乳酸發酵蔬菜萃取物對4-nitroquinoline N-oxid基因毒性及數株癌細胞抑制之研究

Abstract

乳酸菌長久以來被應用在各種發酵食品，除了用以提高產品的保存性，也提供一些特殊的風味。本研究使用MTT細胞毒性試驗檢測乳酸發酵蔬菜 kimchi 及 sauerkraut 抑制4NQO細胞毒性，以及用彗星電泳法 (comet assay) 檢測4NQO基因毒性。 Kimchi 和 sauerkraut 甲醇及水萃取物在 15μg/mL 至 500μg/mL 的濃度下，能夠抑制4NQO對人體腸道細胞 Int-407的細胞毒性，且隨著樣品濃度增加其抑制率也跟著提升，顯示萃取物之抗細胞毒性具有濃度效應。其中以甲醇萃取物抑制率較水萃取物高，kimchi 和 sauerkraut 甲醇萃取物的最高抑制率分別為22.7％及21.2％。在抑制基因毒性方面，甲醇萃取物和水萃取物皆能夠抑制4NQO對Int-407引起的基因毒性。在抗4NQO細胞毒性的機制方面，由分段式預實驗研究顯示，發酵蔬菜萃取物主要為生物抗致突變的作用 (bioantimutagenicity)，即能夠修補4NQO造成的損傷。此外結果顯示，乳酸發酵蔬菜萃取物並沒有抑制人類腸道癌細胞 Caco-2 及 HT-29 的作用。

Lactic acid bacteria has been used in many fermented foods for their preservative properties and unique flavor properties. This study examined the cytotoxicity of two kinds of lactic acid fermentation vegetables kimchi and sauerkraut against 4-nitroquinoline N-oxide (4NQO) by the MTT cytotoxicity assay and the inihibition of 4NQO genotoxicity by the comet assay. Methanol and water extracts of kimchi and sauerkraut inhibited the 4NQO cytotoxicity to intestine cell line Int-407 with concentrations range from 15 to 500 μg/mL. The increase of kimchi and sauerkraut extracts concentrations increase the inhibition rate, showing dose-dependency response. The methanol extracts of fermented vegetables were more inhibitory than their water extracts, the highest inhibition rates of methanol extracts of kimchi and sauerkraut were 22.7％ and 21.2％ respectively. The methanol and water extracts inhibited the 4NQO genotoxicity to Int-407. According to the preincubation studies, the main mechanism of anticytotoxicity against 4NQO was found to be bioantimutagenic. In addition the result showed that lactic acid fermentation vegetables extracts could not inhibit the viability of intestine cancer cells Caco-2 and HT-29.