Plectranthone and Psiadin as anticancer leads

Plants were in the past and still are serving as a good sources for providing lots of bioactive compounds including cytotoxic phytochemicals. Doxorubicin, vinca alkaloids and paclitaxel are just few examples.

Three terpenes, saudinolide (1), plectranthone (2) and psiadin (3), were isolated from the dried aerial parts of Cluytia richardiana, Plectranthus cylindraceus, and Psiadia arabica, respectively. The isolated pure compounds were evaluated for their potential antiproliferative activities. Plectranthone (2) and psiadin (3) exhibited marked growth inhibition on colorectal and hepatocellular cancer cell lines in time- and dose-dependent manners with minimal cytotoxicity against normal human breast cells. The anticancer effects of psiadin on both colorectal and hepatocellular cancer cells were higher than that produced by plectranthone. Saudinolide (1) showed very little antimitogenic effects. Comparison with standard antineoplastic drugs indicated that the effects of 2 and 3 were comparable or even better than the tested cytotoxic drugs including 5FU, doxorubicin, camptothecin and ellipticine.

Fig. 1