In a continuation of studies on biologically active substances of the Paraguayan crude drug "Typychd kuratir" (Scoparia dulcis L., Scrophulariaceae), a polyoxygenated flavone (1) was isolated. Compound 1 was identified as 5,7-dihydroxy-3',4',6,8-tetramethoxyflavone (hymenoxin), marking the first report of its isolation from Scoparia dulcis. The cytotoxic effects of compound 1 were examined in six human cell lines: three cancer cell lines (HeLa 229, HeLa S3, HEp-2) derived from human cancer tissues and three normal cell lines (FL, Chang liver, intestine 407) from human normal tissues. Compound 1 exhibited significant inhibitory effects on the growth of all cell lines, with cancer cell lines being relatively more sensitive than normal ones. However, further detailed in vivo tests are necessary to evaluate its potential as an anti-cancer agent.