Cytotoxicity and apoptosis induction by Fumaria officinalis extracts in leukemia and multiple myeloma cell lines

Ethnopharmacological relevance: Fumaria officinalis (Fumariaceae) is recorded in the Kurdish ethnobotany for various health problems.

Aim of the study: In this study, the cytotoxic activity of F. officinalis extracts on two leukemia and nine multiple myeloma (MM) cell lines was investigated.

Materials and methods: The cytotoxic and ferroptotic activity were examined by resazurin reduction assay. Flow cytometry, immunoblotting assay and fluorescence microscopy were used to measure cell cycle distribution, apoptosis, induction of reactive oxygen species (ROS), loss integrity of mitochondrial membrane potential (MMP) and autophagy. LC-ESI/MS was used to identify chemical constituents present in F. officinalis.

Results: Chloroform (CF) and ethyl acetate (EF) fractions showed drastic cytotoxic effect on CCRF-CEM and CEM/ADR 5000 cells. NCI-H929 cell line exhibited higher sensitivity against CF, while EF demonstrated its higher cytotoxicity on OPM-2 cells with IC₅₀ value 14.80 ± 1.70 and 28.13 ± 1.38 μg/mL respectively. Flow cytometric and morphological studies confirmed that CF and EF induced apoptosis in NCI-H929 cells by loss of MMP, generation of ROS and obvious morphological variations. In DNA histograms, up to 50% of the cells were accumulated by CF and 44% by EF in the sub-G0/G1 phase following 72 h treatment. EF induced autophagic cell death, while CF stimulated iron-dependent cell death. Moreover, two isoquinoline alkaloids and four flavonoids were identified in the active fractions.

Conclusion: To our knowledge, this is the first report demonstrating the cytotoxicity of F. officinalis extracts in MM cell lines. CF and EF fractions inhibited MM cell proliferation through various modes of actions.

Keywords: Apoptosis; Autophagy; Ferroptosis; Fumaria officinalis; Multiple myeloma; Phytotherapy.