Cytotoxic properties, glycolytic effects and high-resolution respirometry mitochondrial activities of Eriocephalus racemosus against MDA-MB 231 triple-negative breast cancer

Abstract

<title>Abstract</title> Triple-negative breast cancer (TNBC) represents a significant global health crisis due to its resistance to conventional therapies and lack of specific molecular targets. This study explored the potential of <italic>Eriocephalus racemosus</italic> (<italic>E. racemosus</italic>) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of <italic>E. racemosus</italic> against the MDA-MB 231 TNBC cell line were evaluated. <bold>Methods</bold>: Hexane solvent and bioactive fraction extractions of <italic>E. racemosus</italic> were performed, while mass spectrometry-based metabolite profiling was used to identify the phytochemical constituents of the extracts. The extracts were further tested against MDA-MB 231 cancer cells to determine their cytotoxicity. The mode of cell death was confirmed using flow cytometry. The activities of caspases 3, 8, and 9 were assessed using a multiplex activity assay kit. Glycolytic activity and High-resolution respirometry measurements of mitochondrial function in the MDA-MB 231 cell line were conducted using the Oroboros O2K. <bold>Results</bold>: Metabolite profiling of <italic>E. racemosus</italic> extracts identified the presence of coumarins, flavonoids, sesquiterpenoids, triterpenoids, and unknown compounds. The extracts demonstrated promising cytotoxic activities, with a half maximal inhibitory concentration (IC₅₀) of 12.84 µg/mL for the crude hexane extract and 15.49 µg/mL for the bioactive fraction. Further, the crude hexane and bioactive fraction extracts induced apoptosis in the MDA-MB-231 cancer cell line, similar to the reference drug cisplatin (17.44%, 17.26% and 20.25%, respectively) when compared with untreated cells. Caspase 3 activities confirmed the induction of the apoptosis pathway in both cisplatin and the plant extracts. Additionally, caspase 8 and 9 activities confirmed the activation of both the intrinsic and extrinsic apoptosis pathways in the plant extracts. Increased levels of glycolytic activities were observed in the crude hexane extract. High-resolution respiratory measurements showed elevated mitochondrial activities in all components examined except for complex-IV activities. <bold>Conclusion</bold>: These findings support further exploration of <italic>E. racemosus</italic> as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects.