Chitosan nanoparticles containing α -pinene and Rosmarinus officinalis L. essential oil: effects on human melanoma cells’ viability and expression of apoptosis-involved genes

Melanoma is the most dreadful type of skin cancer; due to the side effects and drug resistance of chemotherapeutic drugs, the development of new herbal drugs has received more attention. In this study, the chemical composition of Rosmarinus officinalis L. essential oil, one of the most common medicinal plants, using gas chromatography–mass spectrometry (GC–MS) analysis was first identified. Then, chitosan nanoparticles containing the essential oil and α -pinene (identified major compound) with particle sizes of 69 ± 5 and 102 ± 6 nm and zeta potentials of 42.8 ± 0.9 and 41.7 ± 1 mV, respectively, were prepared. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis confirmed the successful loading of the essential oil and α-pinene into the nanoparticles. Besides, a polyethylene oxide–alginate electrospun scaffold (363 ± 20 nm) was proposed as a neutral dressing; it did not affect the viability of A-375 human melanoma cells. Moreover, the efficacy of chitosan nanoparticles containing α -pinene with IC50 value of 76.4 µg/mL was significantly more potent than chitosan nanoparticles containing R. officinalis essential oil (120.0 µg/mL), non-formulated essential oil (474.5 µg/mL), and non-formulated α -pinene (173.5 µg/mL). As the Bax/Bcl2 ratio was greater than 1 in all samples, it was confirmed that their effect on cell viability occurred through the apoptosis pathway. Considering obtained results, chitosan nanoparticles containing α-pinene could be considered for in vivo study.