Extract of Dorema aucheri induces PPAR-γ for activating reactive oxygen species metabolism

Objective: The aim of the present study is to assess the potential anti-diabetic effect of Dorema aucheri extract through the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) pathway. Marerials&methods: In this double-blind, placebo-controlled, randomized clinical trial, 170 patients with type II diabetes were randomly assigned to one of three groups, to receive a daily oral dose of either 200 or 500 mg of D. aucheri extract, or a placebo capsule for a period of 45 days. Blood samples were obtained from subjects and metabolic profiles, expression of PPAR-gamma and the activity of related pathways, were assessed prior to the intervention and then again at day 45. Results: The extract of D. aucheri was shown to influence reactive oxygen species (ROS) metabolic pathways. Notably, a reduction in the production of ROS by D. aucheri through induction of PPAR-gamma was found. After 45 days of treatment with the extract of D. aucheri a significant increase in PPAR-gamma expression was seen, with the 500 mg group displaying a 1.15-2.46-fold increase as distinct from the control group and pre-treatment (P<0.01). The extract also caused a significant increment of plasma superoxide dismutase activity (from 1314.82 +/- 137.99 to 1362.26 +/- 129.90 U/g protein in the 200 mg group, P=0.001, and from 1313.38 +/- 134.24 to 1444.51 +/- 140.42 U/g protein in the 500 mg treatment group, P < 0.0001) and vascular catalase gene activity (from 82.86 +/- 9.13 to 86.04 +/- 8.98 kU/g protein in the 200 mg group, P = 0.003, and from 79.71 +/- 8.91 to 90.32 +/- 10.18 kU/g protein in the 500 mg treatment group, P < 0.0001), when compared to the placebo group and baseline values. Both D. aucheri extract groups also displayed statistically significant reductions in mean plasma glucose, total cholesterol, triglycerides and low density lipoprotein cholesterol levels. Conclusion: These findings indicate that this extract of D. aucheri exerts its biological effects through PPAR-gamma activation, and suggests that it may behave as PPAR-alpha/gamma dual activator. D. aucheri with its rich sesquiterpene content may serve as an alternative or adjuvant treatment for patients with diabetes. (C) 2016 Elsevier GmbH. All rights reserved.