ABSTRACT
It has been proposed that there is a correlation between high-fat diet (HFD), oxidative stress and decreased γ-aminobutyric acid (GABA) levels, but this has not been thoroughly demonstrated. In the present study, we determined the effects of strawberry extract intake on the oxidative stress and GABA levels in the frontal cortex (FC) of obese rats. We observed that an HFD increased lipid and protein oxidation, and decreased GABA levels. Moreover, UV-irradiated strawberry extract (UViSE) decreased lipid peroxidation but not protein oxidation, whereas non-irradiated strawberry extract (NSE) reduced protein oxidation but not lipid peroxidation. Interestingly, NSE increased GABA concentration, whereas UViSE was not as effective. In conclusion, our results suggest that an HFD increases oxidative damage in the FC, whereas strawberry extract intake may ameliorate the disturbances associated with HFD-induced oxidative damage.
ABSTRACT
Flavonoids and polyphenols from the strawberry and other fruits have been proposed to reduce the oxidative stress produced by the obesity and her complications. Moreover, it has been proposed that irradiation with UV-C to strawberry may increase the antioxidant capacity of this fruit. The aim of the present study was to explore the effects of the UV-C on antioxidant capacity of strawberry in vitro and in vivo. Strawberry slices were irradiated with ultraviolet light-C (UV-C) at 1.2 W/m2/16.5 min; then, the power antioxidant was isolated from the nonirradiated and irradiated strawberry slices into an organic phase, which was lyophilized to finally producing a nonirradiated strawberry extract (NSE) and UV-irradiated strawberry extract (UViSE) powder. After the antioxidant capacity of both extracts were determined in vitro using the Trolox equivalent antioxidant capacity (TEAC) assay and in vivo using high-fat diet-induced obese rats. Our results demonstrated that irradiation with UV-C to strawberry slices increased the antioxidants content, which was corroborated in vitro, where the antioxidant capacity of UViSE was higher than the NSE. However, in obese rats, the reduction in the oxidative damage by the UViSE and NSE were similar in peripheral tissues. Interestingly, the UViSE was better than the NSE to reduce the oxidative damage in brain. In conclusion, UV-irradiation increases the antioxidants content of strawberry that is correlated with an increased antioxidant capacity in vitro, but in rats, this antioxidant capacity may be more effective in brain than in peripheral tissues.
ABSTRACT
BACKGROUND: It has been proposed that the γ-aminobutyric acid (GABA) plays a key role in the regulation of food intake and body weight by controlling the excitability, plasticity and the synchronization of neuronal activity in the frontal cortex (FC). It has been also proposed that the high-fat diet (HFD) could disturb the metabolism of glutamate and consequently the GABA levels, but the mechanism is not yet clearly understood. Therefore, the aim of this study was to investigate the effect of a HFD on the GABA levels in the FC and hippocampus of rats. RESULTS: The HFD significantly increased weight gain and blood glucose levels, whereas decreased the GABA levels in the FC and hippocampus compared with standard diet-fed rats. CONCLUSIONS: HFD decreases GABA levels in the FC and hippocampus of rat, which likely disrupts the GABAergic inhibitory processes, underlying feeding behavior.
Subject(s)
Diet, High-Fat , Frontal Lobe/chemistry , Hippocampus/chemistry , gamma-Aminobutyric Acid/analysis , Animals , Blood Glucose/analysis , Body Weight , Feeding Behavior , Frontal Lobe/metabolism , Hippocampus/metabolism , Male , Obesity/metabolism , Rats, Wistar , Reference Values , Weight Gain , gamma-Aminobutyric Acid/metabolismABSTRACT
BACKGROUND: It has been proposed that the γ-aminobutyric acid (GABA) plays a key role in the regulation of food intake and body weight by controlling the excitability, plasticity and the synchronization of neuronal activity in the frontal cortex (FC). It has been also proposed that the high-fat diet (HFD) could disturb the metabolism of glutamate and consequently the GABA levels, but the mechanism is not yet clearly understood. Therefore, the aim of this study was to investigate the effect of a HFD on the GABA levels in the FC and hippocampus of rats. RESULTS: The HFD significantly increased weight gain and blood glucose levels, whereas decreased the GABA levels in the FC and hippocampus compared with standard diet-fed rats. CONCLUSIONS: HFD decreases GABA levels in the FC and hippocampus of rat, which likely disrupts the GABAergic inhibitory processes, underlying feeding behavior.
