TP53 and cancer: Furthermore, benzophenanthridine alkaloid, 1-methoxy-12-methyl-12,13-dihydro-(1,3) dioxolo (4′,5′:4,5) benzo (1,2-c) phenanthridine-2,13-diol, from the aerial parts of Z. buesgenii (Engl.)P.G.Waterman showed moderate to strong cytotoxicity against sensitive and multidrug resistant cancer cells (CCRF-CEM, CEM/ADR5000, MDA-MB231, MDA-MB231/BCRP, HCT116 (p53+/+), HCT116 (p53−/−), U87MG, U87MG.ΔEGFR, and HepG2) with IC50 values of 0.24, 31.58, 30.14, 65.01, 42.46, 62.34, 60.55, 61.84, and 22.37, respectively, while sparing normal human liver (AML12) cells (Sandjo et al., 2014).