Role of Vitamin D and Vitamin D Receptor in Oral Lichen Planus: A Systematic Review

Association of vitamin D levels and oral lichen planus. Systematic review and meta-analysis

BACKGROUND

Oral lichen planus (OLP) is an inmuno-mediated mucocutaneous chronical inflammatory disease. Multiple predisposing factors are considered, such as autoimmune response, microorganisms, medications, dental materials, psychological stress, genetic predisposition or nutritional deficiencies. The deficiency of vitamin D has been related to various autoimmune diseases like OLP.

MATERIAL AND METHODS

The electronic search was conducted in the MEDLINE (Pubmed), Scopus, Cochrane Library and Web of Science databases. To assess any potential risk of bias, the authors critically appraised each study by the Newcastle-Ottawa Scale for cohort and case-control studies. Pooled analyses were performed using a random-effects model. Heterogeneity of the studies was assessed by the I2 statistics. Forest Plots were performed to graphically represent the difference between vitamin D concentrations in the OLP compared to healthy group, with a 95% confidence interval.

RESULTS

After applying our inclusion and exclusion criteria, 7 articles were included in our review. The median concentration vitamin D in ng/ml found in serum for patients with OLP was of 26,6311,75ng/ml and for healthy patients was of 31,438,7ng/ml. Regarding the quantitative analysis, 7 studies were included. The difference in the concentration of vitamin D in healthy patients and patients with OLP statistically significant (Weighted Mean Difference (WMD): -6.20, 95% CI: -11.24 to -1.15, p=0.02 and I2 heterogeneity: 94%, p<0.00001).

CONCLUSIONS

The patients with OLP have statistically lower vitamin D levels than healthy patients.

Fraxin alleviates oral lichen planus by suppressing OCT3-mediated activation of FGF2/NF-κB pathway

Oral lichen planus (OLP) is a carcinogenic chronic inflammatory oral disease, which lacks effective treatments. Fraxin is an active ingredient of the traditional Chinese medicine Qin Pi, which has an anti-inflammatory effect, but its effect on OLP is unclear. The aim of this study was to investigate the therapeutic effect of fraxin on OLP and the underlying mechanism. Human immortalized keratinocytes (HaCat) were incubated with fraxin (10, 20, or 40 µM) for 48 h and then treated with 10 µg/mL LPS for 24 h. Cell viability and apoptosis were detected. Next, the interaction between OCT3 and FGF2 was predicted by online database and verified by Co-IP analysis. Fraxin, Ad-OCT3, sh-OCT3, and sh-FGF2 were, respectively, applied to treat LPS-incubated HaCat cells, and cell viability, apoptosis, and secretion of inflammatory factors were detected with MTT, flow cytometry, and ELISA assays. Then, the involvement of OCT3 and FGF2 in the prevention of fraxin on HaCat cells from LPS-induced cell apoptosis and inflammation was investigated through multiple rescue experiments. In addition, OLP models were constructed in VDR-/- mice and NOD/SCID mice by injecting with human OLP pathological tissue homogenates to verify the therapeutic effect of fraxin on OLP. Fraxin treatment increased cell viability and reduced cell apoptosis and the secretion of IL-6 and TNF-α in a dose-dependent manner. OCT3 was significantly upregulated in oral mucosa tissues of OLP mice. OCT3 silencing inhibited LPS-induced cell apoptosis and secretion of inflammatory factors. Fraxin incubation reduced the expression of OCT3, and OCT3 interacted with FGF2 to upregulate FGF2 protein. FGF2 silencing reduced the expression of p-p65/NF-κB protein and improved LPS-induced cell apoptosis and secretion of inflammatory factors. OCT3 overexpression increased the expression of FGF2 and p-p65/NF-κB proteins, rh-FGF2 aggravated this effect, while FGF2-Neu-Ab reversed this effect. The results of in vivo experiments showed that fraxin alleviated cell apoptosis and inflammation in oral buccal mucosa tissues of OLP mice. Fraxin inhibited cell apoptosis and inflammation by suppressing OCT3-mediated activation of the FGF2/NF-κB pathway, alleviating the progression of OLP.

Association between Vitamin D Receptor Polymorphism and Susceptibility to Oral Lichen Planus and Oral Squamous Cell Carcinoma

Introduction

Oral squamous cell carcinomas (OSCC) comprise 90-95% of oral cancers. Early diagnosis improved the survival rate of OSCC patients to 80-90%. Oral lichen planus (OLP) is a chorionic inflammatory disease with malignancy potential. The vitamin D receptor (VDR) plays a critical role in the pathogenesis of oral cancer. This study aimed to determine the association between VDR rs7975232 (Apa I) polymorphism and potential susceptibility to OLP and OSCC risks.

Materials and Methods

In this prospective case-control study, a total of 120 blood samples were obtained from OSCC patients (n=29), OLP (n=50), and controls (n=40). VDR rs7975232 polymorphism was studied using the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) method. Statistical analysis was performed with SPSS Version 23 software. Data were expressed as means ± standard deviation (SD). Age, sex, allelic frequency, and genotyping were compared using the chi-square test. A p-value of less than 0.05 was regarded as statistically significant. The disease risk was estimated by Odds ratio (OR) with a 95% confidence interval.

Results

A significant age difference was observed between the controls and the OSCC group (p=0.001). A significant difference was observed in Aa and aa genotypes compared with AA between OSCCs and controls. Moreover, dominant (p<0.001), additive (p<0.001), and allelic (p=0.001) models were different between groups.

Conclusion

There was a positive association between rs7975232 VDR polymorphism and susceptibility to OSCC. More experimental evidence must reveal the possible association between rs7975232 and the risk of OLP in a larger cohort.

Platelet-rich plasma protein as a therapeutic regimen for oral lichen planus: An evidence-based systematic review

Oral Lichen Planus (OLP), an autoimmune disorder of unclear pathogenesis affects quality of life of affected individual. Intervention regimens are multiple and still evolving due to its resistance to recover and ability to recur. Platelet rich Plasma (PRP) is a newer, promising treatment modality tested by researchers because of its low cost and negligible adverse effects. Articles were retrieved from search engines of PubMed / Medline, Scopus and Web of Science which fulfilled the eligibility criteria. Cochrane risk of bias tool assessed quality of clinical studies and Joanna Briggs Institute for case reports. A total of 4 articles were included for the systematic review, of which 2 are clinical trials and 2 case reports. All cases were of erosive nature. PRP in case reports were administered when patients did not respond to conventional therapy. PRP demonstrated effective therapeutic benefit in regards to outcome of pain and lesion appearance. PRP can be considered as a potential alternative therapy in treating non-responsive OLP. Further studies are recommended to arrive at a definitive conclusion.