OBJECTIVETo investigate apoptosis-inducing effect and its mechanisms of HY-1, a carbazole alkaloid, on human erythroleukemia K562 cells.

METHODSCell proliferation was detected by sulforhodamine B (SRB) assay after treated with HY-1 at indicated doses. Cell cycle analysis was performed by flow cytometry, mitochondria membrane voltage change was assessed by rhodamine 123 staining, annexin V-PI apoptosis detecting kit and DNA agarose gel electrophoresis were used to identify apoptosis-inducing effect of HY-1. The alterations of apoptosis-relating proteins were detected by Western blot.

RESULTSThe IC(50) of HY-1 in K562 cells was (29.05 +/- 0.90) micromol/L by SRB assay. HY-1 had significant apoptotic inducing effect on K562 cells in a dose- and time-dependent manner as verified by appearance of Sub-G(1) peak on histogram of flow cytometry analysis, reduction of mitochondria membrane voltage, appearance of double positive cell group in Annexin V-PI apoptosis detecting test, and remarkable DNA ladder. The expression of cytosolic cytochrome c was apparently increased. Pro-caspase-9, pro-caspase-3 and PARP were all cleaved to active segments. There was no change in the expression of caspase-8.

CONCLUSIONHY-1 exerts its anticancer activity through triggering apoptosis of K562 cells by mitochondria-activating pathways.

Alkaloids ; isolation & purification ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Carbazoles ; isolation & purification ; pharmacology ; Humans ; K562 Cells ; Mitochondria ; metabolism ; Rutaceae ; chemistry

Experiments were performed to investigate the effects of long-term treatment with adrenergic receptor antagonist on electrical remodeling of the left ventricle with chronic pressure-overload. New Zealand rabbits underwent subtotal banding of superrenal abdominal aorta. At 10 weeks after surgery, echocardiography examination was performed, then action potential (AP), inward rectifier potassium current (I(Ki)), delayed rectifier potassium current (I(K)) and Na(+)/Ca(2+) exchanger current (I(Na(+)/Ca(2+))) were recorded in midmyocardial cells isolated from left ventricle of abdominal aorta banded group (banded group), abdominal aorta banding plus Carvedilol intervention group (Carvedilol group), and normal control group rabbits by using the whole-cell patch-clamp techniques. The results showed that left ventricular mass index in control, banded, and Carvedilol groups were 1.78+/-0.06 (n=7), 2.33+/-0.11 (n=7), and 1.87+/-0.08 (n=7), respectively (banded vs control and Carvedilol, P<0.01). At basic cycle length of 2 s, AP duration (measured at 90% repolarization, APD(90), ms) in control, banded, and Carvedilol groups were 522.0+/-19.5 (n=6), 664.7+/-46.2 (n=7), 567.8+/-14.3 (n=8) respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). At test potential of -100 mV, inward I(Ki) density (pA/pF) in control, banded, and Carvedilol groups were -11.8+/-0.50 (n=8), -8.07+/-0.28 (n=8), -10.69+/-0.35 (n=8) respectively (banded vs control and Carvedilol, P<0.01). At test potential of +50 mV, I(K) tail current density (pA/pF) in control, banded, and Carvedilol groups were 0.59+/-0.04 (n=8), 0.40+/-0.02 (n=9), 0.51+/-0.02 (n=8) respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). At test potential of +60 mV, outward I(Na(+)/Ca(2+)) density (pA/pF) in control, banded, and Carvedilol groups were 1.06+/-0.11 (n=8), 1.54+/-0.10 (n=9), 1.24+/-0.07 (n=8), respectively (banded vs control and Carvedilol, P<0.01). At test potential of -120 mV, inward I(Na(+)/Ca(2+)) density (pA/pF) in control, banded, and Carvedilol groups were -0.54+/-0.06 (n =8), -0.75+/-0.04 (n=9), -0.60+/-0.03 (n=8), respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). It is shown that long-term treatment with Carvedilol not only prevents development of cardiac hypertrophy, but also improves the electrophysiological alterations in rabbit hearts with chronic pressure-overload. This finding may add new electrophysiological evidence for the treatment of heart failure and hypertension with adrenergic receptor antagonist.
Action Potentials ; Adrenergic Antagonists ; pharmacology ; Animals ; Carbazoles ; pharmacology ; Cardiac Output, Low ; physiopathology ; Electrophysiology ; Female ; Male ; Patch-Clamp Techniques ; Propanolamines ; pharmacology ; Rabbits ; Ventricular Remodeling ; drug effects

The paper is aimed to investigate the pharmacokinetic (PK) and the pharmacodynamic (PD) properties of carvedilol using indirect response and effect-compartment link models, and compare the fitness of PK-PD models. Twenty male healthy Chinese volunteers received a single oral dose of 20 mg of carvedilol. The plasma concentrations of carvedilol were determined by reversed-phase HPLC method with fluorescence detection, and the pharmacokinetic parameters were calculated by DAS2.0. The mean arterial blood pressure was measured and the pharmacodynamics of carvedilol was characterized by tail-cuff manometry. The main pharmacokinetic parameters of carvedilol were as follows, t1/2 (4.56 +/- 2.56) h, Cmax (46.29 +/- 21.07) ng x mL(-1), AUC(0-infinity) (173.76 +/- 87.36) ng x mL(-1) x h. The estimated Kin was (0.41 +/- 0.31)% h(-1), Kout was (0.40 +/- 0.26) h(-1), the IC50 value was (24.40 +/- 21.10) ng x mL(-1) and the area under the effect curve (AUE) was (3.82 +/- 1.46)% h for the indirect response PD model. The Ke0 was (0.35 +/- 0.27) h(-1), the EC50 was (24.30 +/- 24.30) ng x mL(-1), and the AUE was (5.65 +/- 2.54)% h for the effect-compartment model. The HPLC method can be used for the pharmacokinetic study of carvedilol. The proposed effect-compartment link model provided more appropriate and better-fitting PK/PD characteristics than the indirect response model in Chinese healthy volunteers according to Akaike's information criterion values.
Antihypertensive Agents ; pharmacokinetics ; pharmacology ; Area Under Curve ; Blood Pressure ; drug effects ; Carbazoles ; blood ; pharmacokinetics ; pharmacology ; Humans ; Male ; Models, Cardiovascular ; Propanolamines ; blood ; pharmacokinetics ; pharmacology

AIMTo design and synthesize new methoxyl carbazole analogues as antitumor compounds.

METHODSMethoxyl-nitrobiphenyls (3a-3c) were prepared through the Ullmann reaction of 4,5-dimethoxyl-2-bromonitrobenzene and methoxyl-iodobenzene compounds with the catalysis of copper powder, and then reduced by P(EtO)3 to obtain methoxyl carbazoles 4a-4c. The modification at 9-position of the methoxyl carbazoles (4a-4c) gives 16 carbazole derivatives (5a-5p). These compounds were confirmed by 1HNMR, MS, IR and elemental analysis.

RESULTIn vitro antitumor activities evaluation in vitro demonstrated that IC50 value of the target compounds 4c, 5a, 5b, 5g, 5h, 5i, 5l, 5n and 5p against HT-29 cells were 12.1, 10.6, 8.1, 3.1, 4.4, 10.1 and 9.2 micromol x L(-1) respectively, and IC50 value of the target compound 4a against KB was 17.7 micromol x L(-1).

CONCLUSIONSome of the target compounds have better inhibitory effects against H-29 and KB cells.

Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Carbazoles ; chemical synthesis ; chemistry ; pharmacology ; HT29 Cells ; drug effects ; Humans ; KB Cells ; drug effects ; Molecular Structure

OBJECTIVETo explore change of ryanodine receptor (RyR) in junior mouse with heart failure (HF) and the effect of β-adrenoreceptor blocker and Radix astragali on RyR in HF in this experiment.

METHODThe animal model of congestive heart failure was established by coarctation of abdominal aorta. Five weeks old mice were randomly divided into 4 groups: (1) HF group without treatment (n = 30); (2) HF group treated with carvedilol (n = 30); (3) HF group treated with carvedilol and Radix astragali(n = 30); (4) Sham-operated group (n = 30). Carvedilol and Radix astragali were administered through direct gastric gavage. After 4 weeks of treatment the high frequency ultrasound was performed. Myocardial sarcoplasmic reticulum (SR) was fractionated with ultra centrifugation. The time courses of Ca(2+) uptake and leak were determined by fluorescent spectrophotometry. The levels of expression of RyR2 in the 4 groups were detected by semi-quantitative reverse transcription-polymerase chain reaction.

RESULTCompared with the sham-operated group, left ventricular diastolic dimension (LVEDD) (P < 0.05), left ventricular systolic dimension (LVESD), interventricular septal thickness at end-diastole (IVSTd), interventricular septal thickness at end-systole (IVSTs), left ventricular posterior wall thickness at end-diastole (LVPWTd), and left ventricular posterior wall thickness at endsystole (LVPWTs) were all significantly increased (P < 0.01), ejection fraction (EF)(%) (HF group without treatment 51.60 ± 1.15, HF treated with carvedilol 72.06 ± 1.39, HF treated with carvedilol and Radix astragali 79.06 ± 1.09, sham-operated group 85.86 ± 1.45) and fractional shortening (FS) (HF group without treatment 44.55 ± 1.20, HF treated with carvedilol 44.55 ± 1.20, HF treated with carvedilol and Radix astragali 53.58 ± 1.30, sham-operated group 59.03 ± 1.67) were decreased (P < 0.01) in HF group without treatment. LVEDD (P < 0.05), LVESD, IVSTd, IVSTs, LVPWTd and LVPWTs were all significantly decreased (P < 0.01), EF and FS were increased (P < 0.01) in the cases with HF treated with carvedilol and carvedilol and Radix astragali when compared with HF group without treatment. EF and FS were much more increased in the group treated with carvedilol and Radix astragali than in those treated with carvedilol (P < 0.05). After adding thapsigargin to the buffer including SR of the four groups, there were fewer Ca(2+) leak (%) in sham-operated group (11.5 ± 4.3), HF group treated with carvedilol (15.6 ± 5.8) and treated with carvedilol and Radix astragali (13.6 ± 4.8) than that of HF group without treatment (65.6 ± 6.2) (P < 0.01), while after adding FK506 and thapsigargin together to the buffer including SR of four groups, there were marked Ca(2+) leak in sham-operated group (60.6 ± 7.8), HF group treated with carvedilol (66.2 ± 4.5)and those treated with carvedilol and Radix astragali (70.2 ± 5.5, P < 0.01). However, there was no additional increase in Ca(2+) leak in HF group (67.3 ± 7.5) compared with that of the group where only thapsigargin was added (P > 0.05). The levels of expression of RyR2 were significantly decreased in HF group and increased in the group treated with carvedilol and the group treated with carvedilol and Radix astragali.

CONCLUSIONThere was more cardiac Ca(2+) leak and the expression of RyR2 mRNA decreased in HF. Carvedilol and Radix astragali can increase expression of RyR2 mRNA and inhibit Ca(2+) leak by restoring the binding of FKBP12.6 back to RyR in HF to improve cardiac function and prevent left ventricle from remodeling.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Astragalus Plant ; Carbazoles ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Heart Failure ; metabolism ; Male ; Propanolamines ; pharmacology ; Rats ; Rats, Wistar ; Ryanodine Receptor Calcium Release Channel ; drug effects ; metabolism

OBJECTIVETo investigate the effects of carvedilol and metoprolol on cardiac fibrosis in rats with experimental myocardial infarction (MI).

METHODSMI was induced in male Sprague-Dawley rats by ligating the left coronary artery. Rats randomly received saline, carvedilol (10 mg.kg(-1).d(-1)) or metoprolol (20 mg.kg(-1).d(-1)) beginning at 4 weeks post MI for 8 weeks per gavage. Sham-operated rats serve as control. Collagen perivascular circumferential collagen area (PCVA), peri-coronary circumferential collagen area (VLCA) and interstitial collagen volume fraction (ICVF) as well as myocardial hydroxyproline content were determined after hemodynamic measurements at the study end.

RESULTSLVEDP were significantly lower and +/- dp/dt significantly higher in carvedilol and metoprolol treated MI rats than that in saline treated MI rats. Myocardial hydroxyproline, PCVA/VLCA ratio and ICVF were significantly reduced in metoprolol, more significantly reduced in carvedilol treated MI rats compared to saline treated MI rats (all P < 0.05).

CONCLUSIONMetoprolol and carvedilol could decrease the concentration of hydroxyproline and ICVF in MI rats.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Carbazoles ; pharmacology ; Collagen ; metabolism ; Disease Models, Animal ; Fibrosis ; Hydroxyproline ; metabolism ; Male ; Metoprolol ; pharmacology ; Myocardial Infarction ; pathology ; Myocardium ; metabolism ; pathology ; Propanolamines ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVEBrain-derived neurotrophic factor (BDNF) and its specific tryrosin kinase receptor-B (TrkB) are highly correlated to the chemoresistance of neuroblastoma (NB) cells and poor prognosis. This study observed the changes of the sensibility of NB cells to chemotherapy drug cisplatin (CDDP) before and after blockage of TrkB-BDNF signal pathway by specific tyrosin kinase inhibitor K252a.

METHODSHuman NB cell line SH-SY5Y (SY5Y) was routinely cultured. Expression of TrkB was induced with nM all trans-retinoid acid (ATRA). Then BDNF, CDDP or K252a were added to the cultured SY5Y cells. Cell livability was assessed by methyl thiazolyl tetrazolium (MTT) assay. TrkB autophosphorylation was determined by Western blot analysis. Cell apoptosis rate was detected by flow cytometry (FCM). The conformation of apoptosis cells was observed by transmission electron microscopy (TEM).

RESULTSThe livability and apoptosis rate in SY5Y cells treated with ATRA, BDNF and CDDP were not different from the blank control group. However, after K252a together with ATRA, BDNF and CDDP treatment, the sensibility of SY5Y cells to chemotherapy drug CDDP increased, the livability decreased and the apoptosis rate increased in SY5Y cells when compared with the blank control group (P <0.01). K252a treatment resulted in blockage of TrkB autophosphorylation.

CONCLUSIONSThe blockage of TrkB-BDNF signal pathway by K252a use can increase sensibility of NB cells to chemotherapy and thus decrease the livability of NB cells.

Apoptosis ; drug effects ; Brain-Derived Neurotrophic Factor ; antagonists & inhibitors ; Carbazoles ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Humans ; Indole Alkaloids ; pharmacology ; Microscopy, Electron, Scanning ; Neuroblastoma ; drug therapy ; pathology ; Receptor, trkB ; antagonists & inhibitors ; Signal Transduction ; drug effects ; Tretinoin ; pharmacology

BACKGROUNDCarvedilol, an antagonist of alpha1- and beta-adrenergic receptors, has shown efficacy in reducing all-cause death and arrhythmia death for ischemic heart disease and congestive heart failure in several large-scale trials. It has been found to prevent ventricular remodeling, and recently was reported to reverse down-regulation of Na+ channel in a chronic heart failure model. This study was conducted to investigate whether carvedilol could reverse the ion remodeling in a myocardial infarction model of rabbit.

METHODSAfter the procedure of coronary ligation, animals were randomized to placebo or carvedilol treatment (5 mg/kg). Action potentials, L-type calcium current (Ica L) and the effect of isoproterenol stimulation on Ica L were measured using whole-cell patch method. Evaluation of the expression of calcium channel subunits was carried out by RT-PCR and Western blot.

RESULTSThe results indicate that mean peak Ica L densities (pA/pF) at +10 mV was reduced in postinfarction myocytes (5.33 +/- 0.45, n = 25) compared to sham myocytes (6.52 +/- 0.21, n = 20). Treatment of myocardial infarction rabbits with carvedilol could restore it partially (5.91 +/- 0.39, n = 20, P < 0.05). However, steady-state activation parameters were similar in three groups. With stimulation by isoproterenol (1 micromol/L) Ica L increased in all three groups, but the increase was smaller in postinfarction myocytes. mRNA levels of calcium channel subunit CaA1 gene was decreased but CaB2a, CaB2b and CaB3 mRNA levels did not change after MI. Corresponding change in CaA1 protein was also observed.

CONCLUSIONSThe results demonstrate that carvedilol restores Ica L density and reverse the downregulation of CaA1 postinfarction.

Action Potentials ; drug effects ; Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium Channels, L-Type ; biosynthesis ; genetics ; metabolism ; Carbazoles ; pharmacology ; Male ; Myocardial Infarction ; metabolism ; physiopathology ; Propanolamines ; pharmacology ; Rabbits ; Random Allocation ; Ventricular Remodeling ; drug effects

The protective effect of carvedilol on abnormality of L-type calcium current induced by oxygen free radical in single guinea pig ventricular myocytes was studied. Whole-cell patch clamp technique was used to study the effect of H2O2 (0.5 mmol/L) on L-type calcium current in single guinea pig ventricular myocytes and the action of pretreatment with carvedilol (0.5 micromol/L). 0.5 micromol/L carvedilol had no significant effect on ICa,L and its channel dynamics. In the presence of 0.5 mmol/L H2O2, peak current of ICa,L was reduced significantly (P<0.001), the I-V curve of ICa,L was shifted upward, steady-state activation curve and steady-state deactivation curve of ICa,L were shifted left and recovery time of ICa,L was delayed significantly (P<0.001). 0.5 micromol/L carvedilol significantly alleviated the inhibitory effect of H2O2 on ICa,L as compared with that in H2O2 group (P<0.01). In addition, carvedilol reversed the changes of dynamics of ICa,L induced by H2O2. It was concluded that carvedilol could alleviate the abnormality of L-type calcium current induced by oxygen free radical in cardiomyocytes. It shows partly the possible mechanism of the special availability of carvedilol in chronic heart failure.
Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium Channels, L-Type ; metabolism ; Carbazoles ; pharmacology ; Female ; Free Radicals ; adverse effects ; Guinea Pigs ; Heart Ventricles ; cytology ; Male ; Myocytes, Cardiac ; metabolism ; pathology ; Oxidative Stress ; Patch-Clamp Techniques ; Propanolamines ; pharmacology

OBJECTIVETo examine serum B-type natriuretic peptide (BNP) levels and BNP expression of protein and mRNA in the right ventricular myocardium in juvenile rats with right heart failure (RHF) and the effects of beta-adrenergic receptor blocker carvedilol on serum and myocardial BNP levels in order to investigate the role of BNP in the diagnosis and treatment of RHF.

METHODSFifty-one four-week-old Sprague-Dawley rats were randomly assigned to 5 groups: RHF 1, RHF 2, carvedilol-treated RHF, control 1 and control 2. RHF was developed 4 weeks after an intraperitoneal injection of monocrotaline in the RHF 1, RHF 2 and carvedilol-treated RHF groups. The rats in the RHF 1 and the control 1 groups were sacrificed after the RHF event for observing pathological changes in the myocardium. After the RHF event, the carvedilol-treated group was given intragastric administration of carvedilol (3.5 mg/kg/d) for 2 weeks. The RHF 2 and the control 2 groups were given distilled water of equal dose instead. The rats were sacrificed 2 weeks after carvedilol or distilled water administration. Serum BNP levels were measured using ELISA. BNP protein and mRNA expression in the right ventricular myocardium were measured by immunohistochemistry and RT-PCR, respectively. Haemodynamics and some physiological indexes were measured.

RESULTSSerum BNP levels and BNP protein and mRNA expression in the right ventricular myocardium were significantly higher in the RHF 1 group than those in the control 1 group (p<0.01). Serum BNP levels and BNP protein and mRNA expression in the right ventricular myocardium increased more significantly in the RHF 2 group. There was a positive correlation between serum BNP levels and myocardial BNP protein expression in the RHF group (r=0.698, p<0.01). Serum BNP levels and BNP protein and mRNA expression in the carvedilol-treated RHF group were significantly reduced when compared with the RHF 2 group (p<0.05). Carvedilol treatment also resulted in improved hemodynamics and relieved right ventricular hypertrophy.

CONCLUSIONSBNP may serve an index for the diagnosis of RHF and the evaluation of severity in children with RHF. Carvedilol shows protections against RHF caused by pressure load.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Carbazoles ; pharmacology ; therapeutic use ; Heart Failure ; blood ; drug therapy ; pathology ; physiopathology ; Natriuretic Peptide, Brain ; blood ; genetics ; Propanolamines ; pharmacology ; therapeutic use ; RNA, Messenger ; analysis ; Random Allocation ; Rats ; Rats, Sprague-Dawley