Synergistic inhibitory effects of combined liposomal formulations of caffeic acid phenethyl ester and vitamin D on melanoma cell proliferation.

BACKGROUND

caffeic acid phenethyl ester (CAPE) and vitamin D inhibit melanoma growth through various anti-tumor mechanisms. The study investigated the impact of a 1:1 molar ratio of CAPE/vitamin D, both in free and liposomal forms, on inducing cytotoxicity in A375 and B16F10 melanoma cell lines, as well as HDF-1 normal human dermal fibroblasts.

METHODS

The physical characteristics of liposomal CAPE/vitamin D prepared by thin-film hydration were analyzed. The cytotoxicity of CAPE and vitamin D combination, in free and liposomal forms, was assessed using the MTT assay, along with their synergy or antagonism analysis. CalcuSyn software was used to calculate the combination index, and the impact of both free and liposomal forms of CAPE/vitamin D on apoptosis and necrosis was examined. Nanomechanical properties and PI3K/AKT1 and BAX/BCL2 gene expression levels were also assessed.

RESULTS

The highest drug release from nanoliposomes was recorded at 88.12% for CAPE and 76.39% for vitamin D in pH = 5.5. The encapsulation efficiency of CAPE and vitamin D within liposomes was found to be 81.04% and 72.35%, respectively. The IC50 values for A375, B16F10 and HDF-1 cells exposed to liposomal formulations were 8.74 µg/mL, 13.36 µg/mL and 32.49 µg/mL, respectively, after 48 h, while cells incubated with a free mixture of CAPE and vitamin D had IC50 values of 18.31 µg/mL, 24.53 µg/mL and 40.68 µg/mL, respectively. Liposomal CAPE/vitamin D induced more apoptosis in cells than the free mixture, caused nanomechanical changes, and reduced the expression ratio of PI3K to AKT1 genes.

CONCLUSION

Liposomes containing CAPE and vitamin D in a 1:1 molar ratio were more effective in inducing A375, B16F10 and HDF-1 cells death compared to their free mixture.