Toxicity of Jatropha curcas L. latex in Allium cepa test / Toxicidade do látex de Jatropha curcas L. no modelo de Allium cepa

The latex obtained from Jatropha curcas (physic nut) is used in traditional medicine to treat a variety of disturbs, including burns, hemorrhoids, ringworm and ulcers. Phytochemical analyses have shown that J. curcas latex contains natural compounds with therapeutic potential. In this study, the toxicity, cytotoxicity and genotoxicity effects of J. curcas latex on the root cells of Allium cepa were examined. Onion seeds and bulbs were exposed to seven different concentrations of latex and then the roots were submitted to macro and microscopic analyses. Water and sodium azide were used as negative and positive controls, respectively. The analysis of root growth showed that J. curcas crude latex or 50% diluted is highly toxic. Cytogenetic results showed that the mitotic index of the onion roots submitted to latex treatment decreased significantly compared to the negative control, which suggests that the latex is cytotoxic. High incidence of chromosome aberrations in the cells treated with J. curcas latex was observed too, indicating that the latex also presents genotoxic effect. The analyses presented in this report suggest the toxic, cytotoxic and genotoxic effects of J. curcas latex. Then, the indiscriminate use of J. curcas latex in folk medicine could bring risk to human health.

O látex obtido de Jatropha curcas (pinhão manso) é usado na medicina tradicional para tratamento de diversos distúrbios, como queimaduras, hemorroida, micose e úlcera. Análises fitoquímicas apontaram que o látex de J. curcas contém compostos naturais com potencial terapêutico. Este estudo avaliou a toxicidade, citotoxicidade e genotoxicidade do látex de J. curcas em células da raiz de Allium cepa. Sementes e bulbos de cebola foram expostos á sete diferentes concentrações de látex e, então, as raízes foram submetidas a análises macro e microscópica. Água e azida sódica foram utilizadas como controle negativo e positivo, respectivamente. A análise do comprimento das raízes mostrou que o látex de J. curcas puro e diluído a 50% é altamente tóxico. O índice mitótico das raízes de cebola submetidas ao tratamento com o látex diminuiu significativamente comparado com o controle negativo, o que sugere que o látex é citotóxico. Uma alta incidência de aberrações cromossômicas em células tratadas com o látex de J. curcas também foi observada, indicando que o látex apresenta efeito genotóxico. Essa análise sugere que o látex de J. curcas possui efeitos tóxico, citotóxico e genotóxico, sendo que o uso indiscriminado do látex de J. curcas na medicina popular pode trazer risco à saúde humana.

Globos de látex de caucho natural: objetos peligros a desterrar de las instituciones de salud / Natural rubber latex balloons: dangerous objects to be banned from health institutions

Los globos de látex de caucho natural y los guantes de examinación del mismo material inflados como globos, que se entregan a los pacientes para aliviar el estrés de la atención sanitaria en las instituciones de salud tanto públicas como privadas, pueden provocar reacciones de hipersensibilidad de tipo I y son una de las causas más comunes de aspiración fatal. La suelta de globos contaminan el ambiente y agravan la extinción de la fauna y de la vida marina. Los pacientes sensibilizados o alérgicos al látex que participan en los festejos donde se utilizan globos de látex corren el riesgo de una reacción anafiláctica, potencialmente fatal. Aconsejarles no concurrir a dichos eventos, implica impedirles el disfrute de las actividades recreativas que es un derecho de la infancia manifestado en la Declaración de los Derechos del Niño. Muchos hospitales de países desarrollados ya cuentan con una política de prohibición de los globos de látex en sus instituciones, que podría replicarse en nuestro medio por las ventajas que conlleva y su muy bajo costo de implementación (AU)

Natural rubber latex balloons and examining gloves of the same material blown up as balloons to entertain patients to alleviate the stress of care at public and private health institutions, may cause reactions of type-1 hypersensitivity and are the most common cause of fatal asphyxia. Balloons that are released up into the air contaminate the environment and aggravate the extinction of fauna and marine life. Patients who are sensitized or allergic to latex and participate in celebrations in which latex balloons are used are at risk of a potentially fatal anaphylactic reaction. To advise them not to participate in these events means to stop them from enjoying recreational activities which is a right manifested in the Declaration of the Rights of the Child. In many hospitals in developed countries a policy of prohibition of latex gloves is already in place. This prohibition may be replicated in our environment considering its advantages and very low cost of implementation (AU)

Evaluation of cytotoxicity and genotoxicity of Hancornia speciosa latex in Allium cepa root model / Avaliação da citotoxicidade e genotoxicidade do látex de Hancornia speciosa usando o modelo da raiz de Allium cepa

Abstract The latex obtained from Hancornia speciosa Gomes (Mangabeira tree) is widely used in traditional medicine to treat a variety of diseases, including diarrhea, ulcer, gastritis, tuberculosis, acne and warts. In this study, the cytotoxicity and genotoxicity effects of H. speciosa latex on the root meristem cells of Allium cepa were examined. Onion bulbs were exposed to different concentrations of latex and then submitted to microscopic analysis using Giemsa stain. Water was used as a negative control and sodium azide as a positive control. The results showed that, under the testing conditions, the mitotic index (MI) of the onion roots submitted to latex treatment did not differ significantly from the negative control, which suggests that the latex is not cytotoxic. Low incidence of chromosome aberrations in the cells treated with H. speciosa latex was also observed, indicating that the latex does not have genotoxic effect either. The MI and the chromosome aberration frequency responded to the latex concentration, requiring more studies to evaluate the dosage effect on genotoxicity. The results indicate that in tested concentrations H. speciosa latex is probably not harmful to human health and may be potentially used in medicine.

Resumo O látex obtido de Hancornia speciosa é amplamente utilizado na medicina popular para tratar uma variedade de doenças, tais como: diarreia, úlcera, gastrite, tuberculose, acne e verrugas. Nesse estudo, foram avaliados os efeitos citotóxicos e genotóxicos do látex de H. speciosa sobre as células meristemáticas das raízes de Allium cepa. Os bulbos das cebolas foram expostos a diferentes concentrações de látex e depois submetidos à analise microscópica usando o corante Giemsa. A água foi usada como controle negativo e a ázida sódica como controle positivo. Os resultados mostraram que o índice mitótico (IM) das raízes de cebola submetidas ao tratamento com látex, nas condições testadas, não diferiram significativamente do controle negativo, e sugerem que o látex não é citotóxico. Também foi observada uma baixa incidência de aberrações cromossômicas nas células tratadas com látex de H. speciosa, o que sugere que o látex também não possui efeito genotóxico. O IM e a frequência de aberrações cromossômicas foram dependentes da concentração de látex. Outros estudos devem ser realizados para avaliar o efeito da dose na genotoxidade. Os resultados indicam que o látex de mangabeira, nas concentrações testadas, provavelmente não é danoso para saúde humana e pode ter potencial para ser usado na medicina.

Citotoxicidade de luvas de procedimentos em látexSupermax® / Cytotoxic of the procedures gloves in latex Supermax®

O objetivo foi avaliar a citotoxicidade de luvas de procedimento em látex. Foram avaliados três diferentestipos de luvas de procedimento divididos em três grupos assim denominados: 1 (Supermax®),2 (Supermax -Powder Free®) e 3 (Supermax-Microtexturizado®). Utilizou-se 3 grupos controle: positivo(C+) detergente celular Tween 80, negativo (C-) PBS, e controle de célula (CC) cujas não foramexpostas a nenhum material. Após confecção dos corpos de prova, os mesmos foram imersos em meiomínimo essencial Eagle (MEM) por 24 hrs. Passado esse período procedeu-se a remoção do sobrenadantee colocação em contato com os fibroblastos L929. Após contato com o meio, as células foramincubadas por mais 15, 30 e 60 minutos, então foram adicionados 100μl do corante vermelho neutro a0,01%. Uma vez coradas, as mesmas foram fixadas com formoaldeido e então realizada contagem decélulas viáveis em espectrofotômetro (BioTek, Winooski, Vermont, USA). Os valores da quantidade decélulas viáveis, foram submetidos à análise de variância (ANOVA) para determinar se havia diferençasestatísticas entre os grupos, e posteriormente ao teste de Tukey (p<0.05). Nos tempos de 15, 30 e 60minutos os grupos 1 e 3 foram os que demonstraram maior quantidade de células viáveis respectivamente.Com 1 hora de contato todos os grupos demonstraram alta toxicidade celular quando comparadoaos C- e CC. Todas as luvas foram citotóxicas nos tempos avaliados. A toxicidade aumentou como aumento de contato das células.

The objective was to evaluate the cytotoxicity of procedure latex gloves. Three different types ofgloves procedure divided into three groups so called: 1 (Supermax®), 2 (Supermax -- Powder Free®)and 3 (Supermax-Microtexturizado®). We used 3 control groups: positive (C +) cell detergent Tween80, negative (C-) PBS, and control of cell (CC) whose cells were not exposed to any material. Aftermaking the bodies of evidence, they were immersed in Eagle minimum essential medium (MEM) for24 hrs. After this period there has been the removal of supernatant and placed in contact with thefibroblasts L929. After contact with the medium, the cells were incubated for another 15, 30 and 60minutes, which were then added 100 the dye neutral red to 0.01%. Once stained, they were fixedwith formoaldeido and then performed counting of viable cells in spectrophotometer (BioTek, Winooski,Vermont, USA). The values of the quantity of viable cells were subjected to analysis of variance(ANOVA) to determine whether there were statistical differences between groups, and then the Tukeytest (p <0.05). In times of 15, 30 and 60 minutes the groups were 1 and 3 showed that the greatestamount of viable cells respectively. 1 hour of contact with all groups showed high cellular toxicity whencompared to the C-and CC. All gloves were cytotoxic in the time evaluated. The toxicity increased withthe increase of cell contact.

Cytotoxicity of orthodontic elastics: in vitro investigation with on L929 mouse fibroblasts

Aim: To test the hypothesis that there is no difference in the cytotoxicity among natural latex elastics of different manufacturers using a L929 cell line culture. Methods: Different latex intra oral elastics (I.D. = 5/16", 4.5 oz.) were tested. The sample was divided into 7 groups of 15 elastic seach: Group AO (American Orthodontics), Group GAC (GAC International), Group TP (TP Orthodontics), Group AD (Aditek), Group AB (Abzil), Group MO (Morelli) and Group UN (Uniden).Cytotoxicity assays were performed by using cell culture medium containing L-929 line cells(mouse fibroblast). The cytotoxicity was evaluated by using the “dye-uptake” test, which wasemployed at two different moments (1 and 24 h). Data were compared by ANOVA and Tukey’s test(P < 0.05). Results: The results showed a significant difference (P < 0.05) between all groups and the group CC (cell control) at 1 and 24 h. Groups AD, AB, MO and UN were noticeably more cytotoxic than the groups AO, GAC and TP at 1 h. After 24 h, a significant decrease in cell viability was observed in all groups. Conclusions: Intraoral elastics from American Orthodontics, GACand TP Orthodontics trademarks induced less cell lysis than Aditek, Abzil, Morelli and Uniden trademarks.

Acute Toxicity Of Euphorbia Royleana Boiss (Euphorbiaceae) latex on freshwater catfish, Heteropneustes Fossilis (Siluriformes, Heteropneustidae) / Toxicidad aguda del látex de Euphorbia royleana Boiss (Euphorbiaceae) en el bagre de agua dulce, Heteropneutes fossilis (Siluriformes, Heteropneustidae)

An acute toxicity test was performed by using a four-day static renewal test to determine the LC50 value of aqueous extract of Euphorbia royleana latex for the freshwater fsh, Heteropneustes fossilis. The LC50 values, their upper and lower confdence limits and slope functions were calculated. The LC50 values for aqueous extract of Euphorbia royleana latex at various exposure periods were 7.758 mg/L for 24 h, 5.847 mg/L for 48 h, 4.474 mg/L for 72 h and 3.090 mg/L for 96 h. The regression coeffcient showed that there was signifcant negative correlation between exposure time and different LC values. Hence, it is concluded that the concentration to produce toxicity of latex of Euphorbia royleana is comparable and close to the concentration to produce toxicity of synthetic organophosphates pesticides for the fsh H. fossilis. Therefore, adequate precautions must be taken when Euphorbia royleana latex is being used near fsh- inhabited areas.

La prueba de la toxicidad aguda fue realizada utilizando un test estático con renovación, de cuatro días de duración, para determinar el valor de la CL50 de un extracto acuoso del látex de Euphorbia royleana, en el pez de agua dulce Heteropneustes fossilis. Se calcularon el valor de la CL50, los límites de confanza máximo y mínimo y la pendiente. Los valores de la CL50 para el extracto acuoso del látex en varios períodos de exposición fueron 7,758 mg/L para 24 h, 5,847 mg/L para 48 h, 4,474 mg/L para 72 h y 3,090 mg/L para 96 h. El coefciente de regresión mostró una correlación negativa signifcativa entre el tiempo de exposición y diferentes valores de la CL50. Se concluye que la concentración del látex de E. royleana que produce toxicidad es comparable y cercana a la de los plaguicidas sintéticos organofosforados para el pez H. fossilis. Por lo tanto, se deben tomar precauciones adecuadas cuando el látex de E. royleana es utilizado cerca de áreas donde habita el pez H. fossilis.

In vitro cytotoxicity of latex orthodonticelastics / Citotoxicidad de los elásticos ortodònticos de látex

Natural latex does not fall into the category of materials known to be entirely inoffensive. The objective of the present in vitro study is to test the hypothesis that there is no difference in the cytotoxicity between natural latex elastics of different colours. The present article compared different latex intra-oral elastics (5/16 = 7.9 mm). The sample was divided into four groups according to their manufacturer: Group N (Natural latex elastic, Morelli), Group R (Red colour elastic, Morelli) Group Y (Yellow colour elastic, Morelli) and Group G (Green colour elastic, Morelli). Cytotoxicity assays were performed by using cell culture medium containing L-929 line cells (mouse fibroblast). The cytotoxicity was evaluated by using the “dyeuptake” test, which was employed at two different moments (1 and 24 h). Data were compared by analysis of variance (ANOVA) and Tukey’s test (p<0.05). The results showed a significant difference (p<0.05) between the groups N, R, Y, G and the negative cytotoxicity control at 1 and 24 h (p<0.05), it did not have presented significant difference between the groups N, R, Y, G tested (p>0.05) at 1 and 24 h. Morelli intra-oral elastics were found to be highly cytotoxic, regardless of their colour and immersion time.

El látex natural no entra en la categoría de materiales que se sabe del todo inofensivo. El objetivo del presente estudio in vitro es poner a prueba la hipótesis de que no hay diferencia en la citotoxicidad entre elásticos de látex natural de diferentes colores. El presente artículo compara diferentes elásticos intraorales de látex (5/16 =7,9 mm). La muestra se dividió en cuatro grupos según su fabricante: Grupo N (elástico látex, Morelli), Grupo I (elástico de color rojo, Morelli) Grupo Y (elástico de color amarillo, Morelli) y el Grupo G (elástico color verde, Morelli). Pruebas de citotoxicidad se realizaron mediante el uso de medio de cultivo celular que contiene líneas celulares L-929 (fibroblastos de ratón). La citotoxicidad se evaluó mediante el test “dye-uptake”, que se empleó en dos momentos diferentes (1 y 24 h). Los datos se compararon mediante análisis de varianza (ANOVA) y test de Tukey (p<0,05). Los resultados mostraron una diferencia significativa (p<0,05) entre los grupos N, R, Y, G y la negativa citotoxicidad del control en 1 y 24 h (p<0,05), no han presentado diferencias significativas entre los grupos N, R , Y, G probado (p>0,05) en 1 y 24 h. Elásticos intraorales Morelli resultaron ser altamente citotóxicos, independientemente de su color y tiempo de inmersión.

Cytotoxicity of latex and non-latex orthodontic elastomeric ligatures on L929 mouse fibroblasts

This study investigated the cytotoxicity exists between latex and non-latex Orthodontic elastomeric ligatures. Six elastomeric ligatures (1 latex, 2 latex-free and 3 polyurethane) from different manufacturers were divided into 6 groups of 15 elastics each: A (Latex-free, American Orthodontics), M (Polyurethane, Morelli), G (Polyurethane,GAC International), Te (Polyurethane, Tecnident), TP (Natural latex,TP Orthodontics) and U (Latex-free,3M Unitek). The cytotoxicity assay was performed using cell cultures (L929 mouse fibroblast cell line), which were subjected to the cell viability test with neutral red ("dye-uptake") at 1, 2, 3, 7 and 28 days. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). No statistically significant differences (p>0.05) were observed between Groups M and Te in all experimental periods, except at 2 days. No significant differences (p>0.05) in cell viability were found either among Groups A, G, TP and U or between Groups M and Te at 24 h or among Groups CC, A, G, TP and U at 2 and 28 days. It may be concluded that latex-free elastomeric ligatures from American Orthodontics and Unitek trademarks induced less cell lysis compared to latex and polyurethane ligatures.

Este estudo investigou a citotoxicidade entre ligaduras elásticas ortodônticas de látex e não-látex. Seis ligaduras elásticas de diferentes fabricantes (1 látex, 2 não-látex e 3 poliuretano) foram divididos em 6 grupos de 15 elásticos cada: Grupo A (látex-free, American Orthodontics), M (Poliuretano, Morelli), G (Poliuretano, GAC International), Te (Poliuretano, Tecnident), TP (látex natural, TP Orthodontics) e U (Látex-free, 3M Unitek). O ensaio de citotoxicidade foi realizado utilizando culturas de células (células da linhagem L929, fibroblastos de camundongo) que foram submetidos ao teste de viabilidade celular com vermelho neutro ("dye-uptake") em 1, 2, 3, 7 e 28 dias. A análise de variância (ANOVA), com comparações múltiplas e teste de Tukey foram empregados (α=0,05). Os resultados mostraram que não houve diferença estatisticamente significante entre os Grupos M e Te em todos os tempos experimentais (p>0,05), exceto em 2 dias. Não houve diferença estatisticamente (p>0,05) entre a viabilidade das células nos grupos A, G, TP e U ou entre os grupos M e Te em 24 h, ou entre os grupos CC, A, G, TP e U em 2 e 28 dias. Concluiu-se que as ligaduras elásticas látex-free das marcas American Orthodontics e Unitek induziram menor quantidade de lise celular comparado às ligaduras de látex ou poliuretano.

Observações sobre abelhas sem ferrão (Hymenoptera: meliponini) coletoras de látex em Abricó do Pará Mammea americana (L.) Jacq. (Clusiaceae), Manaus, Amazonas, Brasil / Observations on stingless bees (Hymenoptera: meliponini) collecting of latex in mammy Mammea americana (L.) Jacq. (Clusiaceae), Manaus, state of Amazonas, Brazil

O conhecimento das espécies de plantas utilizadas pelas abelhas sem ferrão é primordial para a manutenção das mesmas. O objetivo deste trabalho foi verificar a coleta de látex em Mammea americana (Clusiaceae) e os padrões de abundância dos visitantes. O estudo foi conduzido no Bosque da Ciência, Instituto Nacional de Pesquisas da Amazônia, em Manaus-AM. A comunidade de abelhas foi representada por Trigona williana e T. recursa. A espécie presente em maior abundância foi T. recursa (89,4%). Estas abelhas coletam o látex para proteger o ninho contra possíveis inquilinos e predadores, devido a sua ação antimicrobiana.

The knowledge regarding the plant species used by the stingless bees for their survival is a fundamental factor for their maintenance. The objective of this study is to observe collecting latex in Mammea americana tree (Clusiaceae) and abundance patterns of visitors. The study was carried out in the “Bosque da Ciência,” Instituto Nacional de Pesquisas da Amazônia, Manaus-AM. The bee communities were represented by Trigona williana and Trigona recursa. The latter presented the highest abundance (89.4%). These bees probably collect this substance in order to protect their nest against other possible tenants and predators, since it acts as an antimicrobial agent.

Prevalencia y factores de riesgo de sensibilización al látex en personal del Hospital del Trabajador Santiago / Prevalence and risk factors of latex hypersensitivity in workers hospital personnel in Santiago

Los trabajadores de la salud (TS) tienen riesgo de desarrollar alergia al látex, lo que está respaldado por múltiples publicaciones. OBJETIVOS: Establecer prevalencia de sensibilización y alergia a látex en TS del Hospital del Trabajador Santiago (HTS) y determinar factores de riesgo asociados. MATERIALES Y MÉTODOS: Se estudiaron 157 TS con encuesta sobre atopia, tiempo y Los trabajadores de la salud (TS) tienen riesgo de desarrollar alergia al látex, lo que está respaldado por múltiples publicaciones. OBJETIVOS: Establecer prevalencia de sensibilización y alergia a látex en TS del Hospital del Trabajador Santiago (HTS) y determinar factores de riesgo asociados. MATERIALES Y MÉTODOS: Se estudiaron 157 TS con encuesta sobre atopia, tiempo y síntomas con exposición a látex. Se efectuaron prick test con aeroalergenos, látex y frutas (Leti, España), látex amoniacado, prick in prick con guantes de látex y test de parche con látex y aditivos (Trolab, Alemania). RESULTADOS: La sensibilización a látex fue de 13,4por ciento (n=21). Hubo diferencia significativa entre sensibilizados y no sensibilizados en: presencia de atopia (p<0,001), sensibilización a frutas (p<0,001) y presencia de urticaria de contacto (p<0,001). Tres TS de los 19 examinados presentaron test de parche positivo. CONCLUSIONES: La prevalencia de sensibilización a látex es menor a la encontrada en otro estudio nacional realizado por nuestro grupo. La atopia y la sensibilización a frutas tropicales parecen importantes factores para el desarrollo de alergia al látex en la población estudiada.

Latex constituents from Calotropis procera (R. Br.) display toxicity upon egg hatching and larvae of Aedes aegypti (Linn.)

Calotropis procera R. Br. (Asclepiadaceae) is a well-known medicinal plant with leaves, roots, and bark being exploited by popular medicine to fight many human and animal diseases. This work deals with the fractionation of the crude latex produced by the green parts of the plant and aims to evaluate its toxic effects upon egg hatching and larval development of Aedes aegypti. The whole latex was shown to cause 100 percent mortality of 3rd instars within 5 min. It was fractionated into water-soluble dialyzable (DF) and non-dialyzable (NDF) rubber-free materials. Both fractions were partially effective to prevent egg hatching and most of individuals growing under experimental conditions died before reaching 2nd instars or stayed in 1st instars. Besides, the fractions were very toxic to 3rd instars causing 100 percent mortality within 24 h. When both fractions were submitted to heat-treatment the toxic effects were diminished considerably suggesting low thermostability of the toxic compounds. Polyacrylamide gel electrophoresis of both fractions and their newly fractionated peaks obtained through ion exchange chromatography or desalting attested the presence of proteins in both materials. When submitted to protease digestion prior to larvicidal assays NDF lost most of its toxicity but DF was still strongly active. It may be possible that the highly toxic effects of the whole latex from C. procera upon egg hatching and larvae development should be at least in part due to its protein content found in NDF. However the toxicity seems also to involve non protein molecules present in DF.

The molluscicidal activities of some Euphorbia milii hybrids against the snail Indoplanorbis exustus.

The objective of this study was to observe the molluscicidal activities of Euphorbia milli, known as "poysean" in Thailand, against Indoplanorbis exustus. Latex from 12 different E. milii hybrids was screened for its molluscicidal activities. Indoplanorbis exustus were exposed for 24 and 48 hours to the latex at various concentrations ranging from 6 to 25 ppm and mortality rates were recorded. Eight hybrids of latex were effective. The six most effective hybrids were E. milii Dang-udom, E. milii Arunroong, E. milii Raweechotchuong, E. milii Srisompote, E. milii Sri-umporn and E. milii Tongnopakun, which killed all snails after 24 hours of exposure. Under the same conditions, latex of E. milii Dowpraket and E. milii Promsatid killed 50% of the snails. Such results indicate that these 6 hybrids seem promising as natural molluscicidal agents.

Estudo farmacognóstico de Croton urucurana Baillon (sangra dïágua) / Pharmacognostic study of Croton urucurana Baillon (sangra dïágua)

Croton urucurana Baillon, comumente conhecida como "sangra-dïágua", é uma árvore medicinal do sudeste brasileiro utilizada como cicatrizante e antiinflamatóio. A espécie carece de estudos botânicos, químicos e farmacológicos para que possa ser utilizada com segurança. O objetivo deste trabalho foi caracterizar a casca, a folha e o látex obtidos desta espécie, através de estudos farmacognósticos, isolando princípios ativos e verificando a toxicidade e as atividades antiúlcera e cicatrizante. Dentre as principais características macroscópicas podemos citar: (a) casca; enrolada com presença de manhas brancas, fratura fibrosa e sabor adstringente; (b) folha; simples, pubescente, cordiforme, peninérvea e ápice agudo...

Study of the embryofeto-toxicity of Crown-of-Thorns (Euphorbia milii) latex, a natural molluscicide

The crude latex of Crown-of-Thorns (Euphorbia milii var. Hislopii) is a potent plant molluscicide and a promising alternative to the synthetic molluscicides used in schistosomiasis control. The present study was undertaken to investigate the embryofeto-toxic potential of E. Milii latex. The study is part of a comprehensive safety evaluation of this plant molluscicide. Lyophilized latex (0, 125, 250 and 500 mg/kg body weight) in corn oil was given by gavage to Wistar rats (N = 100) from days 6 to 15 of pregnancy and cesarean sections were performed on day 21 of pegnancy. The numbers of implantation sites, living and dead fetuses, resorptions and corpora lutea were recorded. Fetuses were weighed, examined for external malformations, and fixed for visceral examination, or cleared and stained with Alizarin red S for skeleton evaluation. A reduction of body weight minus uterine weight al term indicated that E. Milii latex was maternally toxic over the dose range tested. No latex-induced embryolethality was noted at the lowest dose (125 mg/kg) but the resorption rate was markedly increased at 250 mg/kg (62.5 percent) and 500 mg/kg (93.4 percent). A higher frequency of fetuses showing signs of delayed ossification (control: 17.4 percent; 125 mg/kg: 27.4 percent and 250 mg/kg: 62.8 percent; P<0.05 vs control) indicated that fetal growth was retarded at doses ³125 mg latex/kg body weight. No increase in the proportion of fetuses with skeletal anomalies was observed at the lowest dose but the incidence of minor skeletal malformations was higher at 250 mg/kg body weight (control: 13.7 percent; 125 mg/kg: 14.8 percent; 250 mg/kg: 45.7 percent; P<0.05 vs control). Since a higher frequency of minor malformations was noted only at very high doses of latex which are embryolethal and maternally toxic, it is reasonable to conclude that this plant molluscicide poses no teratogenic hazard or, at least, that this possibility is of a considerably low order of magnitude.

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.

Considerações sobre a alergia ao látex / Latex allergy considerations

A alergia ao látex mediada pela IgE é significativa em todo o mundo. ela é ainda menos prevalente, por razões desconhecidas, em regiões trocipais. No Brasil não existe até o presente estudos epidemiológicos definitivos. A fator de alongamento da borracha (Hev b 1) de 14,6kD é o principal epítopo desta alergia, sendo produzido na manufatura atual do látex proveniente da Hevea brasiliensis. Os fatores de risco para a alergia do tipo I ao látex (urticária de contato, angioedema, asma, rinite, conjuntivite e anafilaxia) são: atopia, dermatite de contato nas mãos, contato profissional freqüente (ambientes médicos, odontológicos, cirúrgicos, radiológicos e da indústria de produção), pacientes com spina bifida e portadores de malformações urogenitais, que requerem cateterismos vesicais e cirurgias freqüentes. Há reações de alergenicidade cruzada com frutas tropicais (kiwi, banana, abacate, maracujá, manga, pêssego, mamão, entre outras) e também nozes e crustáceos. Progressivamente outros aliementos também estão sendo "incriminados", e suas antigenicidades cruzadas com proteínas do látex estão em fase de estudos. O uso freqüente do látex na área da Saúde e a necessidade da prevenção de doenças infecto-contagiosas como a Aids, torna o problema da alergia uma preocupação internacional da maior relevância. Há materiais alternativos de poliuretano e de vinil adequados para a utilização na população alérgica ao látex. Evitar o uso do látex em procedimentos médicos e cirúrgicos pode ser o melhor caminho na busca da prevenção de tal sensibilização.

IgE mediated allergic reactions are worldwide present. They are less frequent in tropical regions for unknown reasons. Latex is extracted from Hevea braliliensis and the main epitope is Hev b 1 (14.6kD rubber elongation factor). Risk factors for latex allergy (contact urticaria, angioedema, asthma, rhinitis, conjunctivitis and anaphylaxis) are: atopy, hand contact dermatitis, professional exposure, and patients with spina bifida and congenital urogenital malformations. There is cross-reactivity with tropical fruits (kiwi, bananas, abacate, "fruit de la passion", mangoes, peaches, papaya), and also to other foods like chestnuts and shellfish. The modern widespread use of latex in Medicine requires special attention to the potentialdevelopment of latex sensitization. Latex-free environment and alternative materials (polyurethane and vynil) should be considered.

Evaluation of temporal, seasonal and geographic stability of the molluscicidal property of Euphorbia splendens latex

Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscacidal principle, with LD90 values of 1.14 ppm (spring), 1.02 ppm (fall), 1.09 ppm (winter), and 1.07 ppm (summer) that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador), demonstrating geographic stability of the molluscacidal effect. The molluscacidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate) and lyophilized, was stable for up to 124 days at room temperature (in natura) and for up to 736 days in a common refrigerator at 10 to 12 degrees C (lyophilized product). A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasis

Evaluation of the genotoxic activity and acute toxicity of Euphorbia splendens latex, a molluscicide for the control of Schistosomiasis

The latex of euphorbia splendens var. hislopii has a molluscicidal action at low concentration (LD90 less than 1.5 ppm or 1.5 */ml) against the vector snails of schistosomiasis. In the present study, the latex in natura or after lyophilization was submitted to the Ames test and the chromotest to evaluate genotoxicity, to the Microtox System to determine acute toxicity, and to the Chinese hamster ovary cell assay (CHO) to measure cytotoxicity. The latex had no mutagenic activity in the presence or absence of S9 toward the TA98 and TA100 strains of Salmonella typhimurium (Ames test) at concentration up to 200 */plate (in natura) and of 200 *g/plate (lyophilized). The lyophilized latex had no genotoxic activity (Chromotest) and acute toxic effect on Photobacterium phosphoreum at concentrations up to 445 *g/ml, whereas the sample in natura had a toxic effect with an EC50 of 148,000 *l/l (or ppm). In the CHO/cytotoxicity assay, the lyophilized latex had no cytotoxicit effect in quantities up to 200 *g. The latex was found to have no acute toxicity or mutagenic at the concentrations of 10 to 12 *g/ml (or ppm) that are being proposed for molluscicidal use in the field

Toxicological study of the molluscicidal latex of Euphorbia splendens: irritant action on skin and eye

Aqueous solutions of the molluscicidal latex of Euphorbia splendens are irritant to the rabbit eye in concentrations higher than 0.35% and to the rabbit skin in concentrations higher than 0.5%. Although this irritant potential does not proclude its use as a molluscicide, special precautions are recommended for hanbdling and application of the product and the hazard of skin tumor-promoting potencial should be carefully investigated before its use for schistosomiasis vector control.