Abstract
BackgroundPeriodontitis is a chronic infection initiated by oral bacterial and their virulence factors, yet the severity of periodontitis is largely determined by the dysregulated host immuno-inflammatory response. Baicalein is a flavonoid extracted from Scutellaria baicalensis with promising anti-inflammatory properties. This study aims to clarify the anti-inflammatory and osteogenic effects of baicalein in periodontal ligament cells (PDLCs) treated with lipopolysaccharides (LPS).MethodsHuman PDLCs were incubated with baicalein (0–100 μM) for 2 h prior to LPS challenge for 24 h. MTT analysis was adopted to assess the cytoxicity of baicalein. The mRNA and protein expression of inflammatory and osteogenic markers were measured by real-time polymerase chain reaction (PCR), western blot and enzyme-linked immunosorbent assay (ELISA) as appropriate. Alkaline phosphatase (ALP) and Alizarin red S (ARS) staining were performed to evaluate the osteogenic differentiation of PDLCs. The expression of Wnt/β-catenin and mitogen-activated protein kinase (MAPK) signaling related proteins was assessed by western blot.ResultsMTT results showed that baicalein up to 100 μM had no cytotoxicity on PDLCs. Baicalein significantly attenuated the inflammatory factors induced by LPS, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), matrix metalloprotein-1 (MMP-1), MMP-2 and monocyte chemoattractant protein 1 (MCP-1) at both mRNA and protein level. Moreover, MAPK signaling (ERK, JNK and p38) was significantly inhibited by baicalein, which may account for the mitigated inflammatory response. Next, we found that baicalein effectively restored the osteogenic differentiation of LPS-treated PDLCs, as shown by the increased ALP and ARS staining. Accordingly, the protein and gene expression of osteogenic markers, namely runt-related transcription factor 2 (RUNX2), collagen-I, and osterix were markedly upregulated. Importantly, baicalein could function as the Wnt/β-catenin signaling activator, which may lead to the increased osteoblastic differentiation of PDLCs.ConclusionsWith the limitation of the study, we provide in vitro evidence that baicalein ameliorates inflammatory response and restores osteogenesis in PDLCs challenged with LPS, indicating its potential use as the host response modulator for the management of periodontitis.
Highlights
Periodontitis is a chronic infection initiated by oral bacterial and their virulence factors, yet the severity of periodontitis is largely determined by the dysregulated host immuno-inflammatory response
With the limitation of the study, we provide in vitro evidence that baicalein ameliorates inflammatory response and restores osteogenesis in periodontal ligament cells (PDLCs) challenged with LPS, indicating its potential use as the host response modulator for the management of periodontitis
We have previously shown that baicalein enables the osteoblastic differentiation of PDLCs through Wnt/β-catenin signaling [18]. This extended study aims to evaluate the effects of baicalein on the inflammatory and osteogenic factors in PDLCs challenged with LPS, as well as the underlying molecular mechanisms
Summary
Periodontitis is a chronic infection initiated by oral bacterial and their virulence factors, yet the severity of periodontitis is largely determined by the dysregulated host immuno-inflammatory response. Periodontal pathogens, which mainly comprised of Gram-negative anaerobic bacterial, are required to initiate periodontitis. It is the dysregulated host immuno-inflammatory response that largely determines the extent and severity of periodontal disease [5]. The infection with the pathogenic microflora, together with their virulence factors like lipopolysaccharides (LPS) and gingipain, drives the influx of neutrophils and macrophages, and activates the constituent cells, e.g. periodontal ligament cells (PDLCs), releasing a plethora of inflammatory mediators that participates in the initiation and progression of periodontitis [5, 6]. Mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-κB) are known to regulate the expression of inflammatory mediators [7], and Wnt/β-catenin signaling is closely involved in bone turnover and remodeling [8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
