Comparison of lycopene and tomato effects on biomarkers of oxidative stress in vitamin E deficient rats.
BACKGROUND
Cohort studies suggested that individuals with higher intake of tomatoes and tomato products have a lower risk of degenerative diseases. Lycopene, an antioxidant and antiproliferative carotenoid, has been hypothesized to be responsible for the health benefits of tomatoes. However, studies demonstrated a higher potential of tomatoes compared to lycopene to reduce oxidative stress or carcinogenesis.


OBJECTIVE
Our study aimed at distinguishing lycopene effect from that of tomato on oxidative stress, by using yellow tomato, a tomato variety devoid of lycopene.


METHODS
Effects of feeding with none (control), 16% freeze-dried yellow tomato (YT), 16% freeze-dried red tomato (RT) or 0.05% lycopene beadlets (LB) were compared in a rat model with mild oxidative stress induced by low vitamin E diet (LVED). Four groups of 10 rats were fed ad libitum for 6 weeks. Physiological parameters such as ingesta, body, spleen and liver weights, cholesterol and triglycerides (TG) levels were assessed. Lycopene and vitamin E concentrations and oxidative stress biomarkers were measured in the plasma and/or liver and/or heart tissue of the rats.


RESULTS
RT, YT, and LB had no effect on rats' ingesta, body and spleen weights. RT, YT and LB had no effect on plasma cholesterol concentration. RT decreased TG level compared to control, YT and LB (P < 0.05). Rats fed RT or LB accumulated lycopene in plasma in contrast with rats fed YT. Heart level of thiobarbituric reactive species (TBARS) in rats fed RT or YT was lower than that in the control and the LB fed rats (P < 0.05). Despite similar concentrations of lycopene in plasma and liver, rats fed LB showed a significantly higher heart level of TBARS than rats fed tomatoes. RT increased erythrocyte superoxide dismutase (eSOD) activity compared with LB and nitric oxide (NO) level compared with control and LB. LB decreased ferric reducing ability of plasma (FRAP) level compared with control, RT and LB (P < 0.05).


CONCLUSIONS
Our study showed for the first time that tomatoes, containing or not containing lycopene, have a higher potential than lycopene to attenuate and or to reverse oxidative stress-related parameters in a mild oxidative stress context.
Gitenay
Delphine
D
Equipe Stress Métabolique et Micronutriments, Unité de Nutrition Humaine, Institut National de Recherche Agronomique, Centre de Clermont-Ferrand/Theix, 63122 Saint-Genès Champanelle, France.
Lyan
Bernard
B
Rambeau
Mathieu
M
Mazur
Andrzej
A
Rock
Edmond
E
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015415:Biomarkers / Q000097:blood; D002338:Carotenoids / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000737:chemistry*; D008297:Male; D009929:Organ Size; D018384:Oxidative Stress / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014280:Triglycerides / Q000097:blood; D014810:Vitamin E / Q000097:blood*; D014811:Vitamin E Deficiency / Q000378:metabolism
D000975:Antioxidants; D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D014280:Triglycerides; D014810:Vitamin E; D002338:Carotenoids; D002784:Cholesterol; D013482:Superoxide Dismutase; D000077276:Lycopene