Naringin vs. Citrus x Paradisi L. Extract: An In Vivo Journey into Oxidative Stress Modulation

Introduction: Oxidative stress is implicated in the pathogenesis of numerous chronic diseases (Figure 1). Citrus x Paradisi L. (grapefruit) contains flavonoids with antioxidant properties, particularly naringin (NR) (1). However, few studies directly compare the in vivo effects of NR and grapefruit ethanolic extract (E) on oxidative stress. This study investigates their ability to mitigate aluminum chloride (AlCl₃)-induced oxidative damage. Aim The study aims to evaluate and compare the antioxidative effects of NR and E in reducing lipid peroxidation and restoring enzymatic and non-enzymatic antioxidant defense systems in mice. Methods A 21-day in vivo study was conducted on Balb C mice (n = 35), divided into seven experimental groups: control, ethanol, AlCl₃, E, NR, E + AlCl₃, and NR + AlCl₃ groups (2-3). Oxidative stress biomarkers, including reduced glutathione (GSH), malondialdehyde (MDA), and catalase (CAT), were analyzed in blood, brain, and liver tissues using spectrophotometric assays Figure 2). Citrus x Paradisi L. ethanolic extract (E) was prepared using ultrasound-assisted reflux extraction with 50% ethanol to maximize flavonoid yield (Figure 3). HPLC quantified flavonoid concentrations in the extracts (4). Results E significantly reduced MDA levels, indicating lipid peroxidation suppression, with decreases in blood (AlCl₃: 241.32 µmol/g vs. E + AlCl₃: 110.78 µmol/g, p < 0.05), liver (AlCl₃: 99.69 µmol/g vs. E + AlCl₃: 47.52 µmol/g), and brain (AlCl₃: 87.66 µmol/g vs. E + AlCl₃: 56.21 µmol/g). NR effectively restored antioxidant defenses, increasing GSH in blood (AlCl₃: 1080.33 µmol/g vs. NR + AlCl₃: 1735.46 µmol/g, p < 0.05), brain (AlCl₃: 0.0023 µmol/g vs. NR + AlCl₃: 0.0193 µmol/g), and liver (AlCl₃: 0.3 µmol/g vs. NR + AlCl₃: 0.31 µmol/g). NR also enhanced CAT activity, improving levels in the brain (AlCl₃: 23.69 U/mg vs. NR + AlCl₃: 63.44 U/mg) and liver (AlCl₃: 489.75 U/mg vs. NR + AlCl₃: 132.33 U/mg). Conclusions E demonstrated superior control over lipid peroxidation, while NR was more effective in restoring antioxidant defenses. Combining E and NR may offer synergistic benefits in oxidative stress management.