Dietary Selenium Modulates Oxidative and Inflammatory Responses to High-Sucrose Feeding in Drosophila melanogaster
Introduction
High dietary sugar intake induces metabolic stress characterised by oxidative imbalance and low-grade inflammation, contributing to diet-related disease risk. Selenium is a redox-active micronutrient, yet its physiological effects under high-sucrose conditions, alone or combined with metformin, remain unclear.
Aim
To evaluate the effects of dietary selenium supplementation on oxidative stress and inflammatory markers in high-sucrose-fed Drosophila melanogaster.
Methods
Adult female Drosophila melanogaster (Harwich strain) were allocated to five groups (n = 150 flies/group; 5 replicates of 30 flies). Flies were fed normal diet (ND) or high-sucrose diet (HSD) for 7 days, followed by 5 days of ND, metformin, sodium selenite, or metformin plus selenite; controls remained on ND. Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), TNF-α and IL-6 were quantified. Data were analysed using one-way ANOVA with Tukey’s post-hoc test; p < 0.05 was considered significant. Results were expressed as mean ± standard deviation.
Results
In comparison with ND, HSD significantly (p < 0.05) reduced CAT activity (27.49±0.55 U/mg protein Vs 24.18±0.59 U/mg protein) and increased MDA (0.65±0.02 µM Vs 0.92±0.01 µM), TNF-α (8.75±0.15 pg/ml Vs 13.49±0.56 pg/ml) and IL-6 (11.68±0.44 pg/ml Vs 17.37±0.45 pg/ml). Selenium supplementation attenuated CAT suppression (28.22±0.72 U/mg protein) and reduced MDA (0.88±0.03 µM), TNF-α (12.22±0.27 pg/ml), and IL-6 (13.69±0.36 pg/ml). Metformin alone further reduced CAT activity (17.61±0.27 U/mg protein), while combined metformin–selenium treatment showed non-additive effects (p>0.05) on CAT (27.74±0.46 U/mg protein) and MDA (1.18±0.12 µM). SOD activity was not significantly altered between ND and HSD controls.
Conclusion
Dietary selenium modulates oxidative and inflammatory responses to high-sucrose feeding, but its interaction with metformin is not uniformly synergistic. These findings highlight the complexity of dietary–pharmacological interactions in metabolic stress.
Keywords: High-sucrose diet; Selenium; Oxidative stress; Inflammation; Drosophila melanogaster; Metabolic stress