466 Influence of the indole compounds on cellular level of glutathione and glutathione-s-transferase activity

Abstract

Cruciferous vegetables such as cauliflower, cabbage, kale, kohlrabi, turnips or broccoli, contain μ g/g levels of glucosinolate glucobassicin (indolyl methyl glucosinolate). Indole-3-carbinol is the major hydrolytic product obtained from glucobrassicin. When the plant cells are damaged by cutting or chewing, a thioglucosidase-mediated autolytic process takes place generating indole-3-carbinol, glucose and thiocyanate ion. Recent reports have shown that indole compounds can modulate cellular response when cells are exposed to variety of environmental xenobiotics. In our previous work we have shown that indole-3-carbinol and cauliflower extract did not induce point mutations in Salmonella typhimurium TA98 and TA100. We have also shown that indole compounds have inhibited formation of point mutations when Salmonella typhimurium TA98 and TA100 were treated with two standard mutagens 4-nitroquinoline-1-oxide (direct acting mutagen) and 2-aminoanthracene (promutagen). In this work we have examined indole-3-carbinol and cauliflower extract for their ability to influence on phase II biotransformation enzyme activities in four cell lines: human laryngeal carcinoma cells (parental HEp2 and their cisplatin resistant subline CK2) and human cervix cancer (parental HeLa and their cisplatin resistant subline CK). We have measured and compared cellular concentration of glutathione and enzymatic activity of total glutathione-S-transferases after 72 hours of treatment of the cells with the highest nontoxic concentrations of indole-3-carbinol and cauliflower extract. Concentrations of glutathione in four cell lines were compared with the basal level of glutathione in untreated cells. It was shown that cauliflower extract and indole-3-carbinol have caused significant increase of glutathione in both, HEp2 and HeLa, parental cells. On the contrary, cisplatin resistant cells have increased basal level of glutathione, and cisplatin resistant cells have increased basal level of glutathione, and both drugs decreased the level of glutathione. The activity of glutathione-S-transferases were increased in parental HEp2 and HeLa cells after treatment with indole-3-carbinol and cauliflower extract. On the other hand, indole compounds caused significant decrease of glutathione-S-transferases activity in resistant cells.