• Journal of Cancer Prevention
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• 제21권3호
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• pp.135-143
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• 2016

Background: Fraxetin (7,8-dihydroxy-6-methoxy coumarin), a coumarin derivative, has been reported to possess antioxidative, anti-inflammatory and neuroprotective effects. A number of recent observations suggest that the induction of heme oxygenase-1 (HO-1) inhibits inflammation and tumorigenesis. In the present study, we determined the effect of fraxetin on HO-1 expression in HaCaT human keratinocytes and investigated its underlying molecular mechanisms. Methods: Reverse transcriptase-PCR and Western blot analysis were performed to detect HO-1 mRNA and protein expression, respectively. Cell viability was measured by the MTS test. The induction of intracellular reactive oxygen species (ROS) by fraxetin was evaluated by 2′,7′-dichlorofluorescin diacetate staining. Results: Fraxetin upregulated mRNA and protein expression of HO-1. Incubation with fraxetin induced the localization of nuclear factor-erythroid-2-related factor-2 (Nrf2) in the nucleus and increased the antioxidant response element-reporter gene activity. Fraxetin also induced the phosphorylation of Akt and AMP-activated protein kinase $(AMPK){\alpha}$ and diminished the expression of phosphatase and tensin homolog, a negative regulator of Akt. Pharmacological inhibition of Akt and $AMPK{\alpha}$ abrogated fraxetin-induced expression of HO-1 and nuclear localization of Nrf2. Furthermore, fraxetin generated ROS in a concentration-dependent manner. Conclusions: Fraxetin induces HO-1 expression through activation of Akt/Nrf2 or $AMPK{\alpha}/Nrf2$ pathway in HaCaT cells.

• Journal of Ginseng Research
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• 제39권4호
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• pp.299-303
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• 2015

Panax ginseng is a well-known economic medical plant that is widely used in Chinese traditional medicine. This species contains a unique class of natural products-ginsenosides. Recent clinical and experimental studies have presented numerous lines of evidence on the promising role of ginsenosides on different diseases including neurodegenerative diseases, cardiovascular diseases, and certain types of cancer. Nowadays, most of the attention has focused on ginsenoside Rd as a neuroprotective agent to attenuate ischemic stroke damages. Some of the evidence showed that ginsenoside Rd ameliorates ischemic stroke-induced damages through the suppression of oxidative stress and inflammation. Ginsenoside Rd can prolong neural cells' survival through the upregulation of the endogenous antioxidant system, phosphoinositide-3-kinase/AKT and extracellular signal-regulated protein kinase 1/2 pathways, preservation of mitochondrial membrane potential, suppression of the nuclear factor-kappa B, transient receptor potential melastatin, acid sensing ion channels 1a, poly(ADP-ribose) polymerase-1, protein tyrosine kinase activation, as well as reduction of cytochrome c-releasing and apoptosis-inducing factor. In the current work, we review the available reports on the promising role of ginsenoside Rd on ischemic stroke. We also discuss its chemistry, source, and the molecular mechanism underlying this effect.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.127-134
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• 2021

Neuroinflammation―a common pathological feature of neurodegenerative disorders such as Alzheimer's disease―is mediated by microglial activation. Thus, inhibiting microglial activation is vital for treating various neurological disorders. 7,3',4'-Trihydroxyisoflavone (THIF)―a secondary metabolite of the soybean compound daidzein―possesses antioxidant and anticancer properties. However, the effects of 7,3',4'-THIF on microglial activation have not been explored. In this study, antineuroinflammatory effects of 7,3',4'-THIF in lipopolysaccharide (LPS)-stimulated BV2 microglial cells were examined. 7,3',4'-THIF significantly suppressed the production of the proinflammatory mediators nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) as well as of the proinflammatory cytokine interleukin-6 (IL-6) in LPS-stimulated BV2 microglial cells. Moreover, 7,3',4'-THIF markedly inhibited reactive oxygen species (ROS) generation. Western blotting revealed that 7,3',4'-THIF diminished LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), glycogen synthase kinase-3β (GSK-3β), and nuclear factor kappa B (NF-κB). Overall, 7,3',4'-THIF exerts antineuroinflammatory effects against LPS-induced microglial activation by suppressing mitogen-activated protein kinase (MAPK) and NF-κB signaling, ultimately reducing proinflammatory responses. Therefore, these antineuroinflammatory effects of 7,3',4'-THIF suggest its potential as a therapeutic agent for neurodegenerative disorders.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.127-138
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• 2023

Glycogen synthase kinase-3β (GSK-3β) is an important serine/threonine kinase that implicates in multiple cellular processes and links with the neurodegenerative diseases including Alzheimer's disease (AD). In this study, structure-based virtual screening was performed to search database for compounds targeting GSK-3β from Enamine's screening collection. Of the top-ranked compounds, 7 primary hits underwent a luminescent kinase assay and a cell assay using human neuroblastoma SH-SY5Y cells expressing Tau repeat domain (Tau_RD) with pro-aggregant mutation ΔK280. In the kinase assay for these 7 compounds, residual GSK-3β activities ranged from 36.1% to 90.0% were detected at the IC₅₀ of SB-216763. In the cell assay, only compounds VB-030 and VB-037 reduced Tau aggregation in SH-SY5Y cells expressing ΔK280 Tau_RD-DsRed folding reporter. In SH-SY5Y cells expressing ΔK280 Tau_RD, neither VB-030 nor VB-037 increased expression of GSK-3α Ser21 or GSK-3β Ser9. Among extracellular signal-regulated kinase (ERK), AKT serine/threonine kinase 1 (AKT), mitogen-activated protein kinase 14 (P38) and mitogenactivated protein kinase 8 (JNK) which modulate Tau phosphorylation, VB-037 attenuated active phosphorylation of P38 Thr180/ Tyr182, whereas VB-030 had no effect on the phosphorylation status of ERK, AKT, P38 or JNK. However, both VB-030 and VB-037 reduced endogenous Tau phosphorylation at Ser202, Thr231, Ser396 and Ser404 in neuronally differentiated SH-SY5Y expressing ΔK280 Tau_RD. In addition, VB-030 and VB-037 further improved neuronal survival and/or neurite length and branch in mouse hippocampal primary culture under Tau cytotoxicity. Overall, through inhibiting GSK-3β kinase activity and/or p-P38 (Thr180/Tyr182), both compounds may serve as promising candidates to reduce Tau aggregation/cytotoxicity for AD treatment.

• Molecules and Cells
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• 제37권3호
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• pp.248-256
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• 2014

N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is a N-acetylhexosamine kinase that belong to the sugar kinase/heat shock protein 70/actin superfamily. In this study, we investigated both the expression and function of NAGK in neurons. Immunohistochemistry of rat brain sections showed that NAGK was expressed at high levels in neurons but at low levels in astrocytes. Immunocytochemistry of rat hippocampal dissociate cultures confirmed these findings and showed that NAGK was also expressed at low levels in oligodendrocytes. Furthermore, several NAGK clusters were observed in the nucleoplasm of both neuron and glia. The overexpression of EGFP- or RFP (DsRed2)-tagged NAGK in rat hippocampal neurons (DIV 5-9) increased the complexity of dendritic architecture by increasing the numbers of primary dendrites and dendritic branches. In contrast, knockdown of NAGK by shRNA resulted in dendrite degeneration, and this was prevented by the co-expression of RFP-tagged NAGK. These results suggest that the upregulation of dendritic complexity is a non-canonical function of NAGK.

• Journal of Ginseng Research
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• 제41권2호
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• pp.227-231
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• 2017

Background: Ginsenosides are active components of Panax ginseng that exert various health benefits including kidney protection effect. The medicinal activity of ginsenosides can be enhanced by modulating their stereospecificity by heat processing. Ginsenosides Rk2 and Rh3 represent positional isomers of the double bond at C-20(21) or C-20(22). Methods: The present study investigated the kidney-protective effects of ginsenosides Rk2 and Rh3 against cisplatin, a platinum based anticancer drug, induced apoptotic damage in renal proximal LLC-PK1 cells. Results: As a result, ginsenoside Rh3 shows a stronger protective effect than that shown by Rk2. Cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38, and cleaved caspase-3 decreased after cotreatment with ginsenoside Rh3. The increase in the percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment also significantly reduced after cotreatment with ginsenoside Rh3. Conclusion: These results demonstrate that inhibition of the JNK and ERK mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of ginsenoside Rh3.

• International Journal of Oral Biology
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• 제44권2호
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• pp.43-49
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• 2019

Tannic acid (TA) is a water-soluble polyphenol compound found in various herbal plants. We investigated the chemopreventive effects of TA on FaDu hypopharyngeal squamous carcinoma cells. In an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, TA showed dose-dependent cytotoxicity with a half maximal inhibitory concentration (IC50) of 50 ?M. Cell cycle analysis and immunofluorescence imaging demonstrated that under low-dose ($25{\mu}M$) treatment, FaDu cells were arrested in G2/M phase, and as the dose of TA was increased, apoptosis was induced with the increase of cell population at sub-G1 phase. The expressions of various cyclins, including cyclin D1 and cyclin-dependent kinases (CDK-1 and CDK-2), were down-regulated at low doses of TA, whereas apoptotic effectors such as cleaved caspase 3, cleaved caspase 7, and poly (ADP-ribose) polymerase (PARP) were expressed in a dose-dependent manner in Western blotting. In addition, TA-induced apoptosis of FaDu cells might be mediated by the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway, with the upregulation of p-AKT/p-PKB (phosphorylated protein kinase B) and p-ERK. Overall, our data support the hypothesis that TA is a potential candidate agent for the treatment of hypopharyngeal cancer.

• 한국응용곤충학회지
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• 제55권1호
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• pp.53-62
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• 2016

본 연구의 목적은 벼메뚜기(Oxya chinensis sinuosa) 분말 섭취가 유산소성 운동훈련(트레드밀 달리기)의 병행 유무에 의해 ICR 생쥐의 에너지 대사를 증가시키는지를 알아보고자 하는 것이다. 이 목적을 달성하기 위하여, 28 마리의 ICR 생쥐를 보통식 대조군(CON), 보통식 대조군으로서 운동훈련 병행군(COEX), 벼메뚜기 분말이 혼합된 사료 섭취군(GH), 그리고 벼메뚜기 분말이 혼합된 사료를 섭취함과 동시에 운동훈련을 병행군(GHEX)으로 구분하였다. 벼메뚜기 분말 사료섭취 및 운동은 6주간 진행하였다. 체중증가율은 유의하지 않았다. 지방량은 GH와 GHEX에서 유의하게 감소하였다. 혈중 glutamic oxaloacetic transaminase와 glutamic pyruvic transaminase 수준은 처치 집단간 변화가 없었다. 제2형 당수송체 및 제4형 당수송체는 처치 집단간 유의한 차이가 없었다. GHEX의 fibronectin type III domain-containing protein 5 단백질 발현량이 가장 높았다. AMP-activated protein kinase 단백질 수준은 GHEX에서 유의하게 증가하였다. Glycogen synthase kinase 3 beta 단백질 발현량은 GHEX가 CON과 비교할 때 감소하였다. 이러한 결과들은 벼메뚜기 분말을 섭취하면서 지구성 운동훈련을 하는 경우에 에너지 대사에 영향을 준다는 것을 제시하고 있다.

• 생명과학회지
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• 제17권12호
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• pp.1627-1633
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• 2007

c-Jun N-terminal kinase (JNK)-interacting protein 1(JIP1)은 비계단백질(scaffold protein)로서 신경 세포와 ??장${\beta}$세포에서 많이 발현된다. 본 연구에서는 배양한 흰쥐 해마신경세포에서 JIP1, JIP-2 및 JIP-3을 모두 인식하는 항체를 이용하여 이들의 세포내 표현을 조사하였다. 전반적으로 JIP은 세포체와 가지돌기에 반점 모양으로 표현되었다. 이 JIP 반점들을 통계적으로 분석한 결과 흥분성 연접후표지인 PSD95 및 ${\alpha}CaMKII$ 반점 과 각각 $54.8{\pm}4.0%$ 및 $94.1{\pm}4.5%$가 겹쳐졌다. 반면에 억제성 연접후표지인 그리신수용체 및 gephyrin 반점과는 각각 단지 $8.6{\pm}0.5%$ 및 $7.3{\pm}0.5%$만 겹쳐졌다. 한편 lipid raft의 표지인 flotillin 반점의 상당부분$(29.3{\pm}1.0%)$이 JIP 반점과 겹쳐졌다. 또한, JIP은 일부 가지돌기의 끝부분에 매우 강하게 발편되었으며 축삭에는 표현이 미미하였다. 이 결과들은 JIP 단백질이 흥분성 연접후구역, 일부 lipid raft, 그리고 일부 가지돌기 끝부분에 주로 위치함을 의미한다.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1159-1168
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• 2021

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.