• Journal of Life Science
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• v.17 no.7 s.87
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• pp.964-969
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• 2007

This study was carried out to investigate the effects of addition of pork fat, olive oil and soybean oil on the quality and sensory of ground pork meat. The samples consisted of the ground pork meat containing 20% pork fat (GP-P), 20% olive oil (GP-O), and 20% soybean oil (GP-S). The chemical composition, surface color, fatty acid composition, water hold-ing capacity, pH, VBN content and TBARS value were determined for the ground pork meat as the quality characteristics, and the sensory score were also evaluated. The moisture, crude protein, crude fat and crude ash content were not different among the GP-P, GP-O and GP-S. The $L^{*}$(lighaess), $a^{*}$(redness) and $b^{*}$(yellowness) of /GP-P were higher than those of the GP-O and GP-S (p<0.05). Palmitic acid was the most abundant among saturated fatty acids, and palmitic acid content of GP-P (24.384%)was higher than that of the GP-O (15.611%) and GP-5 (14.423%). In case of unsaturated fatty acids, oleic acid of GP-P (43.773%) and GP-O (65.040%) were the highest, linoleic. acid for GP-5 (40.762) was the highest. The water holding capacity of GP-P was higher than that of the GP-0 and GP-5, the pH of GP-S was higher than that of the GP-P and GP-O, and the VBN content and TBARS value of GP-P was higher than that of the GP-O and GP-5 (p<0.05). The raw color of GP-0 and GP-S were higher than that of the GP-P (p<0.05), however the raw aroma was not different among the samples. In case of roasted ground pork meat, the aroma was not different among the samples, the taste, texture and palatability or GP-S were the highest among the samples, and the juiciness of GP-O and GP-S were higher than that of the GP-P(p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.896-901
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• 2007

This study was carried out to investigate the effect of the addition of olive and soybean oil on the color, water holding capacity, cooking loss, increase rate of thickness, decrease rate of diameter, pH, VBN content and TBARS value of ground pork loin during cold storage for 15 days. Ground pork loin were prepared by three types such as ground pork loin containing 20% pork fat (GP-P), ground pork loin containing 20% olive oil (GP-O) and ground pork loin containing 20% soybean oil (GP-S). The $L^{\ast}$ (lightness) and $b^{\ast}$ (yellowness) value of GP-P, GP-O and GP-S were not significantly different during storage, and the $L^{\ast}$, $a^{\ast}$ and $b^{\ast}$ value of GP-P were higher than those of GP-O and GP-S (p<0.05). The water holding capacity tended to increase along with storage period, the water holding capacity of GP-P was higher than that of GP-O and GP-S. Also, the cooking loss of GP-P was lower than that of GP-O and GP-S (p<0.05). The increase rate of thickeness by cooking increased along with storage period, but the decrease rate of diameter was tend to decreased with increase in storage period (p<0.05). The pH of all ground pork loins decreased until storage at 5 days, but increased at 15 days (p<0.05). The VBN content of all ground pork loins increased along with storage period, and the VBN content of GP-P was higher than that of GP-O and GP-S (p<0.05). The TBARS value of all ground pork loins increased along with storage period; also, the VBN content of GP-P was the highest among all ground pork loins and GP-O was the lowest among all ground pork loins (p<0.05).

• Natural Product Sciences
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• v.20 no.1
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• pp.1-6
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• 2014

P-glycoprotein (P-gp) is a permeability glycoprotein also known as multidrug resistance protein 1 (MDR1). P-gp is an ATP-binding cassette (ABC) transporter that pumps various types of drugs out of cells. These transporters reduce the intracellular concentrations of drugs and disturb drug absorption. The Caco-2 cell permeability assay system is an effective in vitro system that predicts the intestinal absorption of drugs and the functions of enzymes and transporters. Rhodamine-123 (R-123) and digoxin are well-known P-gp substrates that have been used to determine the function of P-gp. Efflux of P-gp substrates by P-gp has been routinely evaluated. To date, a number of herbal medicines have been tested with Caco-2 cell permeability assay system to assess bioavailability. There are growing efforts to find phytochemicals that potentially regulate P-gp function. The Caco-2 cell permeability assay system is a primary strategy to search for candidates of P-gp inhibitors. In this mini review, we have summarized the P-gp modulation by herbal extracts, decoctions or single components from natural products using Caco-2 cell permeability assays. Many natural products are known to regulate P-gp and herbal medicines could be used in combination with conventional drugs to enhance bioavailability.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.131-135
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• 2007

A previous report recently demonstrated that ultrasound-induced hyperthermia (USHT:0.4 watts (W)/$cm^2$ at $41^{\circ}C$) could increase cellular uptake of P-glycoprotein (P-gp) substrates in P-gp expressing cancer cell lines. Since P-gp plays a major role in limiting drug permeability in the multi-drug resistant (MDR) cells, studies were conducted to elucidate the mechanism of USHT on cellular accumulation of P-gp and non-P-gp substrate in MDR cells. To accomplish this aim, we studied the effects of USHT on the accumulation of P-gp substrate, R123 and non-P-gp substrate, antipyrine in MDR cells. We demonstrated that USHT increased permeability of hydrophobic molecules (R123 and $[^{14}C]$-antipyrine). The enhanced permeability is reversible and size-dependent as USHT produces a much larger effect on cellular accumulation of $[^{14}C]$-antipyrine (MW 188) than that of R123 (MW 380.8). These results suggest that USHT could affect MDR cells more sensitive than BBMECs. Also, the present results point to the potential use of USHT to increase cellular uptake of P-gp recognized substrates, mainly anti-cancer agents into cancer cells.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.293-298
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• 2012

The purpose of this study was to investigate the modification of expression and functionality of the drug transporter P-glycoprotein (P-gp) by tumor necrosis factor-alpha (TNF-${\alpha}$) and interferon-gamma (IFN-${\gamma}$) at the blood-brain barrier (BBB). We used immortalized human brain microvessel endothelial cells (iHBMEC) and primary human brain microvessel endothelial cells (pHBMEC) as in vitro BBB model. To investigate the change of p-gp expression, we carried out real time PCR analysis and Western blotting. To test the change of p-gp activity, we performed rhodamin123 (Rh123) accumulation study in the cells. In results of real time PCR analysis, the P-gp mRNA expression was increased by TNF-${\alpha}$ or IFN-${\gamma}$ treatment for 24 hr in both cell types. However, 48 hr treatment of TNF-${\alpha}$ or IFN-${\gamma}$ did not affect P-gp mRNA expression. In addition, co-treatment of TNF-${\alpha}$ and IFN-${\gamma}$ markedly increased the P-gp mRNA expression in both cells. TNF-${\alpha}$ or IFN-${\gamma}$ did not influence P-gp protein expression whatever the concentration of cytokines or duration of treatment in both cells. However, P-gp expression was increased after treatments of both cytokines together in iHBMEC cells only compared with untreated control. Furthermore, in both cell lines, TNF-${\alpha}$ or IFN-${\gamma}$ induced significant decrease of P-gp activity for 24 hr treatment. And, both cytokines combination treatment also decreased significantly P-gp activity. These results suggest that P-gp expression and function at the BBB is modulated by TNF-${\alpha}$ or/and IFN-${\gamma}$. Therefore, the distribution of P-gp depending drugs in the central nervous system can be modulated by neurological inflammatory diseases.

• Journal of Life Science
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• v.18 no.9
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• pp.1244-1248
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• 2008

P-glycoprotein (P-gp) is a very important drug transporter, which plays an important role in drug disposition and represents an additional mechanism for the development of multidrug resistance. Flavonoids, a major class of natural compounds widely present in foods and herbal products, have been shown to be P-gp inhibitors. The objective of the present study was to identify new chemosensitizer candidates through the screening of various herbal extracts. The inhibitory effects of herbal extracts on P-gp activity were assessed by measuring accumulation of calcein AM using P-gp overexpressed L-MDR1 cells. Curcuma longa showed the most potent inhibition on P-gp function. The inhibitory potential of P-gp was in the order: Curcuma longa > Curcuma aromatica > Ageratum conizoids > Zanthoxylum planispinum > Zedoariae rhizome > Rakta chandan > Dalbergia odorifera > Caesalpinia Sappan > Aloe ferox. To identify individual constituents with inhibitory activity, the herbal extracts were analyzed by LC/MS/MS. Several flavonoids such as curcumin, a well-known P-gp inhibitor, were identified through mass spectral library search. These in vitro data indicate that herbal extracts contain constituents that can potently inhibit the activities of P-gp and suggest that these herbal extracts should be examined for potential chemosensitizer in vivo.

• Biomolecules & Therapeutics
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• v.24 no.2
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• pp.199-205
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• 2016

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 ($2-75{\mu}M$) in LLC-PK1-Pgp, suggesting the involvement of P-gp in phenformin transport. Intrinsic clearance mediated by P-gp was $1.9{\mu}L/min$ while passive diffusion clearance was $0.31{\mu}L/min$. 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 $C_{max}$ 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.

• Journal of Pharmaceutical Investigation
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• v.36 no.5
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• pp.315-320
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• 2006

Silymarin showed P-glycoprptein(P-gp) inhibitory activity as much as verapamil, a well-known P-gp inhibitor, by decreasing $IC_{50}$ value of daunomycin(DNM)($16.0{\pm}0.7{\mu}M$), increasing the DNM accumulation($224.9{\pm}3.2%$), and decreasing DNM efflux($58.5{\pm}6.7%$), concurrently. In this study, we clarified the mechanism of action of silymarin for P-gp inhibitory function. First, silymarin may bind to the ATP-binding site and thus, prevent ATP hydrolysis. Second, the P-gp inhibitory activity of silymarin is not related to changing the cellular P-gp level. Third, the cytotoxicity of silymarin was increased in the presence of verapamil, reflecting that silymarin is a competent P-gp substrate against verapamil in the P-gp-overexpressed adriamycin-resistant MCF-7 breast cancer(MCF-7/ADR) cells. Conclusively, silymarin had the P-gp inhibitory activity through the action of competent binding to the P-gp substrate-binding site. Therefore, silymarin can be a good candidate for safe and effective MDR reversing agent in clinical chemotherapy by administering concomitantly with anticancer drugs.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6039-6045
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• 2012

This study was conducted to assess the predictive value of p-glycoprotein (p-gp) and p53 immunoexpression in human papillomavirus (HPV) infected cases of cervical dysplasia. Expression of both p-gp and p53 proteins was detected in cervical smears from 177 squamous intraepithelial lesions (SIL) cases along with 183 "atypical squamous cells of unknown significance" (ASCUS) and 150 normal cases. HPV 16 and 18 infection was detected by polymerase chain reaction using type-specific primers for HPV sub-types. There were no significant detectable p53 and p-gp expression in the normal cervix smears (p>0.05). In the ASCUS group 10 cases were positive for both p53 and p-gp immunoreactivity. In cervical dysplasia cases, p53 was positive in 86 (48.58%) while p-gp was positive in 93 (52.54%) and the two markers showed a highly significant correlation (r=0.92, p<0.001). Expression of p53 and p-gp was associated with grade of SIL (p<0.001). A positive correlation between the presence of HPV and expression of proteins p53 and p-gp in smears of patients with cervical lesions was also noted (p<0.001). Thus, p53 and p-gp immunostaining in cervical smears may act as an auxiliary biomarker for detection of HPV-associated cervical lesions. Additionally, a significant positive correlation between ascending grades of SIL and labeling indices of markers suggests that p53 and p-gp can be used as an adjunct to cytomorphological interpretation of conventional cervical Pap smears.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1303-1310
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• 2014

A 12 week growth study was carried out to investigate the supplemental effects of dietary garlic powder (GP) on growth, feed utilization and whole body composition changes of fingerling sterlet sturgeon Acipenser ruthenus (averaging weight, 5.5 g). Following a 24-h fasting, 540 fish were randomly distributed to each of 18 tanks (30 fish/tank) under a semi-recirculation freshwater system. The GP of 0.5% (GP0.5), 1% (GP1), 1.5% (GP1.5), 2% (GP2) and 3% (GP3) was added to the control diet (GP0) containing 43% protein and 16% lipid. After the feeding trial, weight gain (WG) of fish fed GP1.5, GP2 and GP3 were significantly higher (p<0.05) than those of fish fed GP0, GP0.5 and GP1. Feed efficiency and specific growth rate (SGR) showed a similar trend to WG. Protein efficiency ratio of fish fed GP1.5, GP2, and GP3 were significantly higher (p<0.05) than those of fish groups fed the other diets. A significant difference (p<0.05) was found in whole body composition (moisture, crude protein, crude lipid, ash, and fiber) of fish at the end of the experiment. Significantly higher (p<0.05) protein and lipid retention efficiencies (PRE and LRE) were also found in GP1.5, GP2, and GP3 groups. Broken-line regression model analysis and second order polynomial regression model analysis relation on the basis of SGR and WG indicated that the dietary optimal GP level could be greater than 1.77% and 1.79%, but less than 2.95% and 3.18% in fingerling sterlet sturgeon. The present study suggested that dietary GP for fingerling sterlet sturgeon could positively affect growth performance and protein retention.