Antifungal activities of leaf extracts from the Capsicum genus

Abstract

The emergence of microorganisms resistant to antimicrobials has driven the search for new substances aimed at the control and prevention of pathogens. Plant antimicrobial peptides have biotechnological applications in the development of drugs and agricultural inputs for this purpose. The present work aims to evaluate the antifungal activity of extracts containing peptides obtained from the leaves of Capsicum plants. The accessions UENF 1626, 1632 and 1381 and the cultivar Carioquinha were used. The leaves were macerated, and then extraction was performed using a 60% methanol and dichloromethane solution in a 1:1 ratio. The hydromethanolic phase was separated and used for testing after evaporation of methanol. All extracts have a similar electrophoretic profile on tricine gel stained with Coomassie Blue, showing 2 bands of approximately 6.5 and 3.5 kDa. Inhibition of fungal growth with 24 h of culture was performed in liquid culture medium in 96-well plates with reading at 620 nm using extracts with a protein concentration of 200 mg mL-1. The filamentous fungi Fusarium solani, Fusarium lateritium, and Colletotrichum lindemuthianum and the yeasts Candida albicans, Candida buinensis, Candida tropicalis, Saccharomyces cerevisiae, Pichia membranifaciens and Kluyveromyces marxianus were used. The extract with the greatest antifungal potential was the leaves of Capsicum annuum cv. Carioquinha, inhibiting the growth of F. solani by 29%, C. lindemuthianum by 15%, Candida buinensis by 22% and K. marxianus by 24%. Therefore, the extract has peptides with biotechnological potential.