Synergistic Effects of Curcumin and Nano-Curcumin against Toxicity, Carcinogenicity, and Oxidative Stress Induced by Tartrazine at Normal and Cancer Cell Levels

In this study, the cellular synergistic and antagonistic effects of mixing tartrazine (TZ) with curcumin (CUR) or curcumin-nanoparticles (CUR-NPs) were investigated. The in vivo administration of TZ, CUR, CUR-NPs, and TZ mixed with CUR or CUR-NPs at 75:25 or 50:50 ratios were tested. The results indicated that CUR and CUR -NPs reduced the cytotoxicity effects of TZ on skin fibroblast BJ-1 (ATCC® CRL-2522™) normal cells. However, among the tested materials, CUR-NPs had highest in vitro and in vivo antioxidant activity compared to TZ. Furthermore, CUR-NPs and CUR exhibited anticancer activity against HepG-2 liver cancer cells via apoptosis induction. The key apoptosis protein genes Caspase-3, p53, and Bax were upregulated, whereas Bc-2, which exhibits anti-apoptosis activity, was downregulated. Our results indicated that the nano-formulation of CUR alters its physicochemical properties, including the size and shape, and increases its antioxidant and anticancer properties. CUR-NPs also overcome the side effect of using TZ as a yellow color and food preservative additive, due to its reduced toxicity, oxidative stress, and carcinogenicity. In agreement with our previous findings, CUR and CUR-NPs were able to protect against cellular oxidative stress by stimulating endogenous antioxidant defense enzymes, including superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), and glutathione-S-transferase (GST). We conclude that the nano-formulation of CUR exhibits economic benefits as a new strategy to use CUR as a food additive at the cellular level.