Effects of (-)-epigallocatechin-3-gallate on cyclooxygenase 2, PGE(2), and IL-8 expression induced by IL-1beta in human synovial fibroblasts.
The objective of this study was to examine the effects of (-)-epigallocatechin-3-gallate (EGCG) on cyclooxygenase 2 (COX-2), prostaglandin E(2) (PGE(2)), and interleukin 8 (IL-8) expression induced by IL-1beta in human synovial fibroblasts. Cells were enzymatically isolated from synovial tissue taken from patients undergoing joint replacement surgery for osteoarthritis. Reverse transcriptase-polymerase chain reaction, immunocytochemistry, and western blotting were used to assess the COX-2 gene and protein expression with the associated mechanisms. PGE(2) and IL-8 secretion into the culture medium was assayed by enzyme-linked immunosorbent assay. COX-2 upregulation in synovial fibroblasts induced by IL-1beta was significantly suppressed by EGCG in a dose-dependent manner. PGE(2) and IL-8 secretion was also induced by IL-1beta stimulation and significantly suppressed by EGCG. The mechanism was associated with the phosphorylation of IKKbeta. EGCG may inhibit the expression of inflammatory mediators, such as COX-2, PGE(2), and IL-8, induced by IL-1beta in human synovial fibroblasts. EGCG may be of value in the treatment of synovial inflammation.
Huang
Guo-Shu
GS
Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei City, Taiwan. gsh5@seed.net.tw
Tseng
Ching-Ya
CY
Lee
Chian-Her
CH
Su
Sui-Long
SL
Lee
Herng-Sheng
HS
D000368:Aged; D000369:Aged, 80 and over; D002392:Catechin / Q000031:analogs & derivatives; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005796:Genes / Q000187:drug effects; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D008875:Middle Aged; D010003:Osteoarthritis / Q000235:genetics / Q000378:metabolism; D011458:Prostaglandins E / Q000378:metabolism / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013583:Synovial Membrane / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
D053583:Interleukin-1beta; D016209:Interleukin-8; D011458:Prostaglandins E; D002392:Catechin; C045651:epigallocatechin gallate; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human