Anti-tumor activity and linear-diarylheptanoids of herbal couple Curcumae Rhizoma-Sparganii Rhizoma and the single herbs

Abstract

Ethnopharmacological relevance: Curcumae Rhizoma and Sparganii Rhizoma (CR-SR) are the classical herbal couple for activating blood circulation and treating tumor in clinics.

Aim of the study: To investigate the anti-tumor activity and to clarify the bioactive ingredients of herbal couple CR-SR and the single herbs Curcumae Rhizoma (CR) and Sparganii Rhizoma (SR).

Materials and methods: The active fractions of CR-SR decoction were fractioned by column chromatography. And isolated compounds were characterized by IR, ESI-MS, 1D and 2D-NMR techniques. Detecting linear-diarylheptanoids in CR-SR, CR and SR was realized through UPLC-LTQ-Orbitrap MSⁿ, based on the fragmentation pathways established in this study, comparison with MS data of isolated compounds and references. The anti-tumor activities of different solvent fractions from CR-SR, CR and SR, as well as isolated ingredients were tested by CCK-8 method.

Results: Ultimately, a new compound (1), having a sulfonic acid group at C-3, named demethoxyshogasulfonic acid, along with another structurally similar 17 known linear-diarylheptanoids were isolated. These linear-diarylheptanoids (1-18) were divided into 12 categories based on the differences of substituents at C-3 and C-5 on the straight chain of seven carbons. Six fragmentation pathways were established by summarizing MS data of the 18 isolated compounds collected from UPLC-MS. Based on that, and retention times and MS fragmentation ions, 47 linear-diarylheptanoids were identified in CR-SR and CR, in which 12 linear-diarylheptanoids were also detected in SR. Most importantly, 5 sulfonated linear-diarylheptanoids were new compounds detected in CR and CR-SR. And the biological assay indicated that compounds 1-4 and 12-15 significantly reduced the proliferation and inhibited colony formation of MCF-7 and HepG2 cells.

Conclusion: The new compound (1) exhibited good anti-cancer activity, which suggests that a great effort has to be paid to investigate the bioactivity of sulfonated compounds. The fractions of CR-SR decoction exhibited stronger anti-tumor activities than that of CR and SR against 5 different cancer cells. As for chemical composition, it is the first time to report that diarylheptanoids are in Sparganiaceae and the sulfonated compounds in Zingiberaceae. Moreover, the linear-diarylheptanoids found in SR which being tested to possess good anti-tumor activity, plus those compounds in CR enhance the capacity of CR-SR. It shows importance of TCM compatibility.

Keywords: Anti-tumor activity; Curcumae Rhizoma and Sparganii Rhizoma; Fragmentation pathways; Herbal couple; Linear-diarylheptanoids.