Beta-carotene and the application of transcriptomics in risk-benefit evaluation of natural dietary components

Beta-carotene is a natural food component that is present in fruits and vegetables and is also used as a food colorant and a supplement. Beta-carotene is an anti-oxidant and a source of vitamin A. It is endowed with health beneficial properties, but a number of studies showed that with high intakes it may increase the risk for lung cancer in at risk individuals (heavy smokers, asbestos workers and alcohol users). To establish the window of benefit, it is necessary to identify early markers of effect and to obtain insight in the mechanism of action of beta-carotene, in the absence and presence of environmental risk factors. Genomics technologies are well suited to dissect the mechanisms of action and identify the markers of effect. Human cell lines can be used to analyse the effects of beta-carotene, but exposure studies with beta-carotene show that cell lines display a widely variant behaviour, which hampers translation to the in vivo situation in humans. Alternatively, animal studies can be used. Especially the ferret seems to be a good model, but little sequence information of this species is available. However, heterologous hybridization on human cDNA seems possible and provides and a new tool for molecular analysis of health effects of beta-carotene.