Antifungal Activity in Extracts of Plants from Southwestern Oklahoma Against Aspergillus Flavus

The use of medicinal plants has been an integral part of human civilization since antiquity. Naturally occurring pesticidal compounds are synthesized by the plant defense system, which includes antimicrobial proteins and lower molecular weight natural products. In this study, plants were collected from southwestern Oklahoma, and plant tissues were extracted and assayed for antifungal activity against Aspergillus flavus, a mycotoxin producing fungus. Out of the 84 plant tissue extracts tested, 40 extracts exhibited complete to very strong inhibition of fungal growth. Extracts were dialyzed in Tris buffer using 3,500 molecular weight cut-off dialysis membrane to remove low molecular weight compounds. After dialysis, the majority of the plant extracts lost antifungal activity against A. flavus. Four plant extracts, however, retained complete activity. The source plants of these four extracts were identified as belonging to Asparagaceae. Three of the extracts came from three different plants of the genus Allium. The fourth extract was from Camassia scilloides