Effects of cannabidiol on biomineralization and inflammatory mediators expression in immortalized murine dental pulp cells and macrophages under pro-inflammatory conditions

Objectives: This study investigated the in vitro effects of cannabidiol (CBD) on dental pulp cells and macrophages under pro-inflammatory conditions.

Materials and methods: Mouse dental pulp cells (OD-21) were pre-stimulated with tumor necrosis factor alpha (10 ng/mL) or left untreated, then exposed to CBD at concentrations of 0.01 µM, 0.1 µM, 1 µM, and 10 µM for 24 h and 7 days. Cell viability was assessed using the MTT assay, while gene expression related to mineralization-Dentin Sialophosphoprotein (Dspp), Dentin Matrix Protein 1 (Dmp1), Runt-related transcription factor 2 (Runx2), TNF-α (Tnf), and prostaglandin-endoperoxide synthase 2 (Ptgs2) were analyzed via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Mineralization nodule formation was evaluated using alizarin red staining. Macrophages (RAW 264.7) were stimulated with lipopolysaccharide (LPS) for 2 h before exposure to the same CBD concentrations. Data analysis included the Shapiro-Wilk normality test and comparisons using ANOVA and Tukey's post-hoc test (α = 0.05).

Results: The findings indicated that CBD did not significantly affect OD-21 cell viability, except for the 10 µM concentration after 7 days (p < 0.05). CBD treatment promoted mineralization, with significant differences observed among groups (p < 0.05). Notably, Ptgs2 expression varied between time points, while Runx2 expression was significantly reduced at 24 h (p < 0.05). In macrophages, Ptgs2 and Tnf levels were downregulated by all tested CBD concentrations (p < 0.05).

Conclusion: These results indicate that cannabidiol positively influence the biomineralization process and modulate inflammatory mediator expression.

Clinical relevance: Our research indicates that cannabidiol presents biomineralization potential within inflammatory contexts, implying its potential as a promisor bioactive substance for regenerating oral tissues by interacting with cells and tissues to induce specific responses.