Intervention of Curcumin Combined with Swimming on Osteoarthritis and circRNA Expression Profiling in Human Synovium

Osteoarthritis (OA) is characterized by progressive cartilage degeneration and synovial inflammation, yet safe long-term strategies that address both structural deterioration and inflammatory activity remain limited. Here we evaluated curcumin, swimming, and their combination in a monosodium iodoacetate (MIA)-induced rat OA model and profiled circular RNA (circRNA) expression in human synovium after anterior cruciate ligament (ACL) injury. Rats were assigned to control, sham, OA model, curcumin, swimming, or combined intervention groups and treated for six weeks, followed by micro-computed tomography, histological assessment, and serum cytokine measurements. Compared with OA model rats, combined curcumin and swimming improved trabecular bone microarchitecture, preserved cartilage matrix staining, and reduced synovial inflammatory changes, accompanied by lower serum IL-1b and TNF-a. In parallel, circRNA sequencing of synovial tissues from patients with acute versus chronic ACL injury identified differentially expressed circRNAs, with host-gene enrichment implicating immune activation, extracellular matrix organization, and inflammatory signaling pathways. Together, these findings suggest that combining curcumin with low-impact aerobic exercise may attenuate experimental OA pathology and provide complementary human synovial circRNA signatures associated with inflammatory and remodeling processes.