J. Alanko et al., Modulation of arachidonic acid metabolism by phenols: Relation to their structure and antioxidant/prooxidant properties, FREE RAD B, 26(1-2), 1999, pp. 193-201
The effects of substituted catechols (3-methylcatechol, 4-methylcatechol, 4
-nitrocatechol, and guaiacol) and trihydroxybenzenes (pyrogallol, propyl ga
llate, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene) on the synthes
is of prostaglandin (PG)E-2, and leukotriene (LT)B-4, were tested in human
A23187-stimulated polymorphonuclear leukocytes. The effects were related to
their peroxyl-radical-scavenging (antioxidant), superoxide-scavenging (ant
ioxidant), and superoxide-generating (prooxidant) properties. In general, c
ompounds with hydroxyl groups in the ortho position increased PGE(2)/LTB4 r
atio, and compounds with hydroxyl groups in the meta position decreased PGE
(2)/LTB4 ratio. Catechols, which have hydroxyl groups in the ortho position
, were the most potent peroxyl radical and superoxide anion scavengers. Tri
hydroxybenzenes (pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxyb
enzene) generated superoxide, whereas dihydroxybenzenes did not. Thus, the
positions and number of hydroxyl groups seem to be the most important prope
rties determining the action of phenolic compounds on PGE(2)/LTB4, ratio an
d their antioxidant/prooxidant activities. (C) 1998 Elsevier Science Inc.