Caffeic acid protects against IL-1β-induced inflammatory responses and cartilage degradation in articular chondrocytes.

Osteoarthritis (OA) is a common articular disease that features cartilage loss and destruction. It has been confirmed that inflammation plays major roles in the progression of osteoarthritis. Caffeic acid (CA), a key dietary nutrient commonly found in coffee, has shown its anti-inflammatory properties in various inflammation diseases. However, the effects of CA in osteoarthritis remain explored. Here we investigated the effects of CA on IL-1β induced increased expression of inflammatory factors as well as the degradation of Collagen II and aggrecan in rat chondrocytes. CA prevented the cartilage damage induced by IL-1β in vivo organ culture of articular cartilage. Besides, the IL-1β induced increased production of inflammation factors such as iNOS and COX2 could be inhibited by CA. Additionally, CA could also suppress IL-1β induced expression of cartilage matrix catabolic enzymes such as ADAMTS5 and MMPs. Moreover, CA could prevent IL-1β induced degradation of Collagen II and aggrecan in chondrocytes. Furthermore, CA inhibited NF-κB activity and the activation of JNK pathway. This study reveals that CA inhibits IL-1β induced inflammation responses through suppression of NF-κB and MAPK related JNK signaling pathways. These results demonstrate that CA may provide new avenues for osteoarthritis treatment in future.