This study aims to evaluate the underlying mechanism of action of A. flaccida crude triterpenoid saponins (AFS) on RA using a type II collagen (CII)-induced arthritis (CIA) rat model, and to assess the anti-inflammatory effects of the main active compounds of AFS, including flaccidoside II, anhuienoside E, glycoside St-I4a, hemsgiganoside B, hederasaponin B, and 3-O-α-l-rhamnopyranosyl (1 → 2)-β-d-glucopyranosyl oleanolic acid 28-O-β-d-glucopyranosyl (1 → 6)-β-d-glucopyranosyl ester, by detecting TNF-α and IL-6 production in lipopolysaccharide (LPS)-treated RAW264.7 cells. Here, IL6 is linked to rheumatoid arthritis.