Antioxidant and antiproliferative activities of edible plants beloging to Asteraceae family growing wild in Calabria

Plant drugs have a long history in both traditional and modern societies as herbal remedies or crude drugs, as purified compounds approved by Food and Drug Administration. A high number of new drugs derived from plant secondary metabolites have been applied towardly in the treatment and/or prevention of cancer [1-2]. Investigations about natural products have recently regained prominence with the increasing understanding of their biological significance and increasing recognition of the origin and function of their structural diversity. Five edible plants from Calabria (Southern Italy), Carduus pycnocephalus L., Cichorium intybus L., Cynara cardunculus L. ssp. cardunculus, Picris hieracioides L. and Sonchus oleraceus L., were evaluated for their in vitro antiproliferative properties, using the Sulforodamine B (SRB) assay [3], on four human cancer cell lines: breast cancer MCF-7, prostate cancer LNCaP, amelanotic melanoma C32 and renal adenocarcinoma ACHN. After 48 h of incubation the most antiproliferative plant extract was Cynara cardunculus ssp. cardunculus on C32 and ACHN cell lines with IC50 of 21 and 18 µg/ml, respectively. The radical scavenging activity was assessed with DPPH test (2,2-diphenyl-1-picrylhydrazyl) [4]. The beta-carotene bleaching test and the Bovine Brain peroxidation assay were used to evaluate the antioxidant activity [5-6]. The best free radical (DPPH) scavenging activity was exerted by Picris hieracioides, and Cichorium intybus leaves extracts (IC50 = 25 and 26 microg/ml, respectively). At the beta-carotene bleaching test after 30 min incubation, Picris hieracioides extract showed the highest inhibition of linoleic acid oxidation (IC50 = 3 microg/ml). Using liposomes prepared from bovine brain, Picris hieracioides extract, the most active ones in the previous assay, revealed the highest antioxidant effect (IC50 = 22 µg/ml). In conclusion, this work reveals that the Calabrian flora, among which the species C. cardunculus L. ssp. cardunculus, Picris hieracioides and C. intybus, can be an interesting source of antioxidant and antiproliferative principles, particularly phenolic compounds and phytosterols, and a potential biomedical application in the combination therapy of cancer diseases may be suggested. This study support the various hypothesis on the fact that the Mediterranean diet is one of the healthiest dietary patterns in the world due to its relation with a low morbidity and mortality for some chronic diseases. The traditional Mediterranean diet is characterized by high consumption of foods of plant origin and relatively low consumption of red meat.