Curcuminoids extract, hydrolyzed collagen and green tea extract synergically inhibit inflammatory and catabolic mediator's synthesis by normal bovine and osteoarthritic human chondrocytes in monolayer

Comblain F, Sanchez C, Lesponne I, Balligand M, Serisier S, Henrotin Y · PLoS One

In IL-1beta-stimulated bovine chondrocytes the curcuminoid extract cut IL-6, iNOS, COX-2, MMP-3, ADAMTS-4 and ADAMTS-5 expression, and the three-compound mixture suppressed MMP-3 expression significantly further than curcuminoids alone. Nearly all of the activity is the curcuminoids: green tea extract alone had no significant effect on IL-1beta-treated human chondrocytes, and hydrolysed collagen alone moved only nitric oxide, at one concentration. The single place the authors call synergy is narrow — in unstimulated human chondrocytes at 1 microgram/ml each, the mixture inhibited MMP-3 production where none of the three did alone. Curcuminoids at 4 micrograms/ml, and the mixture at the same strength, also lowered aggrecan in the culture supernatant.

Population

Normal bovine and osteoarthritic human chondrocytes in monolayer, with and without IL-1beta

Intervention

Curcuminoid extract alone or combined with hydrolysed collagen and green tea extract

Comparator

Untreated and IL-1beta-only controls

Limitations

Monolayer culture with no matrix, funded by Royal Canin (pet nutrition) with company co-authors. The combination has not been tested in a human joint. The aggrecan reduction runs the wrong way for a chondroprotective claim and the paper does not resolve it.