Four flavonoids were isolated from Gynostemma pentaphyllum by chromatography methods and their structures were identified by MS and NMR spectra data as quercetin-3-O-( 2″,6″-di-α-L-rhamnosyl)-β-D-galactopyranoside( 1),quercetin-3-O-( 2″,6″-di-α-L-rhamnosyl)-β-D-glucopyranoside( 2),quercetin-3-O-( 2″-α-L-rhamnosyl)-β-D-galactopyranoside( 3),and quercetin-3-O-( 2″-α-L-rhamnosyl)-β-D-glucopyranoside( 4). Among them,compounds 1-3 were obtained from the Cucurbitaceae family for the first time.The four flavonoids showed potent antioxidant effects against the DPPH,·OH and ■radicals in vitro,especially for DPPH radical scavenging activity with the IC50 values of 71. 4,29. 5,48. 3 and 79. 2 μmol·L~(-1),respectively. Moreover,the four flavonoids displayed strong cytoprotection against AAPH-induced oxidative damage in LLC-PK1 cells by suppressing the increase of malondialdehyde( MDA) and the decrease of the superoxide dismutase( SOD) and glutathione( GSH). Since further research is needed to prove its efficacy in vivo and clinical trial,the study may provide four potential antioxidants from G. pentaphyllum.
Animals ; Antioxidants ; Flavonoids ; Gynostemma ; LLC-PK1 Cells ; Oxidative Stress ; Plant Extracts ; Quercetin ; Swine

After renal injury, selective damage occurs in the proximal tubules as a result of inhibition of glycolysis. The molecular mechanism of damage is not known. Poly(ADP-ribose) polymerase (PARP) activation plays a critical role of proximal tubular cell death in several renal disorders. Here, we studied the role of PARP on glycolytic flux in pig kidney proximal tubule epithelial LLC-PK1 cells using XFp extracellular flux analysis. Poly(ADP-ribosyl)ation by PARP activation was increased approximately 2-fold by incubation of the cells in 10 mM glucose for 30 minutes, but treatment with the PARP inhibitor 3-aminobenzamide (3-AB) does-dependently prevented the glucose-induced PARP activation (approximately 14.4% decrease in 0.1 mM 3-AB-treated group and 36.7% decrease in 1 mM 3-AB-treated group). Treatment with 1 mM 3-AB significantly enhanced the glucose-mediated increase in the extracellular acidification rate (61.1±4.3 mpH/min vs. 126.8±6.2 mpH/min or approximately 2-fold) compared with treatment with vehicle, indicating that PARP inhibition increases only glycolytic activity during glycolytic flux including basal glycolysis, glycolytic activity, and glycolytic capacity in kidney proximal tubule epithelial cells. Glucose increased the activities of glycolytic enzymes including hexokinase, phosphoglucose isomerase, phosphofructokinase-1, glyceraldehyde-3-phosphate dehydrogenase, enolase, and pyruvate kinase in LLC-PK1 cells. Furthermore, PARP inhibition selectively augmented the activities of hexokinase (approximately 1.4-fold over vehicle group), phosphofructokinase-1 (approximately 1.6-fold over vehicle group), and glyceraldehyde-3-phosphate dehydrogenase (approximately 2.2-fold over vehicle group). In conclusion, these data suggest that PARP activation may regulate glycolytic activity via poly(ADP-ribosyl)ation of hexokinase, phosphofructokinase-1, and glyceraldehyde-3-phosphate dehydrogenase in kidney proximal tubule epithelial cells.
Animals ; Cell Death ; Epithelial Cells* ; Glucose ; Glucose-6-Phosphate Isomerase ; Glycolysis ; Hexokinase ; Kidney* ; LLC-PK1 Cells ; Oxidoreductases ; Phosphofructokinase-1 ; Phosphopyruvate Hydratase ; Poly Adenosine Diphosphate Ribose* ; Poly(ADP-ribose) Polymerases* ; Pyruvate Kinase ; Swine

This study aimed to investigate the in vivo relevance of P-glycoprotein (P-gp) in the pharmacokinetics and adverse effect of phenformin. To investigate the involvement of P-gp in the transport of phenformin, a bi-directional transport of phenformin was carried out in LLC-PK1 cells overexpressing P-gp, LLC-PK1-Pgp. Basal to apical transport of phenformin was 3.9-fold greater than apical to basal transport and became saturated with increasing phenformin concentration (2-75 µM) in LLC-PK1-Pgp, suggesting the involvement of P-gp in phenformin transport. Intrinsic clearance mediated by P-gp was 1.9 µL/min while passive diffusion clearance was 0.31 µL/min. Thus, P-gp contributed more to phenformin transport than passive diffusion. To investigate the contribution of P-gp on the pharmacokinetics and adverse effect of phenformin, the effects of verapamil, a P-gp inhibitor, on the pharmacokinetics of phenformin were also examined in rats. The plasma concentrations of phenformin were increased following oral administration of phenformin and intravenous verapamil infusion compared with those administerd phenformin alone. Pharmacokinetic parameters such as Cmax and AUC of phenformin increased and CL/F and Vss/F decreased as a consequence of verapamil treatment. These results suggested that P-gp blockade by verapamil may decrease the phenformin disposition and increase plasma phenformin concentrations. P-gp inhibition by verapamil treatment also increased plasma lactate concentration, which is a crucial adverse event of phenformin. In conclusion, P-gp may play an important role in phenformin transport process and, therefore, contribute to the modulation of pharmacokinetics of phenformin and onset of plasma lactate level.
Administration, Oral ; Animals ; Area Under Curve ; Diffusion ; Intestinal Absorption ; Lactic Acid* ; LLC-PK1 Cells ; P-Glycoprotein* ; Pharmacokinetics ; Phenformin* ; Plasma* ; Rats ; Swine ; Verapamil

NTCP is specifically expressed on the basolateral membrane of hepatocytes, participating in the enterohepatic circulation of bile salts, especially conjugated bile salts, to maintain bile salts homeostasis. In addition, recent studies have found that NTCP is a functional receptor of HBV and HDV. Therefore, it is important to study the interaction between drugs and NTCP and identify the inhibitors/substrates of NTCP. In the present study, a LLC-PK1 cell model stably expressing human NTCP was established, which was simple and suitable for high throughput screening, and utilized to screen and verify the potential inhibitors of NTCP from 102 herbal medicinal ingredients. The results showed that ginkgolic acid (GA) (13 : 0), GA (15 : 1), GA (17 : 1), erythrosine B, silibinin, and emodin have inhibitory effects on NTCP uptake of TCNa in a concentration-dependent manner. Among them, GA (13 : 0) and GA (15 : 1) exhibited the stronger inhibitory effects, with IC50 values being less than 8.3 and 13.5 μmol·L(-1), respectively, than the classical inhibitor, cyclosporin A (CsA) (IC50 = 20.33 μmol·L(-1)). Further research demonstrated that GA (13 : 0), GA (15 : 1), GA (17 : 1), silibinin, and emodin were not substrates of NTCP. These findings might contribute to a better understanding of the disposition of the herbal ingredients in vivo, especially in biliary excretion.
Animals ; Drug Evaluation, Preclinical ; Humans ; Kinetics ; LLC-PK1 Cells ; Models, Biological ; Organic Anion Transporters, Sodium-Dependent ; antagonists & inhibitors ; chemistry ; metabolism ; Plant Extracts ; chemistry ; pharmacology ; Plants, Medicinal ; chemistry ; Structure-Activity Relationship ; Swine ; Symporters ; antagonists & inhibitors ; chemistry ; metabolism

BACKGROUND/OBJECTIVES: This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide (H2O2)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS: 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (*OH), and H2O2 scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against H2O2-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, *OH and H2O2 was greater than that of FSS and AHSS. FSeS also significantly inhibited H2O2-induced (500 microM) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P < 0.05). Following treatment with 100 microg/mL of FSeS and FSS to prevent H2O2-induced oxidation, cell viability increased from 56.7% (control) to 83.7% and 75.6%, respectively. However, AHSS was not able to reduce H2O2-induced cell damage (viability of the AHSS-treated cells was 54.6%). FSeS more effectively suppressed H2O2-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 H2O2-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity.
Animals ; Catalase ; Cats ; Cell Survival ; Glutathione Peroxidase ; Hydrogen Peroxide ; Hydrogen* ; Hydroxyl Radical ; Lipid Peroxidation ; LLC-PK1 Cells ; Oxidative Stress ; Reactive Oxygen Species ; RNA, Messenger ; Sesamum* ; Superoxide Dismutase ; Swine

BACKGROUND/OBJECTIVES: Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS: Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-PK1 cells. RESULTS: Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-kappaB p65, and IkappaB expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. CONCLUSION: The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.
Animals ; Cell Survival ; Cyclooxygenase 2 ; Fermentation* ; Functional Food ; Hydrogen-Ion Concentration ; Hydroxyl Radical ; Lipid Peroxidation ; LLC-PK1 Cells ; Methanol ; Nitric Oxide ; Nitric Oxide Synthase Type II ; Oxidative Stress* ; Superoxides ; Swine ; Vegetables

To establish a pig kidney cell line LLC-PK1/BCRP in which human breast cancer resistance protein was highly expressed, the expression vector pcDNA3.1(+)-BCRP which contained BCRP gene was constructed and transfected into LLC-PKI cells via liposomes. After selecting with G418, population doubling time, flow cytometry and Western blotting analysis were used to evaluate the cell line. MTT assays were employed to determine the drug resistance index of mitoxantrone and doxorubicin. Invert fluorescent microscope was used to observe the efflux of fluorescence dye Hoechst 33342 by BCRP, furthermore, the BCRP's inhibitor GF120918 was applied to reverse the efflux of Hoechst 33342. The experiment results showed that the expression of BCRP protein increased in LLC-PK1/BCRP cell. The population doubling time of LLC-PK1/BCRP cell was a little longer than that of the parental cell LLC-PK1. The resistance indexes to mitoxantrone and doxorubicin were 51.95 and 6.09 times, respectively, higher than LLC-PK1 cell. The efflux of Hoechst 33342 was significantly enhanced and could be reversed by GF120918. So a LLC-PK1/BCRP cell line was established, which highly expressed BCRP protein successfully. This cell line could be a valuable model to further investigate the biological profile of BCRP and select the substrate and inhibitor of BCRP.
ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Acridines ; pharmacology ; Animals ; Benzimidazoles ; metabolism ; Cell Cycle ; Cell Proliferation ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Genetic Vectors ; LLC-PK1 Cells ; cytology ; metabolism ; Mitoxantrone ; pharmacology ; Neoplasm Proteins ; genetics ; metabolism ; Plasmids ; Swine ; Tetrahydroisoquinolines ; pharmacology ; Transfection

Renal impairment is one of frequent and serious complications in patients with multiple myeloma (MM) and is associated with a higher incidence of infections and early death rate. The catalytic activity of Bence Jones proteins (BJP) affects the clinical processes of patients with MM, and can lead to renal impairment. Scientists point out that BJP have peptidolytic and nucleolytic activity, which can lead porcine kidney proximal tubule (LLC-PK1) to apoptosis in vitro experiments. By treating the cytotoxic BJP with serine protease inhibitor (DFP), BJP lost not only their catalytic activity, but also the cytotoxic effects. Therefore, further research on BJP will helpful to understand the pathogenesis of renal impairment in MM patients and may provide a new idea and measure for the treatment of MM with renal impairment. This article reviews the basic research and progress on the catalytic activity of BJP.
Animals ; Apoptosis ; Bence Jones Protein ; metabolism ; Humans ; Kidney ; pathology ; LLC-PK1 Cells ; Multiple Myeloma ; metabolism ; pathology ; Swine

This study was purposed to investigate the relationship between the catalysis of Bence Jones protein (BJP) in urine of patients with multiple myeloma(MM) and toxicity on the renal proximal tubular cells in vitro, and to explore the potential mechanism for the toxicity of BJP to renal impairment in patients with MM. The Michaelis-Menten constant (K(m)) and catalytic constant (k(cat)) of the amidase activity of BJP was calculated by Hanes equation. The LLC-PK1 cells were cultured with different concentration of BJP for 24 h, then proliferation of the cells were determined by MTT method and apoptosis were determined by flow cytometry. The results showed that the BJP from the MM patients with renal impairment significantly inhibited cell proliferation, as compared with that from MM patients without renal impairment. The BJP with higher k(cat) had higher toxicity to LLC-PK1 cells. BJP could induce apoptosis and necrosis of LLC-PK1 cells when reached a certain concentration and this effect enhanced with increase of BJP concentration. It is concluded that the catalysis of BJP and its toxicity to renal tubular epithelial cells has a positive correlation, and toxic effect of BJP on renal tubular epithelial cells results from inhibiting proliferation and inducing apoptosis and necrosis of the cells, which may be one of renal impairment mechanisms in MM patients.
Animals ; Bence Jones Protein ; metabolism ; toxicity ; Catalysis ; Coculture Techniques ; Epithelial Cells ; metabolism ; pathology ; Humans ; Kidney ; metabolism ; pathology ; Kidney Tubules ; cytology ; LLC-PK1 Cells ; Multiple Myeloma ; metabolism ; pathology ; Swine

OBJECTIVETo sift and identify the nephrotoxic components in Zexie for controlling the quality of the herb.

METHODThe fractions of zexie were prepared by Pre-HPLC, then the nephrotoxicity of the fraction was sifted using LLC-PK1 labelled with fluorescein diacetate and MTT assay. Finally, the compounds in the most obvious nephrotoxic fraction were identified with LC-MS.

RESULTUsing MTT and FDA assay, similar results were obtained. Fraction C13 was found to be the most toxic with FDA assay, in which three compounds, alisol C, 16, 23-oxido-alisol B and alisol O, were detected and characterized by multi -stage mass spectrometric analysis.

CONCLUSIONAlisol C, 16, 23-oxido-alisol B and alisol O in Zexie may cause nephrotoxicity.

Alisma ; chemistry ; toxicity ; Animals ; Chromatography, High Pressure Liquid ; Kidney ; drug effects ; LLC-PK1 Cells ; Mass Spectrometry ; Swine