Combined exposure to monosodium glutamate and sodium sulfite in broiler diets: Impacts on growth, oxidative stress, and tissue integrity.

Food additives are extensively utilized to improve the flavor, appearance, and shelf life of food products. Although the safety of many approved additives has been evaluated individually, their potential combined effects remain insufficiently characterized and may pose health risks. This study investigated the safety and biological impacts of two commonly used food additives-monosodium glutamate (MSG) and sodium sulfite-administered separately and in combination in broiler diets from day 1 to day 40. The combined supplementation of MSG (0.75 g/kg) and sodium sulfite (3.5 g/kg) exhibited neither synergistic nor antagonistic effects but resulted in the lowest growth performance compared to the control and single-additive groups. MSG alone produced slight improvements in economic efficiency, whereas sodium sulfite, alone or combined with MSG, did not yield comparable benefits. Biochemical analyses revealed elevated serum levels of superoxide dismutase (SOD) and malondialdehyde (MDA) across all treated groups, indicating increased oxidative stress. The comet assay showed no significant DNA damage in brain cells; however, mild histopathological alterations were observed in cardiac and brain tissues. Overall, these findings underscore the necessity of assessing the combined exposure of food additives in poultry feed formulations to ensure animal health and production safety.