Plant-derived anticancer agents - curcumin in cancer prevention and treatment

Nowadays cancer is still a major public health issue. Despite all the progresses made in cancer prevention, diagnosis and treatment, mortality by cancer is on the second place after the one caused by cardiovascular diseases. The high mortality and the increasing incidence of certain cancers (lung, prostate, colorectal) justify a growing interest for the identification of new pharmacological agents efficient in cancer prevention and treatment. In the last fifty years many plant-derived agents (vinblastine, vincristine, vindesine, paclitaxel, docetaxel, topotecan, irinotecan, elliptinium) played a major role in cancer treatment. Other very promising plant-derived anticancer agents (combrestatins, betulinic acid, roscovitine, purvalanols, indirubins) are in clinical or preclinical trials. Curcumin, a liposoluble polyphenolic pigment isolated from the rhizomes of Curcuma longa L. (Zingiberaceae), is another potential candidate for new anticancer drug development. Curcumin has been reported to influence many cell-signaling pathways involved in tumor initiation and proliferation. Curcumin inhibits COX-2 activity, cyclin D1 and MMPs overexpresion, NF-kB, STAT and TNF-alpha signaling pathways and regulates the expression of p53 tumor suppressing gene. Curcumin is well-tolerated but has a reduced systemic bioavailability. Polycurcumins (PCurc 8) and curcumin encapsulated in biodegradable polymeric nanoparticles (NanoCurc) showed higher bioavailability than curcumin together with a significant tumor growth inhibition in both in vitro and in vivo studies. BILITY.