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

Abstract 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 Eriocephalus racemosus (E. racemosus) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of E. racemosus against the MDA-MB 231 TNBC cell line were evaluated. Methods: Hexane solvent and bioactive fraction extractions of E. racemosus 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. Results: Metabolite profiling of E. racemosus 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. Conclusion: These findings support further exploration of E. racemosus as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects.