Bromelain Extract Exerts Antiarthritic Effects via Chondroprotection and the Suppression of TNF-α–Induced NF-κB and MAPK Signaling

Bromelain, a mixture of proteases in pineapple rhizome, has beneficial biological properties. Following absorption, the compound remains biologically active in mammalian blood and tissues. Bromelain has multiple clinical and therapeutic applications because of its anti-arthritic activities. Anti-inflammation is one of the putative therapeutic effects of bromelain on osteoarthritis (OA) and rheumatoid arthritis (RA), but the molecular mechanisms in cartilage and synovial fibroblast has not been reported. Thus, in this study, interleukin (IL)-1β/oncostatin M-induced porcine cartilage and TNF-α–induced synovial fibroblast were used as the inflamed OA and RA models, respectively. The results demonstrated the chondroprotective effects of bromelain on cartilage degradation and the downregulation of inflammatory cytokine (tumor necrosis factor (TNF)-α, IL-1β, IL-6, IL-8) expression in TNF-α–induced synovial fibroblasts by suppressing NF-κB and MAPK signaling. The evidence from this study supported and explained the anti-inflammatory and analgesic effects of bromelain on arthritis in animal models and clinical studies.