Morphological and Ultrastructural Assessment of Propolis in Rabbit Oral Cavity Wound Healing

Propolis, a natural resinous substance produced by honeybees, has been recognized for its anti-inflammatory, antioxidant, antimicrobial, and tissue-regenerative properties. Its potential to enhance oral cavity wound healing remains underexplored. This study aimed to investigate the effects of topical propolis gel on the morphology and ultrastructure of hard palate wounds in rabbits. Forty-eight adult male Iraqi rabbits (Oryctolagus cuniculus) were randomly divided into eight groups: four control groups (C3, C7, C14, C21) treated daily with propolis-free gel and four treatment groups (T3, T7, T14, T21) treated daily with propolis gel. The numbers indicate the day of evaluation post-incision and treatment (e.g., C3 and T3 were assessed on day 3, C7 and T7 on day 7, etc.). All animals received standardized 10 × 3 mm longitudinal palatal incisions. Wound diameters were measured to monitor contraction for morphological assessment. Ultrastructural evaluation using scanning electron microscopy (SEM) assessed the arrangement of collagen fibers, fibroblast density, extracellular matrix organization, and overall wound closure. Propolis-treated wounds demonstrated accelerated contraction, with a significant reduction in diameter from day 7 onward. By day 21, treated wounds measured ~2 mm versus ~5 mm in controls (p ≤ 0.0001). Histological examination revealed enhanced epithelialization, increased fibroblast proliferation, and dense collagen deposition in treated wounds. SEM confirmed well-organized collagen fibers, abundant fibroblasts, and complete closure of wound margins, whereas control wounds displayed loosely arranged collagen, persistent gaps, and ongoing inflammatory infiltration. Topical propolis gel significantly improves healing in oral cavity injuries, suggesting its potential natural agent to accelerate tissue repair.