The effects of 5-demethylnobiletin on benzo[a]pyrene metabolism

• Main Authors: Yu-Hsuan Lin, 林宇軒
• Other Authors: Min-Hsiung Pan
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/93ryfu

碩士 === 國立臺灣大學 === 食品科技研究所 === 107 === Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants and formed by incomplete combustion of organic matter or charred food. Many studies indicated that PAHs have gene-mutated activity and carcinogenic properties. Among these PAHs, benzo[a]pyrene (BaP) is the most well-known PAHs, and it is classified to group I carcinogen by IARC. Dietary BaP could be metabolized by phase I enzymes, cytochrome P450s (CYPs) such as CYP1A1 and CYP1B1. After metabolization, it could transform the BaP to benzo[a]pyrene diol epoxide (BPDE), and then combine with DNA to form BPDE-DNA adducts, which cause the initiation of cancer. Glutathione S-transferase (GST) and UDP-glucuronosyltransferase (UGT) are phase II enzymes that can conjugate with BaP metabolites and excrete them from body. 5-demethylnobiletin (5-DMNB) is a phytochemical which found in citrus peels, especially in long-storage citrus peels. Researches indicated that 5-DMNB had anti-inflammatory and anti-cancer ability. This study will show that 5-DMNB can change the metabolism of BaP by decreased CYP1B1 level and upregulated the GST and UGT expression, and then decrease BPDE-DNA adducts levels. In conclusion, 5-DMNB can decrease the toxicity of BaP and it maybe have the prevention effect of cancer caused by BaP.