EUGENOL CYTOTOXICITY EVALUATED WITH CONTINUOUS CELL-LINES

The cytotoxicity of eugenol to replicating cells, as mediated by the intracellular level of glutathione and by metabolic activation, was evaluated with the neutral red (NR) assay. The cytotoxicity of eugenol to human HFF fibroblasts and human HepG2 hepatoma cells was increased somewhat in the presence of a hepatic S-9 microsomal fraction from Aroclor-induced rats or hamsters. Exposure of human HepG2 hepatoma cells to eugenol depleted the level of intracellular glutathione. Cells treated with 1-chloro-2,4-dinitrobenzene (CDNB) or buthionine sulphoximine (BSO), agents that deplete intracellular glutathione, were hypersensitive to eugenol. A 1-hr pretreatment with CDNB enhanced the cytotoxicity of eugenol, as did a 24-hr pretreatment with BSO. Intracellular glutathione levels were, apparently, significant in mediating the toxicity of eugenol.