IL6 and osteoarthritis: Andrographolide can downregulate the expression of proinflammatory cytokines, such as IL-1β, IL-6 and TNF-α, and downregulate the expression of TNFR2 in FLSs isolated from the synovial tissue of rats and osteoarthritis patients, thereby reducing the downstream phosphorylation of p65 in the NF-κB signalling pathway, repressing the activity of NF-κB, and mitigating osteoarthritis synovial inflammation (Wang et al., 2021a).