Cytotoxic effects of the biflavonoids isolated from Selaginella trichoclada on MCF-7 cells and its potential mechanism.

[Display omitted] • Three types of biflavonoids (1 – 9) were isolated from Selaginella trichoclada. • An IC 50 value of compounds 2 and 8 was 7.7 and 6.9 μΜ against MCF-7 cells, respectively. • Compound 8 could be expected to induce ferroptosis in MCF-7 cells through RNA-sequencing measure analysis. • Compound 8 could be a highly potent inhibitor for ACSL4 proteins. A new biflavonoid, (2′' S)-6′'-methyl-2′',3′'-dihydroochnaflavone (1), along with two known ochnaflavones (2 , 3), four known amentoflavones (4 – 7) and two known robustaflavones (8 , 9) were obtained from the 70% EtOH extract of Selaginella trichoclada. The chemical structures of isolated compounds were elucidated by extensive spectroscopic analyses. Overall, compounds 1 – 9 displayed moderate cytotoxic effects against human breast cancer MCF-7 cell lines. Among them, compounds 2 and 8 exhibited relatively strong cytotoxic effects against MCF-7 cells with an IC 50 value of 7.7 and 6.9 μΜ, respectively. The results of RNA-sequencing and KEGG functional enrichment analysis showed that 8 could induce ferroptosis in MCF-7 cells by down-regulating the expression of ferroptosis-related genes including ACSL4, NOXO1, NOXA1, ACSL5, STEAP3, LPCAT3, ATG7 and TP53. Then 8 could inhibit the expression of ACSL4 proteins through molecule docking analysis, which showed a strong interaction of − 11.89 Kcal/mol binding energy. Those results indicate that 8 could be chemotherapy agents to fight drug resistance in breast cancer by down-regulating the expression level of ACSL4 proteins via ferroptosis, which needs to be further certified in vitro. [ABSTRACT FROM AUTHOR]