Cresols are monomethyl derivatives of
phenol frequently used as
solvents and intermediates in the production of
disinfectants, fragrances, pesticides,
dyes, and
explosives, which is probably why they are widely distributed in the environment. General population may be exposed to
cresols mainly through inhalation of contaminated air. In this study we evaluated the toxicological effects of
o-cresol on differential gene expression profile of rat liver and prostate. Experiments were conducted on 80 male rats, 60 of which were exposed to
o-cresol (1.5 g kg-1, 5 g kg-1, or 15 g kg-1) through feed for 8 weeks. Three groups of rats were supplemented with 0.1 mg kg-1
selenium (Se, in the form of,
sodium selenite) in addition to
o-cresol to evaluate its effectiveness against
o-cresol toxicity. Control group received neither
o-cresol nor Se, while one group received Se alone. Survival was similar between the exposed and control animals. Rats exposed to 15 g kg-1 of
o-cresol showed a 16 % loss in
body weight by the end of the study, which may have been related to
o-cresol making feed unpalatable at this concentration. Liver and prostate tissue samples were collected at the end of the treatment.
mRNA analysis revealed that apoptotic genes (
CYP3A, COX-2, PPARĪ³, BAX, BCL2, AKT-1, and PKCĪ±) related to
cancer were up-regulated in liver and prostate tissues isolated from groups exposed to 5 g kg-1 and 15 g kg-1o-cresol in comparison to control. Changes in gene expression profile were prevented when rats were supplemented with Se. The exact mechanisms underlying its protective effect remain to be clarified by future studies.