TNF and rheumatoid arthritis: Besides, injection of exosomes derived from ADSCs treated with HQT-containing serum reduced the serum levels of IL-1β (P < 0.0001), IL-6 (P < 0.001) and TNF-α (P < 0.0001) of RA rat model, while injection of exosomes derived from ADSCs treated with blank rat serum had no significant effect on the serum levels of IL-1β, IL-6 and TNF-α of RA rat model (Fig. 7C).