Ornidazole Regulates Inflammatory Response and Odontogenic Differentiation of Human Dental Pulp Cells.

AIM: This study aimed to explore the potential of ornidazole as an alternative treatment for pulpitis, focusing on its effects on human dental pulp cells (hDPCs) and macrophages. We assessed the cytotoxicity of various concentrations of ornidazole, its safety and efficacy in treating inflamed hDPCs, and its regulatory impact on inflammatory markers during inflammation. MATERIALS AND METHODS: Inflammation in hDPCs was induced using lipopolysaccharides (LPS), and varying doses of ornidazole were introduced. Cell proliferation, migration, inflammation regulation, and dentinogenesis under inflammatory conditions were evaluated. Additionally, macrophages were cultured with different doses of ornidazole to analyse the expression of inflammatory genes. If statistically significant differences were observed between the control and treatment groups, this was considered evidence of ornidazole's effects on hDPCs. Statistical analysis was performed using SPSS 26.0, with one-way analysis of variance and Tukey's test for comparisons. A P-value of < 0.05 was considered statistically significant. RESULTS: Ornidazole influenced cell proliferation, inflammation regulation, and dentinogenesis. Concentrations below 10 µg/mL did not exhibit significant cytotoxic effects on hDPCs over a 7-day period, and the cytotoxicity of ornidazole was both concentration- and time-dependent. Ornidazole decreased the expression of proinflammatory markers (IL-6 and TNF-α) while enhancing the expression of anti-inflammatory markers (IL-1Ra and IL-8). It also suppressed alkaline phosphatase (ALP) activity but increased the expression of odontogenic differentiation markers at both mRNA and protein levels in the presence of inflammatory stimuli. Furthermore, ornidazole demonstrated immunomodulatory effects on macrophages. CONCLUSIONS: Low concentrations of ornidazole were found to be safe for hDPCs. Ornidazole modulated the expression of inflammatory markers (IL-6, TNF-α, IL-8, IL-1Ra) in inflamed hDPCs and regulated odontogenesis-related markers. Furthermore, low concentrations of ornidazole enhanced the immune regulation in macrophages, highlighting its potential as a therapeutic agent for pulpitis. CLINICAL RELEVANCE: This study aimed to understand the interactions of ornidazole with hDPCs, its anti-inflammatory properties, and its regulatory effects on odontogenic processes. By examining the impact of different concentrations of ornidazole on cells associated with pulp inflammation, this study provides valuable insights into its therapeutic potential for pulpitis and tends to support its clinical application.