Klenow Stefanie, Jahns Franziska, Pool-Zobel Beatrice L, Glei Michael
Department of Nutritional Toxicology, Institute for Nutrition, Friedrich-Schiller-University Jena, Dornburger Strasse 24, 07743 Jena, Germany.
J Agric Food Chem. 2009 Apr 8;57(7):2999-3004. doi: 10.1021/jf802872b.
Phenolic ingredients of an aqueous carob extract are well characterized and consist of mainly gallic acid (GA). In order to assess possible chemopreventive mechanisms of carob, which can be used as a cacao substitute, effects on expression of genes related to stress response and drug metabolism were studied using human colon cell lines of different transformation state (LT97 and HT29). Stress-related genes, namely catalase (CAT) and superoxide dismutase (SOD2), were induced by carob extract and GA in LT97 adenoma, but not in HT29 carcinoma cells. Although corresponding protein products and enzyme activities were not elevated, pretreatment with carob extract and GA for 24 h reduced DNA damage in cells challenged with hydrogen peroxide (H(2)O(2)). In conclusion, carob extract and its major phenolic ingredient GA modulate gene expression and protect colon adenoma cells from genotoxic impact of H(2)O(2). Upregulation of stress-response genes could not be related to functional consequences.
角豆树水提取物中的酚类成分已得到充分表征，主要由没食子酸（GA）组成。为了评估可作为可可替代品的角豆树可能的化学预防机制，使用不同转化状态的人结肠癌细胞系（LT97和HT29）研究了其对应激反应和药物代谢相关基因表达的影响。在LT97腺瘤中，角豆树提取物和GA可诱导应激相关基因，即过氧化氢酶（CAT）和超氧化物歧化酶（SOD2），但在HT29癌细胞中则不然。尽管相应的蛋白质产物和酶活性没有升高，但用角豆树提取物和GA预处理24小时可减少用过氧化氢（H₂O₂）刺激的细胞中的DNA损伤。总之，角豆树提取物及其主要酚类成分GA可调节基因表达，并保护结肠腺癌细胞免受H₂O₂的遗传毒性影响。应激反应基因的上调与功能后果无关。
