Synthesis, Characterization, and Biological Evaluation of Cu(II) Complexes Containing Triflupromazine with Glycine and Histidine.

Two novel copper (II) complexes [Cu(TFP)(Gly)Cl] ⋅ 2H2 O complex (1) and [Cu(TFP)(His)Cl] ⋅ 2H2 O complex (2) are synthesized, where TFP stands for trifluropromazine, Gly. represents glycine, and His. is histidine. Chemical composition, IR, mass spectra, and magnetic susceptibility tests are performed. Complex binding with macromolecules was investigated using UV-vis, viscosity, gel electrophoresis, and fluorescence quenching. Fluorescence spectroscopy revealed that each complex could replace ethidium bromide (EB). These complexes exhibit grooved, non-covalent, and electrostatic interactions with CT-DNA. Spectroscopy analysis of the BSA interaction showed that complexes bind to protein (Kb values for (1) is 5.89×103  M-1 and for (2) is 9.08×103  M-1 ) more strongly than CT-DNA (Kb values for (1) is 5.43×103  M-1 and for (2) is 7.17×103  M-1 ). Molecular docking analysis and spectral absorption measurements showed high agreement. Antimicrobial, antioxidant, and anti-inflammatory properties were tested in vitro. The druggability of complex (2) should be tested in vivo as it is more biologically active.

Inhibition of human UDP-glucuronosyltransferase enzyme by Dabrafenib: Implications for drug-drug interactions.

Dabrafenib is a novel small molecule tyrosine kinase inhibitor (TKI) which is used to treat metastatic melanoma. The aim of this research was to survey the effects of dabrafenib on human UDP-glucuronosyltransferases (UGTs) and to evaluate the risk of drug-drug interactions (DDIs). The formation rates for 4-methylumbelliferone (4-MU) glucuronide and trifluoperazine-glucuronide in 12 recombinant human UGT isoforms with or without dabrafenib were measured and HPLC was used to investigate the inhibitory effects of dabrafenib on UGTs. Inhibition kinetic studies were also conducted. In vitro-in vivo extrapolation approaches were further used to predict the risk of DDI potentials of dabrafenib via inhibition of UGTs. Our data indicated that dabrafenib had a broad inhibitory effect on 4-MU glucuronidation by inhibiting the activities of UGTs, especially on UGT1A1, UGT1A7, UGT1A8, and UGT1A9, and dabrafenib could increase the area under the curve of co-administered drugs. Dabrafenib is a strong inhibitor of several UGTs and the co-administration of dabrafenib with drugs primarily metabolized by UGT1A1, 1A7, 1A8 or 1A9 may induce potential DDIs.

High content phenotypic screening identifies serotonin receptor modulators with selective activity upon breast cancer cell cycle and cytokine signaling pathways.

Heterogeneity in disease mechanisms between genetically distinct patients contributes to high attrition rates in late stage clinical drug development. New personalized medicine strategies aim to identify predictive biomarkers which stratify patients most likely to respond to a particular therapy. However, for complex multifactorial diseases not characterized by a single genetic driver, empirical approaches to identifying predictive biomarkers and the most promising therapies for personalized medicine are required. In vitro pharmacogenomics seeks to correlate in vitro drug sensitivity testing across panels of genetically distinct cell models with genomic, gene expression or proteomic data to identify predictive biomarkers of drug response. However, the vast majority of in vitro pharmacogenomic studies performed to date are limited to dose-response screening upon a single viability assay endpoint. In this article we describe the application of multiparametric high content phenotypic screening and the theta comparative cell scoring method to quantify and rank compound hits, screened at a single concentration, which induce a broad variety of divergent phenotypic responses between distinct breast cancer cell lines. High content screening followed by transcriptomic pathway analysis identified serotonin receptor modulators which display selective activity upon breast cancer cell cycle and cytokine signaling pathways correlating with inhibition of cell growth and survival. These methods describe a new evidence-led approach to rapidly identify compounds which display distinct response between different cell types. The results presented also warrant further investigation of the selective activity of serotonin receptor modulators upon breast cancer cell growth and survival as a potential drug repurposing opportunity.

Structural requirements for the antitubercular quaternized triflupromazine pharmacophore.

Quaternized triflupromazine derivatives (QTDs) must possess benzyl groups attached to the quaternary nitrogen in order to have significant antitubercular potency. Replacing the quaternary amine with a triazole abolishes antitubercular activity. A modest halogen substitution effect exists, with the 4-bromophenyl QTD 3 having the best selectivity index (>21). All N-benzyl QTDs 1-4 similarly inhibit non-replicating, persistent Mycobacterium tuberculosis with MIC<8 µM, and compounds 1-3 were all nontoxic to mammalian cells in vitro (IC(50)>128 µM).

The identification of inhibitors of Schistosoma mansoni miracidial transformation by incorporating a medium-throughput small-molecule screen.

In Schistosoma mansoni, the miracidium-to-primary sporocyst transformation process is associated with many physiological, morphological, transcriptional and biochemical changes. In the present study, we use a medium-throughput small-molecule screen to identify chemical compounds inhibiting or delaying the in vitro transformation of miracidia to the sporocyst stage. The Sigma-Aldrich Library of Pharmacologically Active Compounds (LOPAC) contains 1280 well-characterized chemical compounds with various modes of action including enzyme inhibitors, antibiotics, cell-cycle regulators, apoptosis inducers and GPCR ligands. We identified 47 compounds that greatly reduce or delay this transformation process during a primary screen of live miracidia. The majority of compounds inhibiting larval transformation were from dopaminergic, serotonergic, ion channel and phosphorylation classes. Specifically, we found that dopamine D2-type antagonists, serotonin reuptake inhibitors, voltage-gated calcium channel antagonists and a PKC activator significantly reduced in vitro miracidial transformation rates. Many of the targets of these compounds regulate adenylyl cyclase activity, with the inhibition or activation of these targets resulting in increased cAMP levels in miracidia and concomitant blocking/delaying of larval transformation.

Effects of chemical manipulation of mitotic arrest and slippage on cancer cell survival and proliferation.

Microtubule-targeting cancer therapies interfere with mitotic spindle dynamics and block cells in mitosis by activating the mitotic checkpoint. Cells arrested in mitosis may remain arrested for extended periods of time or undergo mitotic slippage and enter interphase without having separated their chromosomes. How extended mitotic arrest and mitotic slippage contribute to subsequent cell death or survival is incompletely understood. To address this question, automated fluorescence microscopy assays were designed and used to screen chemical libraries for modulators of mitotic slippage. Chlorpromazine and triflupromazine were identified as drugs that inhibit mitotic slippage and SU6656 and geraldol as chemicals that stimulate mitotic slippage. Using the drugs to extend mitotic arrest imposed by low concentrations of paclitaxel led to increased cell survival and proliferation after drug removal. Cells arrested at mitosis with paclitaxel or vinblastine and chemically induced to undergo mitotic slippage underwent several rounds of DNA replication without cell division and exhibited signs of senescence but eventually all died. By contrast, cells arrested at mitosis with the KSP/Eg5 inhibitor S-trityl-L-cysteine and induced to undergo mitotic slippage were able to successfully divide and continued to proliferate after drug removal. These results show that reinforcing mitotic arrest with drugs that inhibit mitotic slippage can lead to increased cell survival and proliferation, while inducing mitotic slippage in cells treated with microtubule-targeting drugs seems to lead to protracted cell death.

Inhibitors of clathrin-dependent endocytosis enhance TGFbeta signaling and responses.

Clathrin-dependent endocytosis is believed to be involved in TGFbeta-stimulated cellular responses, but the subcellular locus at which TGFbeta induces signaling remains unclear. Here, we demonstrate that inhibitors of clathrin-dependent endocytosis, which are known to arrest the progression of endocytosis at coated-pit stages, inhibit internalization of cell-surface-bound TGFbeta and promote colocalization and accumulation of TbetaR-I and SARA at the plasma membrane. These inhibitors enhance TGFbeta-induced signaling and cellular responses (Smad2 phosphorylation/nuclear localization and expression of PAI-1). Dynasore, a newly identified inhibitor of dynamin GTPase activity, is one of the most potent inhibitors among those tested and, furthermore, is a potent enhancer of TGFbeta. Dynasore ameliorates atherosclerosis in the aortic endothelium of hypercholesterolemic ApoE-null mice by counteracting the suppressed TGFbeta responsiveness caused by the hypercholesterolemia, presumably acting through its effect on TGFbeta endocytosis and signaling in vascular cells.

The effect of calmodulin antagonists on experimental scoliosis: a pinealectomized chicken model.

STUDY DESIGN: Randomized controlled. OBJECTIVE: To evaluate the effects of Tamoxifen (TMX) and trifluoperozine (TFP) on pinealectomized chicken scoliosis. SUMMARY OF BACKGROUND DATA: Pinealectomized chicken develops scoliosis probably due to the lack of melatonin. In addition to other functions, melatonin also acts as a calmodulin antagonist. We postulate that loss of this antagonistic effect may be the cause of scoliosis in this model. TMX and TFP are known calmodulin antagonists, which may alter the incidence and severity of scoliosis. METHODS: Seventy-two newly hatched chicken that underwent surgical pinealectomy within 72 hours of hatching were divided into 3 groups of 24 animals in each as group I (control), group II (TMX), and group III (TFP). TMX and TFP were given to groups II and III, respectively, for 10 weeks with the dose of 0.1 mg/kg/d, whereas the control group received no medication. AP scoliosis radiographs were obtained at seventh and 10th week to evaluate coronal spinal alignment. RESULTS: Three chickens in group I, 2 chickens in group II, and 1 chicken in group III died in the first postoperative week. Scoliosis incidences and magnitudes were similar among groups at seventh and 10th week. TMX and TFP groups showed decreases of incidence of upper cervical, lower cervical, lower cervical-thoracic-lumbar curves at 10th week compared with seventh week. TMX group showed a decline in thoracic region mean Cobb angle, whereas control group showed an increase (P = 0.048). TMX group showed a more prominent decline in cervicothoracic region mean Cobb angle compared with control group (P = 0.009). CONCLUSION: The incidence and magnitude of scoliosis in pinealectomized chicken may be decreased by the administration of TMX, presumably because of this drugs' calmodulin antagonism. Further studies on higher animals and dosage and timing are required.

Monitoring the (photo)genotoxicity of photosensitizer drugs: direct quantitation of single-strand breaks in deoxyribonucleic acid using an oligonucleotide chip.

Oligonucleotide chip-based assays can be a sample-thrifty, time-saving, routine tool for evaluation of chemical-induced DNA strand breaks. This article describes a novel approach using an oligonucleotide chip to determine photosensitizer-induced DNA single-strand breaks. Surface coverage of fluorophore-labeled oligonucleotides on silicon dioxide chip surfaces was determined on alkaline phosphatase digestion. Fluorescence maxima (at 520 nm) of the solutions were converted to molar concentrations of the fluorescein-modified oligonucleotide by interpolation from a predetermined standard linear calibration curve. The photosensitizing activity of chlorpromazine and triflupromazine toward DNA single-strand breaks was then studied at different drug doses and also as a function of photoirradiation time. Photoinduced single-strand breaks calculated using the method described here agreed with values predicted by theoretical extrapolation of the single-strand breaks obtained for plasmid DNAs from agarose gel electrophoresis, and thereby indirectly validated the chip-based assays. Under UV irradiation (>or=93.6 kJ/m2) chlorpromazine (>or=0.08 mM) was found to have significant photogenotoxicity. However, triflupromazine did not exhibit any (photo)genotoxicity over the concentration range studied (0.04-0.20mM). The method developed will be useful for quantitative screening of drug genotoxicity in terms of induction of breaks in DNA.

Modification of the thermal unfolding pathways of myoglobin upon drug interaction in different aqueous media.

In this work, we have analyzed the influence of two structurally related phenothiazine drugs, promazine and triflupromazine hydrochlorides, when bound to myoglobin, a model protein, and how the drug concentration and solution conditions may affect the denaturation process of this protein. In this manner, we derive the thermodynamic quantities of the unfolding process by using a spectroscopic technique such as UV-vis spectroscopy at different drugs concentrations and at pH 2.5, 5.5, and 9.0. To do this, a thermodynamic model was used which included experimental data corresponding to the pre- and post-transition into the observable transition. It has been found that both drugs play a destabilizing role for the protein, at least at low concentrations. In addition, at acidic pH and higher drug concentrations, a stabilizing effect can be observed, which may be related to the formation of some type of protein refolding, subsequent aggregation, or both. The reason for this behavior has been suggested to be the different protein conformations at acidic pH, the increase of solvent-exposed hydrophobic and hydrophilic residues after denaturation and/or binding, and the different strength of drug-protein interactions when changing the solution conditions. For this reason, thermodynamic quantities such as Gibbs energies, DeltaG, and entropies of unfolding, DeltaS(m), increase as the solution pH increases provided that additional solvent-exposed hydrophobic residues are present, which were previously buried at room temperature. Moreover, the larger binding affinity at pH 9.0 due to enhanced electrostatic interactions between protein and drug molecules (drug and protein differ in their net electrical charge) additionally collaborates to this residue exposition to solvent as a consequence of the alteration of protein conformation as due to drug binding. Comparison of thermodynamic data between promazine and triflupromazine hydrochlorides also shows that drug-protein affinity and hydrophobicity also affect the thermodynamic denaturation parameters.

Synthesis and antitubercular activity of quaternized promazine and promethazine derivatives.

Quaternized chlorpromazine, triflupromazine, and promethazine derivatives were synthesized and examined as antitubercular agents against both actively growing and non-replicating Mycobacterium tuberculosis H37Rv. Impressively, several compounds inhibited non-replicating M. tuberculosis at concentrations equal to or double their MICs against the actively growing strain. All active compounds were non-toxic toward Vero cells (IC50 > 128 microM). N-Allylchlorpromazinium bromide was only weakly antitubercular, but replacing allyl with benzyl or substituted benzyl improved potency. An electron-withdrawing substituent on the phenothiazine ring was also essential. Branching at the carbon chain decreased antitubercular activity. The optimum antitubercular structures possessed N-(4- or 3-chlorobenzyl) substitution on triflupromazine.

Effects of inorganic ions on the binding of triflupromazine and chlorpromazine to bovine serum albumin studied by spectrometric methods.

The effects of inorganic salts, NaCl, NaBr, NaI, Na2SO4, KCl, KBr, KI, on the binding constants (Ks) of psychotropic phenothiazine drugs, triflupromazine (TFZ) and chlorpromazine, to bovine serum albumin (BSA) were examined by using second-derivative spectrophotometry. All of the salts examined, with the exception of Na2SO4, decreased the K values significantly, depending on the concentration of the salt, e.g., the decrease in the K values of both drugs were about 40% for 0.1 M NaCl. The results obtained with Na2SO4 indicated that neither Na+ nor SO4(2-) had any affect on the binding of the phenothiazines to BSA. Based on the Na2SO4 results and the finding that the effect of each potassium salt on binding was quite similar to that of the corresponding sodium salt, the effects of these halogen salts can be considered to be derived from their anions, although the phenothiazines are positively charged at pH 7.4. The effectiveness of the anions was determined to occur in the following order: I->>Br->Cl-; these results coincided with the published order of the binding affinity of these anions to albumin. The 19F-NMR spectra of TFZ in the presence of each of these halogen salts revealed a concentration-dependent decrease in the intensity of the signal at 13.8 ppm that had previously been assigned to the TFZ bound to Site II. Consequently, the effects of these anions on the binding of positively charged phenothiazine drugs are thought to be local steric effects caused by the binding of these anions to Site II.

Effects of phosphatidylserine and phosphatidylethanolamine content on partitioning of triflupromazine and chlorpromazine between phosphatidylcholine-aminophospholipid bilayer vesicles and water studied by second-derivative spectrophotometry.

To assess the affinity of psychotropic phenothiazine drugs, triflupromazine (TFZ) and chlorpromazine (CPZ), for the membranes of central nervous system and the other organs in the body, the partition coefficients (Kps) of these drugs to phosphatidylcholine (PC)-phosphatidylserine (PS) and PC-phosphatidylethanolamine (PE) small and large unilamellar vesicles (SUV, LUV) were examined by a second-derivative spectrophotometric method, since PS is abundantly contained in the membranes of the central nervous system and PE is distributed widely in the membranes of the organs in the body. Size and preparation methods of the vesicles did not affect the Kp values at each aminophospholipid content suggesting that the partition of the phenothiazine drugs was not affected by the structural differences in the vesicles such as their curvature or asymmetric distribution of the phospholipids between the outer and inner layers of the bilayer membranes. However, the Kp values of both drugs increased remarkably according to the PS content in the bilayer membranes, i.e., the Kp values for the vesicles of 30 mol% PS content were about 3 times of that for the vesicles of PC alone, while both Kp values slightly reduced with the increase in the content of PE in the bilayer membranes of PC-PE vesicles. The results indicate that both drugs have higher affinity for the PC-PS bilayer membranes than for the PC and PC-PE membranes, which can offer an evidence for the fact that TFZ and CPZ are predominantly distributed and accumulated in the brain and nerve cell membranes that contain PS abundantly.

Romifidine-ketamine anaesthesia in atropine and triflupromazine pre-medicated buffalo calves.

The study was conducted on 10 buffalo calves with a weight of 98.5 +/- 3.9 kg and age 9.7 +/- 1.3 months. Ten trials of two treatments were carried out using a randomized block design. Atropine at the dose of 0.02 mg/kg bodyweight was administered in both the groups. The animals of group I received romifidine at the dose of 10 microg/kg i.v., 10 min after atropine administration, whereas, animals of group II received triflupromazine at the dose of 0.3 mg/kg i.m. and 10 min later romifidine at the dose of 10 microg/kg i.v. immediately followed by ketamine at the dose of 5 mg/kg i.v. The onset of action of romifidine in group I occurred within 2 min and the animals remained under mild sedation for 31 +/- 4.8 min. In group II, the triflupromazine-romifidine-ketamine combination induced anaesthesia for 14 +/- 2.3 min. Hypothermia, significant bradycardia and respiratory depression was noticed in both groups at different time intervals.

19F NMR spectroscopic study on the binding of triflupromazine to bovine and human serum albumins.

The 19F NMR spectrum of triflupromazine hydrochloride (TFZ) in a buffer solution (pH 6.8) showed a single sharp signal of the TFZ CF3 group at 13.5 ppm from the external trifluoroacetic acid. The addition of 1 mM HSA or BSA to the sample solution caused a split of the CF3 signal into two broadened signals shifted to slightly lower (0.2 ppm) and higher (0.7 ppm) fields, respectively, from the original position. Denaturation of the albumins by guanidine hydrochloride (3M) restored the two broadened signals to a slightly broadened single signal, indicating that TFZ has at least two binding sites on HSA and BSA, respectively. From the competitive binding 19F NMR experiments using Warfarin (Site-I ligand), l-tryptophan (Site-II ligand), NaCl, and oleate, the signal at high field was assigned to the TFZ bound to Site II. Comparison of the signal intensity revealed that the affinity of TFZ for Site II on HSA was considerably higher than that on BSA. The low-field signal could be identified as a weight-averaged signal between nonspecifically bound TFZ to HSA (BSA) and free TFZ in the water phase. In the presence of physiological concentrations of NaCl, major binding of TFZ to HSA and BSA was considered to be nonspecific. The present work indicates that 19F NMR is very useful for obtaining important detailed information regarding the binding of fluorinated drugs to serum albumins.

Triflupromazine: a microbicide non-antibiotic compound.

The antipsychotic phenothiazine triflupromazine, possessing a methyl-thio substituent at position 10 and a fluorine moiety at position 2, exhibited significant antibacterial activity against 279 strains of Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) of the drug, according to the agar dilution method, was between 2 and 50 microg/ml for Staphylococcus aureus, and 5 and 100 microg/ml for shigellae and vibrios. Triflupromazine, when injected intraperitoneally into Swiss albino mice at a concentration of 30 microg/mouse (20 g), manifested a significant protection to the mice (p<0.001) when they were challenged with 50 median lethal dose (MLD) of Salmonella typhimurium NCTC 74. Moreover, there was a statistically significant reduction in the number of viable bacteria in organ homogenates and blood of mice treated with this phenothiazine compound.

Dissociation constants of phenothiazine drugs incorporated in phosphatidylcholine bilayer of small unilamellar vesicles as determined by carbon-13 nuclear magnetic resonance spectrometric titration.

The dissociation constants (pKms) of the phenothiazine drugs promazine, chlorpromazine, and triflupromazine, incorporated in the phosphatidylcholine (PC) bilayer of small unilamellar vesicles (SUV), were investigated by a 13C nuclear magnetic resonance (NMR) titration method employing their N-13CH3 (ionizable group) labelled derivatives. Use of the labelled drugs enabled direct observations of the ionization equilibrium of the N-dimethyl group. A second derivative spectrophotometric study proved that 95-98% of the phenothiazine species in the sample solutions (200 microM phenothiazine in the presence of 27 mM PC SUV) were incorporated into the PC bilayer, which simplified the calculation of pKm values by allowing that the phenothiazines in the aqueous phase could be neglected. The pKm values were calculated from the chemical shift dependence of the N-dimethyl 13C NMR signal on the pH value of sample solutions. The pKm values obtained were smaller than those measured in aqueous solutions by about one unit. The existence of cholesterol (30 mol%) in the PC bilayer showed little effect on the pKm values, suggesting that cholesterol in the bilayer does not largely affect the interfacial region where the N-dimethyl group of the incorporated phenothiazines is located. The results offered clear evidence for the pKm decrease and provided their precise values.

Trans-cellular proliferating cell nuclear antigen gene activation in cerebral vascular smooth muscle by endothelial oxidative injury in vivo.

OBJECTIVE: This study was undertaken to assess the role of vascular smooth muscle cell (VSMC) Ca2+ channels and Ca2+/calmodulin-dependent protein kinase II (CaMKII) in gene regulation after oxidative endothelial injury (OEI). METHODS AND RESULTS: OEI was produced by infusion of Na fluorescein (NaFluo) photoactivated by UV light immediately before intravenous injection. Posterior cerebral arteries were studied using immunofluorescence imaging, Western blotting, or patch clamping of isolated cells. After infusion of photoactivated NaFluo, but not NaFluo, (1) superoxide dismutase-1 (SOD-1) was upregulated in endothelium, consistent with oxidant stress; (2) the fraction of VSMC nuclei labeled for proliferating cell nuclear antigen (PCNA) increased 7-fold at 6 hours, preceded by a several-fold increase in nuclear phospho-cAMP-response element binding protein, with PCNA upregulation prevented by pretreatment with polyethylene glycol (PEG)-SOD; (3) in VSMCs, phospho-CaMKII increased 20-fold 5 minutes after OEI, with a 2-fold increase in peak Ca2+ channel currents; and (4) changes in cAMP-response element binding protein and PCNA were blocked by systemic administration of lipophilic (nifedipine) or hydrophilic (amlodipine) 1,4-dihydropyridine Ca2+ channel blockers, the calmodulin inhibitor trifluoperazine, or the CaMKII inhibitor KN-93, with none of these agents preventing SOD-1 upregulation in endothelium. CONCLUSIONS: Activation of VSMC Ca2+ channels and CaMKII is a key early signaling event required for upregulation of PCNA gene expression in VSMCs after oxidative injury to endothelium.

Quantitative NMR imaging study of the mechanism of drug release from swelling hydroxypropylmethylcellulose tablets.

NMR imaging has been used to study the release behavior of two model drugs, triflupromazine-HCl and 5-fluorouracil, from swelling hydroxypropylmethylcellulose (HPMC) tablets. Preliminary experiments were performed on equilibrium mixtures of drug, polymer and water to determine how properties such as NMR relaxation parameters and self-diffusion were affected by the drug and polymer concentrations. The tablet swelling was restricted to one dimension and distributions of the water and model drugs were obtained by 1H and 19F imaging, respectively. The HPMC distribution at each time in the swelling process was determined indirectly from its effect on the relaxation parameters of the water and the drugs. In the one-dimensional swelling tablet, distributions of drug and polymer were compared to determine what factors influenced the release of drug from the swelling tablet. The distributions for triflupromazine-HCl and HPMC paralleled each other and the drug was only released at the eroding edge of the tablet where the HPMC concentration dropped below 10%. In contrast, 5-fluorouracil was released much more rapidly from the tablet and appeared to escape by diffusion from regions as high as 30% HPMC. An empirical measure of the rate of tablet edge movement can be obtained from plots of the edge position as a function of the square root of time. For HPMC, the rate of tablet expansion was determined in this way to be (2.4+/-0.8)x10(-6) cm(2) s(-1). The self-diffusion of triflupromazine-HCl in equilibrated mixtures of similar composition to the eroding tablet edge is approximately 3x10(-6) cm(2) s(-1) while the self-diffusion coefficient of 5-fluorouracil remained higher than this value until the HPMC concentration reached about 30%. This comparison of 'diffusion' properties may be useful in predicting the mechanism of drug release from other swelling hydrophilic matrix systems.

Inhibitory and lytic effects of phenothiazine derivatives and related tricyclic neuroleptic compounds, on Entamoeba histolytica HK9 and HM1 trophozoites.

It has been shown previously that tricyclic neuroleptics like clomipramine and chlorpromazine have lethal effects on Leishmania donovani and L. major, and other studies indicate that the phenothiazine inhibitors of trypanothione reductase are potential anti-trypanosomal and anti-leishmanial drugs. With this in mind and our original observation on the presence of trypanothione in Entamoeba histolytica HK9, we examined the possible inhibitory effects of various phenothiazine and tricyclic derivatives on this human parasite. We found that drugs like clomipramine (KD002), the most potent in vitro inhibitor of trypanothione reductase among 30 tricyclic compounds tested, at 25 microM after 24 h of culture under aerobic conditions, caused a substantial decrease in the number of E. histolytica HK9 trophozoites, from approx. 15 x 10(6) to 5.37 x 10(6) cells, and at 100 microM to 0.8 x 10(6) cells. A substantial inhibitory effect on cell proliferation could also be demonstrated with metronidazol (used clinically against amoebiasis). Under similar experimental conditions other tricyclic and phenothiazine derivatives (OFKs), designed originally to inhibit the trypanothione reductase of trypanosomatides, had an inhibitory effect of 16 to 95%. For comparison, similar results were obtained using clomipramine and a phenothiazine derivative (OFK006) with Trypanosoma cruzi and Crithidia luciliae, except that with the latter the inhibitory effect of clomipramine was less dramatic. Experiments comparing two E. histolytica strains showed that normal cell proliferation under anaerobiosis was higher in strain HK9 than in HM1, which is highly virulent, but that metronidazol and clomipramine were less effective against HM1. Two other drugs tested, diphenydramine (KD005) and a phenothiazine derivative (OFK008), also had significant but lower inhibitory effects on both strains. The inhibitory activity on cell proliferation and the lytic effects on this human parasite by the tricyclic compounds clomipramine, chlorpromazine and others, as well as by the phenothiazine derivatives, indicate that they can be considered potential anti-amoebic agents.