Molecular evidence that oral supplementation with lycopene or lutein protects human skin against ultraviolet radiation: Results from a double-blinded, placebo-controlled, cross-over study

Summary

Background

Increasing evidence suggests photo-protection by oral supplementation with ß-carotene and lycopene.

Objectives

We examined the capacity of lycopene rich tomato nutrient complex (TNC) and lutein, to protect against UVA/B- and UVA1 radiation at a molecular level.

Methods

In a placebo-controlled, double blinded, randomized cross over study two actives containing either TNC or lutein were assessed for their capacity to decrease the expression of UVA1 radiation-inducible genes including heme oxygenase-1 (HO-1), intercellular adhesion molecule-1 (ICAM-1) and matrix metalloproteinase-1 (MMP-1). 65 healthy volunteers were allocated to 4 treatment groups and subjected to a 2-weeks wash-out phase, followed by two 12-weeks treatment phases separated by another 2-weeks wash-out. Volunteers started either with active and switched then to placebo or vice versa. At the beginning and at the end of each treatment phase skin was irradiated and 24 hours later biopsies were taken from untreated, UVB/A- and UVA1 irradiated skin for subsequent RT-PCR analysis of gene expression. Moreover, blood samples were taken after the wash out and the treatment phases for assessment of carotenoids.

Results

TNC completely inhibited UVA1 as well as UVA/B induced upregulation of HO-1, ICAM-1 and MMP1 mRNA no matter of sequence (ANOVA, p<0.05). In contrast, lutein provided complete protection if it was taken in the first period, but showed significantly smaller effects in the second sequence compared to TNC.

Conclusion

Assuming the role of these genes as indicators of oxidative stress, photo-dermatoses and photo-aging these results might indicate that TNC and lutein could protect against solar radiation-induced health damage.

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