Source: CropBiotech Update

Plant foods are a good source of flavonoids, important compounds due to their antioxidant properties. As antioxidants, flavonoids may protect against certain diseases such as cancer by inhibiting oxidative and free-radical damage to lipids and nucleic acids. These plant-derived substances also play a role in the prevention of other diseases associated with aging like cardiovascular disease. In a recent article published in the Journal of Nutrition, scientists in Germany and the Netherlands have succeeded in producing transgenic tomato with enriched levels of flavonoids, and tested the health effects of both genetically-modified and wild-type tomatoes on mice.

Researchers tracked changes in general health indicators such as bodyweight and food intake, and in cardiovascular risk indicators that include plasma C-reactive protein (CRP) and cholesterol levels. They found out that mice fed with wild-type tomato and those with transgenic tomato have higher levels of “good” cholesterol compared with the baseline; however, mice supplied with flavonoid-enriched tomato have significantly reduced levels of CRP – a protein associated with high risk of cardiovascular disease – than those that received wild-type tomato in the diet, indicating lower risk of cardiovascular disease for the group fed with flavonoid-enriched tomato. The results of the study suggest that genetic enhancement of fruits and vegetables may in the future allow an optimization of the human diet and help reduce diseases.

Transgenic Flavonoid Tomato Intake Reduces C-Reactive Protein in Human C-Reactive Protein Transgenic Mice More Than Wild-Type Tomato
Dietrich Rein2, Elio Schijlen3, Teake Kooistra4, Karin Herbers2, Lars Verschuren4,5, Robert Hall3, Uwe Sonnewald6, Arnaud Bovy3 and Robert Kleemann4,5,*
2 BASF Plant Science Holding GmbH, D-67117 Limburgerhof, Germany; 3 Plant Research International B.V., NL-6700 AA Wageningen, The Netherlands; 4 TNO Quality of Life, 2301 CE Leiden, The Netherlands; 5 Leiden University Medical Centre, 2300 RC Leiden, The Netherlands; and 6 Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
* To whom correspondence should be addressed. E-mail: robert.kleemann@tno.nl

ABSTRACT

The increased consumption of fruits and vegetables is associated with reduced cardiovascular disease. The molecular basis of this health effect is not fully understood, yet dietary flavonoids are thought to play an important role. Genetic engineering has enabled us to overexpress specific flavonoids (flavones and flavonols) in tomato fruit. Human C-reactive protein transgenic (CRPtg) mice express markers of cardiovascular risk that allow us to study of the putative health effects of wild-type tomato (wtTom) and flavonoid-enriched tomato (flTom). In this study, we analyzed whether consumption of wtTom, at a dose achievable with a human diet, has beneficial effects on cardiovascular risk markers and whether flTom may enhance such effects. CRPtg mice were fed a diet containing 4 g/kg wtTom, flTom peel, vehicle, or 1 g/kg fenofibrate, which reportedly reduces cardiovascular risk, for 7 wk. Markers of general health (bodyweight, food intake, and plasma alanine aminotransferase activities) and of cardiovascular risk (plasma CRP, fibrinogen, E-selectin, and cholesterol levels) were analyzed. All groups had comparable food intakes and body-weight gains. Plasma alanine aminotransferase activities increased significantly in vehicle and fenofibrate-treated mice. Compared with baseline, wtTom and flTom significantly reduced basal human CRP concentrations by 43 and 56%, respectively. The CRP-lowering effect of flTom significantly exceeded that of wtTom. The effects of flTom on CRP were reversed within a 2-wk washout period. WtTom and flTom did not affect fibrinogen, but comparably repressed E-selectin expression and upregulated HDL cholesterol. Tomato peel consumption improved cardiovascular risk factors in CRPtg mice, a beneficial effect that was further enhanced by enrichment of the flavonoid content.

Source: http://jn.nutrition.org/cgi/content/abstract/136/9/2331

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