TNF and rheumatoid arthritis: Triptolide strongly reduced TNF-α (Figure 5A), IL-1β (Figure 5B), VEGF (Figure 5C) in sera of rats, and IL-1β-induced TNF-α (Figure 6A), IL-17 (Figure 6B), VEGF (Figure 6C) and Ang-2 (Figure 6E) secretion by HFLS–RA cells with a dose-dependent manner.