Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, 608 002, Tamil Nadu, India.
Toxicol Mech Methods. 2007;17(8):467-74. doi: 10.1080/15376510701190797.
ABSTRACT The present study was designed to evaluate the chemopreventive effects of black tea polyphenols (Polyphenon-B) on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in Wistar rats. Intragastric administration of MNNG induced well-differentiated squamous cell carcinomas that showed diminished mitochondrial lipid and protein oxidation and an increase in antioxidants. In contrast to tumor tissue, the liver mitochondria of tumor-bearing animals showed elevated lipid and protein oxidation with compromised antioxidant defenses. Dietary administration of Polyphenon-B effectively suppressed MNNG-induced stomach tumors, modulated mitochondrial lipid and protein oxidation, and enhanced antioxidant enzyme activities in the stomach and liver. Our results suggest that Polyphenon-B may exert its chemopreventive effects by modulating mitochondrial cellular redox status in the tumor as well as in the host liver.
本研究旨在评估红茶多酚（Polyphenon-B）对 N-甲基-N'-硝基-N-亚硝基胍（MNNG）诱导的 Wistar 大鼠胃肿瘤发生的化学预防作用。MNNG 经胃内给药可诱导分化良好的鳞状细胞癌，其表现为线粒体脂质和蛋白质氧化减少，抗氧化剂增加。与肿瘤组织相反，荷瘤动物的肝脏线粒体表现出脂质和蛋白质氧化升高，抗氧化防御受损。Polyphenon-B 的饮食给药可有效抑制 MNNG 诱导的胃肿瘤，调节胃和肝脏线粒体的脂质和蛋白质氧化，并增强抗氧化酶活性。我们的结果表明，Polyphenon-B 可能通过调节肿瘤以及宿主肝脏中线粒体细胞的氧化还原状态发挥其化学预防作用。
