RESUMEN
Tea tree oil (TTO) is used in ophthalmology to maintain healthy eyelid skin and to combat parasitic eyelid infections. Keratocytes belong to the structure of the corneal stoma and enable to maintain corneal homeostasis. TTO that reaches the surface of the eye in too high concentration may disturb the functions of these cells. The aim of the study was to test what concentration of TTO is safe for corneal keratocytes in vitro without causing a toxic effect. A normal human keratocytes (HK) cell line was used in the study. Morphology was visualized by light and fluorescence microscopy, cytometric analysis of the cell cycle and cytometric and spectrophotometric viability evaluation were performed. The level of nitric oxide was tested by Griess spectrophotometric method. TTO concentrations exceeding 0.01% significantly reduced cell viability. The IC50 values were on average 0.057%. Increasing TTO concentrations stimulated HK cells to release NOx. The observed values did not exceed 1 µM. The lowest TTO concentration increased the number of HK cells in the G1 phase of the cell cycle. Increasing TTO concentrations (≥0.1%) increased the number of cells in late apoptosis. TTO at concentrations ranging from 0.1% to 0.5% significantly changed cell morphology. Fluorescence analyzes confirmed that TTO at concentrations ≥0.1% induced apoptotic cell death. TTO exerts strong effect on ocular keratocytes depending on applied concentration. Concentrations exceeding 0.1% have a toxic effect on keratocytes, which die mainly by apoptosis. The ocular surface should be protected from excessive exposure to TTO, which may damage corneal stroma cells.
Asunto(s)
Apoptosis , Proliferación Celular , Supervivencia Celular , Queratocitos de la Córnea , Aceite de Árbol de Té , Humanos , Aceite de Árbol de Té/farmacología , Aceite de Árbol de Té/toxicidad , Queratocitos de la Córnea/efectos de los fármacos , Queratocitos de la Córnea/citología , Supervivencia Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Óxido Nítrico/metabolismo , Microscopía Fluorescente , Células Cultivadas , Línea Celular , Citometría de FlujoRESUMEN
El aceite de árbol de té es una sustancia que se obtiene mediante la destilación de las hojas y ramas frescas del árbol Melaleuca alternifolia. En los últimos años se ha popularizado su uso sobre todo como agente antiinfeccioso tópico en una gran variedad de enfermedades. Se trata de una sustancia natural que tiene un potencial efecto tóxico demostrado sobre todo si se ingiere. Presentamos dos casos de pacientes atendidos en nuestro Servicio de Urgencias tras administración e ingestión accidental de aceite esencial de árbol de té, en ambos casos los padres confundieron el envase con el de la vitamina D. La atención de estos pacientes nos llevó a realizar una búsqueda bibliográfica de casos publicados de intoxicación por ingesta de aceite de árbol de té y a poner de manifiesto la ausencia de advertencias de seguridad en los envases de aceite de árbol de té que actualmente se comercializan en nuestro país (AU)
Tea tree oil is an essential oil obtained by steam distillation of the leaves and terminal branches of Melaleuca alternifolia. In recent years, it has become popular as an antimicrobial agent against a large number of diseases. It is a natural substance that has a potential toxic effect especially if ingested. We report two cases of infants who came to our Emergency Department because they were accidentally given tea tree oil. In both cases parents mistook the tea tree oil bottle with the D vitamin bottle. The care of these patients led us to perform a literature search of published cases of tea tree oil poisoning and highlight the absence of safety warnings on tea tree oil packages currently marketed in our country (AU)