Insights into Clematis cirrhosa L. Ethanol Extract: Cytotoxic Effects, LC-ESI-QTOF-MS/MS Chemical Profiling, Molecular Docking, and Acute Toxicity Study.

Background: In Jordanian traditional medicine, Clematis cirrhosa is commonly employed for the management of different diseases. Numerous investigations have documented the cytotoxic properties of different Clematis species against numerous types of cancer. Previously, we demonstrated the potential cytotoxicity of Clematis cirrhosa against HT-29 colorectal cancer cells. Extending our work, the current research aimed to explore the possible mechanisms underlying its antiproliferative activity with a plant safety evaluation.

Methods: This study evaluates the extract's impact on the cell cycle, apoptosis, and cell migration through in vitro assays, LC-ESI-QTOF-MS/MS analysis, docking studies, and an acute toxicity evaluation.

Results: The Clematis cirrhosa ethanol extract (CEE) induced G2/M phase cell cycle arrest (19.63%), triggered significant apoptosis (41.99%), and inhibited cell migration/wound healing by 28.15%. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed increased expression of the proapoptotic markers BAX (6.03-fold) and caspase-3 (6.59-fold), along with the reduced expression of the antiapoptotic BCL-2, in CEE-treated cells. Moreover, CEE significantly restrained angiogenesis by reducing VEGF mRNA expression by 63.9%. High-resolution LC-ESI-QTOF-MS/MS studies identified 26 metabolites, including phenolic compounds, fatty acids, and triterpenoids. Docking studies suggested that manghaslin had the highest binding affinity for VEGFR-2, followed by calceolarioside B, quercetin 7-O-rhamnopyranoside, luteolin, and quercetin-3,7-O-diglucoside. On the other hand, salvadoraside exhibited the highest binding affinity for the inhibition of caspase-3, followed by quercetin-3,7-O-diglucoside, kaempferol-3,7-O-α-L-dirhamnoside, manghaslin, and tectoridin, supporting the observed apoptotic effects. Interestingly, the outcomes further indicate that a single oral administration of up to 5000 mg/kg CEE is safe for consumption.

Conclusions: These outcomes point to the potential of Clematis cirrhosa as a promising candidate for further exploration in cancer therapy.