• Title/Summary/Keyword: time-dependent effect

Search Result 2,013, Processing Time 0.029 seconds

Effects of Atorvastatin on the Pharmacokinetics of Nicardipine after Oral and Intravenous Administration in Rats

  • Choi, Jun-Shik;Ha, Sung-Il;Choi, Dong-Hyun
    • Biomolecules & Therapeutics
    • /
    • v.18 no.2
    • /
    • pp.226-232
    • /
    • 2010
  • The aim of this study was to investigate the effect of atrovasatatin on the pharmacokinetics of nicardipine after oral and intravenous administration of nicardipine to rats. Nicardipine was administered orally (12 mg/kg) or intravenously (i.v., 4 mg/kg) without or with oral administration of atrovasatatin (0.3 or 1.0 mg/kg) to rats. The effect of atorvastatin on the P-glycoprotein (P-gp) as well as CYP3A4 activity was also evaluated. Atorvastatin inhibited CYP3A4 enzyme activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of 48 ${\mu}M$. Compared to the controls (nicardipine alone), the area under the plasma concentration-time curve (AUC) of nicardipine was significantly (1.0 mg/kg, p<0.05) greater by 16.8-45.4%, and the peak plasma concentration ($C_{max}$) was significantly (1.0 mg/kg, p<0.05) higher by 28.0% after oral administration of nicardipine with atorvastatin, respectively. Consequently, the relative bioavailability (R.B.) of nicardipine was increased by 1.17- to 1.45-fold and the absolute bioavailability (A.B.) of nicardipine with atrovasatatin was significantly greater by 16.7-20.9% compared to that of the controls (14.3%). Compared to the i.v. control, atrovasatatin did not significantly change pharmacokinetic parameters of i.v. administration nicardipine. The enhanced oral bioavailability of nicardipine by atorvastatin suggests that CYP3A subfamily-mediated metabolism were inhibited in the intestine and/or in the liver rather than P-gp-mediated efflux of nicardipine. Based on these results, modification of nicardipine of dosage regimen is required in the patients. Human studies are required to prove the above hypothesis.

Study on the Effects of Podam-hwan on Brain GABA and Glutamate Levels in the Picrotoxin-induced Convulsion (포담환이 Picrotoxin-유도 경련시 뇌중 GABA 및 Glutamate 함량변화에 미치는 영향에 관한 연구)

  • 안철효;이원창;구병수
    • The Journal of Korean Medicine
    • /
    • v.23 no.3
    • /
    • pp.211-222
    • /
    • 2002
  • Currently convulsion is considered to be a chronic central nerve disease characterized by involuntary and severe muscle contraction or spasm. In many recent studies, convulsion's mechanism is due to unbalance between stimulation and suppression of the central nerve system, such as GABA and glutamic acid. Objectives : This study was performed to examine the anticonvulsant effects of Podam-hwan on brain GABA levels and glutamate content in picrotoxin-induced convulsions and to determine the inhibitory activity on GABA transaminase. Methods : Brain GABA levels and glutamate content in the brains of picrotoxin-induced mice using reverse phase HPLC method, anticonvulsant effect in vivo, and the inhibitory effect on GABA transaminase activity in vivo have been investigated. Results : Podam-hwan significantly lengthened the onset time of picrotoxin-induced convulsion at a concentration of 15mg/kg, but did not show a dose-dependent pattern. Also, Podam-hwan shortened the duration of convulsion by 52.2% at a dose of 30mg/kg in comparison with the control group. Podam-hwan inhibited dose-dependently GABA transaminase activity by 35.5% at 30mg/kg, comparing with the control gmup. Podam-hwan also increased the brain GABA level by 38.7% and 68.8% at doses 15mg/kg and 30mg/kg, respectively. In addition, Podam-hwan decreased the brain glutamate level by 9.6% and 17.8% at doses 15mg/kg and 30mg/kg, respectively. Conclusions : Podam-hwan can be prescribed for the treatment of convulsion by enhancement of brain GABA level and inhibition of GABA transaminase activity.

  • PDF

Effect of Bifurcation Angle on Blood Flow in Flexible Carotid Artery (유연한 경동맥 분지관에서 분지각이 혈액의 유동에 미치는 영향에 관한 연구)

  • Lee, Sang Hoon;Choi, Hyoung Gwon;Yoo, Jung Yul
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.37 no.3
    • /
    • pp.229-235
    • /
    • 2013
  • To investigate the effect of the flexible artery wall on the blood flow, three-dimensional numerical simulations were carried out for analyzing the time-dependent incompressible flows of Newtonian fluids constrained by a flexible wall. The Navier-Stokes equations for fluid flow were solved using the P2P1 Galerkin finite element method, and mesh movement was achieved using an arbitrary Lagrangian-Eulerian formulation. The Newmark method was employed for solving the dynamic equilibrium equations for the deformation of a linear elastic solid. To avoid complexity due to the necessity of additional mechanical constraints, we used a combined formulation that includes both the fluid and structure equations of motion to produce a single coupled variational equation. The results showed that the flexibility of the carotid wall significantly affects flow phenomena during the pulse cycle. The flow field was also found to be strongly influenced by the bifurcation angle.

Effects of Imperatae Rhizoma Extract on T helper 2 cell differentiation (백모근 추출물의 T helper 2 세포 분화 조절 효과)

  • Kim, Bok-Kyu;Lim, Jong-Soon;Kil, Ki-Jung
    • The Korea Journal of Herbology
    • /
    • v.29 no.6
    • /
    • pp.27-33
    • /
    • 2014
  • Objectives : The aims of this study were to exploring the therapeutic effect of Imperatae Rhizoma Extract(IRE) on Asthma. Methods : To investigate biological modulation activities of IRE, we conducted the cell-based assay whether IRE could regulate T helper 2 cells activity with EL4 T cells and mouse splenocytes, and followed animal study to conform the efficacy of their therapeutic potential on OVA-induced asthmatic mouse. Results : In cell study, IRE suppress the nuclear translocation of GATA binding protein-3 protein in phorbol 12-myristate 13-acetate/Ionomycin-stimulated EL4 T cells and Interleukine(IL)-4, IL-5 and IL-13 production in splenocytes at concentration dependent manner. In animal study, IRE-treated groups both 100mg/ml and 200mg/ml improve airway hypersensitibility reaction(AHR) response to methacholine about 30% and 40% with positive control group. Peritoneal blood analysis reveal that eosinophil number and ovalbumin-specific IgE is reduced by IRE treatment. Cell number of eosinophil is also reduced in bronchoalveolar lavage of IRE group like to peritoneal cell and real time-polymerase chain reaction data show that expression levels of IL-4, IL-5 and IL-13 were down regulated in lung tissue. Finally, histological analysis indicate that IRE protect the bronchial tissue damages through the accumulation of inflammatory cells and collagen, and these effect may be cause by interfering Th2 cells activity. Conclusions : Our data represent that IRE potentiates therapeutic activities to the allergic diseases such as asthma by regulating Th2 cells differentiation.

Differential Effects of TNF-${\alpha}$ on the Survival and Apoptosis of Human Granulocytes and the Human Myeloid Leukemia Cell Line

  • Yang, Eun Ju;Chang, Jeong Hyun
    • Biomedical Science Letters
    • /
    • v.19 no.2
    • /
    • pp.118-123
    • /
    • 2013
  • Tumor necrosis factor-alpha (TNF-${\alpha}$) is a proinflammatory cytokine that mediates the inflammatory response and immune functions, and modulates the proliferation, differentiation and cell death of cancer cells. The differential functions of TNF-${\alpha}$ in various human cells due to the formation of different stimulating pathway upon the binding of TNF-${\alpha}$ to its receptors. In the present study, we examined the different effects of TNF-${\alpha}$ on the survival and apoptosis between normal granulocytes and human myeloid leukemia HL-60 cells. Although TNF-${\alpha}$ did not affect on the constitutive apoptosis of granulocytes, TNF-${\alpha}$ strongly induced the apoptosis of HL-60 cells in a dose- and a time-dependent manner. TNF-${\alpha}$-induced apoptosis was occurred via the activation of caspase 8, caspase 9 and caspase 3/7 and the induction of ROS production in HL-60 cells. Also, BAY-11-7085, a NF-${\kappa}B$ inhibitor, blocked the TNF-${\alpha}$-induced apoptosis in HL-60 cells. NF-${\kappa}B$ may be involved in TNF-${\alpha}$-induced apoptotic signaling pathway in HL-60 cells. These results suggest that TNF-${\alpha}$ activates apoptotic pathways and its process depends on cell type and many cellular factors. A better understanding of the differential effect of TNF-${\alpha}$ on cell apoptosis and survival may provide important information that can be used to elucidate the specific inhibitory effect of TNF-${\alpha}$ on the cancer dis.

Quercetin induces apoptosis and cell cycle arrest in triple-negative breast cancer cells through modulation of Foxo3a activity

  • Nguyen, Lich Thi;Lee, Yeon-Hee;Sharma, Ashish Ranjan;Park, Jong-Bong;Jagga, Supriya;Sharma, Garima;Lee, Sang-Soo;Nam, Ju-Suk
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.21 no.2
    • /
    • pp.205-213
    • /
    • 2017
  • Quercetin, a plant-derived flavonoid found in fruits, vegetables and tea, has been known to possess bioactive properties such as anti-oxidant, anti-inflammatory and anti-cancer. In this study, anti-cancer effect of quercetin and its underlying mechanisms in triple-negative breast cancer cells was investigated. MTT assay showed that quercetin reduced breast cancer cell viability in a time and dose dependent manner. For this, quercetin not only increased cell apoptosis but also inhibited cell cycle progression. Moreover, quercetin increased FasL mRNA expression and p51, p21 and GADD45 signaling activities. We also observed that quercetin induced protein level, transcriptional activity and nuclear translocation of Foxo3a. Knockdown of Foxo3a caused significant reduction in the effect of quercetin on cell apoptosis and cell cycle arrest. In addition, treatment of JNK inhibitor (SP 600125) abolished quercetin-stimulated Foxo3a activity, suggesting JNK as a possible upstream signaling in regulation of Foxo3a activity. Knockdown of Foxo3a and inhibition of JNK activity reduced the signaling activities of p53, p21 and GADD45, triggered by quercetin. Taken together, our study suggests that quercetin induces apoptosis and cell cycle arrest via modification of Foxo3a signaling in triple-negative breast cancer cells.

Annealing Effect on controlling Self-Organized Ag/Ti Nanoparticles on 4H-SiC Substrate (4H-SiC기판 위의 자기구조화된 Ag/Ti 나노입자 제어를 위한 열처리 분석)

  • Kim, So-Mang;OH, Jong-Min;Koo, Sang-Mo
    • Journal of IKEEE
    • /
    • v.20 no.2
    • /
    • pp.177-180
    • /
    • 2016
  • The effect of varying thickness of Ag/Ti metal bilayer and annealing time have investigated for controlling self-organized nanoparticles (NPs) on 4H-SiC substrate. In addition, Glass and Si substrate which have different surface energy from SiC were fabricated for analyzing interaction of agglomeration. The results of FE-SEM indicated the different formation behaviors of NPs in various ranges of fabrication condition. The surface energy was measured by using a Contact Angle Analyzer. The formation of network-like NPs was observed on Glass and 4H-SiC, respectively, whereas it was not the case on Si substrates. It has been found that the size of NPs increases with decreasing surface energy, due to particle size-dependent hydrophilic properties of substrates. The different formation behavior was explained by using Young's equation for the contact angles between the metal and different substrates.

Naltrexone Inhibits Catecholamine Secretion Evoked by Nicotinic Receptor Stimulation in the Perfused Rat Adrenal Medulla

  • Yu, Byung-Sik;Min, Seon-Young;Seo, Yoo-Seok;Choi, Cheol-Hee;Lee, Eun-Hwa;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.9 no.4
    • /
    • pp.223-230
    • /
    • 2005
  • The purpose of the present study was to examine the effect of naltrexone, an opioid antagonist, on secretion of catecholamines (CA) evoked by cholinergic nicotinic stimulation and membrane-depolarization from the isolated perfused rat adrenal gland and to establish the mechanism of its action. Naltrexone $(3{\times}10^{-6}M)$ perfused into an adrenal vein for 60 min produced time-dependent inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}M)$ , high $K^+$ $(5.6{\times}10^{-2}M)$ , DMPP ($10^{-4}$ M) and McN-A-343 $(10^{-4}M)$ . Naltrexone itself did also fail to affect basal CA output. In adrenal glands loaded with naltrexone $(3{\times}10^{-6}M)$ , the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$, were also inhibited. However, in the presence of met-enkephalin $(5{\times}10^{-6}M)$ , a well-known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Collectively, these experimental results demonstrate that naltrexone inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that this inhibitory effect of naltrexone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

The Anti-Inflammatory Effect of IH-901 in HT-29 Cells

  • Lee, Seung-Min;Kim, Ki-Nam;Kim, Yu-Ri;Kim, Hye-Won;Shim, Boo-Im;Lee, Seung-Ho;Bae, Hak-Soon;Kim, In-Kyoung;Kim, Meyoung-Kon
    • Molecular & Cellular Toxicology
    • /
    • v.3 no.4
    • /
    • pp.254-261
    • /
    • 2007
  • 20-O-($\beta$-D-Glucopyranosyl)-20 (S)-protopanaxadiol (IH-901) is one of the major metabolites of ginsenosides from Panax ginseng, and is suggested that IH-901 has been associated with various pharmacological and physiological activities. In this study, we demonstrate that IH-901 induced anti-inflammation in HT-29 human colon adenocarcinoma cells. Our results showed that IH-901 inhibited cell proliferation of HT-29 in a time- and dose-dependent manner. We also found that IH-901 was significantly decreased expression of iNOS compared with non-treated. We observed effect of IH-901 related with inflammatory genes using by cDNA microarray. We were known that the 34 inflammatory genes such as E2F, CDK6, TNF-$\alpha$, and PKC were down-regulated. Thus, these results suggest that IH-901 may have a potential preventive factor to improving cancer induced by chronic inflammation.

Opposing Effects of ERK and p38 MAP Kinases on HeLa Cell Apoptosis Induced by Dipyrithione

  • Fan, Yumei;Chen, Hui;Qiao, Bo;Luo, Lan;Ma, Hsiaoyen;Li, Heng;Jiang, Jihong;Niu, Dezhong;Yin, Zhimin
    • Molecules and Cells
    • /
    • v.23 no.1
    • /
    • pp.30-38
    • /
    • 2007
  • Dipyrithione (2, 2'-dithiobispyridine-1, 1'-dioxide, PTS2), a pyrithione derivate, is highly bactericidal and fungicidal. In this study we examined its apoptotic effect on HeLa cells. PTS2 induced HeLa cell death in a dose and time dependent manner. ERK1/2 and p38 were markedly activated, but little JNK1/2 activation was detected. Suppression of p38 activation by SB203580 reduced the extent of apoptosis of the HeLa cells and also prevented induction of p21, release of cytochrome c, and cleavage of caspase-3 and PARP. Inhibition of ERK1/2 with PD98059 increased apoptosis, indicating that ERK1/2 activation has an anti-apoptotic effect on PTS2-induced HeLa cell apoptosis. PTS2 also inhibited murine sarcoma 180 and hepatoma 22 tumor growth in an animal tumor model. Our findings indicate that PTS2 possesses anti-tumor activity, that caspase-3 and poly (ADP-ribose) polymerase (PARP) are involved in PTS2-induced HeLa cell apoptosis and that ERK1/2 and p38 have opposing effects on this apoptosis.