Humic Acid Derived from Vermicompost Inhibits Alveolar Bone Degradation and Protects Against Renal Injury in an Experimental Model of Periodontitis

Abstract

Background: Periodontal disease (PD) leads to the destruction of supportive tissues through an inflammatory response induced by biofilm accumulation. This low-grade systemic inflammation from PD increases the risk of comorbidities. Among potential therapeutic agents for PD, humic acids (HAs) are notable for their anti-inflammatory and immunomodulatory properties. This study aimed to evaluate the effects of varying HA doses on PD progression in an experimental model. Methods: Fifty-four Wistar rats were assigned to six groups (n = 8 each): control, PD, PD + 40 mg/kg HA, PD + 80 mg/kg HA, PD + 160 mg/kg HA, and PD + 320 mg/kg HA. HA from vermicompost was administered daily by gavage for 28 days, with PD induced by ligature on day 14. Post-euthanasia, mandibular samples were analyzed histomorphometrically for bone loss and osteocyte density. Alveolar bone topography and elemental composition were examined using Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS). Renal and hepatic tissues were assessed histopathologically. Data were analyzed with Analysis of Variance (ANOVA) and Duncan’s test. Results: HA-treated animals showed reduced epithelial attachment loss and alveolar bone loss, with improved bone quality parameters, such as reduced pore number and diameter and increased osteocyte density compared to the PD group. Renal lesions observed in PD animals were mitigated at 40 and 80 mg/kg HA doses. Conclusions: HA treatment improves alveolar bone integrity and, at lower doses, reduces PD-induced renal lesions.