Acute simvastatin inhibits K ATP channels of porcine coronary artery myocytes.

Background: Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors) consumption provides beneficial effects on cardiovascular systems. However, effects of statins on vascular KATP channel gatings are unknown.

Methods: Pig left anterior descending coronary artery and human left internal mammary artery were isolated and endothelium-denuded for tension measurements and Western immunoblots.

Increased glutathione and mitogen-activated protein kinase phosphorylation are involved in the induction of doxorubicin resistance in hepatocellular carcinoma cells.

Aim:   The human hepatocellular carcinoma (HCC) cell line HepG2 can easily acquire resistance to doxorubicin. However, the mechanism of action is unclear.

Methods:   In the present study, we used confocal microscopy, flow cytometry and other methods to reveal the mechanisms by which HepG2 cells acquire doxorubicin resistance.

Impact of the herbal medicine Sophora flavescens on the oral pharmacokinetics of indinavir in rats: the involvement of CYP3A and P-glycoprotein.

Sophora flavescens is a Chinese medicinal herb used for the treatment of gastrointestinal hemorrhage, skin diseases, pyretic stranguria and viral hepatitis. In this study the herb-drug interactions between S. flavescens and indinavir, a protease inhibitor for HIV treatment, were evaluated in rats.

Investigation of cytochrome P450 1A2 and 3A inhibitory properties of Danshen tincture.

Danshen (Salvia miltiorrhiza Bunge) as a famous Traditional Chinese medicine is widely used in the treatment of cardiovascular and cerebrovascular diseases in the world. Danshen tincture (DT), extracted from Danshen root with a mixture of water and alcohol, is a commonly used preparation method for human consumption. The aim of this study was to investigate the effects of DT on the cytochrome P450 (CYP) 1A2 and 3A activities by human and rat liver microsomes.

Indomethacin and SC236 enhance the cytotoxicity of doxorubicin in human hepatocellular carcinoma cells via inhibiting P-glycoprotein and MRP1 expression.

Doxorubicin is a chemotherapeutic drug widely used for the treatment of hepatocellular carcinoma but its efficacy is restricted by multidrug resistance. Non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX)-2-selective inhibitors exhibit anti-cancer properties as well as abilities to overcome drug resistance. In the present study, indomethacin (a NSAID) and SC236 (a COX-2-selective inhibitor) enhanced the cytotoxicity of doxorubicin in the hepatocellular carcinoma cell line HepG2 and its drug-resistant sub-line R-HepG2.

Mitochondrial monoamine oxidase-A-mediated hydrogen peroxide generation enhances 5-hydroxytryptamine-induced contraction of rat basilar artery.

Background And Purpose: We evaluated the role(s) of monoamine oxidase (MAO)-mediated H₂O₂ generation on 5-hydroxytryptamine (5-HT)-induced tension development of isolated basilar artery of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats.

Experimental Approach: Basilar artery (endothelium-denuded) was isolated for tension measurement and Western blots. Enzymically dissociated single myocytes from basilar arteries were used for patch-clamp electrophysiological and confocal microscopic studies.

Folic acid consumption reduces resistin level and restores blunted acetylcholine-induced aortic relaxation in obese/diabetic mice.

Folic acid supplementation provides beneficial effects on endothelial functions in patients with hyperhomocysteinemia. However, its effects on vascular functions under diabetic conditions are largely unknown. Therefore, the effect(s) of folic acid (5.

Relaxant effects of danshen aqueous extract and its constituent danshensu on rat coronary artery are mediated by inhibition of calcium channels.

In this study, we have investigated the actions of danshensu, an active, water-extractable component of the medicinal herb danshen (Salvia miltiorrhiza), on rat isolated coronary artery rings precontracted with 1 microM 5-hydroxytryptamine (5-HT) and its action compared to the water-extractable fraction of the herb. Extraction of the water-soluble fraction from danshen (S. miltiorrhiza) provided yield of 17.

Activation of the iberiotoxin-sensitive BKCa channels by salvianolic acid B of the porcine coronary artery smooth muscle cells.

In this study, we examined the effects of Salvia miltiorrhiza (Danshen) crude extract, some of its lipid-soluble components (tanshinone I, tanshinone II(A), cryptotanshinone, dihydroisotanshinone I) and the water-soluble compounds (danshensu and salvianolic acid B) on the K(+) channels such as the iberiotoxin-sensitive Ca(2+)-activated K(+) (BK(Ca)) channels and the glibenclamide-sensitive ATP-dependent K(+) (IK(ATP)) channels of the porcine left anterior descending coronary artery smooth muscle cells. Cumulative application of salvianolic acid B (30-300 microM) caused a l-NNA (100 microM)-insensitive, potentiation of the outward BK(Ca) current amplitude with no apparent effect on the IK(ATP) channels opening. Salvianolic acid B (300 microM) caused an ODQ (10 microM, a guanylate cyclase inhibitor)-sensitive enhancement of the outward BK(Ca) current amplitude.

Pharmacological evidence for calcium channel inhibition by danshen (Salvia miltiorrhiza) on rat isolated femoral artery.

This study investigated the relaxant actions of danshen (Salvia miltiorrhiza) and its lipid-soluble- and water-soluble-fractions on endothelium-denuded rat isolated femoral artery rings. Danshen, its water-soluble fraction and its lipid-soluble fraction produced relaxation of the phenylephrine-precontracted artery rings with IC50 values of 149 +/- 20 microg/mL, 160 +/- 25 microg/mL, and 23 +/- 6 microg/mL, respectively. Pretreatment of the artery rings with a non-selective potassium channel inhibitor tetraethylammonium (TEA, 10 mM) produced a significant two-fold rightward shift of the concentration-response curve to danshen and a four-fold shift to its water-soluble fraction, but had no effect on the lipid-soluble fraction.

Placental transfer of Zidovudine in first trimester of pregnancy.

Objective: Zidovudine is one of the most common antiretroviral drugs used to prevent vertical transmission of human immunodeficiency virus. However, it is not recommended for use in the first trimester of pregnancy because of reservations about its potential teratogenicity during the organogenesis phase. The objective of this study was to investigate the placental transfer of zidovudine in the first trimester of human pregnancy.

Mechanisms of the dilator action of Danshen (Salvia miltiorrhiza) on rat isolated femoral artery.

This study investigates the actions of Danshen crude extract (Salvia miltiorrhiza) on rat isolated femoral artery rings precontracted with phenylephrine. Low concentrations of Danshen (10 to 30 microg/mL) enhanced the phenylephrine-precontracted tone by a maximum of 31.20+/-2.

Placental transfer of rosiglitazone in the first trimester of human pregnancy.

Objective: To determine the degree of placental transfer of rosiglitazone in early human pregnancy.

Design: Prospective observational study.

Setting: University teaching hospital.