Ellagic acid toxicity and interaction with benzo[a]pyrene and benzo[a]pyrene 7,8-dihydrodiol in human bronchial epithelial cells

Ellagic acid, a plant phenol present in various foods consumed by humans, has been reported to have both anti-mutagenic and anti-carcinogenic potential. To evaluate the potential anti-carcinogenic property of ellagic acid, we tested its effects on the toxicity of ben-zoa]pyrene and benzoa]pyrene, 7,8-dihydrodiol and binding of benzoa]yrene to DNA in cultured human bronchial epithelial cells. The toxicity of ellagic acid itself for human bronchial epithelial cells was also determined. Using a colony-forming efficiency assay, it was found that a nontoxic concentration of ellagic acid (5 g/ml) enhanced the toxicity of benzoa]pyrene.7,8-dihydrodiol in human bronchial epithelial cells. In contrast, ellagic acid at concentrations of l.5 and 3.0 g/ml inhibited binding of benzoa]pyrenemetabolites to DNA in these cells. An explanation for the potentiating effect of ellagic acid on the toxicity of benzoa]pyrene, 7,8-dihydrodiol will require further investigation into the possible mechanisms of interaction between these two compounds.Abbreviations Ba]P benzoa]pyrene - Ba]P 7,8-DHD (±)trans-7,8-dihydro-7,8-dihydroxybenzoa]pyrene - Ba]PDE-1 (±)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzoa]pyrene - Ba]PDE-2 (±) 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzoa]pyrene - Ba]PDE-1:dG N²-]10{7,8,9-dihydroxy-7,8,9,10-tetrahydrobenzoa]pyrene]yl}:deoxyguanosine - Ba]PDE-2:dG NZ-{10-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzoa]pyrene]yl}:deoxyguanosine - CFE colony forming efficiency - EA ellagic acid - HBE human bronchial epithelial