Untargeted metabolomic on urine samples after α-lipoic acid and/or eicosapentaenoic acid supplementation in healthy overweight/obese women

Abstract

BackgroundEicosapentaenoic acid (EPA) and α-lipoic acid (α-LA) have been investigated for their beneficial effects on obesity and cardiovascular risk factors. In the current research, the goal was to evaluate metabolomic changes following the dietary supplementation of these two lipids, alone or combined in healthy overweight/obese sedentary women following an energy-restricted diet. For this purpose, an untargeted metabolomics approach was conducted on urine samples using liquid chromatography coupled with time of flight mass spectrometry (HPLC-TOF-MS).MethodsThis is a short-term double blind placebo-controlled study with a parallel nutritional design that lasted 10 weeks. Participants were assigned to one of the 4 experimental groups [Control, EPA (1.3 g/d), α-LA (0.3 g/d) and EPA+α-LA (1.3 g/d + 0.3 g/d)]. All intervention groups followed an energy-restricted diet of 30% less than total energy expenditure. Clinically relevant biochemical measurements were analyzed. Urine samples (24 h) were collected at baseline and after 10 weeks. Untargeted metabolomic analysis on urine samples was carried out, and principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were performed for the pattern recognition and characteristic metabolites identification.ResultsUrine samples were scattered in the PCA scores plots in response to the supplementation with α-LA. Totally, 28 putative discriminant metabolites in positive ionization, and 6 in negative ionization were identified among groups clearly differentiated according to the α-LA administration. Remarkably is the presence of an ascorbate intermediate metabolite (one of the isomers of trihydroxy-dioxohexanoate, or dihydroxy–oxohexanedionate) in the groups supplemented with α-LA. This fact might be associated with antioxidant properties of both α-LA and ascorbic acid. Correlations between phenotypical parameters and putative metabolites of provided additional information on whether there is a direct or inverse relationship between them. Especially interesting are the negative correlation between ascorbate intermediate metabolite and asymmetric dimethylarginine (ADMA) and the positive one between superoxide dismutase (SOD) and α-LA supplementation.ConclusionsThis metabolomic approach supports that the beneficial effects of α-LA administration on body weight reduction may be partly explained by the antioxidant properties of this organosulfur carboxylic acid mediated by isomers of trihydroxy-dioxohexanoate, or dihydroxy–oxohexanedionate.Trial registrationClinicaltrials.gov NCT01138774.Electronic supplementary materialThe online version of this article (10.1186/s12944-018-0750-4) contains supplementary material, which is available to authorized users.

Alpha‐lipoic acid supplementation significantly reduces the risk of obesity in an updated systematic review and dose response meta‐analysis of randomised placebo‐controlled clinical trials

“…Out of these articles, four studies recognised significant effects of ALA supplementation on weight loss as compared with the placebo group, whereas changes in weight was not statistically significant in other studies. As for BMI, 6 studies reported a significant reduction in the ALA‐treated group compared with the placebo group, whereas changes in BMI were not statistically significant in other studies. Furthermore, significant reduction in WC was observed only two studies .…”

“…Additionally, study by Masharani et al and Konrad et al because of low sample size were not included in this study. As a result, totally, 24 studies were included in the current systematic review and meta‐analysis, whereas 21, 18 and 11 studies were included in the meta‐analysis of the effects of ALA on BMI, weight and WC, respectively.…”

“…Four studies employed a parallel design. Eighteen studies included both genders, and six studies included only female or male subjects. Most studies were conducted in China and Iran .…”

“…The remaining studies were performed in the Turkey, Mexico, Spain, South Korea, United States, Bosnia and Herzegovina, India, New Zealand and Germany . Included studies had recruited patient with type 2 diabetes, stroke, schizophrenia, chronic spinal cord injury, rheumatoid arthritis, metabolic syndrome, impaired fasting glucose, Parkinson's disease, subclinical hypothyroidism, non‐alcoholic fatty liver disease (NAFLD), apparently healthy obese and overweight people, cardiac autonomic neuropathy and patients undergoing haemodialysis . All studies prescribed ALA alone while Huerta et al assessed the effect of ALA along with calorie restricted diet intervention in both placebo and intervention groups.…”

“…Furthermore, significant reduction in WC was observed only two studies . WHR was reported in only three studies, and the information about fat mass was available in only one study, therefore, data analysis was not performed for these parameters.…”