Cytotoxic Activity and Related Mechanisms of Prenylflavonoids Isolated from Mallotus conspurcatus Croizat.

Five prenylflavonoids, 6-prenylnaringenin (1), 8-prenylnaringenin (2), 7-O-methyl-8-prenylnaringenin (3), 7-O-methyl-6-prenylnaringenin (4), and 4'-O-methyl-6-prenylnaringenin (5), were isolated from the traditional herb Mallotus conspurcatus Croizat (Euphorbiaceae). Compounds 1-5 revealed cytotoxic activity against cervical cancer (HeLa) cells with IC50 values ranging from 10.08 to 60.16 μm by MTT method, and interestingly, these prenylflavonoids were less toxic to normal HL-7702 cells. Furthermore, compounds 1 and 5 could inhibit the c-myc expression and telomerase activity and cause mitochondrial dysfunction. These findings might contribute to a better understanding of the biological activities of prenylflavonoids and lay the foundation for further studies on the cytotoxic activity of natural products isolated from M. conspurcatus.