Antiproliferative activity against human tumor cell lines and toxicity test on Mediterranean dietary plants

Sixteen edible plants from Southern Italy were evaluated for their in vitro antiproliferative properties,using the sulforodamine B (SRB) assay, on four human cancer cell lines: breast cancer MCF-7, prostatecancer LNCaP, amelanotic melanoma C32 and renal adenocarcinoma ACHN. After 48 h of incubationthe most antiproliferative plant extract was Cynara cardunculus ssp. cardunculus on C32 and ACHN celllines with IC50 of 21 and 18 lg/ml, respectively. Mentha aquatica showed a selective antiproliferativeactivity on breast cancer while significant activity was exerted by Cichorium intybus on melanoma. Thesespecies contained the highest amount of phenolics. The acute toxicity of the hydroalcohol extracts fromall the plants were evaluated by using the Microtox acute toxicity test. This bacterial test measures thedecrease in light emission from the marine luminescent Vibrio fischeri bacteria when exposed to organicextracts. This inhibition test was revealed to be highly sensitive, cost effective and easy to operate, requiringjust 15 min to predict the sample toxicity. All the extracts analyzed resulted to give values very lessthan a limit of 20% value, demonstrating so an irrelevant toxicity for the human health. In contrast, Echiumvulgare and Malva sylvestris showed bioluminescence inhibition values of 19.42% and 17.32%, respectively,just under the established limit.