RESUMO
BACKGROUND: The pathogenesis of diabetes is accompanied by oxidative stress. Citrulline can be considered as a potent antioxidant. The present study aimed to examine the effects of citrulline supplementation on the status of oxidative stress and serum levels of nitrite/nitrate (NOx) in patients suffering from type 2 diabetes (T2DM). METHODS: The present study comprises a double-blind placebo-controlled randomised clinical trial. The study subjects include 54 patients with T2DM chosen from specialised clinics of Tabriz University of Medical Sciences. The patients were allocated to one of the placebo or intervention groups. The patients in the placebo and the intervention group received one sachet of microcrystalline cellulose or l-citrulline (3 g), respectively, every day for 2 months. Malondialdehyde (MDA), glutathione peroxidase (GPx), total antioxidant capacity (TAC), superoxide dismutase (SOD), serum levels of fasting blood sugar (FBS), citrulline and NOx were assessed before and after the intervention. RESULTS: Forty-five patients completed the trial. Significant decreases were found in serum levels of FBS and MDA. Serum levels of TAC, citrulline and NOx in the intervention group increased compared to those of the placebo group, after adjusting the data for the baseline values and confounders. Differences between and within the two groups were statistically nonsignificant for GPx and SOD at the end of the study. Body mass index and energy intake were not changed significantly after the intervention. CONCLUSIONS: The results of the present study show the positive effects of citrulline supplementation with respect to attenuating FBS levels and oxidative stress, as well as boosting NOx status, in patients with T2DM.