Synthesis and biological evaluation of novel imidazolidine derivatives as candidates to schistosomicidal agents

ABSTRACT Introduction: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives. Material and methods: We synthesized two novel imidazolidine derivatives: (LPSF/PTS10) (Z)-1-(2-chloro-6-fluorobenzyl)-4-(4-dimethylaminobenzylidene)-5-thioxoimidazolidin-2-one and (LPSF/PTS23) (Z)-1-(2-chloro-6-fluoro-benzyl)-5-thioxo-4-(2,4,6-trimethoxy-benzylidene)-imidazolidin-2-one. The structures of two compounds were determined by spectroscopic methods. During the biological assays, parameters such as motility, oviposition, mortality and analysis by Scanning Electron Microscopy were performed. Results: LPSF/PTS10 and LPSF/PTS23 were considered to be active in the separation of coupled pairs, mortality and to decrease the motor activity. In addition, LPSF/PTS23 induced ultrastructural alterations in worms, after 24 h of contact, causing extensive erosion over the entire body of the worms. Conclusion: The imidazolidine derivatives containing the trimetoxy and benzylidene halogens showed promising in vitro schistosomicidal activity.

Compostos coordenados híbridos de platina no tratamento do câncer / Platinum hybrid coordinated compounds in cancertreatment

O câncer, ou neoplasia, é uma doença caracterizada pela propagação descontrolada de formas anormais das próprias células corporais e corresponde à segunda doença que mais causa mortes no mundo. A história da platina no tratamento do câncer teve início com a descoberta da sua atividade, em 1965, com a aprovação para uso clínico acontecendo apenas após 10 anos. Atualmente, os fármacos com platina estão entre os mais bem sucedidos agentes anticancerígenos, onde se destacam cisplatina (1), carboplatina (2) e oxaliplatina (3). Seus mecanismos de ação são similares: estes fármacos formam adutos com o DNA, impedindo a sua síntese e reparo, levando à morte celular. Contudo, os efeitos adversos desencadeados pelo tratamento e o desenvolvimento de resistência ao medicamento têm limitado suas aplicações. Uma das principais estratégias para a diminuição de tais efeitos consiste em alterar a estrutura destas moléculas, levando à formação de compostos híbridos, que se caracterizam pela presença de pelo menos dois fragmentos funcionais distintos em uma mesma molécula e podem apresentar maior espectro de atividade antitumoral. Dentre as alterações mais comuns encontram-se a modificação da solubilidade, através da inserção de grupos abandonadores mais ou menos hidrofóbicos e a introdução de ligantes com atividade biológica própria. Dessa forma, esta revisão visa verificar os avanços mais recentes na síntese de compostos híbridos de platina, bem como as melhorias na atividade anticâncer dos novos compostos platinados...

Cancer, or neoplasm, is a disease characterized by the uncontrolled propagation of abnormal cells of the body and is the second leading death-causing disease. The history of platinum in cancer treatment goes back to the discovery of its activity in 1965 and its approval for clinical use just 10 years later. Some of the most successful anticancer agents are Pt-based chemotherapeutics, among which cisplatin (1), carboplatin (2), and oxaliplatin (3) stand out. They have similar mechanisms of action: they form adducts with DNA, preventing its synthesis and repair and leading to cell death. However, adverse effects triggered by treatment and the development of resistance to these drugs have limited their application. One of the most important strategies to reduce such effects is to carry out structural modifications of these molecules, leading to hybrid compounds that are characterized by the presence of at least two distinct functional fragments on the same molecule and can exhibit a broader antitumor activity spectrum. Among the most typical modifications are changes to the solubility pattern, created by the insertion of leaving groups with high or low hydrophobicity, and the introduction of biologically active ligands as non-leaving groups. The purpose of these strategies is to obtain compounds capable of reducing systemic toxicity and/or overcoming acquired resistance factors to cisplatin. Therefore, the aim of this review is to discuss the most recent advances in the synthesis of hybrid platinum compounds, as well as improvements in the anticancer activity of Pt-compounds...

The research practice of anti-arrhythmic agents targeting on potassium ion channel / 药学学报

Due to the complicated pathogenesis of cardiac arrhythmia, the safe and effective therapeutic strategies for cardiac arrhythmia remain an urgent medical problems in the recent years. In this paper, we introduced the research practice of anti-arrhythmic agents targeting on potassium ion channel. The research progress of anti-arrhythmic agents in up-to-date literatures were also reviewed and prospected.

Immunological studies and in vitro schistosomicide action of new imidazolidine derivatives

Schistosomiasis is a major public health problem with 207 million people infected and more than 779 million at risk. The drug of choice for treating schistosomiasis is praziquantel (PZQ); however, it is inefficient against immature forms of schistosomes. The aim of this study was to test new imidazolidine derivatives LPSF/PT09 and LPSF/PT10 against adult Schistosoma mansoni worms. IC50, cytotoxicity, immune response and cell viability assays were also available for these imidazolidines. Different concentrations of imidazolidine, from 32 to 320 »M, promoted motor abnormalities in breeding and unpaired worms, and death in 24 hours at higher concentrations. Although LPSF/PT09 and LPSF/PT10 did not affect IFN-³ and IL-10 production, they induced nitric oxide production and showed a similar behavior to praziquantel on cell death test. Thus, these new imidazolidine derivatives should undergo further study to develop schistosomiasis drugs.

Aldose Reductase Inhibitor Ameliorates Renal Vascular Endothelial Growth Factor Expression in Streptozotocin-Induced Diabetic Rats

PURPOSE: The vascular endothelial growth factor (VEGF) expression of podocyte is one of the well-known major factors in development of diabetic nephropathy. In this study, we investigated the effects of aldose reductase inhibitor, fidarestat on diabetic nephropathy, and renal VEGF expression in a type 1 diabetic rat model. MATERIALS AND METHODS: Twenty four Sprague-Dawley male rats which were performed intraperitoneal injection of streptozotocin and normal six rats were divided into four groups including a normal control group, untreated diabetic control group, aldose reductase (AR) inhibitor (fidarestat, 16 mg.kg(-1).day(-1)) treated diabetic group, and angiotensin receptor blocker (losartan, 20 mg.kg(-1).day(-1)) treated diabetic group. We checked body weights and blood glucose levels monthly and measured urine albumin-creatinine ratio (ACR) at 8 and 32 weeks. We extracted the kidney to examine the renal morphology and VEGF expressions. RESULTS: The ACR decreased in fidarestat and losartan treated diabetic rat groups than in untreated diabetic group (24.79 +/- 11.12, 16.11 +/- 9.95, and 84.85 +/- 91.19, p < 0.05). The renal VEGF messenger RNA (mRNA) and protein expression were significantly decreased in the fidarestat and losartan treated diabetic rat groups than in the diabetic control group. CONCLUSION: We suggested that aldose reductase inhibitor may have preventive effect on diabetic nephropathy by reducing renal VEGF overexpression.

Bicalutamide-induced Interstitial Lung Disease / 결핵및호흡기질환

Androgen deprivation therapy, which is the standard treatment for metastatic prostate cancer, includes nonsteroidal antiandrogenic drugs, such as flutamide, nilutamide and bicalutamide. Of them, bicalutamide rarely induces interstitial pneumonia. We report a case of bicalutamide-induced interstitial pneumonia. A 68-year old male diagnosed with prostate cancer and multiple bone metastases presented with dry cough and low grade fever for 3 days. He had taken bicalutamide (50 mg/day) for 13 months. High resolution computed tomography revealed ground glass opacity in his right upper lung. The laboratory studies showed no eosinophilia in the serum and bronchoalveolar lavage fluid. Despite the use of antimicrobial agents for 2 weeks, the extent of the lung lesions increased to the left upper and right lower lung. He had no environmental exposure, collagen vascular disease and microbiological causes. Under the suspicion of bicalutamide-induced interstitial pneumonia, bicalutamide was stopped and prednisolone (1 mg/kg/day) was initiated. The symptoms and radiologic abnormalities were resolved with residual minimal fibrosis.

Renin-angiotensin system blocking agents reverse the myocardial hypertrophy in experimental hyperthyroid cardiomyopathy via altering intracellular calcium handling / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the mechanisms of myocardial hypertrophy induced by Levothyroxine (L-Thy).</p><p><b>METHODS</b>A rabbit model of hyperthyroidism was established by daily intraperitoneal injections of L-Thy (45 microg/kg per day) for 28 days. New Zealand rabbits were randomly divided into four groups (n = 10 each): control group, L-Thy group (L-Thy alone), imidapril group (L-Thy + 0.5 mg/kg imidapril), and valsartan group (L-Thy + 8 mg/kg valsartan). All rabbits were treated for 4 weeks. At the end of the treatments, all rabbits underwent echocardiography and IVS, LV and LVPW thickness were measured. Ventricular tissues were then collected.Cardiac hypertrophy index, cardiomyocyte diameter, structural and ultrastructural changes were obtained. Ventricular myocytes were isolated by enzymatic digestion method and intracellular Ca2+ concentration was determined with the fluorescent Ca2+ indicator Fluo3/AM and laser scanning confocal microscopy. Activity of Sarco/Endoplasmic reticulum Ca2+ ATPase (SERCA) was evaluated with P-NPP method.mRNA expression of L-type Ca2+ channel (LCC), ryanodine receptor (RyR), and SERCA was semi-quantified with RT-PCR. Protein of IP3R was localized by immunostaining and semi-quantified with pathological image analytic system.</p><p><b>RESULTS</b>Compared with control group, rabbits treated with L-Thy displayed remarkable myocardial hypertrophy and morphological changes in both structure and ultrastructure levels. Increased intracellular Ca2+ concentration [(576.2 +/- 41.7) nmol/L vs. (314.6 +/- 35.6) nmol/L, P < 0.01] and decreased SERCA activity [(0.062 +/- 0.013) micromol x min(-1)xg(-1) vs. (0.133 +/- 0.022) micromol x min(-1)xg(-1), P < 0.01] were detected in L-Thy treated rabbits. RT-PCR analysis and (or) immunohistochemistry revealed decreased mRNA expression of LCC mRNA (0.48 +/- 0.11 vs. 0.75 +/- 0.16, P < 0.01) and increased RyR mRNA (1.19 +/- 0.21 vs. 0.73 +/- 0.15, P < 0.01), SERCA mRNA (1.01 +/- 0.08 vs. 0.76 +/- 0.09, P < 0.01) and IP3R protein (65.3 +/- 13.7 vs. 47.9 +/- 10.2, P < 0.01) expression in L-Thy treated rabbits. Both imidapril and valsartan could significantly attenuate cardiomyocyte hypertrophy and structural remodeling induced by L-Thy. Compared with L-Thy group, decreased intracellular Ca(2+) concentration [(376.4 +/- 32.5) nmol/L vs. (576.2 +/- 41.7) nmol/L, P < 0.01 and (392.6 +/- 41.2) nmol/L vs. (576.2 +/- 41.7) nmol/L, P < 0.01, respectively], and increased LCC mRNA (0.68 +/- 0.14 vs. 0.48 +/- 0.11, P < 0.01; 0.64 +/- 0.13 vs. 0.48 +/- 0.11, P < 0.01, respectively) and SERCA activity [(0.115 +/- 0.019) micromol x min(-1)xg(-1) vs. (0.062 +/- 0.013) micromol x min(-1)xg(-1), P < 0.01; (0.109 +/- 0.015) micromol x min(-1)xg(-1) vs. (0.062 +/- 0.013) micromol x min(-1)xg(-1), P < 0.01, respectively] were found in both imidapril and valsartan treated rabbits, but expression of RyR, SERCA and IP3R remained unchanged.</p><p><b>CONCLUSION</b>Intracellular Ca(2+) overload may play important roles in myocardial hypertrophy induced by L-Thy. Imidapril and valsartan may exert beneficial effects on hyperthyroid myocardial hypertrophy via altering intracellular calcium handling.</p>

Antiarrhythmic drugs: present and future.

The treatment of cardiac arrhythmias has undergone a sea change with the advent of catheter ablative procedures (radiofrequency ablation) and use of implantable cardioverter defibrillator (ICD). The antiarrhythmic drugs at times are used to prevent device related arrhythmia rather than being used for primary treatment of arrhythmias. Antiarrhythmic drugs are grouped according to their drug action as proposed by Vaughan William or by their action on ion channels. Currently amiodarone is the most commonly used drug followed by sotalol, class II, class IV and other class III drugs. It is now well known that amiodarone has several non-cardiac toxic effects particularly on long term therapy. Efforts are on to develop newer drugs which have efficacy of amiodarone without complex pharmacokinetics and toxicity. Newer drugs like azimilide with class III action are also being developed.

Long-term effectiveness of luteinizing hormone-releasing hormone agonist or antiandrogen monotherapy in elderly men with localized prostate cancer (T1-2): a retrospective study / 亚洲男科学杂志(英文版)

<p><b>AIM</b>To evaluate the long-term effectiveness, side effects and compliance rates of two types of drugs (luteinizing hormone-releasing hormone [LHRH] agonist and antiandrogen) that were used individually to treat patients with localized prostate cancer (T1-2) at our institution.</p><p><b>METHODS</b>Ninety-seven patients who were diagnosed in the period from April 1997 to January 2000 as having clinically localized prostate cancer (T1-2) received either LHRH agonist (leuprolide acetate 7.5 mg/month) monotherapy (group 1, n = 62) or antiandrogen monotherapy (group 2, n = 35; 18 received bicalutamide 50 mg q.d., 13 received nilutamide 150 mg t.i.d. and 4 received flutamide 250 mg t.i.d.). The mean age in both groups was 76 years.</p><p><b>RESULTS</b>The mean follow-up time was (50.8 +/- 8.5) months in group 1 and (43.1 +/- 2.2) months in group 2. Prostate-specific antigen (PSA) levels rose in only 1 of the 62 patients (1.6%) in group 1, and in 20 of the 35 patients (57.1%) in group 2. In group 2, 10 of the 20 patients (50%) with increasing PSA levels were treated with LHRH salvage therapy, and eight (80%) responded. Hot flashes (54.8%) and lethargy (41.9%) were the most common side effects in group 1. In contrast, nipple-tenderness (40%) and light-dark adaptation (17.1%) were more often seen in group 2. Only 1 of the 62 patients (1.6%) in group 1 switched to another medication because of adverse side effects; whereas 8 of the 35 patients (22.9%) in group 2 did so.</p><p><b>CONCLUSION</b>Unlike antiandrogen monotherapy, LHRH agonist monotherapy provided long-term durable control of localized prostate cancer (T1-2). It can also be an effective treatment option for patients whose disease failed to respond to antiandrogen monotherapy. The limitations of our study are the lack of health outcomes analysis and a small sample size.</p>

New imidazolidinic bioisosters: potential candidates for antischistosomal drugs

The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies the potential of substituent groups in the derivatives (Z)3-benzyl-5-(2-fluoro-benzylidene)-imidazolidine-2,4-dione NE4, 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin -2-ona PT5, 3-benzyl-5-(3-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one JT53; 3-benzyl-1-methyl-5-(4-methyl-benzylidene)-2-thioxo-imidazolidin-4-one JT63; 3-benzyl-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo -imidazolidin-4-one JT68; 3-(4-chloro-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT69; 3-(4-phenyl-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT72 by determining the viability in vitro of adult S. mansoni worms in the presence of these derivatives. The susceptibility of the worms obtained from mice and kept in culture in the presence of different concentrations was determined by way of schistosomacide kinetic, observed every 24 h over a period of eight days. The results show that the worms were more sensitive to the PT5 derivative at a concentration of 58 æM which killed 100 percent of the worms after 24 h of contact, also giving rise to alterations in the tegument surface of the worms with the formation of bubbles and peeling. These observations suggest a strong electronic contribution of the arylazo grouping in the biological response.

Effects of aldose reductase on the expression of fibronectin and collagen IV in cultured rat renal mesangial cells / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the effect of aldose reductase (AR) on expression of fibronectin and collagen IV in cultured rat renal mesangial cells (MsC).</p><p><b>METHODS</b>AR expression plasmid vector (pCDNA3-AR) was constructed by restriction endonuclease digestion and ligation procedures. Stable expression of AR in MsC was established by Lipofectin transfection. Western blot and immunofluorescence analyses were performed to verify the transfection efficiency. Expression of fibronectin and collagen IV proteins were analyzed using Western blot.</p><p><b>RESULTS</b>Expression of fibronectin and collagen IV in naive MsC treated with TGF-beta1 was upregulated in comparison to that of the untreated naive MsC (P < 0.01). MsC transfected with pCDNA3-AR showed a remarkable increase of expression of fibronectin and collagen IV (P < 0.01). Aldose reductase inhibitors (Sorbinil and Zopolrestat) significantly inhibited the expression of fibronectin and collagen IV in naive MsC (P < 0.05).</p><p><b>CONCLUSIONS</b>Overexpression or inhibition of AR activity significantly alters the expression of fibronectin and collagen IV proteins in cultured rat MsC, suggesting that AR plays a significant role in the pathogenesis of glomerulosclersis.</p>

Effects of aldose reductase transfection on the proliferation of rat mesangial cells in vitro / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the effects of aldose reductase (AR) on the proliferation of rat mesangial cells (MsC) in vitro and to investigate its mechanism.</p><p><b>METHODS</b>Cell proliferation was assessed by MTT colorimetric assay. Cell cycle and apoptosis were analyzed by flow cytometry. The growth of normal MsC and AR transfected MsC was compared. The proliferation of PDGF-BB and cellular growth stimulation by 10% NBS were investigated using AR inhibitors (ARI) Sorbinil and Zopolrestat. The effects of PDGF-BB on the expression of AR, p65 and c-Jun were assessed by Western blot. Activation of AP-1 was measured by EMSA.</p><p><b>RESULTS</b>AR expression of transfected MsC was distinctly higher than that of the control. Transfected MsC grew quicker than normal cells. ARI partially inhibited the proliferation of transfected MsC under the stimulation of PDGF-BB and 10% NBS, whereas 10% NBS had no effect on normal MsC. PDGF-BB upregulated the expression of AR and c-Jun, but had no effect on p65. The upregulation of c-Jun and the activation of AP-1 could be attenuated by ARI.</p><p><b>CONCLUSION</b>AR may participate in the pathological proliferation of MsC through the pathway related to the activation of AP-1.</p>

Effect of imidapril on the effective refractory period and sodium current of ventricular noninfarction zone in healed myocardial infarction / 药学学报

<p><b>AIM</b>To investigate the effects of imidapril (IMI) on effective refractory period (ERP) and sodium current (I(Na)) of myocytes in ventricular noninfarction zone of healed myocardial infarction (HMI) in rabbit models.</p><p><b>METHODS</b>Rabbits with left coronary artery ligation were prepared and IMI (0.625 mg x kg(-1) x d(-1), 8 weeks) was orally administered. The ERP and sodium current were recorded.</p><p><b>RESULTS</b>The ERP in HMI heart was prolonged. The ERP in IMI group was lower significantly than that of HMI group. The I(Na) density of myocyte in HMI ventricle decreased obviously. V 1/2 of steady state inactivation of I(Na) shifted to hyperpolarization, and time constant (tau) of recovery from inactivation in HMI ventricular myocyte was longer than that of sham ventricular myocyte. I(Na) density in IMI group increased markedly as compared with that of HMI group.</p><p><b>CONCLUSION</b>IMI was shown to reverse the abnormal prolongation of ERP in rabbit heart with the HMI and increase I(Na) density. It may be the mechanism of IMI preventing against antiarrhythmia in healed myocardical infarction.</p>

Long-term effects of imidapril on calcium and potassium currents in rabbit left ventricular hypertrophic myocytes / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the long-term effects of imidapril (IMI) on action potential and calcium and potassium currents in rabbit left ventricular hypertrophic myocytes.</p><p><b>METHODS</b>Rabbits were randomly divided into three groups: IMI-treated, hypertrophic and sham-operated control groups. Cardiac hypertrophy was induced in hypertrophy group by partial ligation of the abdominal aorta. In the IMI-treated group, the rabbits were administered IMI (1.5 mg x kg(-1) x d(-1)) for 8 weeks after surgery. In the sham-operated control group, the animals underwent an abdominal laparotomy without further procedure. Whole-cell patch clamp technique was used to record ionic currents.</p><p><b>RESULTS</b>Membrane capacitance was larger in hypertrophic cells than in sham-operated cells or IMI-treated cells. Action potential duration was lengthened in hypertrophic cells and was remarkably shortened by IMI. The density of ICa, L was reduced from 12.8 +/- 0.7 pA/pF in the sham-operated cells, to 7.7 +/- 0.8 pA/pF in hypertrophic cells, while it resembled the control cells after IMI treatment (11.9 +/- 1.0 pA/pF). After IMI treatment, the density of I(Ks,tail) was enhanced from 2.5 +/- 0.1 pA/pF in hypertrophic cells to 4.7 +/- 0.6 pA/pF (n = 7, P < 0.01), which was similar to the sham-operated cells. The densities of Ito and IK1 were significantly increased in IMI-treated cells, from 3.8 +/- 0.4 pA/pF and 3.7 +/- 0.5 pA/pF in the hypertrophic cells to 6.4 +/- 0.8 pA/pF and 6.5 +/- 0.3 pA/pF, respectively, but the IKr densities were not different in the three groups.</p><p><b>CONCLUSION</b>IMI could reverse the increase in membrane capacitance in hypertrophic cells, shorten action potential duration, and increase the densities of ICa, L, IKs, Ito and IK1 in hypertrophic cells.</p>