Investigation of in vitro odonto/osteogenic capacity of cannabidiol on human dental pulp cell

Introduction: Vital pulp treatment (VPT) maintains tooth vitality with certain dental materials by protecting pulp from noxious stimulation and promoting repair through enhancing cell proliferation/differentiation, migration, and inducing odontogenesis. As a non-psychotropic cannabis constituent, cannabidiol (CBD) process the properties of analgesic, anti-inflammation, and osteogenesis. Therefore, we hypothesize that CBD may induce the odonto/osteogenesis of human dental pulp cells (HDPCs), a critical feature using as effective pulp capping agent for VPT.

Materials and methods: In this in vitro study, the cytotoxicity of CBD on HDPCs was determined by MTT assay. Scratch assay was performed to analyze HDPCs migration. The biomineralization was examined by collagen synthesis and calcium nodule formation and related odonto/osteogenic and angiogenic genes. Cannabinoid receptor (CB) specificity was evaluated by Western blotting and Von Kossa staining using specific antagonists AM251 for cannabinoid receptor 1 (CB1) and AM 630 targeted at cannabinoid receptor 2 (CB2). In addition, the underlying molecular mechanism of CBD-induced biomineralization were investigated by examining CB-dependent MAPK signaling pathways.

Results: CBD demonstrated bi-phasic effects on HDPCs viability in tested concentrations. We found CBD significantly promoted cell migration, enhanced collagen synthesis and mineralized deposits in HDPCs when treated by 1 μM CBD supplemented in the differentiation media. RT-PCR revealed CBD-induced increased the expression of angiogenic and odontogenic genes, such as DSPP, DMP-1, OPN, ALP, Runx2, VEGFR1 and ICAM-1. These effects were via MAPK activation in a manner mainly mediated by CB2.

Conclusion: The results from this study suggested that CBD can induce odonto/osteogenesis from HDPCs and has the potential to develop new therapeutics in VPT in dentistry.