• BMB Reports
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• 제53권4호
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• pp.218-222
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• 2020

Excessive and hyperactive osteoclast activity causes bone diseases such as osteoporosis and periodontitis. Thus, the regulation of osteoclast differentiation has clinical implications. We recently reported that dehydrocostus lactone (DL) inhibits osteoclast differentiation by regulating a nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), but the underlying mechanism remains to be elucidated. Here we demonstrated that DL inhibits NFATc1 by regulating nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and nuclear factor-erythroid 2-related factor 2 (Nrf2). DL attenuated IκBα phosphorylation and p65 nuclear translocation as well as decreased the expression of NF-κB target genes and c-Fos. It also inhibited c-Jun N-terminal kinase (JNK) but not p38 or extracellular signal-regulated kinase. The reporter assay revealed that DL inhibits NF-κB and AP-1 activation. In addition, DL reduced reactive oxygen species either by scavenging them or by activating Nrf2. The DL inhibition of NFATc1 expression and osteoclast differentiation was less effective in Nrf2-deficient cells. Collectively, these results suggest that DL regulates NFATc1 by inhibiting NF-κB and AP-1 via down-regulation of IκB kinase and JNK as well as by activating Nrf2, and thereby attenuates osteoclast differentiation.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.570-575
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• 2022

Stress breaks body balance, which can cause diverse physiological disorders and worsen preexisting diseases. However, recent studies have reported that controllable stress and overcoming from stress reinforce resilience to resist against more intense stress afterwards. In this study, we investigated the protective effect of corticosterone (CORT), a representative stress hormone against hydrogen peroxide (H₂O₂)-induced neuronal cell death and its underlying molecular mechanism in SH-SY5Y cells, a human neuroblastoma cell line. The decreased cell viability by H₂O₂ was effectively restored by the pretreatment with low concentration of CORT (0.03 μM for 72 h) in the cells. H₂O₂-increased expression of apoptotic markers such as PUMA and Bim was decreased by CORT pretreatment. Furthermore, pretreatment of CORT attenuated H₂O₂-mediated oxidative damages by upregulation of antioxidant enzymes via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). These findings suggest that low concentration of CORT with eustressed condition enhances intracellular self-defense against H₂O₂-mediated oxidative cell death, suggesting a role of low concentration of CORT as one of key molecules for resilience and neuronal cell survival.

• 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.

• 생명과학회지
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• 제31권3호
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• pp.338-345
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• 2021

고장초는 오랫동안 식용 및 의약 목적으로 차를 만드는 데 사용되어 왔다. 그러나 고장초를 고부가가치 식용 재료로 사용하는 연구는 불충분하다. 이전 연구에서 우리는 tricin이 고장초의 주요 화합물임을 확인했다. 본 연구에서는 고장초 추출물의 HepG2 세포 보호 효과를 조사하였다. 고장초 추출물 또는 tricin의 HepG2 세포에 대한 독성 실험 결과, 사용한 모든 농도에서 고장초 추출물 또는 tricin에 대한 독성은 나타나지 않았다. 또한 tert-butyl hydroperoxide (t-BHP)에 의해 감소된 세포 생존율은 고장초 추출물(100 ㎍/ml에서 69.23%) 또는 tricin (100 ng/ml에서 74.47%)에 의해 증가되었다. 또한 고장초 추출물(250 ㎍/ml) 또는 tricin (250 ng/ml)은 산화적 손상에 의한 활성 산소종(ROS) 생성을 효과적으로 억제했다. 또한 항산화 효소로 알려진 superoxide dismutase 1(SOD1), catalase, heme oxygenase-1 (HO-1), nuclear factor erythroid-related factor 2 (Nrf2)의 단백질 발현은 고장초 추출물(100 ㎍/ml에서 2.1, 1.6, 1.7, 1.5배) 또는 tricin (250 ng/ml에서 2.6, 1.8, 2.2, 2.0배) 처리로 증가했으며, 이는 고장초 추출물의 HepG2 세포 보호 효과는 tricin의 활성과 관련이 있다는 것을 시사한다. 종합하면 고장초는 간 기능개선 관련 기능성 식품 소재로 개발이 가능할 것으로 기대된다.

• 한방재활의학과학회지
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• 제30권3호
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• pp.71-87
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• 2020

Objectives Even though the various alternative herbal medicine has applied for osteoarthritis (OA) treatment, its scientific proof remains uncertain. The aim of the present study evaluates the effects of Chulbu-tang on inflammatory responses in a monosodium iodoacetate (MIA)-induced osteoarthritis rat model. Methods OA rat model was established by MIA injection in intra-joint of rats. 7 days after, OA rats except OA control rats were administrated Chulbu-tang (100 or 200 mg/kg) or Indomathacin (5 mg/kg) once a day for 14 days. The weight-bearing ability of hind paws were measured when group isolation 0, 7, and 14 days. Western blotting was performed to examine the knockdown/overexpressing efficiency of Chulbu-tang. In addition, cartilage destruction was measured histologically. Results Chulbu-tang treatment significantly reduced the protein expressions of inflammatory mediators such as inducible nitric oxide synthase and cyclooxygenase 2, and inhibited inflammatory cytokines including tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6 through nuclear factor-kappa B (NF-κB) inactivation. Moreover, anti-oxidant enzymes such as superoxide dismutase and glutathione peroxidase-1/2 through nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway significantly increased. Our findings indicate that Chulbu-tang has the potential therapeutic effect on OA through inhibiting the inflammatory responses via inactivating NF-κB signaling pathway. In addition, upregulation of Nrf2 led to anti-oxidant effects. Conclusions Taken together, Chulbu-tang is believed to have antioxidant, anti-inflammatory effects, and cartilage protection for arthritis-causing rats.

• 대한약침학회지
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• 제19권1호
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• pp.59-69
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• 2016

Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL) against oxidative stress (hydrogen peroxide, $H_2O_2$) and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS) generation and deoxyribonucleic acid (DNA) damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and $H_2O_2$ in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2)-specific small interfering ribonucleic acid (siRNA) was conducted to understand the relationship between Nrf2 expression and $H_2O_2$-induced growth inhibition. Results: The results showed that EGL effectively inhibited $H_2O_2$-induced growth and the generation of ROS. EGL markedly suppressed $H_2O_2$-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 ($p-{\gamma}H2AX$), a widely used marker of DNA damage, suggesting that EGL prevented $H_2O_2$-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1), with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against $H_2O_2$-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL augments the cellular anti-oxidant defense capacity through activation of Nrf2/HO-1, thereby protecting C2C12 myoblasts from $H_2O_2$-induced oxidative cytotoxicity.

• 대한한의학방제학회지
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• 제26권1호
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• pp.1-12
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• 2018

Objectives : Cheongnoimyungshin-hwan (CNMSH) is a Herbal compound prescription that is composed mainly of herbal medicines such as Ginseng Radix Alba, Angelicae Gigantis Radix, Dioscoreae Rhizoma, Longan Arillus and cornus cervi parvum, and for the purpose of improving memory and preventing dementia. Methods : In this study, it was investigated whether CNMSH could suppress inflammatory response and oxidative stress in the lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. As a result, CNMSH decreased expression of inducible nitric oxide (NO) synthase and cyclooxygenase-2, and also inhibited production of NO, prostaglandin E2. Results : This effect was associated with the suppression of the expression of p65, one of the nuclear factor-kappaB ($NF-{\kappa}B$) subunits, and increased expression of $I{\kappa}B-{\alpha}$, inhibit the $NF-{\kappa}B$ transcription factor. In addition, CNMSH significantly blocked intracellular reactive oxygen species accumulation in response to LPS stimulation. Furthermore, CNMSH increased expression of nuclear factor erythroid 2-related factor (Nrf)-2 activation and heme oxygenase (HO)-1. Conclusions : Therefore, it has been shown anti-inflammatory and antioxidant effects by inhibiting the expression and production of inflammatory mediators in LPS-stimulated macrophages, and is associated with ROS generation and is activated by Nrf2/HO-1 signaling pathway.

• Journal of Ginseng Research
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• 제47권4호
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• pp.552-560
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• 2023

Background: Ginseng Radix (Panax ginseng Meyer, Araliaceae) has been used medicinally to treat the brain and nervous system problems worldwide. Recent studies have revealed physiological effects that could potentially benefit cognitive performance or mood. The present study aimed to investigate the antidepressant effects of Korean red ginseng water extract (KGE) and its active component in an unpredictable chronic mild stress (UCMS)-induced animal model and elucidate the underlying mechanisms. Methods: The antidepressant potential of the UCMS model was evaluated using the sucrose preference test and open field tests. The behavioral findings were further corroborated by the assessment of neurotransmitters and their metabolites from the prefrontal cortex and hippocampus of rats. Three doses of KGE (50, 100, and 200 mg/kg) were orally administered during the experiment. Furthermore, the mechanism underlying the antidepressant-like action of KGE was examined by measuring the levels of brain-derived neurotrophic factor (BDNF)/CREB, nuclear factor erythroid 2-related factor 2 (Nrf2), and Kelch-like ECH-associated protein 1 (Keap1) proteins in the prefrontal cortex of UCMS-exposed rats. Results: KGE treatment normalized UCMS-induced depression-related behaviors. Neurotransmitter studies conducted after completing behavioral experiments demonstrated that KGE caused a reduction in the ratio of serotonin and dopamine, indicating a decrease in serotonin and dopamine turnover. Moreover, the expression of BDNF, Nrf2, Keap1 and AKT were markedly increased by KGE in the prefrontal cortex of depressed rats. Conclusion: Our results provide evidence that KGE and its constituents exert antidepressant effects that mediate the dopaminergic and serotonergic systems and expression of BDNF protein in an animal model.

• Journal of Ginseng Research
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• 제45권3호
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• pp.408-419
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• 2021

Background: The decreased renal function is known to be associated with biological aging, of which the main pathological features are chronic inflammation and renal interstitial fibrosis. In previous studies, we reported that total saponins from Panax japonicus (SPJs) can availably protect acute myocardial ischemia. We proposed that SPJs might have similar protective effects for aging-associated renal interstitial fibrosis. Thus, in the present study, we evaluated the overall effect of SPJs on renal fibrosis. Methods: Sprague-Dawley (SD) aging rats were given SPJs by gavage beginning from 18 months old, at 10 mg/kg/d and 60 mg/kg/d, up to 24 months old. After the experiment, changes in morphology, function and fibrosis of their kidneys were detected. The levels of serum uric acid (UA), β2-microglobulin (β2-MG) and cystatin C (Cys C) were assayed with ELISA kits. The levels of extracellular matrix (ECM), matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), inflammatory factors and changes of oxidative stress parameters were examined. Results: After SPJs treatment, SD rats showed significantly histopathological changes in kidneys accompanied by decreased renal fibrosis and increased renal function; As compared with those in 3-month group, the levels of serum UA, Cys C and β2-MG in 24-month group were significantly increased (p < 0.05). Compared with those in the 24-month group, the levels of serum UA, Cys C and β2-MG in the SPJ-H group were significantly decreased. While ECM was reduced and the levels of MMP-2 and MMP-9 were increased, the levels of TIMP-1, TIMP-2 and transforming growth factor-β1 (TGF-β1)/Smad signaling were decreased; the expression level of phosphorylated nuclear factor kappa-B (NF-κB) was down-regulated with reduced inflammatory factors; meanwhile, the expression of nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling was aggrandized. Conclusion: These results suggest that SPJs treatment can improve age-associated renal fibrosis by inhibiting TGF-β1/Smad, NFκB signaling pathways and activating Nrf2-ARE signaling pathways and that SPJs can be a potentially valuable anti-renal fibrosis drug.

• 대한본초학회지
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• 제39권6호
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• pp.25-32
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• 2024

Objective : Cloves, the dried flower buds of Syzygium aromaticum, have been used to treat various allergic disorders and relieve abdominal pain caused by chills. In this study, cytoprotective and antioxidant effects of cloves extracts (CLE) were investigated in tert-butyl hydoroperoxide (tBHP)-treated HepG2 cells. Methods : CLE was prepared by extracting 100 g of ground clove in 1 L of pretanol for 48 h. Several biomarkers that modulate cell viability and oxidative stress, including caspases and glutathione (GSH), were determined using Western blotting and commercial kits. Results : In HepG2 cells, tBHP induced oxidative stress and inhibited cell viability. However, CLE reduced oxidative stress via inhibiting the increase of reactive oxygen species (ROS) and depletion of GSH caused by tBHP. In TUNEL assay, tBHP-induced oxidative stress led apoptosis, but apoptosis was suppressed by CLE. The expression changes of apoptosis-related proteins, including AIF, procaspase-3, and PARP were also restored by CLE. Moreover, CLE increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibited the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 induced by tBHP. Conclusion : These results demonstrate the protective effect of CLE against tBHP-induced apoptosis in HepG2 cells, suggesting that the antioxidant activity of CLE, which scavenges ROS and restores GSH depletion via Nrf2 and JNK/p38 signaling pathways, contributes to cytoprotection.