R. Aeschbach et al., ANTIOXIDANT ACTIONS OF THYMOL, CARVACROL, 6-GINGEROL, ZINGERONE AND HYDROXYTYROSOL, Food and chemical toxicology, 32(1), 1994, pp. 31-36
Antioxidants minimize oxidation of the lipid components in foods. Ther
e is an increasing interest in the use of natural and/or synthetic ant
ioxidants in food preservation, but it is important to evaluate such c
ompounds fully for both antioxidant and pro-oxidant properties. The pr
operties of thymol, carvacrol, 6-gingerol, hydroxytyrosol and zingeron
e were characterized in detail. Thymol, carvacrol, 6-gingerol and hydr
oxytyrosol decreased peroxidation of phospholipid liposomes in the pre
sence of iron(III) and ascorbate, but zingerone had only a weak inhibi
tory effect on the system. The compounds were good scavengers of perox
yl radicals (CCl3O2; calculated rate constants > 10(6) M(-1) sec(-1))
generated by pulse radiolysis. Thymol, carvacrol, 6-gingerol and zinge
rone were not able to accelerate DNA damage in the bleomycin-Fe(III) s
ystem. Hydroxytyrosol promoted deoxyribose damage in the deoxyribose a
ssay and also promoted DNA damage in the bleomycin-Fe(III) system. Thi
s promotion was inhibited strongly in the deoxyribose assay by the add
ition of bovine serum albumin to the reaction mixtures. Our data sugge
st that thymol, carvacrol and 6-gingerol possess useful antioxidant pr
operties and may become important in the search for 'natural' replacem
ents for 'synthetic' antioxidant food additives.