Effect of berrycactus fruit (Myrtillocactus geometrizans) on glutamate, glutamine, and GABA levels in the frontal cortex of rats fed with a high-fat diet

Abstract

In addition to the known metabolic alterations, obesity has consequences at the brain level, driving imbalance in neurotransmitters such as glutamate (Glu), glutamine (Gln), and gamma-aminobutyric acid (GABA). The consumption of fruits with antioxidant properties, such as the berrycactus Myrtillocactus geometrizans, could have beneficial effects in such an imbalance. The study objective was to evaluate frontal cortex neurotransmitter levels and weight changes in rats fed with a high-fat diet (HFD) and MG. To achieve that, five groups of Wistar rats received different diets for 24 weeks: standard diet (SDt), HFD, HFD + MG extract 150 mg (HMg150), HFD + MG extract 300 mg (HMg300), and HFD + MG extract 450 mg (HMg450); rats received MG extract for the last 4 weeks. Weight and food intake were recorded every week, and also neurotransmitter levels were quantified using high-performance liquid chromatography. Groups fed with HFDs had increased Glu and Gln levels, decreased GABA, and also gained more weight compared to the SDt group; MG extract of 450 mg decreased Glu levels. Concentrations of 300 and 450 mg of MG extract decreased weight compared to the HFD and HMg150 groups. This study reports that HFDs have an impact on neurotransmitter levels and weight, MG extract showed a reduction in Glu concentration and weight.

Keywords: GABA; berrycactus; glutamate; glutamine; high-fat diet.

Figure 1

Effect of MG on body weight gain, SDt, HFD, HMg150, HMg300, and HMg450. Data are reported as the mean value ± SEM. In the bars, values with the same letter means no significant differences by Kruskal–Wallis and Z-based post hoc rank test at P ≤ 0.05.

Figure 2

Effect of HFD on food intake during treatment, SDt, HFD, HMg150, HMg300, and HMg450. Data are given as the mean value ± SEM.