Efficiency of a few retinoids and carotenoids in vivo in controlling benzo[a]pyrene-induced forestomach tumour in female Swiss mice

The anticarcinogenic effect of vitamin A2 (dehydroretinol and 3-hydroxyretinol) compounds was studied and compared with that of vitamin A1 (retinoic acid, retinol and retinal) and carotenoids (lutein and β-carotene) in the benzo[a]pyrene (B(a)P)-induced forestomach tumour model of female Swiss mice in vivo. Tumour growth and gross tumour incidence observed after the administration of B(a)P (eight doses of 1 mg, twice weekly for 4 weeks) and retinoids/carotenoids (2·5 and 4·7 μm per animal per d, 2 weeks before, during and 2 weeks after B(a)P) showed that the groups supplemented with lutein and 3-hydroxyretinol produced the best results in inhibiting tumour growth and had low tumour incidence compared with the control group given B(a)P only (P