Lutein prevents the effect of high glucose levels on immune system cells in vivo and in vitro.

Diabetic patients present an increased susceptibility to frequent and protracted infections. The recognition of an impaired immune system has implications for the diagnosis, treatment and outcome of infections. Nuclear Factor kappa B (NF-kappaB) is a redox sensitive transcription factor involved in immune response, cell proliferation and apoptosis that has been associated to the development of diabetic complications. Herein we study the effects of high glucose on oxidative stress markers (malondialdeyde and glutathione contents) and NF-kappaB activity in U937 cells (a human promonocytic cell line). Furtheremore effects of lutein treatment in lymphocytes from diabetic rats was studied. The results show that high glucose induces oxidative stress in immune system cells, both in vitro and in vivo, as well as an increase in their NF-kappaB activity. It is also showed that lutein, a natural antioxidant without hypoglycemiant properties, is able to prevent all the alterations observed. Thus, this study confirms the role of oxidative stress in the immune system impairment described in diabetes, and allows the proposal of antioxidants for the clinical management of the diabetes-associated susceptibility to infections.