Metabolic stability and inhibitory effect of O-methylated theaflavins on H2O2-induced oxidative damage in human HepG2 cells. Issue 7 (3rd July 2014)

• Record Type: Journal Article
• Authors: Tanaka, Yoshihisa; Kirita, Masanobu; Abe, Yuko; Miyata, Satoshi; Tagashira, Motoyuki; Kanda, Tomomasa; Maeda-Yamamoto, Mari
• Is Part Of: Bioscience, biotechnology, and biochemistry. Volume 78:Issue 7(2014)
• Page Start: 1140
• Page End: 1146
• Publication Date: 2014-07-03
• Subjects: black tea -- polyphenol -- O-methylated theaflavin -- oxidative damage -- metabolic stability; Biotechnology -- Periodicals; Biochemistry -- Periodicals; 660.6
• DOI: 10.1080/09168451.2014.917268
• Languages: English
• ISSNs: 0916-8451

Abstract

Abstract: Seven new O -methylated theaflavins (TFs) were synthesized by using O -methyltransferase from an edible mushroom. Using TFs and O -methylated TFs, metabolic stability in pooled human liver S9 fractions and inhibitory effect on H2 O2 -induced oxidative damage in human HepG2 cells were investigated. In O -methylation of theaflavin 3′- O -gallate (TF3′G), metabolic stability was potentiated by an increase in the number of introduced methyl groups. O -methylation of TF3, 3′G did not affect metabolic stability, which was likely because of a remaining 3- O -galloyl group. The inhibitory effect on oxidative damage was assessed by measuring the viability of H2 O2 -damaged HepG2 cells treated with TFs and O -methylated TFs. TF3, 3′G and O -methylated TFs increased cell viabilities significantly compared with DMSO, which was the compound vehicle ( p < 0.05), and improved to approximately 100%. Only TF3′G did not significantly increase cell viability. It was suggested that the inhibitory effect on H2 O2 -induced oxidative damage was potentiated by O -methylation or O -galloylation of TFs. Graphical abstract: : Seven new O -methylated theaflavins (3 –9 ) were synthesized. Metabolic stability and inhibitory effect of O -methylated theaflavins on H2 O2 -induced oxidative damage in human HepG2 cells were investigated.