Inhibition of cyclooxygenase-2 expression and prostaglandin E2 production in chondrocytes by avocado soybean unsaponifiables and epigallocatechin gallate.
OBJECTIVE
To evaluate the anti-inflammatory effect of the combination of avocado soybean unsaponifiables (ASU) and epigallocatechin gallate (EGCG) on cyclooxygenase-2 (COX-2) expression and prostaglandin E(2) (PGE(2)) production in cytokine-activated equine chondrocytes.


METHODS
Production of type II collagen and aggrecan was verified by immunohistochemistry and Western blot. Chondrocytes were incubated with: (1) control media alone, (2) ASU (4 microg/ml; 8.3 microg/ml), (3) EGCG (4, 40, 400 ng/ml), or (4) the combination of ASU and EGCG for 24h. Cells were next incubated with control medium alone or with IL-1beta (10 ng/ml) and TNF-alpha (1 ng/ml). COX-2 gene expression by real-time PCR analysis and NF-kappaB nuclear translocation by immunohistochemistry were performed after 1h of incubation. PGE(2) production was determined by immunoassay after 24h of incubation.


RESULTS
Equine chondrocytes responded to cytokine activation by up-regulated gene expression of COX-2 and increased PGE(2) production. Activation was associated with NF-kappaB translocation. Individually, ASU and EGCG marginally inhibited COX-2 expression and PGE(2) production in activated chondrocytes. In contrast, the combination of ASU and EGCG reduced COX-2 expression close to non-activated control levels and significantly inhibited PGE(2) production. These reductions were statistically greater than those of ASU or EGCG alone. The inhibition of COX-2 expression and PGE(2) production was associated with inhibition of NF-kappaB translocation.


CONCLUSIONS
The present study demonstrates that the anti-inflammatory activity of ASU and EGCG is potentiated when used in combination. This combination may offer an attractive supplement or alternative to non-steroidal anti-inflammatory drugs (NSAIDs) in the management of osteoarthritis.
Heinecke
L F
LF
Nutramax Laboratories, Inc., Edgewood, MD 21040, USA.
Grzanna
M W
MW
Au
A Y
AY
Mochal
C A
CA
Rashmir-Raven
A
A
Frondoza
C G
CG
D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D000975:Antioxidants; D002358:Cartilage, Articular / Q000201:enzymology / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D019902:Chondrocytes / Q000201:enzymology / Q000378:metabolism*; D024043:Collagen Type II / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015232:Dinoprostone / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D015870:Gene Expression; D006736:Horses; D053583:Interleukin-1beta / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D027421:Persea; D010641:Phenotype; D010936:Plant Extracts / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000032:analysis; D013025:Glycine max; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D053674:Aggrecans; D000975:Antioxidants; D024043:Collagen Type II; D053583:Interleukin-1beta; D016328:NF-kappa B; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D002392:Catechin; C045651:epigallocatechin gallate; D051546:Cyclooxygenase 2; D015232:Dinoprostone