TABLE 1.

Inhibition of RA-induced transactivation of the RARβ and CYP26A1 genes by apolycopenoids

Lycopenoid	RARβ (% of RA Induction)	CYP26A1 (% of RA Induction)
apo-11-lycopenal	75, 90, 93, 99	92, 105, 111
apo-11-lycopenoic acid	69, 95, 104	79, 91, 97
apo-13-lycopenone	50, 66, 67, 68	22, 35, 50
apo-15-lycopenal	40, 62, 63	37, 48
apo-15-lycopenoic acid	64	63

HepG2 cells were incubated as described in Materials and Methods in the presence of 10 nM RA and 10 nM of the indicated lycopene cleavage products. The levels of mRNA for RARβ and CYP26A1 were determined by RT-PCR. Results are expressed as the percent of the fold induction observed with RA alone that is defined as 100%. The absolute fold induction with 10 nM RA alone for RARβ varied from 11- to 26-fold and for CYP26A1 varied from 68- to 135-fold in independent experiments.