Lycopene and vitamin C concentrations increase in plasma and lymphocytes after tomato intake. Effects on cellular antioxidant protection

Objective: This study seeks to verify whether the regular consumption of small amounts of tomato products can protect lymphocyte DNA and lipids from oxidative damage. Design: Standardized dietary intervention. Subjects: Twelve healthy female subjects ( mean age 25.2 y). Intervention: Subjects were instructed to follow a standardized diet for 1 week, followed by 3 weeks consumption of the same diet enriched with small amounts of different tomato products providing as a mean 8 mg lycopene, 0.5mg beta-carotene and 11 mg vitamin C per day. Plasma and lymphocyte concentrations of carotenoids, vitamin C and vitamin E were analysed. Ex vivo protection of lymphocyte DNA from oxidative injury produced by iron ions was evaluated by means of the Comet assay, and lipid peroxidation by HPLC analysis of malondialdehyde (MDA). Results: Dietary intervention with tomato products increased lycopene concentration both in plasma (P<0.001) and lymphocytes (P<0.01). Vitamin C concentrations increased by similar to35% in plasma ( P<0.05) and by similar to 230% in lymphocytes ( P<0.005). Vitamin E decreased significantly in plasma ( P<0.0001) but not in lymphocytes. Finally, there was an improved protection from DNA oxidative damage ( P<0.05) with no significant effect on MDA levels. Conclusions: Our results suggest that tomato products are not only good sources of lycopene but also sources of bioavailable vitamin C. A Regular intake of small amounts of tomato products can increase cell protection from DNA damage induced by oxidant species. This effect may originate from the synergism of different antioxidants present in tomatoes. Sponsorship: Supported by the Ministry of University and Scientific Research (MURST).