Humic Acid Derived from Vermicompost Improves Bone Mineral Content and Alters Oxidative Stress Markers in Ovariectomized Mice

<b>Background:</b> Estrogen depletion alters bone mineralization and oxidative stress. Antioxidants like humic acids (HA) may help mitigate bone demineralization and redox imbalances. Thus, this study evaluated the effects of HA on bone mineral composition and oxidative stress markers in an experimental menopause model. <b>Methods:</b> Twenty-four female C57BL/6 mice were divided into four groups (n = 6/group): Sham; Sham + HA; Ovariectomized (OVX); and OVX + HA. The menopause model was induced by bilateral ovariectomy at the beginning of the experiment. HA derived from biomass vermicompost was administered daily by gavage for 28 days. After euthanasia, femurs and fragments of the gastrocnemius muscle, liver, and kidney were collected. Bone elemental composition was analyzed using scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Superoxide dismutase (SOD), catalase (CAT), and hydrogen peroxide (H₂O₂) activities were assessed in muscle, renal, and hepatic tissues. Data were analyzed using two-way ANOVA and Bonferroni’s post hoc test. <b>Results:</b> Untreated OVX mice exhibited a significant reduction in femoral calcium content (<i>p</i> < 0.05). However, HA treatment increased calcium levels and improved the Ca/P ratio (<i>p</i> < 0.05). H₂O₂ activity was reduced in the liver and kidney of OVX + HA mice compared to untreated animals (<i>p</i> < 0.05). CAT activity in muscle increased in the OVX + HA group compared to the OVX (<i>p</i> < 0.05). <b>Conclusions:</b> HA treatment improved femoral elemental composition and modulated oxidative stress markers in an experimental menopause model.