The Neuroprotective Activities of the Novel Multi-Target Iron-Chelators in Models of Alzheimer's Disease, Amyotrophic Lateral Sclerosis and Aging.

The concept of chelation therapy as a valuable therapeutic approach in neurological disorders led us to develop multi-target, non-toxic, lipophilic, brain-permeable compounds with iron chelation and anti-apoptotic properties for neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD), age-related dementia and amyotrophic lateral sclerosis (ALS). Herein, we reviewed our two most effective such compounds, M30 and HLA20, based on a multimodal drug design paradigm. The compounds have been tested for their mechanisms of action using animal and cellular models such as APP/PS1 AD transgenic (Tg) mice, G93A-SOD1 mutant ALS Tg mice, C57BL/6 mice, Neuroblastoma × Spinal Cord-34 (NSC-34) hybrid cells, a battery of behavior tests, and various immunohistochemical and biochemical techniques. These novel iron chelators exhibit neuroprotective activities by attenuating relevant neurodegenerative pathology, promoting positive behavior changes, and up-regulating neuroprotective signaling pathways. Taken together, these results suggest that our multifunctional iron-chelating compounds can upregulate several neuroprotective-adaptive mechanisms and pro-survival signaling pathways in the brain and might function as ideal drugs for neurodegenerative disorders, such as PD, AD, ALS, and aging-related cognitive decline, in which oxidative stress and iron-mediated toxicity and dysregulation of iron homeostasis have been implicated.

IOX1 activity as sepsis therapy and an antibiotic against multidrug-resistant bacteria.

Sepsis is caused by organ dysfunction initiated by an unrestrained host immune response to infection. The emergence of antibiotic-resistant bacteria has rapidly increased in the last decades and has stimulated a firm research platform to combat infections caused by antibiotic-resistant bacteria that cannot be eradicated with conventional antibiotics. Strategies like epigenetic regulators such as lysine demethylase (Kdm) has received attention as a new target. Thus, we sought to investigate the epigenetic mechanisms in sepsis pathophysiology with the aim of discovering new concepts for treatment. A transcriptome analysis of dendritic cells during their inflammatory state identified Kdm as a critical molecule in sepsis regulation. Next, 8-hydroxyquinoline-5-carboxylic acid (IOX1) ability to control endotoxemia induced by Lipopolysaccharide and bacterial sepsis was demonstrated. IOX1 has been shown to regulate endotoxemia and sepsis caused by Escherichia coli and carbapenem-resistant Acinetobacter baumannii and has also contributed to the suppression of multidrug-resistant bacterial growth through the inhibition of DNA Gyrase. These findings show that IOX1 could be a component agent against bacterial sepsis by functioning as a broad-spectrum antibiotic with dual effects.

Genetic analysis of a novel antioxidant multi-target iron chelator, M30 protecting against chemotherapy-induced alopecia in mice.

BACKGROUND: Chemotherapy-induced alopecia has been well documented as a cause of distress to patients undergoing cancer treatment. Almost all traditional chemotherapeutic agents cause severe alopecia. Despite advances in the treatment of chemotherapy-induced alopecia, there is no effective treatment for preventing chemotherapy-induced alopecia. METHODS: In the present study, we investigated the potential role of a multi-target iron chelator, M30 in protecting against cyclophosphamide-induced alopecia in C57BL/6 mice implanted with an osmotic pump. M30 enhanced hair growth and prevented cyclophosphamide-induced abnormal hair in the mice. Furthermore, we examined the gene expression profiles derived from skin biopsy specimens of normal mice, cyclophosphamide-treated mice, and cyclophosphamide treated mice with M30 supplement. RESULTS: The top genes namely Tnfrsf19, Ercc2, Lama5, Ctsl, and Per1 were identified by microarray analysis. These genes were found to be involved in the biological processes of hair cycle, hair cycle phase, hair cycle process, hair follicle development, hair follicle maturation, hair follicle morphogenesis, regulation of hair cycle. CONCLUSION: Our study demonstrates that M30 treatment is a promising therapy for cyclophosphamide-induced alopecia and suggests that the top five genes have unique preventive effects in cyclophosphamide-induced transformation.

Iron-Chelating Drugs Enhance Cone Photoreceptor Survival in a Mouse Model of Retinitis Pigmentosa.

Purpose: Retinitis pigmentosa (RP) is a group of hereditary retinal degeneration in which mutations commonly result in the initial phase of rod cell death followed by gradual cone cell death. The mechanisms by which the mutations lead to photoreceptor cell death in RP have not been clearly elucidated. There is currently no effective treatment for RP. The purpose of this work was to explore iron chelation therapy for improving cone survival and function in the rd10 mouse model of RP. Methods: Two iron-chelating drugs, 5-(4-(2-hydroxyethyl) piperazin-1-yl (methyl)-8-hydroxyquinoline (VK28) and its chimeric derivative 5-(N-methyl-N-propargyaminomethyl)-quinoline-8-oldihydrochloride (VAR10303), were injected intraperitoneally to rd10 mice every other day starting from postnatal day 14. We investigate the effects of the two compounds on cone rescue at three time points, using a combination of immunocytochemistry, RT-PCR, Western blot analysis, and a series of visual function tests. Results: VK28 and VAR10303 treatments partially rescued cones, and significantly improved visual function in rd10 mice. Moreover, we showed that the neuroprotective effects of VK28 and VAR10303 were correlated to inhibition of neuroinflammation, oxidative stress, and apoptosis. Furthermore, we demonstrated that downregulation of NF-kB and p53 is likely to be the mechanisms by which proinflammatory mediators and apoptosis are reduced in the rd10 retina, respectively. Conclusions: VK28 and VAR10303 provided partial histologic and functional rescue of cones in RD10 mice. Our study demonstrated that iron chelation therapy might represent an effective therapeutic strategy for RP patients.

A Novel Iron Chelator-Radical Scavenger Ameliorates Motor Dysfunction and Improves Life Span and Mitochondrial Biogenesis in SOD1G93A ALS Mice.

The aim of the present study was to evaluate the therapeutic effect of the novel neuroprotective multitarget brain permeable monoamine oxidase inhibitor/iron chelating-radical scavenging drug, VAR10303 (VAR), co-administered with high-calorie/energy-supplemented diet (ced) in SOD1G93A transgenic amyotrophic lateral sclerosis (ALS) mice. Administration of VAR-ced was initiated after the appearance of disease symptoms (at day 88), as this regimen is comparable with the earliest time at which drug therapy could start in ALS patients. Using this rescue protocol, we demonstrated in the current study that VAR-ced treatment provided several beneficial effects in SOD1G93A mice, including improvement in motor performance, elevation of survival time, and attenuation of iron accumulation and motoneuron loss in the spinal cord. Moreover, VAR-ced treatment attenuated neuromuscular junction denervation and exerted a significant preservation of myofibril regular morphology, associated with a reduction in the expression levels of genes related to denervation and atrophy in the gastrocnemius (GNS) muscle in SOD1G93A mice. These effects were accompanied by upregulation of mitochondrial DNA and elevated activities of complexes I and II in the GNS muscle. We have also demonstrated that VAR-ced treatment upregulated the mitochondrial biogenesis master regulator, peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) and increased PGC-1α-targeted metabolic genes and proteins, such as, PPARγ, UCP1/3, NRF1/2, Tfam, and ERRα in GNS muscle. These results provide evidence of therapeutic potential of VAR-ced in SOD1G93A mice with underlying molecular mechanisms, further supporting the importance role of multitarget iron chelators in ALS treatment.

Computer-assisted designed "selenoxy-chinolin": a new catalytic mechanism of the GPx-like cycle and inhibition of metal-free and metal-associated Aß aggregation.

Using support from rational computer-assisted design, a novel series of hybrids (selenoxy-chinolin) designed by fusing the metal-chelating agent CQ and the antioxidant ebselen were synthesized and evaluated as multitarget-directed ligands. Most of the hybrids demonstrated significant ability to mimic GPx, which is highly consistent with the prediction results of DFT studies for the selenenyl sulfide intermediates in the computational design. Using (77)Se, (1)H and (13)C NMR spectroscopy and high-resolution mass spectroscopy (HRMS), a novel catalytic mechanism, including a new selenium quinone active species, was first demonstrated. 2D NMR studies indicated that the typical hybrid has an effective interaction with Aß. In addition, the optimal compound 12k was found to possess an excellent ability to scavenge peroxide and to inhibit self- and metal-induced Aß aggregation, and an ability to disassemble preformed self- and metal-induced Aß aggregates effectively. Furthermore, 12k was able to penetrate the central nervous system (CNS) and did not exhibit any acute toxicity in mice at doses up to 2000 mg kg(-1). Overall, we demonstrated that hybrid 12k, through rational structure-based computational design, shows a potential for development as a therapeutic agent in AD.

Multi-target iron-chelators improve memory loss in a rat model of sporadic Alzheimer's disease.

AIM: Novel effective treatment is urgently needed for sporadic Alzheimer's disease (sAD). M30 ([5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline]) and HLA-20 (5-{4-propargylpiperazin-1-ylmethyl}-8-hydroxyquinoline) are brain permeable, iron chelating compounds with antioxidant activity, showing also neuroprotective activity in animal models of neurodegeneration.Weaimed to explore their therapeutic potential in non-transgenic (non-Tg) rat model of sAD developed by intracerebroventricular administration of streptozotocin (STZ-icv). MAIN METHODS: Therapeutic effects of chronic oral M30 (2 and 10 mg/kg) and HLA20 (5 and 10 mg/kg) treatment on cognitive impairment in STZ-icv rat model were explored by Morris Water Maze (MWM) and Passive Avoidance (PA) tests in neuropreventive and neurorescue paradigms. Data were analysed by Kruskal­Wallis and Mann­Whitney U test (p b 0.05). KEY FINDINGS: Five-day oral pre-treatment with M30 and HLA20 dose-dependently prevented development of spatial memory impairment (MWM probe trial-time +116%/M30; +60%/HLA20) in STZ-icv rat model (p b 0.05). Eleven-week oral treatment with M30 (3×/week), initiated 8 days after STZ-icv administration dosedependently ameliorated already developed cognitive deficits in MWM test (reduced number of mistakes 3 months after the STZ-icv treatment ­ 59%; p b 0.05) and fully restored them in PA test (+314%; p b 0.05). Chronic M30 treatment fully restored (−47%/PHF1;−65%/AT8; p b 0.05) STZ-induced hyperphosphorylation of tau protein and normalized decreased expression of insulin degrading enzyme (+37%; p b 0.05) in hippocampus. SIGNIFICANCE: The results provide first evidence of therapeutic potential of M30 and HLA20 in STZ-icv rat model of sAD with underlying molecular mechanism, further supporting the important role of multi-target ironchelators in sAD treatment.

A new quinoline alkaloid from the roots of Dictamnus angustifolius.

AIM: To investigate the quinoline alkaloids from the roots of Dictamnus angustifolius G.Don ex Sweet (Rutaceae). METHOD: The quinoline alkaloids were isolated by various column chromatographic methods and their structures were elucidated on the basis of spectral analysis. RESULTS: A new quinoline alkaloid, 5-methoxylrobustine (1), along with five known quinoline alkaloids were obtained, and their structures were identified as dictamnine (2), robustine (3), isopteleine (4), γ-fagarine (5), and skimmianine (6). Cytotoxicity testing of these alkaloids showed that all of them had weak cytotoxic activities against human breast cancer cells (MCF7). CONCLUSION: Compound 1 is a new quinoline alkaloid. Alkaloid 3 showed stronger anti-proliferation effect than the other alkaloids.

The long and winding road for the development of tasquinimod as an oral second-generation quinoline-3-carboxamide antiangiogenic drug for the treatment of prostate cancer.

IMPORTANCE OF THE FIELD: Prostate cancer is the mostly commonly diagnosed non-skin cancer in males. The culmination of the last 70 years of clinical drug development has documented that androgen ablation plus taxane-based systemic chemotherapy enhances survival, but is not curative, in metastatic prostate cancer. To effect curative therapy, additional drugs must be developed that enhance the response when combined with androgen ablation/taxane therapy. AREAS COVERED IN THIS REVIEW: The history of the discovery and development of tasquinimod as a second-generation oral quinoline-3-carboxamide analogue for prostate cancer will be presented. WHAT THE READER WILL GAIN: The mechanism for such anticancer efficacy is via tasquinimod's ability to inhibit the 'angiogenic switch' within cancer sites required for their continuous lethal growth. TAKE HOME MESSAGE: Tasquinimod is a novel inhibitor of tumor angiogenesis that enhances the therapeutic anticancer response when combined with other standard-of-care modalities (radiation, androgen ablation, and/or taxane-based chemotherapies) in experimental animal models, but does not inhibit normal wound healing. It has successfully completed clinical Phase II testing in humans and will shortly enter registration Phase III evaluation for the treatment of metastatic prostate cancer.

Recent advances in coumarins and 1-azacoumarins as versatile biodynamic agents.

Coumarins, also referred as benzopyran-2-ones, and their corresponding nitrogen counterpart, 1-azacoumarins also referred to as carbostyrils, are a family of nature-occurring lactones and lactams respectively. The plant extracts containing coumarin-related heterocycles, which were employed as herbal remedies in early days, have now been extensively studied for their biological activities. These investigations have revealed their potentials as versatile biodynamic agents. For example, coumarins with phenolic hydroxyl groups have the ability to scavenge reactive oxygen species and thus prevent the formation of 5-HETE and HHT in the arachidonic pathway of inflammation suppression. Recent in vivo studies have revealed the role of coumarins in hepatotoxicity and also in depletion of cytochrome P450. Similarly 1-azacoumarins which is part of quinoline alkaloids, are known for their diverse biological activity and recently, a 6-functionalized 1-aza coumarins are undergoing human clinical trials as an orally active anti-tumor drug in view of its farnesyl protein-inhibiting activity in the nanomolar range. Furthermore, several synthetic coumarins with a variety of pharmacophoric groups at C-3, C-4 and C-7 positions have been intensively screened for anti-microbial, anti-HIV, anti-cancer, lipid-lowering, anti-oxidant, and anti-coagulation activities. Specifically, coumarin-3-sulfonamides and carboxamides were reported to exhibit selective cytotoxicity against mammalian cancer cell lines. The C4-substituted aryloxymethyl, arylaminomethyl, and dichloroacetamidomethyl coumarins, along with the corresponding 1-azacoumarins, have been demonstrated to be potential anti-microbial and anti-inflammatory agents. To expand the structural diversity of synthetic courmarins for biological functions, attempts have also been made to attach a chloramphenicol side chain at C-3 position of courmarin. In addition, the bi- and tri-heterocyclic coumarins and 1-azacoumarins with benzofuran, furan and thiazole ring systems along with biocompatible fragments like vanillin have shown remarkable potency as anti-inflammatory agents in animal models. Photobiological studies on pyridine-fused polycyclic coumarins have highlighted their potential as thymine dimer photosensitisers and the structurally related compounds of both coumarin and carbostyrils have also been found to act via the DNA gyrase pathway in their anti-bacterial activity. Apart from the above works, the present review also addresses the potential roles of coumarins and carbostyrils as protease inhibitors, or fluorescent probes in mechanistic investigation of biochemical pathways, and their application for QSAR in theoretical studies. Though 1-Azacoumarins have received less attention as compared to coumarins in the literature, an attempt has been made to compare both the systems at various stages, so that it can spark new thoughts on synthetic methodologies, reactivity pattern and biological activities.

Linomide improves the effect of interstitial laser thermotherapy in a rat liver tumour model.

AIM: The aim of this study was to investigate if Linomide affects growth and spread of a rat liver tumour when given alone and in combination with interstitial laser thermotherapy (ILT). MATERIALS AND METHODS: Experiments were performed in Wistar rats using a dimethyl-hydrazine-induced adenocarcinoma implanted into the left lateral lobe of the liver. The rats were randomised to one of the following groups: a) ILT and Linomide, b) ILT only, c) sham ILT, d) Linomide only, or e) control. ILT was intentionally suboptimal. Linomide (100 mg/kg/day) was given in the drinking water from the start of treatment for five days. ED1, ED2 macrophages and v Willebrand (factor VIII) were determined by an immunohistochemical technique. RESULTS: Linomide reduced viable liver tumour volume both when it was given alone (p < 0.01) and when combined with ILT (p < 0.05), whereas it lowered intraperitoneal spread in ILT-treated rats alone. Six days after ILT, there was a reduction in the number of newly-recruited macrophages and blood vessels in the viable tumour tissue in rats receiving Linomide. CONCLUSION: Linomide reduced the growth of an adenocarcinoma transplanted into rat liver, when given alone or combined with laser thermotherapy and reduced the spread of tumour in laser-treated rats. The effects of Linomide in laser-treated rats appeared, at least in part, to be due to a reduction in newly-formed vessels, which might have been secondary to a reduced number of tumour-associated macrophages.

Prevention of prostate-related cancers in Lobund-Wistar rats.

BACKGROUND: Since prostate cancer (PC) development involves a combination of genetic predisposition and promotional mechanisms, especially the metabolic conversion of testosterone to 5alpha dihydrotestosterone (DHT) by 5alpha reductase, how do mechanisms in man relate to prostate-seminal vesicle (P-SV) tumor development in Lobund-Wistar (L-W) rats? The disease in man and in L-W rats shares developmental mechanisms and characteristics to the extent that prevention of P-SV tumors in L-W rats could be predictive of similar results in man. The epidemiology of PC in man and P-SV tumors in L-W rats indicates that both are hormone-related diseases based on genetic predisposition, high production of androgens (which are activated to DHT by 5alpha reductase), and early development of androgen-dependent and metastasizing late androgen-independent stages of adenocarcinomas, all after long latency periods. METHODS: L-W rats at risk of developing spontaneous or induced P-SV tumors were subjected to putative antitumor agents or procedures. These included dietary restriction, testosterone ablation, soybean-derived isoflavones, antiangiogenic linomide, tamoxifen, and a vitamin D analogue. RESULTS: L-W rats subjected to 1) early onset of dietary restriction manifested suppression of spontaneous and induced development of P-SV tumors; 2) testosterone-ablation by nonesterified DHT (NE-DHT) suppressed early onset of induced P-SV tumors and to a lesser extent late onset of spontaneous tumors; 3) diets containing soy protein isolate (high isoflavones) manifested marginal suppressive effects against induced P-SV tumors, but in 12-month-old rats, the development of spontaneous tumors was reduced in incidence; 4) early administrations of antiangiogenic linomide suppressed development of induced P-SV tumors and of transplanted prostate adenocarcinoma III (PA-III) tumors, but linomide had little antitumor effect against large advanced stage tumors; and 5) tamoxifen and vitamin D analogue suppressed development of P-SV tumors. Results in conditions 1-3 were negative when tested against PA-III tumors. CONCLUSIONS: Developing stages of P-SV tumors were prevented in L-W rats with autochthonous spontaneous and induced tumors, but most of the agents tested were of no therapeutic benefit against advanced-stage and transplanted PA-III tumors. However, early administrations of antiangiogenic linomide suppressed early growth of induced and transplanted PA-III tumors.

Amelioration of diabetes in nonobese diabetic mice with advanced disease by linomide-induced immunoregulation combined with Reg protein treatment.

Oral linomide, (quinoline-3-carboxamide), has been shown to prevent autoimmune insulitis, islet destruction, and diabetes in NOD mice treated at an early stage of the disease, but confers only partial protection in animals with advanced disease. Reg protein, the gene product of a complementary DNA isolated from a regenerating rat islet library, has been previously shown to induce expansion of beta-cell mass in pancreatectomized rats. To determine the effect of treatment combining immunomodulation and Reg protein on advanced autoimmune diabetes, we treated female NOD mice with oral linomide and i.p. Reg protein injections. In 14-week-old animals with less severe disease (glucose tolerant), treatment with each agent alone resulted in amelioration of diabetes, as did treatment with Reg alone in 5-week-old prediabetic mice. In 14-week-old animals with more severe disease (glucose intolerant), only treatment with the combination of both agents, but not that with each separately, resulted in amelioration of diabetes. Our study suggests that treatment aimed at abrogation of autoimmunity combined with expansion of beta-cell mass constitutes a potential therapeutic approach for treatment of insulin-dependent diabetes mellitus.

Modulation of experimental systemic lupus erythematosus with linomide.

OBJECTIVE: The objective of this study was to assess the beneficial effects of an early administration of low dose linomide, a new immunomodulator, in an animal model of experimental systemic lupus erythematosus (SLE). METHODS: Experimental SLE was induced in naive BALB/c mice, by immunization with anti-DNA mAb (MIV-7). Control Mice immunized with irrelevant human IgM served as controls. The immunized mice were treated with linomide (0.1 mg/ml in the drinking water), four weeks prior to the first immunization, at an early stage of the disease induction (one month after boost injection), or at a later stage (3 months following boost immunization). The treatment duration was 3 months in all schedules. The follow-up studies continued for 8 weeks after discontinuation of the treatment. The presence in the serum of autoantibodies against ssDNA, dsDNA histones, phospholipids and an irrelevant autoantigen-pyruvate dehydrogenase, was determined by enzyme-linked immunosorbent assay (ELISA). The clinical parameters assessed included erythrocyte sedimentation rate, peripheral blood cell counts and proteinuria. RESULTS: There was a 50-64% decrease in autoantibody levels in the sera of mice immunized with anti-DNA (MIV-7) mAb at the early stage of experimental SLE in mice which received linomide for a period of 3 months. No effect of linomide was noted in mice which received the drug during the later stages of experimental SLE when the disease was fully developed. Linomide had a preventive effect on the induction of experimental SLE in naive mice, when the treatment was initiated before the induction of the disease. This effect was abolished following cessation of the treatment. CONCLUSIONS: Linomide proved to be effective at the early stages of induction of the experimental SLE. However, the autoantibody levels rose following discontinuation of the therapy.

[Experience in using new drug preparations for treating adult patients with acute intestinal infections]. / Opyt primeneniia nekotorykh novykh lekarstvennykh preparatov dlia lecheniia vzroslykh bol'nykh s ostrymi kishechnymi infektsiiami.

Ciprofloxacin (Bayer, FRG), a derivative of hydroxyquinolone acid, was used for the treatment of patients with shigellosis and salmonellosis and for the sanitation of Salmonella carriers. The drug turned out to exert a positive effect on bacteriological sanitation of the body. In order to treat patients with food toxinfection of unknown etiology, use was made of intetrix (Farmacos, Socialist Federal Republic of Yugoslavia). Inclusion of the drug into combined treatment of patients with food toxinfections did not show any material advantages.

Comparison of prophylactic tetracycline and clioquinol in a rabbit model of intestinal infection with Vibrio cholerae and Escherichia coli.

The ability of tetracycline and clioquinol to prevent intestinal colonization of Vibrio cholerae and Escherichia coli was tested in a rabbit model. In the model 10(10) bacteria are given via oro-gastric tube following intravenous cimetidine and oral sodium bicarbonate and prior to intraperitoneal tincture of opium. Eighteen hours after challenge the rabbits are sacrificed, and the numbers of the challenge strain remaining in the jejunum and ileum are determined. Tetracycline interrupted the intestinal colonization of V. cholerae and E. coli. Clioquinol however, had minimal effect on the colonization process. Our studies demonstrate the efficacy of prophylactic tetracycline but do not support the use of clioquinol to prevent intestinal infection due to these organisms. This rabbit model may also be useful to study the efficacy of other antibiotics against these bacterial infections.

Successful treatment of autoimmunity in MRL/1 mice with LS-2616, a new immunomodulator.

Autoimmune MRL/1 mice were treated with a recently developed substance with immunomodulating properties, LS-2616. Treatment was initiated at the age of 8 weeks, before the onset of clinically apparent disease, and at 16 weeks of age, after development of established lupus disease. Beneficial therapeutic effects were obtained, even when LS-2616 was administered at the lowest dose tested (1 mg/mouse/week) to 16-week-old mice. The effects of LS-2616 on longevity, as well as on development of lymphadenopathy, splenomegaly, glomerulonephritis, and vasculitis, were pronounced and were comparable with those of cyclophosphamide. The results obtained suggest a potential role for LS-2616 in the treatment of autoimmune disease in humans.

Effect of clioquinol, an 8-hydroxyquinoline derivative, on rotavirus infection in mice.

Rotavirus particles are unique in their configuration. They have a double-shelled protein capsid, inside which are the viral RNA fragments and a viral polymerase. The outer shell is involved in the infectivity of the virus particle; without it the particle is not infective. At the cellular level during the infection process, this outer shell is made permeable by an unknown mechanism. This makes the RNA polymerase within the particle accessible to precursors of new RNA. Transcription begins, and progeny virus RNA and protein soon accumulate in the cell. In vitro studies show that chelators such as EDTA and EGTA may be used to make the virion permeable, allowing the measurement of viral RNA polymerase activity. These chelators remove divalent cations such as Ca++ from the virus particle, thereby altering the outer shell of the virus [2]. We were interested in measuring the effect on rotavirus of chelators that have been used to treat diarrheal disease, such as clioquinol, an 8-hydroxyquinoline derivative and the principal ingredient of Entero-Vioform (Ciba Pharmaceutical Co, Summit, NJ). Seven of 10 three-day-old Icr white mice simultaneously inoculated with EDIM and administered a single dose of clioquinol developed diarrhea 48 hr after inoculation, although none had displayed diarrhea at 24 hr. These mice, therefore, developed diarrhea 24 hr later than six of eight untreated animals (P = 0.004 at 24 hr by Fisher's exact test). Moreover, no animals receiving doses of clioquinol every 12 hr had developed diarrhea by 48 hr after inoculation (P = 0.006 at 24 hr and P = 0.0001 at 48 hr, compared to untreated mice).(ABSTRACT TRUNCATED AT 250 WORDS)

[Topical antimicrobial therapy: the efficacy of clioquinol- and tribromphenolbismuth- zinc oxide preparations]. / Antimikrobielle Lokaltherapie: Zur Wirksamkeit von Clioquinol- und Tribromphenolwismut-Zinkoxid-Zubereitungen.

Clioquinol- and tribromphenolwismut zinc oxide preparations were tested in vitro in order to investigate their bactericidal and bacteriostatic efficacy against strains of staphylococcus aureus, E. coli, pseudomonas as well as against the fungi candida albicans and trichophyton rubrum. The results show that there was both a bacteriostatic and a bacteriocidal effect of clioquinol except against pseudomonas. Tribromphenolwismut has less efficacy. In spite of some suggestions in the literature our results confirm that the efficacy of clioquinol is not impaired if combined with zinc oxide. The use of this well tolerated preparation is recommended in the treatment of infectious dermatoses even today.