Lycopene and ß-carotene protect in vivo iron-induced oxidative stress damage in rat prostate

Abstract It has been suggested that iron overload may be carcinogenic. In thepresent study, we evaluated the effect of plasma and prostate caro-tenoid concentration on oxidative DNA damage in 12-week-old Wistarrats treated with intraperitoneal ( ip ) ferric nitrilotriacetate (Fe-NTA)(10 mg Fe/kg). Plasma s-carotene and lycopene concentrations weremeasured as a function of time after ip injection of carotenoids (10 mgkg -1 day s-carotene or lycopene) in rats. The highest total plasmaconcentration was reached 3 and 6 h after ip injection of lycopene ors-carotene, respectively. After 5 days of carotenoid treatment, lyco-pene and s-carotene were present in the 0.10-0.51 nmol/g wet tissuerange in the prostate. Using a sensitive method to detected 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) by HPLC/EC, the level of8-oxodGuo in rat prostate DNA was significantly higher (6.3 ± 0.6residues/10 6 dGuo) 3 h after Fe-NTA injection compared with controlrats (1.7 ± 0.3 residues/10 6 dGuo). Rats supplemented with lycopeneor s-carotene for 5 days prior to Fe-NTA treatment showed a reductionof about 70% in 8-oxodGuo levels to almost control levels. Comparedwith control rats, the prostate of Fe-NTA-treated animals showed a78% increase in malondialdehyde accumulation. Lycopene or s-carotene pre-treatment almost completely prevented lipid damage.Epidemiological studies have suggested a lower risk of prostatecancer in men reporting a higher consumption of tomato products.However, before associating this effect with tomato sauce constitu-ents, more information is required. The results described here maycontribute to the understanding of the protective effects of carotenoidsagainst iron-induced oxidative stress.