Cycloartane-type saponins from Curculigo orchioides and their anti-inflammatory activity

Abstract

Curculigo orchioides is a traditional medicinal plant used in Asia for treating inflammation and related ailments. In this study, nine compounds were isolated, including six novel cycloartane-type saponins, namely curculigosaponins P–U (1–6) and three known compounds. Among the six new compounds, compound 1 exhibited moderate inhibition of NO production (IC₅₀ = 37.21 μM) in LPS-stimulated RAW 264.7 macrophages. It also suppressed the expression of TNF-α and IL-6, and downregulated iNOS and COX-2 protein levels, confirming its anti-inflammatory activity. Molecular docking analysis revealed favorable binding interactions of compound 1 with key inflammatory targets (iNOS, IL-6, TNF-α, and COX-2), supporting its proposed mechanism of action. These results suggest that compound 1 (curculigosaponins P) is a promising anti-inflammatory lead compound from C. orchioides and deserves further investigation.