Tetragonula biroi–Derived Nanoemulsion Propolis Extract Impact on Inflammatory Cytokines and Osteoclastogenesis in Wistar Rats Subjected to Different Orthodontic Mechanical Forces

Understanding the roles of interleukin (IL)-10, -1β, tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), receptor activator nuclear kappa beta (RANK), and its ligand (RANKL) in orthodontic mechanical force (OMF) is essential. This study aimed to evaluate the effect of nanoemulsion propolis extract (NPE) from Tetragonula biroi on IL-10, IL-1β, TNF-α, and RANK–RANKL–OPG expression during OMF (10 and 20 g) in Wistar rats (Rattus norvegicus). Fifty healthy male Wistar rats were randomly assigned to groups with or without OMF and treated with 10 or 20 g OMF, with or without daily NPE administration. Orthodontic force was applied by connecting the maxillary central incisor to the maxillary left first molar using a ligature wire and an 8 mm nickel–titanium closed coil spring. NPE was administered into the gingival sulcus once daily for 7 or 14 days. The animals were then euthanized, and immunohistochemical analysis was performed to assess IL-10, IL-1β, TNF-α, RANK, RANKL, and OPG expression in the alveolar bone. The 20 g OMF group without NPE exhibited the highest expression of IL-1β, TNF-α, RANK, and RANKL on day 7 at the compression side of the alveolar bone. Conversely, the 20 g OMF group with NPE showed the highest IL-10 and OPG expression on day 7, with significant differences between groups (p ≤ 0.05). The administration of NPE reduced IL-1β, TNF-α, RANK, and RANKL expression while increasing IL-10 and OPG expression in the alveolar bone under 20 g OMF in Wistar rats.