THH Relieves CIA Inflammation by Reducing Inflammatory-related Cytokines

Tripterygium hypoglaucum hutch (THH) is a plant of the genus tripterygium, which is also known as colquhounia, Gelsemiun elegan, and so on. It is mainly distributed in Yunnan, Guizhou, and Sichuan regions and other places in China. To study the immune mechanism of THH on related inflammatory cytokines in collagen II-induced arthritis (CIA) mice, healthy male C57BL/6 mice were used to model CIA mice. Mice received THH 420 mg/kg/day or the same amount of normal saline (NS) by gavage for 20 days. The thickness of the ankle joint in mice was observed, and the arthritis index was calculated. Related inflammatory cytokines were detected by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that after treatment with THH, the CIA mice had less swelling and destruction of the joints as well as decreased foot size and arthritis index. The mRNA and protein levels of TNF-α, IFN-γ, and IL-17A were lower in the THH-treated group than in the NS group (P < 0.05). In summary, THH has great significance in the treatment of CIA mice, including reduced related inflammatory cytokines expression level in both joint tissue and serum. The mechanism of THH in the treatment of CIA may be through the inhibition of the NF-kB-STAT3-IL-17 pathway, which also requires further experimental investigation.