Determination of the cyto-genotoxic effects of sodium acetate and sodium sulfite by MTT and comet assays

Abstract

Sodium acetate (NaA) and sodium sulfite (NaS) are two food additives in the class of preservatives. In this study, 3-(4,5-dimethyl thiazolyl-2)-2,5 diphenyltetrazolium bromide (MTT) assay was established to detect the cytotoxicity, and comet assay was used to determine the genotoxicity of NaA and NaS. For the MTT assay, human hepatocellular carcinoma (HepG2) cells were treated with different concentrations of each preservative (15.63, 31.25, 62.50, 125, 250, 500, 1000 and 2000 µg/mL for NaA; 3.91, 7.81, 15.62, 31.25, 62.50, 125, 250 and 500 µg/mL for NaS, respectively) for 24-h. non-treated wells used as control (only medium) were included. Comet assay was performed on lymphocytes isolated from healthy donors with multiple concentrations of NaA (15.63, 31.25, 62.50, 125, 250 µg/mL) and NaS (3.91, 7.81, 15.62, 31.25, 62.50 µg/mL) for 1 h. A negative (distilled water) and a positive control (100 µM H2O2) were also included. Significant cytotoxic activity was detected for NaA and NaS only at the highest concentration. Besides, both substances significantly increased DNA damage compared to the control at almost all concentrations (except at low concentrations). In general, both food preservatives exhibited weak cytotoxic effects in HepG2 cells. These food preservatives showed genotoxic activity, especially at higher concentrations.