Figure 2.

Effect of sulforaphane (10 μM) on the activity (a) and mRNA expression (b) of carbonyl-reducing enzymes in rat hepatocytes treated or non-treated with β-naphthoflavone (10 μM). Primary rat hepatocytes were incubated at 37 °C for 24 h. All enzyme activities were assessed in the cytosolic fraction. Specific enzyme activities of NADPH-quinone oxidoreductase (NQO1), carbonyl reductase 1 (CBR1) and aldo-keto reductase 1C (AKR1C) were determined as nmol of formed product (NQO1, AKR1C) or consumed cofactor (CBR1) per min per mg of protein. The data are expressed as the mean ± SD (n = 3). The mRNA and enzyme activity significantly altered (p ≤ 0.01) compared to control (*) or β-naphthoflavone (+). BNF β-naphthoflavone; SFN sulforaphane; BNF + SFN co-administration of BNF + SFN; BNF→SFN 6-h BNF pre-treatment followed by SFN addition; n.d. not determined.