Ranunculus ternatus Thunb. alkaloids attenuate colorectal cancer metastasis through EMT suppression

Background

Distant metastasis remains a major contributor to treatment failure and poor prognosis in colorectal cancer (CRC), emphasizing the urgent need for novel anti-metastatic strategies. Ranunculus ternatus Thunb. (RT), a traditional herbal medicine historically used to treat tuberculosis, has recently shown emerging potential in oncology. However, its efficacy against CRC metastasis remains uninvestigated, and the pharmacologically active components along with the underlying mechanisms responsible for its anti-CRC and metastasis-inhibitory effects are yet to be elucidated.

Purpose

This study aims to investigate the anti-metastatic efficacy of bioactive components derived from RT and elucidate their mechanisms of action against CRC.

Methods

The active fraction of RT was identified using HCT116 and CT26 cell lines, alongside ectopic tumor-bearing mouse models. The chemical composition of this fraction was characterized by UPLC-Q-TOF/MS analysis. Transcriptomics profiling integrated with KEGG pathway enrichment analysis was performed, followed by core target prediction using CytoHubba and MCODE algorithms. RT-PCR, ELISA and Western Blot assays were employed for target validation. Drug-target interactions were confirmed via the cellular thermal shift assay (CETSA). The anti-metastatic effects of RT alkaloids (RTAs) were further evaluated through Transwell invasion assays, wound healing experiments, and tail vein injection-induced metastatic murine models.

Results

Both in vivo and in vitro experiments revealed that alkaloids from RT (RTAs) are the principal active ingredients exerting anti-CRC effects. Transcriptomic profiling and bioinformatics analyses demonstrate that RTAs inhibit epithelial-mesenchymal transition (EMT), with MMP3 and CCL5 identified as critical targets. Validation assays confirmed that RTAs significantly reduced levels of TGF-β and CCL5 in tumor tissues and serum of CRC-bearing mice. In addition, RTAs downregulated MMP3, MMP9, and β-catenin, while upregulating E-cadherin expression. These findings suggest that RTAs inhibit metastasis by modulating multiple EMT-related pathways. Furthermore, both in vitro and in vivo assays confirmed the ability of RTAs to significantly suppress distant metastasis in CRC models.

Conclusion

This study provides the first experimental evidence that RT exerts anti-metastatic effects against CRC. The bioactive alkaloid fraction (RTAs) mitigates CRC progression and metastasis by regulating the EMT process, highlighting its potential as a promising therapeutic candidate for metastatic CRC treatment.