Synthesis of nano curcumin using black pepper oil by O/W Nanoemulsion Technique and investigation of their biological activities

Curcumin is an important biologically active polyphenolic compound that has been found to contain the ability of a wide range of beneficial biological activities. The aim of this study was to develop a method for the preparation of curcumin nanoparticles (Nano-CUR) with a view to improve its aqueous-phase solubility and examine the effect on its biological properties. Nano-CUR were prepared in black pepper oil (BP oil) as an oil phase and Tween 80 as the surfactant. Nano-CUR was prepared by a modified microemulsion technique and was found to have a narrow particle size distribution in the ranges of 8-26 nm. Nano-CUR was obtained with a spherical shape and mean particle size of 15.7 ± 3.55 nm when the following optimal conditions were adopted as water/oil (5:1) and oil/surfactant (1:9). Unlike curcumin (bulk), Nano-CUR is readily dispersed in aqueous media. The FTIR spectrum indices can be used in order to differentiate nano and non-nano emulsion solutions. Antioxidant activity tests were applied to the Emulsion components, Nano-CUR, and also to Tween 80 + BP oil. Results demonstrated that Nano-CUR has maximum antioxidant activity. In vitro cytotoxicity effect of Nano-CUR was also investigated, which was detected in the treated Neuro2A cells to be up to 15.6 μg/mL.