In Vitro and In Vivo Anti-Inflammatory Activities of Tupistra chinensis Baker Total Saponins

Tupistra chinensis Baker, traditionally used in southern China as a folk remedy for sore throat and pharyngitis, has long been consumed as a medicinal tea. Steroidal saponins are considered the major bioactive constituents of its rhizome, yet systematic studies on their extraction and biological effects remain scarce. In this study, total steroidal saponins from T. chinensis (TCS) were prepared through optimized extraction and enrichment processes. Response surface methodology identified optimal conditions, and subsequent purification with D-101 resin increased the saponin content to 67.3%. The anti-inflammatory activity of TCS was evaluated in vitro and in vivo. In LPS-stimulated RAW264.7 macrophages, TCS significantly inhibited nitric oxide production and downregulated the expression of iNOS, COX-2, and pro-inflammatory cytokines, partly through suppression of NF-κB activation. In a rat model of acute pharyngitis, TCS alleviated pathological symptoms, preserved mucosal integrity, and reduced NF-κB expression. These findings demonstrate that TCS possesses strong anti-inflammatory activity and may serve as a promising candidate for the development of functional foods or natural therapeutics aimed at pharyngitis management.