L. (alfavaca-de-cobra) was investigated as a potential source of anticancer compounds. Leaf extracts obtained using solvents of different polarities were evaluated for their phytochemical profiles and cytotoxic activities against a panel of human cancer cell lines (glioblastoma LN-229, lung NCI-H1563, breast MDA-MB-231, liver HepG2, renal 769-P, cervical HeLa, and melanoma A-375) and a noncancerous HEK-293 cell line. LC-ESI-MS/MS analysis confirmed that the extracts are rich in polyphenols, including phenolic acids and flavonoids. Cytotoxicity was assessed via MTT and SRB assays, demonstrating dose-dependent antiproliferative effects. Among the extracts, the ethanolic fraction (PJ-E) exhibited the strongest cytotoxicity, with an IC of 11.82 µg/mL against HeLa cells, while displaying a significantly higher IC (139.42 µg/mL) against HEK-293, indicating tumor selectivity. The water extract (PJ-W) showed selective activity against lung cancer cells (IC = 87.69 µg/mL), with minimal toxicity toward normal cells. The methanol/acetone extract (PJ-M) displayed intermediate activity, whereas the hexane extract (PJ-H) was the least effective. These findings highlight , particularly its ethanolic extract, as a promising source of natural anticancer agents. Further research focusing on the isolation of active constituents, formulation development, and in vivo validation is warranted to support its therapeutic potential.