Screening of some medicinal plants for isolation of antifungal proteins and peptides

About three quarters of the world population rely mainly on plants and plant extracts for health care. The global annual sale of botanicals is over $ 62 billion. This data clearly depict the importance of medicinal plants in health and economy. The extracts of some potential medicinal plants such as Hygrophila auriculata, Abrus precatorius, Moringa oleifera, Withania somnifera, Croton tiglium, Solanum nigrum and Psoralea corylifolia were investigated against pathogenic fungal strains of Aspergillus tamarii, Rhizopus solani, Mucor mucedo and Aspergillus niger. After extraction the extracts were purified by ammonium sulphate precipitation followed by gel filtration chromatography (Sephadex G-100) by using Tris HCl as an extraction buffer. Antifungal activity of the extracts was determined by disc diffusion assay. Antifungal activity was found lost in many extracts after treatment with trypsin, which shows that the activity was due to proteins or peptides, but not due to some other compounds.