RESUMEN
Fusarium oxysporum is an ascomycete facultative fungus which generally affects to plants. However, it is recently known as a serious emerging opportunistic pathogen of human and other animals. F. oxysporum shows broad resistance to commonly used antifungal agents and therefore development of alternative therapeutic agents is required. In this study, we investigated the antifungal efficacy of plant based natural lawsone against pathogenic F. oxysporum. Antifungal susceptibility test determined the concentration dependent growth inhibition of lawsone against F. oxysporum with minimum inhibitory concentration (MIC) at 100µg/mL. Ultra-structural analysis indicates the prominent damage on cell wall of the mycelium after lawsone treatment, and suggests that it could increase the membrane permeability and disintegration of cells leading to cellular death. Propidium iodide (PI) uptake assay results showed the higher level of cell death in lawsone treated F. oxysporum which further confirms the loss of plasma membrane integrity. Also, detection of reactive oxygen species (ROS) using DCFH-DA has clearly indicated that lawsone (100µg/mL) can induce the ROS level in the filaments of F. oxysporum. MTT assay results showed the loss of viability and germination capacity of F. oxysporum spores by lawsone in concentration dependent manner. Moreover, lawsone treatment induced the mRNA expression of two autophagy related genes (ATG1 and ATG8) indicating that lawsone may activate the autophagy related pathways in F. oxysporum due to the oxidative stress generated by ROS. F. oxysporum infected zebrafish has recovered after lawsone therapy as a topical treatment suggesting that lawsone is a potential natural antifusariosis agent.
Asunto(s)
Antifúngicos/farmacología , Fusarium/efectos de los fármacos , Naftoquinonas/farmacología , Animales , Antifúngicos/administración & dosificación , Autofagia/efectos de los fármacos , Autofagia/genética , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Permeabilidad de la Membrana Celular/efectos de los fármacos , Pared Celular/efectos de los fármacos , Pared Celular/ultraestructura , Modelos Animales de Enfermedad , Enfermedades de los Peces/tratamiento farmacológico , Enfermedades de los Peces/microbiología , Fluoresceínas , Fusarium/genética , Fusarium/crecimiento & desarrollo , Fusarium/patogenicidad , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Genes Fúngicos/efectos de los fármacos , Hifa/efectos de los fármacos , Técnicas In Vitro , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Confocal , Microscopía Electrónica de Rastreo , Músculos/microbiología , Músculos/patología , Naftoquinonas/administración & dosificación , Control Biológico de Vectores , Enfermedades de las Plantas/microbiología , Extractos Vegetales/farmacología , Propidio , ARN Mensajero/biosíntesis , ARN Mensajero/efectos de los fármacos , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Esporas Fúngicas/efectos de los fármacos , Esporas Fúngicas/crecimiento & desarrollo , Pez Cebra/microbiologíaRESUMEN
In this study, we prepared and characterized the oats origin of nano scale ß-glucan (NBG) and investigated the immunomodulatory properties in zebrafish larvae. Newly prepared NBG (average particle size of 465 nm) was fully soluble in water. Zebrafish larvae survival rate was increased against pathogenic bacteria Edwardsiella tarda, when NBG was added to the water (500 µg/mL) compared to NBG non-exposed controls. Moreover, quantitative real time PCR (qRT-PCR) results showed up-regulation of immune functional genes including TNF-α, IL-1ß, ß-defensin, lysozyme, IL 10, IL 12 and C-Rel indicating higher survival rate could be due to stronger immunomodulatory function of NBG (500 µg/mL). Thus, non-toxic, water soluble and biodegradable NBG from oats could be considered as the potential immunostimulant for larval aquaculture.