation of HO-1, which is an adaptive response to oxidative stress.

• Journal of Life Science
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• v.29 no.4
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• pp.402-409
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• 2019

Korean red ginseng made from steaming and drying fresh ginseng has long been used as a traditional herbal medicine due to its effects on the immune, endocrine, and central nerve systems and its anti-inflammatory activity. In this study, we investigated the molecular mechanism responsible for the anti-inflammatory effects of a formulated Korean red ginseng extract (RGE) in response to lipoteichoic acid (LTA), a cell wall component of gram-positive bacteria. RGE inhibited LTA-induced nitric oxide (NO) secretion and inducible nitric oxide synthase (iNOS) expression in BV-2 microglial cells, without affecting cell viability. RGE also inhibited nuclear translocation of nuclear factor kappa B ($NF-{\kappa}B$) p65 and degradation of $I{\kappa}B-{\alpha}$. In addition, RGE increased the expression of heme oxygenase-1 (HO-1) in a dose-dependent manner, and the inhibitory effect of RGE on iNOS expression was abrogated by small interfering RNA-mediated knockdown of HO-1. Moreover, RGE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. Furthermore, the phosphoinositide-3-kinase (PI-3K) inhibitor and mitogen-activated protein kinase (MAPK) inhibitors suppressed RGE-mediated expression of HO-1, and RGE enhanced the phosphorylation of Akt, extracellular signal-regulated kinases (ERKs), p38, and c-JUN N-terminal kinases (JNKs). These results suggested that RGE suppressed the production of NO, a proinflammatory mediator, by inducing HO-1 expression via PI-3K/Akt- and MAPK-dependent signaling in LTA-stimulated microglia. The findings indicate that RGE could be used for the treatment of neuroinflammation induced by grampositive bacteria and that it may have therapeutic potential for various neuroinflammation-associated disorders.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.466-477
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• 2018

In this study, the anti-inflammatory activities of the extracts of different parts of Hovenia dulcis such as leaves, stems, and roots were investigated. Among them, the roots extract (RE) showed the most potent suppressive effect against pro-inflammatory mediators in LPS-stimulated mouse macrophage cells. RE induced dose-dependent reduction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and concomitantly reduced the production of NO and $PGE_2$. Additionally, pre-treatment with RE significantly suppressed the production of inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin $(IL)-1{\beta}$, and IL-6, as well as mRNA levels. Moreover, phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear translocation of nuclear factor-kappa B (NF-kB) were also strongly attenuated by RE in RAW264.7 cell. Furthermore, RE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increase HO-1 activity in RAW264.7 macrophages. Therefore, these results indicate that RE strongly inhibits LPS-induced inflammatory responses by blocking NF-kB activation, inhibiting MAPKs phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that RE of H. dulicis and a major component, 27-O-protocatechuoylbetulinic acid could be applied as a valuable natural anti-inflammatory material.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.139-150
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• 2016

Few studies have been reported that horse-bone extract(HBE) can prevent and treatment of bone diseases. However, HBE' therapeutic activities are still not fully understood. This study determined whether HBE up-regulates hemeoxygenase 1(HO-1) and this mediates its anti-inflammatory effect in murine macrophages.Nitric oxide(NO) assay, MTT assay and DPPH assay were performed. In addition, Western blotting and real time PCR were used to determine protein expression, and gene expression, respectively. HBE significantly inhibited NO production without observable cytotoxicity. In addition, HBE attenuated inducible nitric oxide synthase (iNOS), cyclooxygenase-2(COX-2) and phospho (p)-ERK protein expressions in LPS(0.1㎍/ml) stimulated RAW264.7 cells. On the other hand, HBE alone up-regulated HO-1 and Nrf-2 expressions, which mediated HBE's anti-inflammatory effect in RAW264.7 cells. Finally, HBE up-regulated HO-1 and impaired ERK1/2 signaling pathways, and thus it may provide protection against cellular oxidation and inflammation.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.275-284
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• 2014

This study was orchestrated with the purpose of uncovering new nutraceutical resources possessing biological activities in the plant kingdom. To fulfill our objective, we analyzed several Chinese plants and selected three possessing powerful anti-oxidative activities. The anti-oxidative and anti-inflammatory effects these three Chinese plants, Malus hupehensis, Ophiorrhiza cantonensis, and Psychotria rubra ethanol extracts were then evaluated. First of all, they possessed potent scavenging activity against 1,1-diphenyl-2-picryl hydrazyl, similar with that of ascorbic acid, used as a positive control. Moreover, they inhibited lipopolysaccharide (LPS)- and hydrogen peroxide-induced reactive oxygen species, in a dose-dependent manner, in RAW 264.7 cells. Also, they induced the expression of an anti-oxidative enzyme, heme oxygenase 1, and its upstream transcription factor, nuclear factor-E2-related factor 2. Furthermore, they suppressed LPS-induced nitric oxide (NO) formation, without cytotoxicity. The inhibition of NO formation was the result of the down regulation of inducible NO synthase (iNOS). The suppression of NO and iNOS by the three extracts might be the result of modulation by the upstream transcription factors, nuclear factor ${\kappa}B$ and activator protein-1. Taken together, these results indicate that these three Chinese plants possess potent anti-oxidative and anti-inflammatory activities. Therefore, they might be utilized as promising materials in the field of nutraceuticals.