The antioxidant N-acetylcysteine in vitro improves several functions of peritoneal leucocytes from old mice approaching their values to those of adult animals

The age-related deterioration of the function of immune cells, or immunosenescence, is based on oxidative stress (an imbalance between the levels of oxidants and antioxidant defences with an increase of the former). Accordingly, the ingestion of a diet supplemented with thiolic antioxidants such as N-acetylcysteine (NAC), a glutathione precursor, by aged subjects improved their leucocyte functions. The aim of the present study was to show if NAC improves in vitro several functions of leucocytes from chronologically old mice and if this antioxidant is able to bring the values of these functions to the levels of those of adult animals. Six concentrations of NAC (in a range from 0.001 mM to 2.5 mM) were investigated on several functions of peritoneal leucocytes from old (78±2 weeks of age) BALB/c mice. These functions were those of the phagocytic process in macrophages, namely: adherence to substrate, directed migration or chemotaxis, phagocytosis of inert particles and superoxide anion levels as a measure of digestion capacity, as well as of the adherence and chemotaxis of lymphocytes. These functions were also studied in peritoneal leucocytes from adult (18±2 weeks of age) mice. The results showed that NAC in vitro improves all the functions studied, especially at the highest concentrations, which had shown impaired values in old mice, approaching those of adult animals. Since the immune functions studied are markers of health and predictors of longevity, the administration to aged subjects of NAC, which shows a direct action in leucocytes, seems to be a good strategy to improve their immune system and, therefore, to reach a healthy longevity.