
Peppers Put
the Heat on PestsBy Jan Suszkiw March 15, 2001Cayenne pepper, a popular spice for
flavoring food, is known for its heat-producing properties from the substance
capsaicin. Agricultural Research Servicescientists also have found that cayenne peppers contain another potent
substance in the saponin chemical family that kills several noxious fungi and
yeasts. And because this pepper saponin, called CAY-1, is not toxic to human cells
at microbial-killing doses, MycoLogics,
Inc., a Denver, Colorado, firm, has begun testing its potential as a
candidate drug for treating patients with fungal infections. MycoLogics is
doing so under an agreement with ARS's
Southern
Regional Research Center in New Orleans, La., according to Anthony DeLucca,
a microbiologist there. He and chemists John Bland and Craig Vigo discovered CAY-1 during research
to identify plant compounds that could be used as crop protectants against
spoilage microorganisms such as Aspergillus fungi, which make
aflatoxins. Cayenne peppers topped an unusual list of organisms--including
Cecropia moths, tree frogs, and bacteria--that produce other novel antifungal
compounds. Though CAY-1 proved active against Aspergillus and other important
microbial crop pests, DeLucca speculated its properties might also interest
medical researchers seeking candidate drug compounds to fight emerging fungal
threats to human health. That curiosity led to collaborative studies with
National Institutes of Health scientist Tom
Walsh, University of Cincinnati researcher
Melanine Cushion, and MycoLogic president Claude Seltrennikoff. In a paper undergoing peer review, they report results from bioassay studies
in which germinating and non-germinating cultures of four bacterial, six fungal
and one yeast species were exposed to different CAY-1 concentrations. For
example, in one test against Candida albicans, which causes thrush and
other human infections, a 2.6 microgram-per-milliliter dose curbed the
microbe's growth by 93 percent. Additionally, none of the antimicrobial
concentrations used caused harm to human cervix cell cultures. CAY-1 also
wasnt toxic to cells from lung tissue, where Aspergillus andPneumocystis carinii fungi can cause serious infections in
immuno-compromised patients. ARS, the U.S. Department of
Agricultures chief scientific research agency, has filed a patent on
CAY-1. Scientific contact: Tony J. De Lucca, ARS Southern Regional Research
Center, New Orleans, La., phone (504) 286-4253, fax (504) 286-4419,
[email protected]. U.S. Department of Agriculture | |