Discovery of synergistic anti-inflammatory compound combination from herbal formula GuGe FengTong Tablet

Multi-components in herbal formulae exert holistic effects in synergistic or additive manners. However, appropriate strategies and supportive evidences are still lacking to uncover the synergistic or additive combinations. The present investigation aimed at seeking a screening strategy to identify the targeted combinations in GuGe FengTong Tablet (GGFTT), an herbal formula. Two compounds, belonging to different chemical classes, were combined with different concentration ratios and their anti-inflammation effects were investigated. The most significant anti-inflammatory combinations were evaluated by combination index (CI) method (additive effect, CI = 1; synergism, CI < 1; antagonism, CI > 1). The modulating effects of candidate combinations on pro-inflammatory cytokines and MAPKs signaling pathway were also detected. Two combinations, "biochanin A + 6-gingerol" (Bio-6G) and "genistein + 6-gingerol" (Gen-6G), showed synergistic effects (CI < 1), and Bio-6G was selected for further study. Compared with single compound, Bio-6G could synergistically inhibit the production of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and the activation of MAPKs signaling pathway in LPS-stimulated RAW264.7 cells. The combined results showed that Bio-6G was a synergistic anti-inflammatory combination in GGFTT. Our results could provide a useful strategy to screen the synergistic combinations in herbal formulae.