Antioxidant response to artichoke leaf extract supplementation in metabolic syndrome: A double-blind placebo-controlled randomized clinical trial

Background: Oxidative stress is associated with most components and complications of Metabolic Syndrome (MetS). Artichoke Leaf Extract (ALE) has demonstrated anti-oxidant properties in both laboratory and animal studies. Aim: This study was designed to examine the effects of ALE on oxidative stress indices in patients with MetS. Methods: In the current double-blind placebo-controlled randomized clinical trial, 80 patients with MetS were randomly allocated to either "ALE group" (received 1800 mg ALE as four tablets per day) or "Placebo group" (received placebo containing cornstarch, lactose and avicel as four tablets per day) for 12 weeks. Serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), oxidized-LDL (ox-LDL), red blood cell glutathione peroxidase (GPx) and superoxidase dismutase (SOD), as well as dietary intakes were assessed at baseline and at the end of the study. Results: A total number of 68 patients completed the study (ALE group = 33; placebo group = 35). Dietary intakes of energy, macronutrients, and micronutrients were not significantly different between two groups throughout the trial, with the exception of zinc (p < 0.05). The concentration of ox-LDL decreased significantly in ALE group in comparison to the placebo group (-266.8 +/- 615.9 vs -129.5 +/- 591.2 ng/L; p < 0.05). However, no significant inter- and intra-group changes in MDA, SOD, GPx, and TAC concentrations were observed. Conclusion: ALE decreased serum ox-LDL level in patients with MetS, with no beneficial effects on other antioxidant indices. Clinical trial registration number: IRC1201409033320N9. (C) 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.