Adipose tissue concentrations of non-persistent environmental phenols and local redox balance in adults from Southern Spain

Abstract

The aim was to evaluate the associations of environmental phenol and paraben concentrations with the oxidative microenvironment in adipose tissue. This study was conducted in a subsample (n=144) of the GraMo cohort (Southern Spain). Concentrations of 9 phenols and 7 parabens, and levels of oxidative stress biomarkers were quantified in adipose tissue. Associations were estimated using multivariable linear regression analyses adjusted for potential confounders. Benzophenone-3 (BP-3) concentration was borderline associated with enhanced glutathione peroxidase (GPx) activity [exp(β)=1.20, p=0.060] and decreased levels of reduced glutathione (GSH) [exp(β)=0.55, p=0.070]. Concentrations of bisphenol A (BPA) and methylparaben (MeP) were associated to lower glutathione reductase (GRd) activity [exp(β)=0.83, exp(β)=0.72, respectively], and BPA was borderline associated to increased levels of oxidized glutathione (GSSG) [exp(β)=1.73, p-value=0.062]. MeP was inversely associated to both hemeoxygenase-1 (HO-1) and superoxide dismustase (SOD) activity, as well as to the levels of thiobarbituric acid reactive substances (TBARS) [0.75 < exp(β) < 0.79]. Our results suggest that some specific non-persistent pollutants may be associated with a disruption of the activity of relevant antioxidant enzymes, in addition to the depletion of the glutathione stock. They might act as a tissue-specific source of free radicals, contributing to the oxidative microenvironment in the adipose tissue.