• 한방비만학회지
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• 제19권1호
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• pp.1-11
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• 2019

Objectives: The purpose of the present study was to evaluate the preventive effects of ethanol extract of Polygalae radix (EEPR) against oxidative stress (hydrogen peroxide, $H_2O_2$)-induced DNA damage and apoptosis in Chang liver cells. Methods: Chang liver cells were pretreated with various concentrations of EEPR and then challenged with 0.5 mM $H_2O_2$. The cell viability and apoptosis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis, respectively. The levels of reactive oxygen species (ROS), mitochondrial membrane potentials (MMPs) and adenosine tri-phosphate (ATP) contents were measured. Expression levels of Bcl-2 and Bax were also determined using Western blot analysis. Results: The results showed that the decreased survival rate induced by $H_2O_2$ could be attributed to the induction of DNA damage and apoptosis accompanied by the increased production of ROS, which was remarkably protected by EEPR. In addition, the loss of $H_2O_2$-induced MMPs and ATP contents was significantly attenuated in the presence of EEPR. The inhibitory effect of EEPR on $H_2O_2$-induced apoptosis was associated with up-regulation of Bcl-2 and down-regulation of Bax, thus reducing the Bax/Bcl-2 ratio. Conclusions: Our data prove that EEPR protects Chang liver cells against $H_2O_2$-induced DNA damage and apoptosis by scavenging ROS and thus suppressing the mitochondrial-dependent apoptosis pathway.

• 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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• 제34권10호
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• pp.701-712
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• 2024

후코이단(fucoidan)은 갈조류에서 발견되는 다당류로, 면역 증강, 항암, 항염증 등 다양한 생리 활성을 나타내는 것으로 알려져 있다. 본 연구에서는 조골세포(osteoblast)와 유사한 생물학적 특성을 지닌 MC3T3-E1 세포에서 최종당산화물에 의해 유도되는 세포와 미토콘드리아 손상, 조골세포 분화, 조골 및 파골 활동성의 변화에 미치는 후코이단의 효과를 관찰하였다. 최종당산화물로 처리한 세포군에서는 MTT 환원능의 감소와 함께 카스파아제(caspase)의 활성화, 세포 사멸의 증가가 관찰되었다. 후코이단을 사전 처리하면 최종당산화물에 의한 이들 세포 손상 지표들이 현저히 완화되었다. 후코이단은 또한 최종당산화물에 의해 유도된 미토콘드리아 막 전위 감소, 세포 내 ATP 고갈, 미토콘드리아 막 투과성 전이(mitochondrial permeability transition) 형성을 유의하게 억제하여, 미토콘드리아의 기능적 손상을 완화하는 효과를 보였다. 최종당산화물로 처리한 세포군에서는 반응성 산소종(reactive oxygen species)과 과산화 지질 및 과산화 단백의 생성이 현저히 증가하였으며, 후코이단은 이를 유의하게 억제하였다. 조골세포 분화능의 지표로 뼈형태발생단백-2(bone morphogenetic protein, BMP2), 알칼리 인산분해효소(alkaline phosphatase, ALP), 오스테오칼신 (osteocalcin, OC), 제1형 콜라젠(collagen-I, Col-I)의 mRNA 발현 정도를 정량 실시간 역전사 중합효소 연쇄반응(qRT-PCR) 검사로 분석한 결과 최종당산화물로 처리 시 이들 mRNA들의 발현이 현저히 감소하였으며, 후코이단은 이들 지표 mRNA들의 발현 감소를 유의하게 차단하였다. 조골 활동성(osteogenic activity)의 지표로 알칼리 인산분해효소 활성과 무기질 침착을 측정한 결과도 mRNA 발현의 변화와 일치하는 결과를 보였다. 반면에 파골 활동성(osteoclastic activity)을 나타내는 지표들인 인터루킨-6(interleukin-6)와 NF-kB 리간드 수용체 활성 인자(receptor activator of NF-kB ligand, RANKL)의 분비는 최종당산화물로 처리한 세포군에서 증가하였으며, 후코이단은 이를 유의하게 억제하였다. 이상의 결과를 종합하면 후코이단은 MC3T3-E1 세포에서 최종당산화물에 의해 유도되는 세포 및 미토콘드리아 손상과 조골세포 분화 저해, 조골 활동성 저하를 완화하는 효과를 나타내는 것으로 사료된다.

• Molecules and Cells
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• 제38권12호
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• pp.1054-1063
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• 2015

Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth phenotype, mitochondrial membrane potential (MMP), and intracellular ATP and mitochondrial superoxide levels of 33 single ETC component-deleted strains during the chronological aging process. Among the ETC mutant strains, 14 ($sdh1{\Delta}$, $sdh2{\Delta}$, $sdh4{\Delta}$, $cor1{\Delta}$, $cyt1{\Delta}$, $qcr7{\Delta}$, $qcr8{\Delta}$, $rip1{\Delta}$, $cox6{\Delta}$, $cox7{\Delta}$, $cox9{\Delta}$, $atp4{\Delta}$, $atp7{\Delta}$, and $atp17{\Delta}$) showed a significantly shorter life span. The deleted genes encode important elements of the ETC components succinate dehydrogenase (complex II) and cytochrome c oxidase (complex IV), and some of the deletions lead to structural instability of the membrane-$F_1F_0$-ATP synthase due to mutations in the stator stalk (complex V). These short-lived strains generated higher superoxide levels and produced lower ATP levels without alteration of MMP. In summary, ETC mutations decreased the life span of yeast due to impaired mitochondrial efficiency.

• The Korean Journal of Physiology and Pharmacology
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• 제24권5호
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• pp.403-412
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• 2020

Diabetic nephropathy (DN) is a hyperglycemia-induced progressive development of renal insufficiency. Excessive glucose can increase mitochondrial reactive oxygen species (ROS) and induce cell damage, causing mitochondrial dysfunction. Our previous study indicated that cilostazol (CTZ) can reduce ROS levels and decelerate DN progression in streptozotocin (STZ)-induced type 1 diabetes. This study investigated the potential mechanisms of CTZ in rats with DN and in high glucose-treated mesangial cells. Male Sprague-Dawley rats were fed 5 mg/kg/day of CTZ after developing STZ-induced diabetes mellitus. Electron microscopy revealed that CTZ reduced the thickness of the glomerular basement membrane and improved mitochondrial morphology in mesangial cells of diabetic kidney. CTZ treatment reduced excessive kidney mitochondrial DNA copy numbers induced by hyperglycemia and interacted with the intrinsic pathway for regulating cell apoptosis as an antiapoptotic mechanism. In high-glucose-treated mesangial cells, CTZ reduced ROS production, altered the apoptotic status, and down-regulated transforming growth factor beta (TGF-β) and nuclear factor kappa light chain enhancer of activated B cells (NF-κB). Base on the results of our previous and current studies, CTZ deceleration of hyperglycemia-induced DN is attributable to ROS reduction and thereby maintenance of the mitochondrial function and reduction in TGF-β and NF-κB levels.

• Molecules and Cells
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• 제46권6호
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• pp.374-386
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• 2023

Thermal stress induces dynamic changes in nuclear proteins and relevant physiology as a part of the heat shock response (HSR). However, how the nuclear HSR is fine-tuned for cellular homeostasis remains elusive. Here, we show that mitochondrial activity plays an important role in nuclear proteostasis and genome stability through two distinct HSR pathways. Mitochondrial ribosomal protein (MRP) depletion enhanced the nucleolar granule formation of HSP70 and ubiquitin during HSR while facilitating the recovery of damaged nuclear proteins and impaired nucleocytoplasmic transport. Treatment of the mitochondrial proton gradient uncoupler masked MRP-depletion effects, implicating oxidative phosphorylation in these nuclear HSRs. On the other hand, MRP depletion and a reactive oxygen species (ROS) scavenger non-additively decreased mitochondrial ROS generation during HSR, thereby protecting the nuclear genome from DNA damage. These results suggest that suboptimal mitochondrial activity sustains nuclear homeostasis under cellular stress, providing plausible evidence for optimal endosymbiotic evolution via mitochondria-to-nuclear communication.

• 한국식품영양과학회지
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• 제14권2호
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• pp.145-150
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• 1985

지의류(lichens) 수용성 추출물에 약리적인 효과를 알기위해 $CCl_4$로 흰쥐의 간손상을 유도시킨 후 단기간, 장기간 사육시켜서 간장조직의 mitochondrial respiration측정을 하였고 간장조직내의 lactate, malate와 fumarate glutamate, 혈청 glucose 및 간장조직의 glucose-6-phosphatase의 활성도를 측정하였다. 그 결과 급성 만성의 간장애를 받은 쥐에서 4가지호흡지수(state 3 respiration P/O ratio, respiratory control, 합성된 ATP)로 측정된 mitochondrial respiration 기능이 지의류(lichens) 추출물을 섭취한 실험군이 대조군 보다 높았고, serum glucose, 간장내의 lactate, glutamate, malate와 fumarate및 glucose-6-phosphatase 활성도 실험군이 높은값을 나타내었다. 이것으로 지의류추출물은 간장조직의 mitochondrial respiration에 대해 보호작용과 해당과정을 촉진하는 작용이 있다는 것으로 추정된다.

• 셀메드
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• 제3권1호
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• pp.9.1-9.10
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• 2013

In traditional systems of medicine including homeopathy, the Condurango extract (Con) is often used to cure stomach cancer mainly, without having any scientific validation of its anti-cancer ability. Con has therefore been tested against non-small-cell lung cancer cells (NSCLC) A549 and NCI-H522 (H522) known to contain the KRAS mutation, making them resistant to most chemotherapeutic agents. As cancer cells generally defy cytotoxicity developed by chemopreventive agents and escape cell death, any drug showing the capability of preferentially killing cancer cells through apoptosis is worth consideration for judicious application. A549 and H522 cells were exposed to $0.35{\mu}g/{\mu}l$ and $0.25{\mu}g/{\mu}l$ of Con, respectively, for 48 h and analysed based on various protocols associated with apoptosis and DNA damage, such as MTT assay to determine cell viability, LDH assay, DNA fragmentation assay, comet assay, and microscopical examinations of DNA binding fluorescence stains like DAPI, Hoechst 33258 and acridine orange/ethidium bromide to determine the extent of DNA damage made in drug-treated and untreated cells and the results compared. Changes in mitochondrial membrane potential and the generation of reactive oxygen species were also documented through standard techniques. Con killed almost 50% of the cancer cells but spared normal cells significantly. Fluorescence studies revealed increased DNA nick formation and depolarized membrane potentials after drug treatment in both cell types. Caspase-3 expression levels confirmed the apoptosis-inducing potential of Con in both the NSCLC lines. Thus, overall results suggest considerable anticancer potential of Con against NSCLC in vitro, validating its use against lung cancer by practitioners of traditional medicine including homeopathy.

• 대한한방내과학회지
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• 제42권6호
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• pp.1269-1284
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• 2021

Objectives: Phragmitis Rhizoma is the fresh or dried rhizome of Phragmites communis Trin., which has been prescribed in traditional Korean medicine to relieve fever and vomiting and to nourish the body fluids. Recently, the protective effect of Phragmitis Rhizoma extract or its components on myelotoxicity and inflammatory responses have been reported, but no study has yet been conducted on oxidative stress. Methods: The present study investigated whether an ethanol extract of Phragmitis Rhizoma (PR) could protect against cellular damage induced by oxidative stress in Chang liver cells. Results: Pretreatment with PR significantly suppressed the hydrogen peroxide (H₂O₂)-induced reduction of Chang cell viability and generation of reactive oxygen species (ROS), thereby deferring apoptosis. PR also markedly inhibited H₂O₂-induced comet tail formation and phospho-γH2AX expression, suggesting that PR protected against oxidative stress-mediated DNA damage. PR also effectively prevented the inhibition of ATP synthesis in H₂O₂-treated Chang cells by inhibiting the loss of mitochondrial membrane potential, indicating that PR maintains energy metabolism through preservation of mitochondrial function while eliminating ROS generated by H₂O₂. Immunoblotting results indicated that PR attenuated the H₂O₂-induced downregulation of Bcl-2 and upregulation of Bax expression. Conclusions: PR protects against oxidative injury in Chang liver cells by regulating energy homeostasis via ROS generation blockade, which is at least partly mediated through inactivation of the mitochondria-mediated apoptosis pathway.

• 동의생리병리학회지
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• 제28권4호
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• pp.379-383
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• 2014

The purpose of this study is to investigate the effects of silkworm extracts (SWE) on reactive oxygen species formation in mice (C57BL/6). Mice were administrated intraperitoneally with SWE (20 mg/kg/day) for 14 days. All animals were sacrificed 24 hours after the last SWE treatment and then extracted the blood and brain tissue in mouse. The researcher measured several parameters related to reactive oxygen species formation, malondialdehyde (MDA) and hydrogen peroxide ($H_2O_2$) contents in serum, whole brain, cerebral cortex and cerebellum. The results showed that MDA content of pre-SWE treatment was decreased significantly in serum, mitochondrial and cytosolic fraction of whole brain and cerebellum (P<0.01). The $H_2O_2$ content of pre-SWE treatment was decreased significantly in mitochondrial fraction of whole brain, cerebral cortex and cerebellum (P<0.01). These results suggest that SWE plays an important role for inhibition of oxidative damage of cells as well as antioxidant effect, aging delay and cells protected from irradiation.