Evaluation of the biological activity of nanoemulsions fabricated by walnut oil ( Juglans regia L.)

Abstract Herbal medicines are currently attracting much attention as a potential cancer treatment. Juglans regia ’s wide variety of anticancer actions have been demonstrated. The aim of this study is evaluating the cytotoxic and antioxidant effects of walnut oil ( J. regia ) nanoemulsion (WO‐NE) on CT26 colon cancer cell line. The dimensions and structure of the nanoemulsion were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) technique was used to determine whether or not the nanoemulsions had any antioxidant properties. The cytotoxic effects of 3‐[4,5‐dimethylthiazol‐2‐yl‐2‐5‐[diphenyltetrazolium bromide] (MTT) on CT26 colon cancer cells and umbilical vein endothelial cells (HUVEC) as normal cells were measured. The DPPH experiment demonstrated that the manufactured nanoemulsion had the ability to scavenge free radicals in a dose‐dependent manner, with an IC ₅₀ of approximately 500 µg/mL. The WO‐NE were found to be toxic to both HUVEC and CT26 cancer cells, with an IC ₅₀ of 10 ± 2.6 µg/mL for the CT26 and 160 ± 7.1 µg/mL for the HUVEC after 24 h of incubation. For comparison the effects of walnut oil also have been investigated. Due to their antioxidant and anticancer capabilities, the WO‐NE synthesized here have been proposed for future study as potential anti‐tumour agents.