THE EFFECT OF ENCEPHALITOZOON INTESTINALIS ON OXIDATIVE STRESS AND CYTOKINE LEVELS IN U937 CELLS: AN IN VITRO STUDY

This in vitro study was performed to investigate the changes in nitric oxide (NO), malondialdehyde (MDA), total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) levels in human monocytic (U937) cells infected with Encephalitozoon intestinalis. E. intestinalis was first cultured in the African green monkey renal epithelial (Vero) cells to obtain sufficient amount of parasite for the study. U937 human macrophage cell line and E. intestinalis 50506 (ATCC) strain were used in the study. U937 macrophages were infected with 5x10⁶ spores after stimulation with Phorbol 12-Myristate 13-Acetate (PMA) and uninfected U937 cells were used as control. Culture media were collected at the 6^th, 12^th, and 24^th hour after infection to determine NO, MDA, TAC, TNF-α and IL-10 levels. NO levels significantly increased at the 6^th, 12^th and 24^th hour. There was no significant difference in MDA and TAC levels at the 6^th and 12^th hour, but a significant increase in MDA, and a significant decrease in TAC was observed at the 24^th hour. TNF-α levels did not differ in all sampling times, and IL-10 level decreased only at the 6^th hour. In conclusion, E. intestinalis caused oxidative stress by increasing the levels of oxidants (NO and MDA) and by suppressing TAC level without no significant changes in cytokine levels in U937 cell line.