The effect of lycopene on oxidative stress and dna damage in diethylnitrosamine administered rats

Diethylnitrosamine (DEN) is a carcinogenic material that is present in insecticide, chemicals used in agriculture, cheese, milk, wheat, overcooked bakery products, meat and fish products, cigarette smoke and alcoholic beverages. The study was conducted to examine the effects of lycopene on oxidative stress and DNA damage in DEN administered rats. In the study, 56 Wistar-Albino male rats of 3-months-old obtained from Firat University Experimental Research Center were used. The rats were divided in 8 groups as 7 rats in each group. The groups were formed as 1st Group: Control group, 2nd Group: Lycopene (10 days), 3rd Group: Short-term DEN (30 days), 4th Group: Long-term DEN (90 days), 5th Group: Lycopene+DEN (30 days), 6th group: Lycopene+DEN (90 days), 7th Group: DEN+Lycopene (30 days), 8th Group: DEN+Lycopene (90 days). No treatment was applied to the rats in the control group. Lycopene was administered to rats every other day at 10 mg/kg/bw, gavage for 10 days to the lycopene groups. DEN was administered to rats at 200 mg/kg/bw, a single dose intraperitoneal (i.p.) to the DEN groups. DEN was administered for 30 days in 3rd, 5th, and 7th groups and 90 days in 4th, 6th, and 8th groups. Lycopene was started to be administered 10 days before the DEN administration in 5th and 6th groups and together with the DEN administration in 7th and 8th groups. At the end of the administrations, malondialdehyde (MDA), reduced glutathione (GSH) levels, catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST), superoxide dismutase (SOD) activity, expression levels of CAT enzyme by using RT-PCR in the blood and liver tissue samples and plasma aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) activities and cholesterol levels were measured. Plasma and liver MDA levels were observed to increase while blood and liver GSH level, CAT, GSH-Px, SOD and GST activities were observed to decrease in short- and long-term DEN administered groups compared with the control group (p<0.001). MDA and GSH levels, CAT, GSH-Px, GST and SOD activities were not determined statistically significant difference in lycopene and lycopene groups were started together with the DEN administration individually compared with the control group. MDA levels were observed to decrease while GSH levels, CAT, GSH-Px, GST and SOD activities were observed to increase when all the groups in which lycopene administration was started before DEN and together with DEN administration compared with the DENadministered groups (p<0.001). GST activity could not be measured in the blood to levels that can not be read. Blood and liver gene expression levels of CAT were found increase in the DEN administered groups (p<0.05, p<0.001). Gene expression levels of CAT enzyme were not determined statistically significant difference in all groups which lycopene group and lycopene were started before DEN administration and together with DEN administration compared with the control group. Gene expression levels of CAT enzyme were observed to decrease in all groups which DEN was administered together and lycopene compared with the DEN administered groups (p<0.05, p<0.001). In plasma AST, ALT, ALP, LDH activities and cholesterol levels were observed in significant increased in DEN administered groups compared with the control group (p<0.05, p<0.001). In plasma AST, LDH activities and cholesterol levels were not determined significant difference in lycopene and lycopene groups were started together with DEN administered compared with the control group. In plasma AST, ALT, ALP, LDH activities and cholesterol levels were observed to increase in all groups which lycopene administration was started before DEN administration and together with the DEN administration were compared with the DEN administered groups. It is thought that the difference between the CAT activity and gene expression level can be caused by the variation in mRNA and protein conversion. It has been reached conclusion that lycopene, having a strong antioxidant quality, may be used clinically and may prevent oxidative stress and DNA damage occurring due to DEN.