ARS | Publication request: CAY-1, A FUNGICIDAL SAPONIN FROM CAPSICUM SP. FRUIT

Submitted to: Medical Mycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2002
Publication Date: June 1, 2002
Citation: De Lucca II, A.J., Bland, J.M., Vigo, C.B., Cushion, M., Selitrennikoff, C.P., Peter, J., Walsh, T.J. 2002. Cay-1, a fungicidal saponin from Capsicum sp. fruit. Medical Mycology. 40:131-137.

Interpretive Summary: Spices from plants have been used for centuries to enhance flavor and retard microbial growth. Capsicum is a family of plant that produces a spice commercially known as cayenne pepper in which no antimicrobials have been found. We thought it possible that cayenne contains antimicrobials that could help protect other plants from microbial disease. Extractions of cayenne pepper resulted in the purification of a natural detergent, called CAY-1, that killed members of the Aspergillus, Candida, and Pneumocystis families of fungi. CAY-1 was not lethal to two types of mammalian cells at the fungal-killing concentrations, indicating that it is safe for humans and animals. However, CAY-1 did not kill several types of bacteria tested. Results show that CAY-1 is a new fungicide from a food source that is safe for humans and animals. Should CAY-1 become commercially available, it will be a value-added product benefitting farmers and could be used to protect plants, foodstuffs, and serve as an antifungal treatment.

Technical Abstract: A novel saponin, CAY-1, with a molecular weight of 1243.35 Da, was isolated and purified to homogeneity from commercially available dry, ground fruit of Capsicum frutescens. CAY-1 was shown to be a potent fungicide for the germinating conidia of Aspergillus flavus, A. fumigatus, A. parasiticus, and A. niger. Activity against some Aspergillus species was affected by the test medium used. In vitro assays also showed that CAY-1 was effectiv against Pneumocystis carinii and Candida albicans. CAY-1 had no effect on the viability of the nongerminating conidia of the aforementioned filamentous fungi or on either conidial type of Fusarium oxysporum. It had no effect on Enterobacter agglomerans, Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. CAY-1 was not cytotoxic to A 549 lung carcinoma cells or HeLa cells at an effective fungicidal concentration. These results indicate CAY-1 is an effective fungicide for Aspergillus species, C. albicans, and P. carinii at concentrations below the threshold for mammalian cell toxicity.