• Title/Summary/Keyword: Pharmaceutics

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Isomeric Folate-Conjugated Polymeric Micelles Bind to Folate Receptors and Display Anticancer Effects

  • Dong, Qing;Xie, Zuo-Xu;Xie, Cao;Lu, Wei-Yue;Zhang, Qian;Li, Xue;Liu, Min
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7363-7369
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    • 2014
  • The present study aimed to prepare and evaluate polymeric micelles conjugated with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups for antitumor efficacy. The isomeric block copolymers, ${\alpha}$- and ${\gamma}$-folate-polyethyleneglycol-distearoyl phosphatidylethanolamine (${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE), were produced by solid phase peptide synthesis. Three types of doxorubicin (DOX)-loaded polymeric micelles (MPEG-DSPE-DOX and ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPEDOX micelles) were prepared via the film formation method. Compared with MPEG-DSPE-DOX micelles, the ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPE-DOX micelles presented a higher cellular uptake behavior in the live cell study. Cell viability percentages were 81.8%, 57.3%, 56.6% at 2 hours for MPEG-DSPE-DOX, ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles, respectively (p<0.05). Using the KB xenograft tumor model, both ${\alpha}$- and ${\gamma}$-folate-conjugated micelles were found to have better antitumor effects with lower toxicity in comparison with MPEG-DSPE-DOX micelles. No difference in in vivo antitumor efficacy was found between ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles. The folate-conjugated micelles might be a potentially useful strategy for tumor targeting of therapeutic agents, whether grafting with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups.

Modulation of Activator Protein-1 (AP-1) and MAPK Pathway by Flavonoids in Human Prostate Cancer PC3 Cells

  • Gopalakrishnan, Avanthika;Xu, Chang-Jiang;Nair, Sujit S.;Chen, Chi;Hebbar, Vidya;Kong, Ah-Ng Tony
    • Archives of Pharmacal Research
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    • v.29 no.8
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    • pp.633-644
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    • 2006
  • In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with $20\;{\mu}M$ concentrations of quercetin, chrysin and genistein and $50\;{\mu}M$ concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration $(500\;{\mu}M)$, cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

Macromolecular Cytosolic Delivery: Cell Membranes as the Primary Obstacle

  • Larson, Gretchen M.;Lee, Kyung-Dall
    • Archives of Pharmacal Research
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    • v.21 no.6
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    • pp.621-628
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    • 1998
  • The "evolution" of a thing, a custom, an organ is thus by no means its progressus toward a goal, even less a logical progressus by the shortest route and with the least expendit ure of force, but a succession of more or less profound, mutually independent processes of subduing, plus the resistances they encounter, the attempts at transformation for the purpose of defense and reaction, and the results of successful counteractions. The form is fluid, but the "meaning" is even more so (Friedrich W. Nietzsche).

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Validation Process of HPLC Assay Methods of Drugs in Biological Samples (생체시료내 약물의 HPLC 분석법에 대한 유효성 검토방법)

  • Chi, Sang-Cheol;Jun, H.-Won
    • Journal of Pharmaceutical Investigation
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    • v.21 no.3
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    • pp.179-188
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    • 1991
  • An HPLC assay method of a drug to be applied to the pharmacokinetic studies of the drug should be completely validated. The validation process for an HPLC assay method in a biological sample was discussed using the data obtained from the development of HPLC method for the simultaneous quantitation of verapamil and norverapamil in human serum. The validation criteria included were specificity, linearity, accuracy, precision, sensitivity, recovery, drug stability, and ruggedness of an assay method.

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Signal Transduction Events Elicited by Natural Products: Role of MAPK and Caspase Pathways in Homeostatic Response and Induction of Apoptosis

  • Kong, Ah-Ng Tony;Yu, Rong;Chen, Chi;Mandlekar, Sandhya;Primiano, Thomas
    • Archives of Pharmacal Research
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    • v.23 no.1
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    • pp.1-16
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    • 2000
  • Many natural products elicit diverse pharmacological effects. Using two classes of potential chemopreventive compounds, the phenolic compounds and the isothiocyanates, we review the potential utility of two signaling events, the mitogen-activated protein kinases (MAPKs) and the ICE/Ced-3 proteases (caspases) stimulated by these agents in mammalian cell lines. Studies with phenolic antioxidants (BHA, tBHQ), and natural products (flavonoids; EGCG, ECG, and isothiocyanates; PEITC, sulforaphane), provided important insights into the signaling pathways induced by these compounds. At low concentrations, these chemicals may activate the MAPK (ERK2, JNK1, p38) leading to gene expression of survival genes (c-Fos, c-Jun) and defensive genes (Phase II detoxifying enzymes; GST, QR) resulting in survival and protective mechanisms (homeostasis response). Increasing the concentrations of these compounds will additionally activate the caspase pathway, leading to apoptosis (potential cytotoxicity). Further increment to suprapharmacological concentrations will lead to nonspecific necrotic cell death. The wider and narrow concentration ranges between the activation of MAPK/gene induction and caspases/cell death exhibited by phenolic compounds and isothiocyanates, respectively, in mammalian cells, may reflect their respective therapeutic windows in vivo. Consequently, the studies of signaling pathways elicited by natural products will advance our understanding of their efficacy and safety, of which many man become important therapeuitc drugs of the future.

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Effect of Nitric Oxide on the Sinusoidal Uptake of Organic Cations and Anions by Isolated Hepatocytes

  • Song, Im-Sook;Lee, In-Kyoung;Chung, Suk-Jae;Kim, Sang-Geon;Lee, Myung-Gull;Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.25 no.6
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    • pp.984-988
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    • 2002
  • The issue of whether or not the presence NOx (NO and oxidized metabolites) in the hepatocytes at pathological levels affects the functional activity of transport systems within the sinusoidal membrane was investigated. For this purpose, the effect of the pretreatment of isolated hepatocytes with sodium nitroprusside (SNP), a spontaneous NO donor, on the sinusoidal uptake of tributylmethylammonium (TBuMA) and triethylmethyl ammonium (TEMA), representative substrates of the organic cation transporter (OCT), and taurocholate, a representative substrate of the $Na^+$/taurocholate cotransporting polypeptide (NTCP), was measured. The uptake of TBuMA and TEMA was not affected by the pretreatment, as demonstrated by the nearly identical kinetic parameters for the uptake ($i.e., V_{max}, K_{m} and CL_{linear}$). The uptake of mannitol into hepatocytes was not affected, demonstrating that the membrane integrity remained constant, irregardless of the SNP prutreatment. On the contrary, the uptake of taurocholate was significantly inhibited by the pretreatment, resulting in a significant decrease in V_{max}$, thus providing a clear demonstration that NOx preferentially affects the function of NTCP rather than OCT on the sinusoidal membrane. A direct interaction between NOx and NTCP or a decrease in $Na^+/K^+$ ATPase activity as the result of SNP pretreatment might be responsible for this selective effect of NOx.

Role of hyperforin in diabetes and its associated hyperlipidemia in rats

  • Ineedi, Srikanth;Shakya, Anshul;Singh, Gireesh Kumar;Kumar, Vikas
    • CELLMED
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    • v.2 no.3
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    • pp.25.1-25.6
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    • 2012
  • The aim of the present study was to evaluate the possible roles of hyperforin against hyperglycemia, hyperlipidemia and oxidative stress in streptozotocin-induced diabetic rats. Diabetes was induced by a single intraperitoneal injection of streptozotocin (65 mg/kg). Biochemical parameters were measured following hyperforin treatment (10 mg/kg, i.p.) for 7 days. Hyperforin treatment significantly reversed the elevations in plasma glucose, triglycerides, total cholesterol and LDL-cholesterol. Hyperforin also reversed the declines in plasma HDL-cholesterol and liver glycogen, but did not reverse the change in plasma insulin levels when compared to the diabetic control rats. Hyperforin treatment also reversed the oxidative stress induced by streptozotocin. Moreover, the effect of the hyperforin on peripheral glucose utilization in normal rats was evaluated by an oral glucose tolerance test (OGTT). Hyperforin treatment significantly increased (p < 0.05) the glucose tolerance compared to the vehicle in OGTT. The antihyperglycemic, antihyperlipidemic and antioxidant activities of hyperforin (10 mg/kg, i.p.) were comparable qualitatively to glibenclamide (1 mg/kg, p.o.). In conclusion, we report for the first time through an in vivo study that hyperforin is potentially valuable for the treatment of diabetes and its associated hyperlipidemia and oxidative stress by enhancing the glucose utilization by peripheral tissues such as muscle and adipose tissues.

HPLC Assay and Renal Excretion Characteristics of Theophylline and Its Metabolites in Rat (테오필린과 그 대사체의 HPLC 동시 정량 및 신(腎) 배설 특성)

  • Kuh, Hyo-Jeong;Shim, Chang-Koo;Lee, Min-Hwa;Kim, Shin-Keun
    • Journal of Pharmaceutical Investigation
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    • v.21 no.1
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    • pp.33-41
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    • 1991
  • A high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of theophylline(TP) and its metabolites, 1-methyluric acid (1-MU) and 1,3-dimethyluric acid (1,3-DMU), in rat plasma and urine. An $100\;{\mu}l$ aliquot of a plasma or urine sample was mixed with $250\;{\mu}l$ of acetonitrite and vortexed. After centrifugation, $200\;{\mu}l$ (plasma) or $20\;{\mu}l$ (urine) aliquot of the supernatant was dried by $N_2$ stream and redissolved in $100\;{\mu}l$ (plasma) or $200\;{\mu}l$ (urine) of the mobile phase. A $20\;{\mu}l$ of the mobile phase solution was injected onto a $C_{18}$ reversed-phase column. The column was maintained at $45^{\circ}C$ by the aid of electric heating jacket. The mobile phase was a 3%(v/v) methanol solution in deionized water which contains sodium acetate (100 mM) and tetrabutyl ammonium hydroxide (4 mM). pH of the mobile phase was adjusted 4.5 by the addition of acetic acid. Detection limits for TP, 1-MU, and 1,3-DMU in plasma were 0.2, 0.1 and $0.1\;{\mu}/ml$, respectively and the corresponding values in urine were all $5\;{\mu}g/ml$. Inter- and intra-day variability of the assay for all compounds in the plasma samples was less than 5.5 and 3.8%, respectively. The retention times for 1-MU, 1,3-DMU, and TP were approximately 7, 8.5 and 18 min, respectively. Sample preparation procedure used in this method was simple, rapid and reproducible. Renal clearance of TP and its metabolites in rats showed plasma concentration dependency indicating renal tubular secretion and reabsorption of them.

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Estimating the Burden of Cancers Attributable to Smoking Using Disability Adjusted Life Years in Indonesia

  • Kristina, Susi Ari;Endarti, Dwi;Sendjaya, Natalia;Pramestuty, Octy
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1577-1581
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    • 2016
  • Tobacco use is a well-established risk factor for many types of cancers. Recent data on selected cancer incidence and mortality related to smoking in the Indonesian population are provided in this study. Morbidity and mortality data were derived from GLOBOCAN 2012 and the population attributable fraction (PAF) was estimated using the standard methodology developed by the World Health Organization. Using these data, we calculated disability adjusted life year (DALY) values for smoking-related cancer. The DALY was estimated by summation of the years lived with disability (YLD) and years life lost due to premature death (YLL). The cancer cases related to smoking in Indonesia numbered 45,132, accounting for 35,580 cancer deaths. The morbidity and mortality of lung cancer can be considered as the highest priority in both men and women. Furthermore the greatest YLD due to smoking in Indonesian men and women were from pancreas and lung cancers. For YLL among men, the highest years lost were from lung and liver cancers. On the other hand, among women lung oral cavity and lip were most important. Based on the DALY indicator, burden priorities for Indonesian men were lung cancer (298,980), liver cancer (60,367), and nasopharynx (46,185), while among Indonesian women they were lung cancer (34,119), cervix uteri (9,213) and pancreas cancer (5,433). In total, Indonesian burden of cancers attributed to smoking was 638,682 DALY. This study provides evidence about the burden of cancers caused by smoking as a rational basis for initiating national tobacco control policies in Indonesia.