Journal
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
Volume 48, Issue 7, Pages 2736-2743Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jf000066d
Keywords
theaflavin-3,3 '-digallate; EGCG; xantine oxidase; ROS; superoxide; hydrogen peroxide; allopurinol
Ask authors/readers for more resources
The inhibitory effects of five tea polyphenols, namely theaflavin (TF1), theaflavin-3-gallate (TF2), theaflavin-3,3'-digallate (TF3), (-)-epigallocatechin-3-gallate (EGCG), and gallic acid, and propyl gallate (PG) on xanthine oxidase (XO) were investigated. These six antioxidant compounds reduce oxidative stress. Theaflavins and EGCG inhibit XO to produce uric acid and also act as scanvengers of superoxide. TF3 acts as a competitive inhibitor and is the most potent inhibitor of XO among these compounds. Tea polyphenols and PG all have potent inhibitory effects (>50%) on PMA-stimulated superoxide production at 20 similar to 50 mu M in HL-60 cells. Gallic acid (GA) showed no inhibition under the same conditions. At 10 mu M, only EGCG, TF3, and PG showed significant inhibition with potency of PG > EGCG > TF3. The superoxide scavenging abilities of these six compunds are as follows: EGCG > TF2 > TF1 > GA > TF3 > PG. PG was the most potent inhibitor of PMA-stimulated H2O2 production in HL-60 cells. The order of H2O2 scavenging ability was TF2 > TF3 > TF1, EGCG > PG, GA. Therefore, the antioxidative activity of tea polyphenols and PG is due not only to their ability to scavenge superoxides but also to their ability to block XO and related oxidative signal transducers.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available