Innovative pharmaceutical strategies for niclosamide repositioning / Estratégias farmacêuticas inovadoras para o reposicionamento da niclosamida

The antiparasitic niclosamide has shown promising anticancer activity in preclinical studies against several types of cancer, such as colorectal and prostate. Thus, the objective of this work was to develop innovative formulations for the repositioning of niclosamide as an anticancer agent. In chapter I, a critical review of the literature on the physicochemical properties of the drug was carried out, in addition the results of clinical studies against colorectal and prostate cancer. Besides, a review was carried out on studies that developed formulations containing this drug, as well as hypotheses to improve the biopharmaceutical performance of this molecule. In chapter II, the development of solid amorphous dispersion containing niclosamide was carried out. Drug/polymer solutions were acoustic levitated and characterized by synchrotron X-ray light. This set allowed fast, high quality measurements, as well as the identification of niclosamide recrystallization. Plasdone® and Soluplus® demonstrated better properties to form amorphous dispersions, with the latter showing superior solubility enhancement. The study showed that the developed formulation increased the apparent saturation solubility of niclosamide in water by two times. In chapter III the objective was the development, physicochemical characterization and in vitro anticancer activity of a niclosamide nanoemulsion, having HCT-116 cells as a cellular model. Preliminary results indicated Capmul® MCM C8 as the best liquid lipid for the system, but the first nanoemulsions containing this lipid were not stable to justify its usage. On the other hand, Miglyol® 812 indicated to be a suitable liquid lipid for the system. The niclosamide nanoemulsion (~200 nm) with Miglyol® 812 and poloxamer 188 was stable for 56 days, with a monomodal particle size distribution. Cell viability assay against HCT-116 cells demonstrated that niclosamide cytotoxicity is time and concentration dependent. Results herein obtained encourage further research to understand and optimize niclosamide performance as an anticancer drug substance

O antiparasitário niclosamida tem apresentado promissora atividade anticâncer em estudos pré- clínicos contra diversos tipos de câncer, como coloretal e próstata. Assim, o objetivo deste trabalho foi desenvolver formulações inovadoras para o reposicionamento da niclosamida como agente anticâncer. No capítulo I foi realizada revisão crítica da literatura sobre as propriedades físico-químicas do fármaco, além de resultados de estudos clínicos da niclosamida contra câncer de coloretal e de próstata. Além disso, foi feita revisão sobre estudos que desenvolveram formulações contendo esse fármaco, bem como hipóteses para melhorar o desempenho biofarmacêutico dessa molécula. No capítulo II foi realizado o desenvolvimento de dispersão solida amorfa contendo niclosamida. Soluções de fármaco/polímero foram levitadas em levitador acústico e caracterizadas por raios-X de luz síncrotron. Este conjunto permitiu medições rápidas e de alta qualidade, bem como identificação de recristalização da niclosamida. Plasdone® e Soluplus® demonstraram melhores propriedades para formar as dispersões amorfas, com o último apresentando aumento de solubilidade superior. O estudo mostrou que a formulação desenvolvida aumentou em duas vezes a solubilidade aparente de saturação da niclosamida em água. No capítulo III o objetivo foi o desenvolvimento, a caracterização físicoquímica e atividade anticâncer in vitro de uma nanoemulsão de niclosamida, tendo células HCT-116 como modelo celular. Resultados preliminares indicaram o Capmul® MCM C8 como o melhor lipídio líquido para o sistema, mas as primeiras nanoemulsões contendo este lipídio não foram estáveis para justificar seu uso. Por outro lado, Miglyol® 812 indicou ser um lipídio líquido adequado para o sistema. A nanoemulsão de niclosamida (~200 nm) com Miglyol® 812 e poloxâmero 188 foi estável por 56 dias, com distribuição monomodal do tamanho de partícula. O ensaio de viabilidade celular contra células HCT-116 demonstrou que a citoxicidade da niclosamida é dependente do tempo e da concentração. Os resultados aqui obtidos encorajam mais pesquisas para entender e otimizar o desempenho da niclosamida como uma substância anticancerígena

The effect of Niclosamide in acetic acid induce colitis: an experimental study

Ulcerative colitis is an idiopathic chronic inflammatory disease of the colon for which a lot of treatment modalities are present. However, significant side effects are associated with them, and there is a need for a search for other tretment options. This study was aimed to assess the contribution of niclosamide in experimentally established colitis in rats. Animals were categorized into 5 groups; the control group undergoes no induction of UC, colitis group in which UC was induced, and animals receive no treatment, the niclosamide group that received niclosamide and sulfasalazine group that received sulfasalazine. Each group was composed of 10 animals. After the completion of a one-month period of the experiment animals were sacrificed and the following meausres were done: the weight of the colon, determination of the area of mucosal damage by mm2, histological scoring after hematoxylin and eosin stain together with MAC score and immunohistochemistry of IL-6, TNF-alpha, MPO, MDA, CD62, and ICAM1. The results of the current study revealed that Nicosamide was able to reduce the area of mucosal damage, colon weight, histological and Mac scores and immunohistochemical scores of inflammatory and oxidative markers, significantly when contrasted to a group of colitis (P< 0.05). It has been concluded that Niclosamide was proved to have a significant effect as an adjuvant mode of therapy for colitis through its, anti-inflamatory and anti-oxidant effects (AU)

Himenolepiasis por Hymenolepis nana, a propósito de 2 casos / Hymenolepiasis due to Hymenolepis nana, in relation to 2 cases

La himenolepiasis es una infección parasitaria cosmopolita; su prevalencia global oscila entre 0.1 y 58%, es más frecuente en niños. El agente etiológico es el cestodo Hymenolepis nana, que evoluciona mediante ciclos vitales: monoxénico (en el cual existe un único huésped definitivo e intermediario que puede ser el ser humano, ratas y ratones) y un ciclo heteroxénico (en el que un artrópodo ­pulga o gorgojo­ consume los huevos presentes en las materias fecales y desarrolla el cisticercoide ­larva­). Este vector es ingerido por el huésped definitivo (humano o rata) desarrollando posteriormente la infección. Los síntomas dependerán del grado de afectación de las vellosidades del intestino delgado; se destacan: dolor abdominal, meteorismo, diarrea, irritabilidad, prurito anal y anorexia. El tratamiento de elección es el praziquantel 25 mg/kg dosis única. Presentamos 2 casos de usuarios adultos que acuden al Centro de Salud de San Antonio de Pichincha ­ Quito, con sintomatología inespecífica, a los que se les realiza examen coproparasitario como control al primero y como sospecha por contacto con roedor al segundo; en ambos casos se encuentra el parásito. Aunque se decide iniciar el tratamiento con praziquantel, no se lo consigue, por lo que se prescribe niclosamida 2 g por día durante 2 días; desapareció el cuadro sintomático y el parásito en el examen de control de laboratorio (AU)

Hymenolepiasis is a parasitic infection with a cosmopolitan distribution, it has a global prevalence ranging from 0.1 to 58%. Is more frequent in children and is produced by the Hymenolepis nana basket, which evolves through life cycles: monoxenic, with a single final host and an intermediate host, which can be a man, rats or mice. In the heterocyclic cycle, it's evident the presence of an arthropod (flea or weevil) that consumes eggs in fecal matter and develops the cysticercoid (larva). Then, this vector is ingested by the definitive host (human or rat) who is going to develop the infection subsequently. Symptoms depend on the degree of involvement of villi in the small intestine, including abdominal pain, bloating, diarrhea, irritability, anal pruritus and anorexia. The treatment of choice is praziquantel in a single dose of 25 mg. In the present work, we describe the cases of users who visited the Health Center of San Antonio de Pichincha in Quito. They came with nonspecific symptomatology. At first, they were analyzed through a coproparasitary examination of the control and the suspicion of contact with the rodent at second. In both cases with the pathology. It was decided to start the treatment. However, this medication was not obtained, so a dose of 2 g per day for 2 days of niclosamide was given for disappearing of the clinical picture. (AU)

Bioensaio de atividade moluscicida adaptado para a avaliação de extratos de plantas medicinais / Bioensayo de actividad moluscicida adaptado para evaluación de extractos de plantas medicinales / Bioassay of molluscicidal activity adapted for the evaluation of medicinal plant extracts

Nesta nota é apresentada detalhadamente a metodologia (preparação dos extratos, adaptação dos caramujos, ensaio de atividade, destino dos caramujos) usada para a avaliação da atividade moluscicida de extratos de plantas frente a caramujos da espécie Biomphalaria glabrata. A adaptação desta metodologia tem o propósito de avaliar extratos naturais para a busca de produtos alternativos mais baratos, biodegradáveis, seguros e disponíveis localmente, para o controle das populações de caramujos.

The methodology (extract preparation, adaptation of the snails, activity test, destiny of the snails) used for the evaluation of the molluscicidal activity of plant extracts in relation to snails from the Biomphalaria glabrata species appears in detail in this note. The adaptation of this methodology has the purpose of evaluating natural extracts in order to find cheaper, biodegradable, safe and easily available alternative products for the control of the populations of snails.

En este apunte se presenta detalladamente la metodología (preparación de los extractos, adaptación de los caracoles, ensayo de actividad, destino de los caracoles) utilizada para la evaluación de la actividad moluscicida de extractos de plantas frente a caracoles de la especie Biomphalaria glabrata. La adaptación de esta metodología tiene el propósito de evaluar extractos naturales para la búsqueda de productos alternativos más baratos, biodegradables, seguros y disponibles localmente, para el control de las poblaciones de caracoles.

Field trials of low dose Bayluscide on snail hosts of schistosome and selected non-target organisms in sahelian Cameroon

More than 85 percent of all cases of schistosomiasis in Cameroon occur in the northern sahelian half of the country representing 20 percent of the population. Several workers have advocated the integrated approach to schistosomiasis control, including snail control, but the death and decay of aquatic organisms, and fish kill that often follows Bayluscide application at the dose of 1g/m³ decrease its acceptability. The present study was designed to assess the effect of lower Bayluscide doses on snail host and non-target fish, frog, the tadpole kill. Bayluscide was applied to study ponds at concentrations of 0, 0.25, 0.5, and 1 g/m³ (ppm). Pre and post application assessment of snails hosts of schistosomes, fish, frog, and tadpole kill were carried out. All 0.25, 0.5, and 1 g/m³ Bayluscide concentrations reduced snail population significantly. Bayluscide concentration of 0.50 g/m³ applied in two rounds of 0.25 g/m³ resulted in high snail mortality and low lethality to fish, frogs, and tadpoles. Further studies are needed to assess the cost-effectiveness of Bayluscide in the control of schistosomiasis following the simplified approach.

Molluscicidal effect of nicotinanilide and its intermediate compounds against a freshwater snail Lymnaea luteola, the vector of animal schistosomiasis

The molluscicidal effect of nicotinanilide was evaluated and compared with niclosamide (2',5-dichloro-4'-nitrosalicylanilide, ethanolamide salt) against different stages of the freshwater snail Lymnaea luteola i.e., eggs, immature, young mature, and adults. Calculated values of lethal concentrations (LC50 and LC90 ) showed that both nicotinanilide and niclosamide as toxic against eggs, immature, and adults. The young mature stage of the snails was comparatively more tolerant to both molluscicides than the other stages. The toxicity of the intermediate compounds of nicotinanilide against the young mature stage of the snails showed them as ineffective. The mortality pattern of the snails exposed to LC90 concentration of these molluscicides showed niclosamide to kill faster (within 8 to 9 h) than nicotinanilide (26 to 28 h). In view of the above studies it may be concluded that both molluscicides are toxic against all the stages of the L. luteola snails.

The molluscicidal activity of niclosamide (Bayluscide WP70®) on Melanoides tuberculata (Thiaridae), a snail associated with habitats of Biomphalaria glabrata (Planorbidae)

The aim of this study was to determine the toxicity of niclosamide (Bayluscide ®) on Melanoides tuberculata and Biomphalaria glabrata under laboratory conditions. The latter species is the intermediate host of Schistosoma mansoni (Sambon 1917). M. tuberculata was successfully used as competitor of B. glabrata in biological control programs in French West Indies. Both molluscicide and biological control using M. tuberculata have proved to be successful in reducing the population density of B. glabrata. The associated use of molluscicide in this area would be an effective measure if M. tuberculata were less susceptibility to the molluscicide than B. glabrata. Three hundreds individuals each of B. glabrata and of M. tuberculata, collected in Sumidouro, State of Rio de Janeiro, were used in the experiment. The molluscs were exposed to 14 different concentrations of niclosamide as recommended by the World Health Organization. Probit analysis was used to determine the LC 50 and LC 90. The LC 50 and LC 90 values for B. glabrata were 0.077 mg/l and 0.175 mg/l, respectively and the LC 50 and LC 90 values for M. tuberculata were 0.082 mg/l and 0.221 mg/l respectively. As the lethal concentrations of niclosamide were approximately the same to both species, this could be a disadvantage when controlling B. glabrata with niclosamide in an area of M. tuberculata occurrence. It migth therefore be preferable to utilize the latex extracted from the Euphorbia splendens, which presented a much higher efficiency for B. glabrata than to M. tuberculata

Aspectos histopatológicos de Biomphalaria glabrata Say, 1817, hospedeiro intermediário de Schistosoma mansoni, submetida a Niclosamida / Histological change in Biomphalaria glabrata, Say, 1817, Schistosoma mansoni intermediary host, submitted to Niclosamide

Foi feita uma avaliaçäo histológica de moluscos da espécie Biomphalaria glabrata submetidos a soluçöes aquosas de niclosamida, em concentracöes subletais. Os experimentos foram realizados de acordo com os parâmetros descritos pela Organizaçäo Mundial da Saúde para testes com moluscicidas. Os resultados demonstraram lesöes focais na glândula digestiva, rim e gônadas, e uma correlaçäo entre a concentraçäo da soluçäo e a extensäo das lesöes

Teniosis: serie clínica en 35 pacientes / Teniosis: a clinical serie of 35 human cases

Se presenta una serie clínica de 35 pacientes con teniosis. Los pacientes tenían un rango de edad que fluctuaba entre 4 a 71 años, 32 pacientes eran de zona urbana. En la serie se demostró la presencia de 6 casos con Taenia solium, 24 con Taenia saginata, 4 con Taenia spp, 1 caso con Diphyllobothrium latum. El motivo de consulta en 34 casos fue la eliminación de proglótidas. Entre los antecedentes de riesgo 27 pacientes tenían como antecedentes consumir carne cruda de vacuno y 5 de ellos consumían además carne cruda de cerdos. El tiempo de eliminación de proglótidas varió entre 4 días a 40 años. Los pacientes fueron tratados con niclosamida o praziquantel sin presentar reacciones adversas a los medicamentos

Infección por dypilidium caninum en un lactante / A case of infection by dypilidium caninum in an infant

Dypilidium caninum es un cestode común en perros y gatos distribuido en todo el mundo. El ser humano, huesped accidental, adquiere la infección a través de las pulgas en asociación con las mascotas infectadas, siendo esta enfermedad más frecuente en niños. Presentamos el caso de una niña de un año y medio de edad, que durante siete meses eliminó proglótidas en las deposiciones, consultando en numerosas oportunidades siendo tratada con fármacos dirigidos a protozoos y nematelmintos. Finalmente, luego de la identificación del Dypilidium caninum se trató a la paciente con niclosamida, evolucionando satisfactoriamente

Effects of bayluscide WP 70 on the survival and water-leaving behaviour of Biomphalaria straminea, snail host of schistosomiasis in northeast Brazil

The toxic and behavioural effects of niclosamide (Bayluscide WP 70) on Biomphalaria straminea from a highly endemic area of schistosomiasis in northeastern Brazil were investigated through laboratory bioassays. The LD50 and LD90 were 0.114 mg/l and 0.212 mg/l, respectively. Water-leaving behaviour occured among 14 per cent to 30 per cent of snails in the presence of sublethal doses of niclosamide and among 16 per cent of the controls. It was concluded that both relatively low susceptibility to niclosamide and water-leaving behaviour of local B. straminea may be responsable for the recolonization of transmission foci after mollusciciding. It was suggested that recently improved measures of snail control, such as controlled-release formulations of niclosamide and plant molluscicides should be considered in areas where snail control is recommended.

Evaluation of the molluscicidal properties of Euphorbia splendens var. hislopii (N.E.B.) Latex: experimental test in an endemic area in the state of Minas Gerais, Brazil

Following the positive results obtained regarding the molluscicidal properties of the latex of Euphorbia splendens that were corroborated in laboratory and field tests restrited conditions, a field study was conducted in experimental streams located in an endemic area. After recording the average annual fluctuation of vectors in three streams, a solution of E. splendens latex at ppm was applied in stream A, a solution of niclosamide at 3 ppm that applied in stream B and a third stream (C) remained untreated for negative control. Applications of E. splendens and niclosamide resulted in a mortality of 100 per cent among the snails collected in the streams A and B. No dead snails were found in the negative control stream. A monthly follow-up survey conducted during three consecutive months confirmed the return of vectors to both experimental streams treated with latex and niclosamide. This fact has called for a need to repeat application in order to reach the snails that remained buried in the mud substrate or escaped to the water edge, as well as, newly hatched snails that did not respond to the concentration of these molluscicides. Adults snails collected a month following treatment led us to believe that they had migrate from untreated areas of the streams to those previously treated.

Effect of Niclosamide (Bayluscide WP 70), Anacardium occidentale hexane extract and Euphorbia splendens latex on behavior of Biomphalaria glabrata (Say, 1818), under laboratory conditions

The repellent effect of the molluscicides Niclosamide (Bayluscide WP 70), Anacardium occidentale and the latex of Euphorbia splendens on Biomphalaria glabrata was observed through the investigation of the occurrence of escape behavior among molluscs that were exposed to dosages lower than the LD 50. The total number of individuals out of water among the surviving snails in the control group provided a "Natural Escape Index". The comparison between this total and the total number of surviving snails in each group exposed to the different dosages of the molluscicides after 24 hr provided the "Molluscicide Escape Index" and the detection of a "Repellency Range" to these snails. The escape indexes for Niclosamide, A. occidentale and E. splendens were 10, 6.22 and 6.44 respectively. Repellency occurred at the following concentration ranges: 0.01, 0.02 and 0.03 ppm Bayluscide, 0.1, 0.2 and 0.3 ppm A. occidentale and 0.05, 0.10, 0.15 and 0.20 ppm E. splendens. The Natural Escape Index obtained in the control group was zero.

Estudo de variáveis que podem influenciar na evoluçäo da esquistossomose mansônica: efeito da terapêutica específica e da interrupçäo da transmissäo / Study of variables that may influence in the evolution of the hepatosplenic form of Schistosomiasis mansoni: effect of specific therapy and interruption of the transmission

O desenvolvimento da forma hepatatoesplênica da esquistossomose mansônica, ainda näo foi completamente esclarecido. Geralmente säo invocadas a intensidade da carga parasitária, as reinfecçöes sucessivas ou periódicas, a resposta imunológica do hospedeiro, a raça e a terapêutica específica, como fatores marcantes para explicar a razäo pela qual, somente pequeno percentual dos parasitados desenvolve essa forma de doença. O presente trabalho faz parte do "Projeto sobre Esquistossomose na Chapada Diamantina - Bahia - Brasil", tendo como objetivo contribuir para o conhecimento do papel das variáveis intensidade de carga parasitária, reinfecçöes sucessivas, terapêutica específica e raça, no desenvolvimento da forma hepatoesplênica, por ser esta, a mais frequênte das formas graves da doença. Um programa de controle da esquistossomose foi desenvolvido em uma área hiperendêmica de esquistossomose, através do uso de moluscicida durante dez anos, com a ajuda da comunidade local. Exames clínicos e parasitológicos de fezes foram realizados antes, durante o período de interrupçäo da transmissäo e após o retorno da transmissäo da parasitose. Ao longo dos quinze anos de seguimento dessa populaçäo, algumas pessoas fizeram uso de medicaçäo anti-esquissomótica, por demanda espontânea e outras näo. A avaliaçäo parasitológica foi feita através os exames de fezes qualitativo e quantitativo, determinando a prevalência e a intensidade da carga parasitária, pelo número de ovos eliminados nas fezes e sua média geométrica. A avaliaçäo da evoluçäo clínica foi feita pela análise do tamanho do fígado e do baço, e pela classificaçäo das formas clínicas, comparando-se o exame inicial com os exames subsequentes. Os principais parâmetros clínicos de evoluçäo - hepatomegalia, esplenomegalia e forma hepatoesplênica - foram analisados em relaçäo à populaçäo geral e ao tratamento específico. Em cada uma dessas situaçöes, os dados foram analisados de acordo com a idade e a raça. O processamento e a análise dos dados foram feitos de acordo com o modelo estatístico mais apropriado para determinado caso, utilizando-se pacotes estatísticos adequados e considerando-se como significante o encontro de p menor que 0,05. Os resultados obtidos permitem confirmar que a intensidade da carga parasitária está diretamente relacionada com o desenvolvimento da forma hepatoesplênica e que o grupo racial negro apresenta maior resistência a desenvolver esta forma clínica da doença...

Spectrophotometric determination on niclosamide in chewable tablets

Amostras de comprimidos mastigáveis contendo niclosamida foram analisadas por método espectrofotométrico no ultravioleta padronizado a 333 nm. A reta de calibraçäo com coeficiente de correlaçäo r= 0,9884 passa pela origem. A lei de Lambert-Beer é obedecida no intervalo de concentraçäo 6,4 a 20,8 g/mL. O coeficiente de variaçäo foi de 0,27 por cento e 0,51 por cento para amostras comerciais e simuladas, respectivamente. Os excipientes näo interferem na determinaçäo

The prolonged use of niclosamide as a molluscicide for the control of Schistosoma mansoni

Applications of niclosamide at three-monthly intervals were undertaken for 14 years in foci of Biomphalaria glabrata in the water sources of Peri-Peri (Capim Branco, MG). All the residents of the area were submitted to an annual fecal examination (Kato/Katz) and those individuals eliminating Schistosoma mansoni eggs were treated with oxamniquine. A malacological survey was undertaken at three-monthly intervals by means of ten scoops with a perforated ladle each ten metres along the two banks of the ditches and streams of the region. Where snails were found, molluscicide was applied by means of dripping or aspersion using a 3 ppm aqueous suspension of niclosamide. Initially, a mean of 14.3% of snails in the region were found to be eliminating cercariae. Following the first four applications of molluscicide, this was reduced to 0.0% and maintained at about 1.5% throughout the program. Thus, there was a continued possibility of schistosomiasis transmission in the area and it was observed that the population of snails reestablished itself within three months of molluscicide application. The results obtained in this study do not encourage the continual use of niclosamide as the only method of control of schistosomiasis