Launaea nudicaulis (L.) Hook. f., Asteraceae, is a wild plant growing in Egypt, used traditionally for treatment of many diseases. LC-HRMS analysis of different polarity soluble extracts allowed the annotation of fifteen compounds: three alkaloids, four flavonoids, three phenolic acids, three coumarins, one sphingolipid, and one triterpene. Chemical investigation led to isolation and identification of caffeic acid, luteolin, luteolin7-O-glucoside, lupeol, β-sitosterol, and palmitic acid. Cytotoxic evaluation for hexane, CH2Cl2, ethyl acetate, and n-butanol extracts using MTT assay against three cancer cell lines HL-60, HT-29, and MCF-7 showed a remarkable cytotoxic activity for the CH2Cl2-soluble extract against HL-60 and HT-29 with IC50 5.8 and 8.26 µg/ml, respectively, as well the n-butanol extract showed good activity against HL-60 and HT-29 with IC50 11.6 and 9.6 µg/ml, respectively. Docking study was performed on topoisomerase enzymes (I, IIα, and IIβ) and provided a rationale for the biological outcomes where three natural compounds in the plant strongly bound to the proteins, particularly, luteolin-7-(6″-malonylneohesperidoside) with binding affinities of − 11.341, − 10.866, and − 10.111 kcal/mol, respectively, and kaempferol-3-O-[6″-malonyl-β-d-apiofuranosyl-(1 → 2)-β-d-glucopyranoside] with binding affinities of − 10.796, − 10.102, and − 9.916 kcal/mol, respectively. Also, luteolin-7-O-β-d-glucopyranoside docked with higher binding affinity to topoisomerase I (− 10.367 kcal/mol) compared to topoisomerases IIα and IIβ.
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