Integrated high-throughput drug screening microfluidic system for comprehensive ocular toxicity assessment.

Traditional experimental methodologies suffer from a few limitations in the toxicological evaluation of the preservatives added to eye drops. In this study, we overcame these limitations by using a microfluidic device. We developed a microfluidic system featuring a gradient concentration generator for preservative dosage control with microvalves and micropumps, automatically regulated by a programmable Arduino board. This system facilitated the simultaneous toxicological evaluation of human corneal epithelial cells against eight different concentrations of preservatives, allowing for quadruplicate experiments in a single run. In our study, the IC50 values for healthy eyes and those affected with dry eyes syndrome showed an approximately twofold difference. This variation is likely attributable to the duration for which the preservative remained in contact with corneal cells before being washed off by the medium, suggesting the significance of exposure time in the cytotoxic effect of preservatives. Our microfluidic system, automated by Arduino, simulated healthy and dry eye environments to study benzalkonium chloride toxicity and revealed significant differences in cell viability, with IC50 values of 0.0033% for healthy eyes and 0.0017% for dry eyes. In summary, we implemented the pinch-to-zoom feature of an electronic tablet in our microfluidic system, offering innovative alternatives for eye research.

Toxicity assessment of the alcoholic leaves extract of Reinwardtia indica

The present study aimed to evaluate the safety of the alcoholic leaves extract of Reinwardtia indica in Charles foster rats through an acute and sub-acute oral administration.For assessment of acute oral toxicity test, ratswere orally treated with single dose of the alcoholic leaves extract of Reinwardtia indica at the doses of 50, 250, 500, 1000 2000 and 5000 mg/kg. In sub-acute toxicity study, using the OECD guidelines no. 407, the extract was administered at the doses of 50, 250, 500, 1000, 2000 mg/kg/day for 28 consecutive days and at the dose of 2000 mg/kg satellite group also used for 6 weeks.In acute toxicity above mentioned doses neither showed mortality nor exterior signs of toxicity. In sub-acute, study no significant changes found in haematological and biochemical level ofthe treated rat after 14 days and 28 days in comparison to control. The histopathology of rat brain, kidney, liver, and heart also showed the no cellular changes after extract treated rat.The alcoholic leaves extract of Reinwardtia indica was found non-toxic in single drug dose administration up to 5000 mg/kg (acute study) and in sub-acute administration up to 2000 mg/kg.

Toxicity of the feathers of Yellow Grosbeak, Pheucticus chrysopeplus (Passeriformes: Cardinalidae), a chemically defended neotropical bird / Toxicidad de las plumas del Picogrueso amarillo, Pheucticus chrysopeplus (Passeriformes: Cardinalidae), un ave neotropical con defensa química

Abstract Chemical defense is a widespread mechanism on many animals and plants. However, just a few cases are known for avian species. In this study we evaluate the toxicity of Pheucticus chrysopeplus feather extract via lethality test with brine shrimp (Artemia salina) as an in vivo model. Mortality of A. salina was evaluated after 24 hour exposure to artificial seawater, methanol, and the methanolic feather extract. Kruskal-Wallis test showed a significant difference in mortality between treatments (X2 = 65.25, P < 0.0001, n = 50). With this we describe P. chrysopeplus as the first known toxic avian species of Guatemala and Central America, raising awareness about its conservation and the identification of the toxic substance present in its feathers. We also highlight the possible mimicry mechanism taking part between P. chrysopeplus and two sympatric oriole species (Icterus pectoralis and I. pustulatus).(AU)

Resumen La defensa química es un mecanismo que se encuentra presente en varios animales y plantas. Sin embargo, pocos casos son conocidos para especies de aves. En este estudio evaluamos la toxicidad de extractos de plumas de Pheucticus chrysopeplus con un ensayo de letalidad utilizando artemia (Artemia salina) como modelo in vivo. La mortalidad de A. salina se evaluó luego de ser expuesta por 24 horas a agua marina artificial, metanol y extracto metanólico de plumas de P. chrysopeplus. La prueba de Kruskal-Wallis mostró que existe una diferencia significativa entre los porcentajes de mortalidad de los tratamientos evaluados (X2 = 65.25, P < 0.0001, n = 50). Con esto, describimos a P. chrysopeplus como la primera especie de ave tóxica reportada para Guatemala y Centroamérica, resaltando la importancia de su conservación, así como la identificación de la sustancia tóxica presente en sus plumas. También destacamos el posible mecanismo de mimetismo que podría estar ocurriendo entre P. Chrysopeplus y dos especies simpátricas de orioles (Icterus pectoralis e I. pustulatus).(AU)

Test de toxicidad sobre la especie Atriplex lampa, su aplicación para la evaluación de riesgo asociado a derrames de petróleo en suelos de la Patagonia / The application of toxicity test on the specie Atriplex lampa in the risk assessment of oil spills in Patagonian soils

Se estudiaron suelos contaminados con hidrocarburos del petróleo, en cercanías de la ciudad de Comodoro Rivadavia (Chubut, Argentina). Además de cuantificar el contenido de hidrocarburos totales en suelo (TPH), se realizaron bioensayos, utilizando especies vegetales como organismos de prueba. Los índices utilizados fueron: el porcentaje de germinación (G), la elongación de la radícula (R) y del hipocotilo (H) en Lactuca sativa L y dos especies autóctonas de la región patagónica, Atriplex lampa y Prosopis denudans. Se consideró, además, el efecto de la salinidad sobre los bioensayos, en base a la medición de la conductividad eléctrica del suelo (CE). Los resultados obtenidos del análisis por componentes principales, muestran que la primera componente explica el 58,3 % de la variabilidad total con un gradiente de toxicidad al cual contribuyen, principalmente, el porcentaje de germinación de Lactuca sativa L (GL) y Atriplex lampa (GA), en este orden de significancia. La segunda componente explica el 16,9 % y la misma está caracterizada por TPH y CE. Además, no se ha encontrado una correlación simple y directa entre TPH y toxicidad, lo cual sugiere que TPH, en conjunción con ensayos ecotóxicos, parece ser una herramienta más adecuada para definir el punto final de una remediación. La especie autóctona Atriplex lampa mostró tener una sensibilidad similar a la especie Lactuca sativa L por lo que podría considerarse su utilidad como una especie fitoindicadora en las evaluaciones de riesgo ambiental (AU)

Oil spills near of the Comodoro Rivadavia city (Chubut, Argentina) were studied. Total petroleum hydrocarbon (TPH) is used to characterize the samples and bioassays were carried out using plants as test organisms. The percentage germination (G), the root elongation (R) and the hypocotyls elongation (H) in Lactuca sativa L and two native species to Patagonian region, Atriplex lampa and Prosopis denudans were used as toxicological indexes. It was considered the effect of salinity on the bioassays, based on the measurement of the electrical conductivity of soil (EC). Application of principal component analysis to experimental data showed that the first component accounted for more than 58.3 % of variance. The 1st PC is largely influenced by the germination percentage of Lactuca sativa L (GL) and Atriplex lampa (GA), in that order of significance. The second component accounted 16.9 % of variance. The 2nd PC is largely influenced by TPH and EC. A simple and direct correlation between TPH and toxicity was not found suggesting that TPH in conjunction with ecotoxicity test would be more successfully tool to define the end point of a remediation. The native specie Atriplex lampa showed to have a similar sensibility to the Lactuca sativa L suggesting that it could be used as a phytoindicator in assessement of environmental risk (AU)

Estudio de la irritación ocular y dérmica de Pochonia chlamydosporia var. catenulata / Ocular and dermal irritation study of Pochonia chlamydosporia var. catenulata

Pochonia chlamydosporia var. catenulata, cepa Vcc 108 es un agente eficaz en el control de Meloidogyne spp. Para determinar el potencial de irritación dérmica y ocular se emplearon los métodos in vivo descritos por la Agencia de Protección Ambiental (EPA) y dos ensayos in vitro como alternativos a irritación ocular, el método de la membrana corioalantoidea del huevo de gallina (HET-CAM) y el ensayo cuantitativo con tinción de azul de tripán (CAM-TBS). En los estudios in vitro se aplicaron cuatro concentraciones del hongo vivo e inactivado y en los in vivo se emplearon dosis límite. Aunque cada método utiliza diferentes categorías de irritación, en todos los ensayos Pochonia chlamydosporia var. catenulata se clasificó como No irritante dérmico y ocular (AU)

Pochonia chlamydosporia var. catenulata , stump Vcc 108 is an effective agent in the control of Meloidogyne spp. In order to determine the potential of dermal and ocular irritation, the following methods were used: 1) the method in vivo, described by the Environmental Protection Agency (EPA) and 2) two different in vitro assay, as alternatives to ocular irritation. These two alternative methods were the hen ́s egg-chorioallantoic membrane test (HET-CAM) and the quantitative chorioallantoic membrane test using the trypan blue stain (CAM-TBS). Four concentrations of the alive and inactive mushroom were applied in the in vitro studies and the dose limit in the in vivo test. Although each method uses different irritation categories, in all of the assays, Pochonia chlamydosporia var. catenulata was classified as being non irritating to skin and eyes (AU)

Padronização de spot tests para uso em laboratórios com atendimento em emergências toxicológicas / Using stardardization spot tests in laboratories with toxicological emergencies service

A padronização de métodos simples e confiáveis em laboratórios de análises clínicas que atuam em emergências toxicológicas é importante, visto o alto índice de intoxicações apresetnado nas mais diversas regiões do país. Dentre as intoxicações, as de maior destaque são as medicamentosas. Os medicamentos mais envolvidos são os analgésicos, os benzodiazepínicos e os barbitúricos (fenobarbital). Assim foram padronizados alguns spot tests, segundo Brito Filho, para a pesquisa destes medicamentos em sangue e urina. Os resultados mostraram-se satisfatórios, com valor de sensibilidade de 0,1 e 0,3mg/mL, consistindo em provas simples, rápidas, de baixo-custo e de fácil implantação em laboratórios clínicos.