• 한국식품영양과학회지
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• 제43권11호
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• pp.1674-1680
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• 2014

잡곡밥 메탄올 추출물이 가지는 산화적 스트레스 개선 효과를 확인하기 위하여 $H_2O_2$로 유도된 산화적 스트레스에 대한 LLC-PK1 세포의 보호 효과를 조사하였다. $250{\mu}M$의 $H_2O_2$에 의한 산화적 스트레스가 유발된 LLC-PK1 세포에 시료추출물을 처리한 결과, WR, TMR, GR 순으로 $H_2O_2$ 처리군에 비해 세포 생존율이 증가하였다(P<0.05). 특히 GRS와 GRK에서 정상군에 가까운 세포 생존율을 나타내어 $H_2O_2$에 의한 산화적 스트레스로 유발된 세포 손상에 대한 잡곡밥 추출물의 보호 효과를 확인할 수 있었다. 세포 내 활성산소(ROS)의 수준과 세포 내 지질과산화물질(MDA)의 생성 억제 효과 역시 WR, TMR, GR, GRK, GRS 순으로 증가하는 것을 관찰하였다. $H_2O_2$로 인하여 세포 내 항산화 효소인 SOD, CAT와 GSH-px 등의 활성이 감소된 LLC-PK1 세포에 잡곡밥 추출물을 처리했을 때 이들 효소의 활성이 증가했으며 특히 GRK, GRS군에서 현저하게 증가되었다. LLC-PK1 세포에서 $H_2O_2$에 의해 발생하는 산화적 스트레스에 대한 보호 효과를 측정한 결과 잡곡밥 추출물은 세포 손상을 억제하고 세포 내 활성산소(ROS)의 수준과 지질과산화물질(MDA)의 생성을 억제하며, 세포 내 항산화 효소의 활성을 증가시키는 효과를 가지는 것으로 보인다. 또한 항산화 효소유전자 발현에서도 위와 비슷한 효과를 나타내었다. 이상의 결과로 잡곡밥 메탄올 추출물, 특히 기능성 물질인 카레가루와 상황버섯 추출물이 첨가된 잡곡밥은 LLC-PK1 세포에 대한 보호 작용과 in vitro에서의 항산화 효과가 높은 것으로 확인되었다.

• Nutrition Research and Practice
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• 제8권2호
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• pp.138-145
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• 2014

BACKGROUND/OBJECTIVES: This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide ($H_2O_2$)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS: 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\bullet}OH$), and $H_2O_2$ scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against $H_2O_2$-induced oxidative damage in LLC-PK1 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation, and endogenous antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) were measured. RESULTS: The ability of FSeS to scavenge DPPH, $^{\bullet}OH$ and $H_2O_2$ was greater than that of FSS and AHSS. FSeS also significantly inhibited $H_2O_2$-induced ($500{\mu}M$) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P < 0.05). Following treatment with $100{\mu}g/mL$ of FSeS and FSS to prevent $H_2O_2$-induced oxidation, cell viability increased from 56.7% (control) to 83.7% and 75.6%, respectively. However, AHSS was not able to reduce $H_2O_2$-induced cell damage (viability of the AHSS-treated cells was 54.6%). FSeS more effectively suppressed $H_2O_2$-induced ROS generation and lipid peroxidation compared to FSS and AHSS (P < 0.05). Compared to the other sauces, FSeS also significantly increased cellular CAT, SOD, and GSH-px activities and mRNA expression (P < 0.05). CONCULUSIONS: These results from the present study suggest that FSeS is an effective radical scavenger and protects against $H_2O_2$-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity.

• Journal of Pharmaceutical Investigation
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• 제40권6호
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• pp.363-366
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• 2010

Identification of compounds that function as P-glycoprotein (P-gp) substrates or inhibitors can facilitate the selection and optimization of new drug candidates. The purpose of this study is to optimize the experimental conditions for in vitro P-gp assay using LLC-GA5 cells, which is a well-known transformant cell line derived by transfecting LLC-PK1 with human MDR1. The amount of rhodamine123 transported by the LLC-GA5 and LLC-PK1 cells was evaluated under the following experimental conditions: 3 different types of transport media, colchicine pretreatment or nontreatment of the cells in the culture media, and with and without poly-L-lysine coating of the culture plates. The assay sensitivity was found to considerably differ depending on the diluents used in the transport media. P-gp-mediated transport in LLC-GA5 cells was most clearly characterized in the Hanks' balanced salt solution based transport media. The sensitivity of P-gp-mediated transport was not changed by colchicine pretreatment or poly-L-lysine coating of the culture plates.

• Journal of Ginseng Research
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• 제42권1호
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• pp.75-80
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• 2018

Background: The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells. Methods: LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay. Results: Reduction in cell viability by $60{\mu}M$ FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 ($10{\mu}M$ and $50{\mu}M$). Conclusion: The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

• Preventive Nutrition and Food Science
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• 제18권1호
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• pp.18-22
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• 2013

To investigate radical scavenging effects and protective activities of bitter melon (Momordica charantia) against oxidative stress, in vitro and a cellular system using LLC-$PK_1$ renal epithelial cells were used in this study. The butanol (BuOH) fraction of bitter melon scavenged 63.4% and 87.1% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at concentrations of 250 and $500{\mu}g/mL$, respectively. In addition, the BuOH fraction of bitter melon effectively scavenged hydroxyl radicals (${\cdot}OH$). At all concentrations tested, the scavenging activity of the BuOH fraction was more potent than that of the positive control, ascorbic acid. Furthermore, under the LLC-$PK_1$ cellular model, the cells showed a decline in viability and an increase in lipid peroxidation through oxidative stress induced by pyrogallol, a generator of superoxide anion ($O_2{^-}$). However, the BuOH fraction of bitter melon significantly and dose-dependently inhibited cytotoxicity. In addition, 3-morpholinosydnonimine (SIN-1), a generator of peroxynitrite ($ONOO^-$) formed by simultaneous releases of nitric oxide and $O_2{^-}$, caused cytotoxicity in the LLC-$PK_1$ cells while the BuOH fraction of bitter melon ameliorated oxidative damage induced by $ONOO^-$. These results indicate that BuOH fraction of bitter melon has protective activities against oxidative damage induced by free radicals.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.311-318
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• 2005

Oxidative stress has been reported to elevate ceramide level during cell death. The purpose of the present study was to modulate cell death in relation to cellular glutathione (GSH) level and GST (glutathione S-transferase) expression by regulating the sphingolipid metabolism. LLC­PK1 cells were treated with H$_2$O$_2$ in the absence of serum to induce cell death. Subsequent to exposure to H$_2$O$_2$, LLC-PK1 cells were treated with desipramine, sphingomyelinase inhibitor, and N-acetylcysteine (NAC), GSH substrate. Based on comparative visual observation with H202-treated control cells, it was observed that 0.5 $\mu$M of desipramine and 25 $\mu$M of NAC exhibited about 90 and $95\%$ of cytoprotection, respectively, against H$_2$O$_2$-induced cell death. Desipramine and NAC lowered the release of LDH activity by 36 and $3\%$ respectively, when compared to $71\%$ in H$_2$O$_2$-exposed cells. Cellular glutathione level in 500 $\mu$M H202-treated cells was reduced to 890 pmol as compared to control level of 1198 pmol per mg protein. GST P1-1 expression was decreased in H$_2$O$_2$-treated cells compared to healthy normal cells. In conclusion, it has been inferred that H$_2$O$_2$-induced cell death is closely related to cellular GSH level and GST P1-1 expression in LLC-PK1 cells and occurs via ceramide elevation by sphingomyelinase activation.

• 대한한방내과학회지
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• 제32권1호
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• pp.56-67
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• 2011

Objectives : Recent etiological studies show that oxidative stress might play a major role in the diabetes and its complications. Mori Ramulus (MR) has been known to have antioxidative, anti-inflammatory and antidiabetic effects. The methanol extract of MR was tested for its effectiveness in LLC-PK1 cells exposed to high glucose. Methods : The cytoprotective effect of MR was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The antioxidative effect was measured in terms of generation amount of ${\cdot}O_2^-$ by 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), NO by 4,5-diaminofluorescein (DAF-2), $ONOO^-$ by dihydrorhodamine 123 (DHR 123) in the high glucose -treated LLC-$PK_1$ cells. Western blotting was performed using anti-AGE, anti-RAGE, anti-MAPKs(ERK1/2, JNK, p38), anti-PI3K, anti-Akt, and anti-NF-${\kappa}$B (p50, p65) respectively. Results : MR extract reduced cell death and inhibited the generation of ${\cdot}O_2^-$, NO, $ONOO^-$ in the high glucose-treated LLC-$PK_1$ cells. MR inhibited the expression of AGE, RAGE, MAPKs, PI3K, and Akt by means of decreasing NF-${\kappa}$B activation. MR also inhibited NF-${\kappa}$B activation itself. Conclusions : These results indicate MR has cytoprotective, antioxidative, and anti-inflammatory effects. Therefore it is suggested that MR might prevent and cure diabetes and its complications.

• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.35-43
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• 1997

Cis-dichlorodiammine platin${\mu}M$II (Cisplatin), an effective chemotherapeutic agent, induces acute renal failure by unknown mechanisms. To investigate direct toxic effects of cisplatin on the renal proximal tubular transport system, LLC-$PK_1$ cell line was selected as a cell model and the sugar transport activity was evaluated during a course of cisplatin treatment. Cells grown to confluence were treated with cisplatin for 60 min, washed, and then incubated for up to 5 days. At appropriate intervals, cells were tested for sugar transport activity using ${\alpha}-methyl-D-[^{14}C]glucopyranoside$ (AMG) as a model substrate. In cells treated with 100 ${\mu}M$ cisplatin, the AMG uptake was progressively impaired after 3 days. The viability of cells was not substantially changed with cisplatin of less than 100 ${\mu}M$, but it decreased markedly with 150 and 200 ${\mu}M$. In cisplatin-treated cells, the $Na^+$ -dependent AMG uptake was drastically inhibited with no change in the $Na^+$ -independent uptake. Kinetic analysis indicated that Vmax was suppressed, but Km was not altered. The $Na^+$ -dependent phlorizin binding was also decreased in cisplatin-treated cells. However, the AMG efflux from preloaded cells was not apparently retarded by cisplatin treatment. These data indicate that the cisplatin treatment impairs $Na^+$ -hexose cotransporters in LLC-$PK_1$ cells and suggest strongly that defects in transporter function at the luminal plasma membrane of the proximal tubular cells constitute an important pathogenic mechanism of cisplatin nephrotoxicity.

• Preventive Nutrition and Food Science
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• 제18권4호
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• pp.227-233
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• 2013

This study investigated the protective effect of the butanol (BuOH) fraction from fermented Laminaria japonica extract (BFLJ) on AAPH-induced oxidative stress in porcine kidney epithelial cells (LLC-PK1 cells). L. japonica was fermented by Aspergillus oryzae at $35{\pm}1^{\circ}C$ for 72 h. Freeze-dried fermented L. japonica was extracted with distilled water, and the extracted solution was mixed with ethanol and then centrifuged. The supernatant was subjected to sequential fractionation with various solvents. The BuOH fraction was used in this study because it possessed the strongest antioxidant activity among the various solvent fractions. The BuOH fraction of fermented L. japonica had a protective effect against the AAPH-induced LLC-PK1 cells damage and increased cell viability while reducing lipid peroxidation formation and increased activities of antioxidant enzymes such as superoxide dismutase and glutathione peroxidase. The inhibitory effect of BFLJ on lipid peroxidation formation had a higher value of $0.11{\pm}0.01nmol$ MDA at $100{\mu}g/mL$ concentration in comparison with intact BuOH fraction showing $0.22{\pm}0.08nmol$ MDA at the same concentration. Furthermore, BFLJ treatment increased glutathione concentration. GSH concentration in the cell treated with BFLJ of $100{\mu}g/mL$ was $1.80pmol/L{\times}10^5cells$. These results indicate that BFLJ protects the LLC-PK1 cells against AAPH-induced cell damage by inhibiting lipid peroxidation formation and increasing antioxidant enzyme activities and glutathione concentration.

• Environmental Analysis Health and Toxicology
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• 제9권1_2호
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• pp.25-35
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• 1994

Many nephrotoxic agents exert their effect primarily on the cells of the proximal tubules. We used the LLC-$PK_1$, kidney epithelial cell line as a model system for studies on nephrotoxicity and investigated whether the uptake of $\alpha$-methylglucose($\alpha$-MG) could serve as a parameter to assess effects of nephrotoxicants on the functional integrity of the cells at an early time of toxicity. The enzyme leakage test which has been used to be as a conventional cytotoxic parameter in vitro, was conducted to compare with $\alpha$-MG uptake. Treatment with cisplatin for 24 and 48 hours significantly increased activities of lactate dehydrogenase and $\gamma$-glutamyltransferase in culture medium at a concentration of 50$\mu$M. However, above 100$\mu$M of concentration, activities of these enzymes in media were dramatically decreased by cisplatin. These observations indicate that cisplatin has direct inhibitory effect on the activities of these enzymes and make it doutful to use enzyme leakage test to demonstrate damage of kidney cells by chemicals such as cisplatin over the appropriate range of concentration. Cisplatin inhibited $\alpha$-MG uptake at a low concentration which enzymes were not leaked. Also cadmium chloride and mercuric chloride which are acutely nephrotoxic in vivo, significantly inhibited $\alpha$-MG uptake at a low concentration. These results indicate that the uptake of $\alpha$-methylglucose in LLC-$PK_1$cell line is a useful biomarker for the study of nephrotoxicity.