Effect of various kimchi extracts on the hepatic glutathione S-transferase activity of mice

To investigate the effect of various kimchis on the induction of hepatic glutathione S-transferase activity of mice, the extract of kimchi was administered to ICR female mice via gavage for 5 days. Separately, volatile sulfur compounds in the extract of kimchi were analyzed by GC/MS. The amount of isothiocyanates including sulforaphane decreased remarkably in extract of turnip kimchi or red cabbage kimchi which contains relatively small amount of sulfides. Meanwhile there was a small decrease of sulfides in green onion kimchi where isothiocyanates were not detected. The induction of hepatic GST activity in mice administered with kimchi extracts was significant (p < 0.05); 1.64-fold for green onion kimchi, 1.49-fold for turnip kimchi and 1.37-fold for red cabbage kimchi. However, there was no significant GST induction (1.11 to 1.20-fold) with mustard leaf kimchi or leek kimchi. Further study indicates that the GST induction by the extract of green onion kimchi, turnip kimchi or red cabbage kimchi was comparable to that by the extract of the respective fresh vegetable. These results imply that kimchis have a capability of inducing GST activity, and the GST induction may be possibly ascribed to sulfides as well as isothiocyanates in kimchi extracts. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.