Theaflavins inhibit the ATP synthase and the respiratory chain without increasing superoxide production.

ABSTRACT: Four dietary polyphenols, theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate and theaflavin-3,3'-digallate (TF3), have been isolated from black tea, and their effects on oxidative phosphorylation and superoxide production in a model system (Escherichia coli) have been examined. The esterified theaflavins were all potent inhibitors of the membrane-bound adenosine triphosphate (ATP) synthase, inhibiting at least 90% of the activity, with IC(50) values in the range of 10-20 μM. ATP-driven proton translocation was inhibited in a similar fashion, as was the purified F(1)-ATPase, indicating that the primary site of inhibition was in the F(1) sector. Computer modeling studies supported this interpretation. All four theaflavins were also inhibitory towards the electron transport chain, whethe

SUBMITTER: Li B 

PROVIDER: S-EPMC8717676 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature