Background: The addition of 5 mM N-acetylcysteine (NAC) to 3T3-L1 adipocytes culture inhibits the accumulation of triglycerides (Tg) by 50%, but after 48 h uptake was only 16% of total NAC available. Based on these results, the aim of this study is to increase the NAC cellular uptake by encapsulating it in silica nanoparticles (NPs). Materials & methods: Silica NPs, 20 ± 4.5 nm in size, were developed, with an inner cavity loaded with 5 mM NAC. At 48 h after treatment, there was a dose-dependent cytotoxic effect. We attempted to reduce the cytotoxicity of silica NPs by coating them with bovine serum albumin. Results: While we obtained nontoxic bovine serum albumin coated NPs, their effect on Tg cellular accumulation was also reduced.

Aims: Reports regarding the effects of antioxidants in obesity have been contradictory. Antioxidant N-acetylcysteine is usually considered a nutritional supplement. Our aim is to evaluate bioactivity of N-acetylcysteine (NAC) on mature adipocytes, which is a close model to in vivo condition. Study Design: In vitro study. Place and Duration of Study: Department of Basic Science (Universidad Nacional de Lujan), Department of Chemical Biology (Universidad de Buenos Aires), CONICET – INEDES and CONICET – IQUIBICEN, between March 2017 and June 2019. Methodology: We evaluated the bioactivity of different concentrations of NAC for 5 days (0.01 mM to 5 mM) on fully differentiated 3T3-L1 cells (mature adipocytes). Results: We demonstrated that NAC treatment was not toxic to mature adipocytes. Only 5mM NAC inhibited reactive oxygen species production. 5 mM NAC treatment resulted in a 60% decrease in cellular triglycerides content and inhibited 70% cholesterol accumulation.  We also determined the mRNA and protein expression levels of Peroxisome Proliferator-Activated Receptor g as well as, mRNA levels of lipid protein Perilipin in NAC treated adipocytes; we observed that 5mM NAC treatment caused nearly 30% decrease in the expression of these parameters. Conclusion: These results suggest that NAC could avoid lipid accumulation in mature adipocytes; the antioxidant NAC could be beneficial in obesity treatment.