The influence of L-ascorbic acid on the antibacterial-toxic activity of aflatoxins on adsorbent layer.
OBJECTIVE
To substantiate the role of formaldehyde (HCHO) and its reaction products in the mechanism of the antibacterial-toxic effect of aflatoxins B1 (AFB1), B2, G1 and G2.


RESULTS
Toxins were separated by overpressured layer chromatography, which was followed by biological evaluation directly on the adsorbent layer (BioArena system with Pseudomonas savastanoi pv. phaseolicola indicator bacteria). HCHO formed in this system was eliminated with exogenously added capturer molecule dimedone and L-ascorbic acid (AA) and measured as the adduct of dimedone and HCHO. The amount of HCHO was higher in the toxin-containing spots, particularly in the most toxic AFB1 spot, compared to a toxinless background. 0.1 mg ml(-1)AA augmented, 0.2 mg ml(-1) dimedone or 0.5 and 1 mg ml(-1) AA reduced the antibacterial effect of all four aflatoxins.


CONCLUSIONS
The antibacterial-toxic effect of aflatoxins may be mediated by HCHO (and/or its reaction products) generated from bound HCHO forms in the bacterial cells. Basis of antibacterial-toxic activity of the four aflatoxins appears the same.


CONCLUSIONS
Involvement of HCHO as a key molecule in the effect of aflatoxins indicates a totally new mechanism of action of these dangerous molecules. The BioArena system is useful to dissect the mode of action of antimicrobial compounds from different biological matrices.
Department of Chemical Technology and Environmental Chemistry, L. Eötvös University, Budapest, Hungary. moricz_am@yahoo.com
A M
AM
Móricz
P G
PG
Ott
F
F
Billes
K H
KH
Otta
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Tyihák
D000327:Adsorption; D000348:Aflatoxins / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001230:Aspergillus / Q000378:metabolism; D001431:Bacteriological Techniques; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D005557:Formaldehyde / Q000737:chemistry / Q000494:pharmacology*; D011042:Poisons / Q000494:pharmacology*; D011549:Pseudomonas / Q000187:drug effects
D000348:Aflatoxins; D000900:Anti-Bacterial Agents; D004202:Disinfectants; D011042:Poisons; D005557:Formaldehyde; D001205:Ascorbic Acid