Effects of combined nutritional supplementation with biotin, omega-3 polyunsaturated fatty acids and vitamin D in depression: a preclinical study

Objectives: To evaluate the antidepressant-like effects of combined nutritional supplementation with omega-3 fatty acids, vitamin D, and biotin, alone and in combination with half-dose fluoxetine, in a Chronic Unpredictable Mild Stress (CUMS) model of depression in rats. Methods: Thirty Sprague–Dawley rats were divided into five groups: control, disease control, fluoxetine-treated (5 mg/kg), nutrient combination (omega-3 fatty acids, vitamin D, and biotin), and nutrient combination with half-dose fluoxetine (2.5 mg/kg). Depression was induced using the CUMS model for four weeks. Behavioral assessments were performed using the sucrose preference test and elevated plus maze (EPM). Biochemical parameters including malondialdehyde (MDA), superoxide dismutase (SOD), catalase, thiol levels, and brain-derived neurotrophic factor (BDNF) were estimated. Histopathological examination of hippocampus and dentate gyrus was conducted. Data were analyzed using one-way analysis of variance followed by Tukey’s post hoc test. Results: The nutrient combination and half-dose fluoxetine with nutrient combination groups showed significant behavioral improvement vs. the disease control group, with higher sucrose preference and greater open-arm time in the EPM. Catalase activity was significantly higher in the nutrient combination group (2.50 ± 0.71 vs. 0.16 ± 0.03 pmol/ min), while the half-dose fluoxetine with nutrient combination group demonstrated significantly higher SOD (2.11 ± 0.03 vs. 0.07 ± 0.01 milliunit/mg protein) and lower MDA (1.35 ± 0.10 vs. 4.70 ± 0.09 μM/L) compared with disease control. Both these groups showed increased healthy neurons in the hippocampus and dentate gyrus in histopathological analysis, suggesting neuroprotection and neuronal regeneration. Conclusions: Combined nutrient supplementation demonstrated significant antidepressant-like effects compared to fluoxetine alone, indicating potential adjunctive benefits requiring further validation.