Modulatory effect of crocetin on aflatoxin B1 cytotoxicity and DNA adduct formation in C3H10T1/2 fibroblast cell.

Crocetin is a carotenoid isolated from the seeds of Cape jasmine (Gardenia jasminoides). The cytotoxicity and DNA-adduct formation of rat microsome-activated aflatoxin B1 (AFB1) in the C3H10T1/2 cells were significantly inhibited by pretreatment of crocetin. Most significant inhibition was found at the time of 9 h after crocetin pretreatment. Under these experimental conditions, consistent elevation in the cytosolic glutathione (GSH) levels and the activities of GSH S-transferase (GST) and GSH-peroxidase (GSH-Px) were observed. Crocetin treatment also resulted in a decrease in AFB1-DNA adduct formation in vitro, while no effect of crocetin on the formation of AFB1-8,9-oxide in vitro system was detected as measured by the Trisdiol method. From these results, we suggested that the protective effect of crocetin on the AFB1-cytotoxicity in C3H10T1/2 cells might be due to the cellular defense mechanisms that elevated the cytosol GSH and the activities of GST and GSH-Px.