title: Antimicrobial activity and inhibition of aflatoxin B1 formation by olive plant tissue constituents.
abstract: Ethanolic extracts of olive callus tissues, added at 0.5 or 1.0% to media on which Aspergillus flavus was grown, inhibited aflatoxin production by 90% without inhibiting the fungal growth. The extract was found to contain mainly caffeic acid and, to a lesser extent, catechin and coumarins. The fungicidal and bactericidal activity of caffeic acid, catechin, coumarin and p-, o- or m-coumaric acid were tested and only caffeic acid and o-coumaric acid inhibited aflatoxin production. The inhibitory effect had no correlation with the growth of the fungus. Only coumarin at 10 mmol/1 totally inhibited fungal growth. Of the phenolic constituents of callus tissues tested, catechin and caffeic acid (10 mmol/l) showed bactericidal activity towards Pseudomonas aeruginosa and Staphylococcus aureus.
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000037:antagonists & inhibitors*; D001231:Aspergillus flavus / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000348:Aflatoxins; D010936:Plant Extracts; D016604:Aflatoxin B1