Anti-melanoma potential of inclusion complexes containing phyllacanthone in -cyclodextrin and sulfobutyl-ether--cyclodextrin

The bis-nor-diterpene phyllacanthone (PHY) was isolated from the chloroform fraction of the stem barks from Cnidoscolus quercifolius Pohl (Euphorbiaceae). PHY/beta-CD and in PHY/SB-E-beta-CD inclusion complexes were obtained and characterized using NMR, SEM and FT-IR techniques. In silico approach show that most stable conformations presenting binding energies of -89.8068 kcal/mol (PHY/beta-CD) and -87.4032 kcal/mol (PHY/SB-E-beta-CD), corroborating FTIR and H-1 NMR results. The in vitro dissolution assay demonstrated a fast PHY release from both complexes, indicating that the complexation improved its solubility. PHY/beta-CD and PHY/SB-E-beta-CD inclusion complexes presented high entrapment efficiency rates (89.60% and 77.56%, respectively). PHY, PHY/beta-CD and PHY/SB-E-beta-CD inclusion complexes induced growth inhibition in A2058 melanoma cells when compared to the control group, suggesting that both (natural or chemically modified) CDs can be used as carriers of PHY in pharmaceutical formulations or drug delivery systems as a strategy to improve its stability and ensure better bioavailability.