Therapeutic potential of Citrus bergamia leaf extract (LF) in modulating lipid metabolism and enhancing hepatic antioxidant capacity in obesity model

Citrus bergamia leaf extract (LF), often discarded as waste by the Italian pharmaceutical industry, represents a valuable source of bioactive compounds, particularly phenolic compounds. These compounds exhibit potent antioxidant properties. Such characteristics suggest that LF may contribute to mitigating metabolic disorders and reducing oxidative stress associated with obesity, ultimately supporting liver health. This study evaluates the impact of LF on hepatic fatty acid metabolism and oxidative stress levels in obese rats. Wistar rats were fed either a control diet (C) or a high-sugar high-fat diet (HSF), to induce obesity, over 20 weeks. The animals were then redistributed into four groups: C, C+LF, HSF, and HSF+LF. LF was administered by gavage (50 mg/kg/day) for 10 weeks. Body weight(g) and adiposity index (AI, %) were measured. In liver tissue, gas chromatography (%), cholesterol levels (mg/dL), protein carbonylation (PC, nmol/mg protein), advanced oxidation protein products (AOPP, μmol/L chloramine unit/g protein), superoxide dismutase (SOD, U/g protein/min), and catalase activity (pmol/g protein/min) were assessed (CEUA: 1393/2021). Data were analyzed using two-way ANOVA with Tukey’s post-hoc test or Kruskal-Wallis with Dunn’s post-hoc test (p=0.05). The HSF group exhibited increased body weight (p=0.003) and higher levels of PC (p=0.043), AOPP (p=0.026), AI, hepatic cholesterol, and fatty acids (caproic, palmitic, elaidic, and heneicosanoic; p<0.001), along with reduced levels of SOD (p=0.048), catalase (p=0.012), linolelaidic, oleic (p<0.001), and cis-5,8,11,14,17-eicosapentaenoic acids (p=0.003), compared to the control group. In the HSF+LF group, there were significant reductions in AI (p=0.049), PC (p=0.004), AOPP (p=0.002), body weight, hepatic cholesterol, and fatty acids (caproic, elaidic, heneicosanoic; p<0.001), and palmitic acid (p=0.003). Additionally, there were increases in SOD, catalase, linolelaidic, oleic acids (p<0.001), and cis-5,8,11,14,17- eicosapentaenoic acid (p=0.015). LF improved lipid metabolism by modulating fatty acids associated with obesity and oxidative stress, while enhancing hepatic antioxidant capacity in obese rats, highlighting its therapeutic potential.