Thymoquinone loaded mesoporous silica nanoparticles retard cell invasion and enhance in vitro cytotoxicity due to ROS mediated apoptosis in HeLa and MCF-7 cell lines.

Thymoquinone (TQ) loaded monodispersed mesoporous silica nanoparticles (TQ-MSNPs) with size of 188 ± 3 nm were prepared and characterized using DLS, TEM and FTIR. These TQ-MSNPs overcome the limitations of free TQ like hydrophobicity, low aqueous and photo stability and thus enhance its anticancer activity. In vitro release kinetics showed biphasic drug release where up to 50% was released in first 8 h and subsequently 98% released after 48 h. Enhanced cytotoxicity of TQ-MSNPs was observed against MCF-7 and HeLa cell lines as compared to free TQ. DAPI and Annexin V-FITC/PI staining confirmed the induction of apoptosis in cancer cells following treatment with TQ-MSNPs. Also, TQ-MSNPs exhibited enhanced anti-invasion properties against both cell lines as very low concentration of loaded TQ imparts similar benefits as free TQ. Both TQ and TQ-MSNPs exerted their cytotoxicity via reactive oxygen species (ROS) generation, as addition of an antioxidant NAC attenuated their killing activity. Unlabelled Image • Thymoquinone has been successfully loaded within mesoporous silica nanoparticles (TQ-MSNPs). • Encapsulation enhanced its anticancer activity evaluated against MCF-7 and HeLa cell lines. • In vitro release kinetics showed biphasic release pattern of TQ with complete release at the end of 48 h. • Staining with DAPI, AnnexinV-FITC/PI and transwell invasion assay showed apoptotic and anti-invasion activity of TQ-MSNPs. • TQ-MSNPs exhibited ROS mediated apoptosis in cancer cells as addition of NAC hamper the cytotoxicity and ROS production. [ABSTRACT FROM AUTHOR]