Among natural chemicals used as cancer chemo-preventive and/or chemotherapeutic agents, saponins represent one of the most promising and interesting family of compounds. In this work, we aimed to elucidate the biological effects on human cells of six saponin fractions (SFs) obtained from in vitro cultures of Astragalus verrucosus Moris, a poorly characterized species. Interestingly, SF (3) showed a strongly inhibitory effect on the proliferation of human colon adenocarcinoma cell line (HCT116) via activation of a p53-dependent apoptotic pathway. In addition, SF (3) and the other SFs did not display genotoxic activity in human peripheral lymphocytes.