The ability of indole-3-carbinol (indole-3-methanol) to trap a metasta
ble synthetic-free radical is presented. Indole-3-carbinol is capable
of acting as a scavenger of free radicals in an in vitro system. The p
resence of indole-3-carbinol determines the disappearance of the free
radicals, the reaction being time- and concentration-dependent. The sc
avenging activity of different indoles is compared. Indole-3-carbinol
and indole-3-acetic acid are both able to scavenge free radicals, but
indole-3-carbinol is more effective. Other indoles such as indole-3-al
dehyde and indole-3-carboxylic acid do not show the ability to trap fr
ee radicals. Indole-3-aldehyde appears as a product of iudole-3-carbin
ol reaction with free radicals. The formation of an adduct between the
free radical generated in vitro and indole-3-carbinol has also been d
etected. Stability of indole-3-carbinol in buffered media at different
pH values and formation of 3,3'-diindolylmethane from indole-3-carbin
ol is also studied. The scavenging activity of indole-3-carbinol and i
ts implications on the anti-carcinogenesis process is discussed.