Anticancer properties of the abietane diterpene 6,7-dehydroroyleanone obtained by optimized extraction

Aim: 6,7-dehydroroyleanone (DHR) is a cytotoxic abietane present in the essential oil of Plectranthus madagascariensis. Methods/results: Different extraction parameters were tested, and its extraction optimization was accomplished with a Clevenger apparatus-based hydrodistillation. After isolation, its effect on microtubules, P-glycoprotein and caspases was assessed on several cell lines and the compound was coupled with hybrid nanoparticles. The results show that DHR does not interfere with microtubule formation, but evades the resistance mechanisms of P-glycoprotein. Strong activation of caspases-3 and -9 indicates that DHR is able to induce apoptosis by triggering the intrinsic cell death pathway. Moreover, the assembly of DHR with hybrid nanoparticles was able to potentiate the effect of DHR in cancer cells. Conclusion: DHR seems to be a promising starting material with anticancer properties to further be explored.