Humic acid from biomass attenuates ovariectomy-induced metabolic and bone changes in mice

Objective Estrogen deficiency promotes metabolic dysfunction and bone loss. This study thus evaluated the effects of biomass-derived humic acid (HA) on ovariectomy-induced metabolic and bone alterations in mice.Method Female C57BL/6 mice (n = 6/group) were assigned to Sham, Sham + HA, ovariectomized (OVX) or OVX + HA groups. Estrogen deprivation was induced by bilateral ovariectomy. After a 14-day recovery period, HA (80 mg/kg/day) was administered orally for 28 days. Body mass, food intake, serum glucose, lipid profile, creatinine, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. Tibial calcium and phosphorus content and bone surface topography were assessed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) staining intensity in the femoral head was evaluated by immunohistochemistry. Data were analyzed using two-way analysis of variance with the Bonferroni post hoc test.Results OVX animals presented increased body mass gain, fasting glucose, dyslipidemia, creatinine and AST compared with Sham animals (p < 0.05). HA attenuated these alterations (p < 0.05) and reduced body weight gain. OVX-induced reductions in tibial mineral content and increased bone porosity were partially reversed by HA (p < 0.05), with a descriptive shift toward a less pro-resorptive RANKL/OPG staining profile.Conclusion Biomass-derived HA mitigates metabolic dysfunction and bone loss from estrogen deficiency, supporting its potential as adjunct therapy.