Effects of tacrolimus on antioxidant status and oxidative stress in glioma cells.

OBJECTIVE

After organ transplantation, some patients suffer from mild neurologic symptoms, ranging from tremor to severe complications, including seizures and encephalopathy. Among the immunosuppressants, tacrolimus can cause neurologic side effects. However, the mechanisms of encephalopathy by tacrolimus are not fully understood. We measured the antioxidant status, hydrogen peroxide level, and malondialdehyde level in glioma cells after tacrolimus treatment.

METHODS

The production of hydrogen peroxide was determined by the modified xylenol orange method. The amount of malondialdehyde was measured by the thiobarbituric acid assay, which is based on malondialdehyde reaction with thiobarbituric acid to give a red species absorbing at 535 nm. Total antioxidant status (TAS) was measured using TAS kits (NX2332).

RESULTS

Tacrolimus resulted in dose- and time-dependent increases in the production of hydrogen peroxide by glioma cells. The antioxidant status decreased in the glioma cells after tacrolimus treatment. Malondialdehyde level was unchanged in the glioma cells after tacrolimus treatment.

CONCLUSIONS

Increased production of reactive oxygen species and decreased antioxidant status by tacrolimus in glioma cells may contribute to neurologic side effects.