Theaflavin, a black tea extract, is a novel anti-inflammatory compound.
OBJECTIVE
Tea has been around for centuries, and its medicinal properties have been purported in the literature but never fully confirmed. Interleukin-8 is a principle neutrophil chemoattractant and activator in humans. We determined the effects of theaflavin, a black tea-derived polyphenol, on tumor necrosis factor-alpha-mediated expression of the interleukin-8 gene in A549 cells.


METHODS
Prospective laboratory study.


METHODS
University laboratory.


METHODS
A549 cells.


METHODS
A549 cells were exposed to varying concentrations of theaflavin and analyzed for tumor necrosis factor-alpha-mediated interleukin-8 gene expression.


RESULTS
Theaflavin inhibited tumor necrosis factor-alpha-mediated interleukin-8 gene expression, as measured by luciferase assay and Northern blot analysis, at concentrations of 10 and 30 microg/mL. This effect appears to primarily involve inhibition of interleukin-8 transcription because theaflavin inhibited tumor necrosis factor-alpha-mediated activation of the interleukin-8 promoter in cells transiently transfected with an interleukin-8 promoter-luciferase reporter plasmid. In addition, theaflavin inhibited tumor necrosis factor-alpha-mediated activation of IkappaB kinase and subsequent activation of the IkappaB-alpha/nuclear factor-kappaB pathway. Theaflavin also significantly reduced tumor necrosis factor-alpha-mediated DNA binding of activator protein-1.


CONCLUSIONS
We conclude that theaflavin is a potent inhibitor of interleukin-8 gene expression in vitro. The proximal mechanism of this effect involves, in part, inhibition of IkappaB kinase activation and activator protein-1 pathway.
Aneja
Rajesh
R
Division of Critical Care Medicine, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, and Children's Hospital Research Foundation, Cincinnati, OH, USA.
Odoms
Kelli
K
Denenberg
Alvin G
AG
Wong
Hector R
HR
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D044946:Biflavonoids / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D018929:Cell Culture Techniques; D004268:DNA-Binding Proteins / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism; D010936:Plant Extracts; D051818:Replication Protein C; D020545:Respiratory Mucosa / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013662:Tea; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects* / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D044946:Biflavonoids; D004268:DNA-Binding Proteins; D016209:Interleukin-8; D016328:NF-kappa B; D010936:Plant Extracts; D013662:Tea; D014409:Tumor Necrosis Factor-alpha; C056068:theaflavin; D002392:Catechin; D051818:Replication Protein C