Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cilostazol is a selective orally active phosphodiesterase (PDE) III inhibitor. This study was conducted to evaluate whether inhibition of PDE subtype III can reduce bronchial responsiveness. We examined the effects of cilostazol on bronchial responsiveness to methacholine in eight normal subjects by a single-blinded, crossover study. Each subject received 200 mg of cilostazol or placebo in random order. The subjects underwent methacholine challenge test 3 h after administration of each drug on two occasions separated by 5 d or more. The geometric mean value of provocative concentration of methacholine causing a 20% fall in FEV1 (PC20-FEV1) and the mean value (+/- SEM) of maximum expiratory flow on partial flow-volume curve at isovolume of 40% FVC above residual volume (PEF40) after administration of cilostazol were 25.3 (geometric standard error of the mean [GSEM], 1.35) mg/ml and 3.78 +/- 0.31 L/s, which were significantly (p < 0.02 and p < 0.05) greater than those after the placebo administration (6.81 [GSEM, 1.42] mg/ml and 2.71 +/- 0.39 L/s). All subjects complained of mild to severe headache when cilostazol was given. These findings suggest that PDE III inhibitors such as cilostazol have bronchodilator and bronchoprotective effects in humans. Further studies regarding smaller oral dosing of or aerosol administration of cilostazol or the other PDE III inhibitors are needed to determine clinical usefulness.
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PMID:Bronchodilator and bronchoprotective effects of cilostazol in humans in vivo. 781 59

In this study, we evaluated the effect of therapeutic doses of cilostazol on human venous smooth muscle. Saphenous vein rings (two to four per patient sample) were suspended in tissue baths for isometric tension recordings. At the beginning of the experiment, optimal tension for isometric contraction was achieved for each ring in a stepwise fashion in the presence of norepinephrine (10(-2) M). Norepinepherine was then added cumulatively in half-molar increments and isometric tension developed by the rings was measured, thereby obtaining a dose-response curve. Following washout and reequilibration, the rings were precontracted with a 30-50% submaximal dose of norepinepherine determined from the dose-response curve and allowed to contract until a stable plateau was reached. Cilostazol was then added in a cumulative manner (680-2,720 microg/L), and the tension generated was recorded. A total of 76 venous rings were tested, and all relaxed in the presence of cilostazol. The amount of relaxation increased as the concentration of cilostazol increased. Relaxation of 15 +/- 1.9% (mean +/- SEM) at low cilostazol doses (680 microg/L) to 37+/-3% at high cilostazol doses (2,720 microg/L) was demonstrated. A second finding of this study was demonstrated when the patient samples were divided according to the presence or absence of risk factors for arteriosclerosis. The specific risk factors examined included diabetes mellitus, smoking, hypercholesterolemia, and hypertension. The presence or absence of hypertension (n = 52) or hypercholesterolemia (n = 18) did not affect the amount of relaxation of the venous rings. Smokers (n = 46) had less relaxation 16 +/- 2.4% (680 microg/L) to 41 +/- 3.6% (2,720 microg/L) compared to nonsmokers (n = 53) who relaxed 22 +/- 3.5% (680 microg/L) to 48 +/- 5.7% (2720 microg/L). This did not reach statistical significance at any concentration cilostazol (p = 0.11-0.18). Diabetics (n = 53) did have statistically significantly less relaxation at every concentration of cilostazol compared to nondiabetics (n = 11, p < 0.05). All venous rings relaxed in the presence of cilostazol. Veins of nondiabetics relaxed statistically significantly more than those of diabetics. Smokers had less relaxation than non-smokers, but this was not statistically significant. We are the first to demonstrate that human venous smooth muscle cells undergo relaxation when exposed to therapeutic concentrations of cilostazol.
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PMID:Effects of cilostazol on human venous smooth muscle. 1581 59

Diabetic nephropathy is a major complication of diabetes leading to end-stage renal disease, which requires hemodialysis. Although the mechanism by which it progresses is largely unknown, the role of hyperglycemia-derived oxidative stress has recently been the focus of attention as the cause of diabetic complications. Constituent cells of the renal glomeruli have the capacity to release reactive oxygen species (ROS) upon stimulation of NADPH oxidase activated by protein kinase C (PKC). Hyperglycemia and insulin resistance in the diabetic state are often associated with activation of PKC and tumor necrosis factor (TNF)-alpha, respectively. The aim of this study is to clarify the signaling pathway leading to ROS production by PKC and TNF-alpha in rat glomeruli. Isolated rat glomeruli were stimulated with phorbol 12-myristate 13-acetate (PMA) and TNF-alpha, and the amount of ROS was measured using a chemiluminescence method. Stimulation with PMA (10 ng/ml) generated ROS with a peak value of 136+/-1.2 cpm/mg protein (mean+/-SEM). The PKC inhibitor H-7, the NADPH oxidase inhibitor diphenylene iodonium and the phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin inhibited PMA-induced ROS production by 100%, 100% and 80%, respectively. In addition, TNF-alpha stimulated ROS production (283+/-5.8/mg protein/20 min). The phosphodiesterase inhibitor cilostazol activates protein kinase A and is reported to improve albuminuria in diabetic rats. Cilostazol (100 microg/ml) inhibited PMA, and TNF-alpha-induced ROS production by 78+/-1.8, and 19+/-2.7%, respectively. The effects of cilostazol were not additive with wortmannin. Cilostazol arrests oxidative stress induced by PKC activation by inhibiting the PI-3 kinase-dependent pathway, and may thus prevent the development of diabetic nephropathy.
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PMID:Induction of reactive oxygen species from isolated rat glomeruli by protein kinase C activation and TNF-alpha stimulation, and effects of a phosphodiesterase inhibitor. 1734 51

Improvement in dissolution of the drugs having poor solubility is a challenge in pharmaceutical industry. Micronization is one technique, employed for dissolution enhancement of cilostazol, a BCS class II drug. However, the obtained micronized drug possesses poor flowability. The aim of this study was to improve the dissolution rate and flow properties of cilostazol by crystal engineering, using habit modification method and compare with micronized cilostazol bulk drug. Simulation studies were performed to predict the effect of solvents on cilostazol crystal habit. Cilostazol crystals with different habits were prepared by solvent:anti-solvent crystallization technique. SEM, FTIR, DSC, TGA and PXRD were used for solid state characterization. The results revealed that cilostazol re-crystallized from methanol-hexane system were hexagonal and ethanol-hexane system gave rods. Cilostazol engineered habits showed increased dissolution rate than unprocessed drug but similar dissolution rate when compared to micronized cilostazol. Micronized cilostazol showed a dissolution efficiency of 75.58% where as cilostazol recrystallized from methanol-hexane and ethanol-hexane systems resulted in a dissolution efficiency of 72.63% and 68.63%, respectively. In addition, crystal engineering resulted in improved flow properties of re-crystallized habits when compared to micronized form of the drug. In conclusion, crystal engineering by habit modification show potential for dissolution enhancement with an added advantage of improved flow properties over micronization technique, for poorly soluble drugs like cilostazol.
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PMID:Can crystal engineering be as beneficial as micronisation and overcome its pitfalls?: A case study with cilostazol. 2606 97