Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3X9.
Food Chem. 2012 Sep 15;134(2):742-8. doi: 10.1016/j.foodchem.2012.02.172. Epub 2012 Mar 6.
Epigallocatechin gallate (EGCG), the major polyphenol in green tea and the main bioactive compound responsible for the health benefits of tea consumption, has been proposed as a functional ingredient for food and natural health products. However, EGCG is hydrophilic with poor cellular absorption and thus compromised bioefficiency in vivo. In order to enhance the lipophilicity of EGCG for improved bioefficiency and to take advantage of the health beneficial omega 3 fatty acids, the EGCG molecule was esterified with docosapentaenoic acid (DPA), upon which a mixture of ester derivatives with different degrees of substitution was produced. The EGCG-DPA esters were evaluated for their anti-inflammatory activity in LPS (lipopolysaccharides)-stimulated murine RAW 264.7 macrophages. The production of pro-inflammatory mediators nitric oxide (NO) and prostaglandin (PGE(2)) was significantly inhibited by treatment of EGCG-DPA esters, and the inhibition was largely due to their down-regulatory effect on iNOS (inducible NO synthase) and COX (cyclooxygenase)-2 gene expression at transcriptional level. The EGCG-DPA esters effectively suppressed the expression of iNOS and COX -2 proteins as well as their mRNA, as observed with western blotting and RT-PCR analyses. Ester derivatives of EGCG with other fatty acids (stearic acid, SA; eicosapentaenoic acid, EPA; and docosahexaenoic acid, DHA) were also prepared in the form of pure tetraesters, which also exhibited anti-inflammatory effect in the macrophages. The results suggest that EGCG ester derivatives with anti-inflammatory potentials may be useful in preventing/treating inflammation-mediated diseases and health conditions.
没食子儿茶素没食子酸酯（EGCG）是绿茶中的主要多酚类物质，也是茶叶饮用带来健康益处的主要生物活性化合物，已被提议作为功能性成分用于食品和天然保健品。然而，EGCG 具有亲水性，细胞吸收能力差，因此体内生物效率降低。为了提高 EGCG 的亲脂性，以提高生物效率，并利用有益健康的 omega-3 脂肪酸，将 EGCG 分子与二十二碳五烯酸（DPA）酯化，生成具有不同取代度的酯衍生物混合物。评估了 EGCG-DPA 酯在 LPS（脂多糖）刺激的鼠 RAW264.7 巨噬细胞中的抗炎活性。EGCG-DPA 酯可显著抑制促炎介质一氧化氮（NO）和前列腺素（PGE2）的产生，抑制作用主要归因于其对 iNOS（诱导型一氧化氮合酶）和 COX-2（环氧化酶）基因表达的下调作用转录水平。EGCG-DPA 酯通过 Western blot 和 RT-PCR 分析有效地抑制了 iNOS 和 COX-2 蛋白及其 mRNA 的表达。还以纯四酯的形式制备了 EGCG 与其他脂肪酸（硬脂酸，SA；二十碳五烯酸，EPA；和二十二碳六烯酸，DHA）的酯衍生物，它们在巨噬细胞中也表现出抗炎作用。结果表明，具有抗炎潜力的 EGCG 酯衍生物可用于预防/治疗炎症介导的疾病和健康状况。
