Fabrication and characterization of pigmented secondary metabolites bound liposomes with improved cytotoxic activity against prostate and hepatic cancer

Interactions of the pigmented secondary metabolites butylcycloheptylprodigiosin (BcProd) and resistomycin (Res) with liposomes as model membranes were subjected to physical characterization, including transmission electron microscopy (TEM), particle size, polydispersity, zeta potential, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. The morphology of all liposomes was almost spherical, less aggregated, and well-dispersed for both empty and encapsulated vesicles. Incorporating BcProd and Res within liposomal membranes increases the zeta potential values and, in the case of BcProd, shifts the main peak of free liposomes to a lower temperature, indicating a conformational order within the phospholipids. The inclusion of Res into liposomes resulted in maintaining pure liposomes’ main characteristic endothermic peak. FTIR study confirmed the interaction of BcProd and Res with the liposome’s moieties. The anticancer activities of the butylcycloheptylprodigiosin in liposomes (Lipo-BcProd) and resistomycin in liposomes (Lipo-Res) were evaluated against prostate carcinoma (PC3) and hepatocellular carcinoma (HEPG-2) cell lines. The results of the cytotoxic activity revealed that Lipo-Res exhibited the highest activity against the PC3 and HEPG-2cell lines (IC 50 = 4.30 and 2.1 μg/ml, respectively). Moreover, the Lipo-BcProd was potent against PC3 and HEPG-2 cancer cells (IC 50 = 7.7 and 7.1 µg/ml, respectively). The data obtained propose the possible use of liposomes loaded with butylcycloheptylprodigiosin and resistomycin as a promising anticancer agent.