TNF and rheumatoid arthritis: The IL-1β, IL-6, IL-10, IL-15, TNF-α, and VEGF levels in RA rats treated with the n-butanol fractions (0.64 g/kg, 0.32 g/kg, and 0.16 g/kg) (p < 0.05, p < 0.01) and ethyl acetate fraction (0.64 g/kg) (p < 0.05) of the 70% alcohol-soluble fraction of S. parviflora Wall.