Carotenoids inhibit DNA synthesis in human aortic smooth muscle cells

Quiescent, serum-starved human aortic smooth muscle cells were restimulated with 20% foetal calf serum in Dulbecco's modified Eagle medium, in the presence and absence of p-carotene, canthaxanthin, zeaxanthin, lycopene, lutein or beta-cryptoxanthin, at final concentrations up to 23 mu M. Concentration-dependent inhibition of DIVA synthesis, measured by [methyl-H-3]thymidine incorporation, was observed for the carotenoids, except for canthaxanthin and lutein which had no effect. Lycopene was the most potent of the carotenoids tested. The results suggest that antiproliferative effects of dietary carotenoids might be of significance in vivo. (C) 1999 Federation of European Biochemical Societies.