Carrot phytoalexin alters the membrane permeability of Candida albicans and multilamellar liposomes.
The biochemical basis for the antimicrobial effect of the carrot phytoalexin 6-methoxymellein (6-MM) was examined. At fungistatic concentrations 6-MM retarded the ability of Candida albicans to incorporate radioactive thymidine, uridine and leucine into biopolymers. When C. albicans was incubated with 6-MM, 260-nm-absorbing materials and 3H-labelled compounds leaked from the cells. The inhibitory effects of 6-MM on cell growth and membrane functions were, however, reduced as the concentration of divalent metal cations added to the medium was increased. 6-MM interacted with multilamellar liposomes constituted from phosphatidylcholine, cholesterol and dicetyl phosphate, or from phosphatidylcholine only, resulting in the release of glucose trapped in these liposomes. These results suggest that 6-MM exerts its toxic effects on susceptible cells as a result of its interaction with their membranes and disturbance of membrane-associated functions.
D002176:Candida albicans / Q000187:drug effects*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D007930:Leucine / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D012717:Sesquiterpenes; D013729:Terpenes; D013936:Thymidine / Q000378:metabolism; D014529:Uridine / Q000378:metabolism; D014675:Vegetables / Q000032:analysis; D000094162:Phytoalexins
D008081:Liposomes; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D007930:Leucine; D008274:Magnesium; D013936:Thymidine; D014529:Uridine; D000094162:Phytoalexins