(55) Effects of VEGA and CHX on cytokine expression and cell viability of human gingival fibroblasts with or without Porphyromonas gingivalis

Introduction: Periodontitis is a disease that leads to tissue breakdown in the presence of bacterial species such as Porphyromonas gingivalis (P.gingivalis). Chlorhexidine gluconate (CHX) has been used to reduce bacterial presence in the oral cavity after dental surgeries as well as scaling and root planing procedures for periodontitis. Chlorhexidine is a potent bactericidal agent but has also been shown to be cytotoxic to human gingival fibroblasts. VEGA oral health care rinse (VEGA), a homeopathic mouth rinse that has been advocated to improve healing, have antimicrobial properties, and facilitate bacterial reduction after periodontal therapy. There currently appears to be no studies examining the cytokine expression of VEGA. The purpose of this study was to investigate the cytokine expression from healthy gingival fibroblasts (HGF) in the presence of P. gingivalis LPS with exposure to either 0.12% chlorhexidine (CHX), or vega oral care gel (VEGA).

Methods: Human gingival fibroblasts (HGF) from fresh non-inflamed gingival connective tissue were grown on blood agar plates. HGFs were incubated for 72 hours in a serum-free medium in the presence or absence of 0.00012% chlorhexidine gluconate, 10% VEGA oral health rinse, LPS from P. gingivalis (1 µg/ml), or a combination of LPS (1 µg/ml) and 0.00012% chlorhexidine or LPS (1 µg/ml) and 10% VEGA oral rinse. After 72 hours, equal volumes of conditioned media were collected from each sample and assessed for changes in cytokine expression via cytokine density measurements of cytokines such as IL-1, IL-6, IL-8, TNF-a, and growth factors such as rhPDGF-bb, EGF, TGF-b and more. Group comparisons were made using ANOVA, followed by pair-wise tests using Fisher’s Protected Least Significant Differences to control the overall significance level at 5%.

Results: Compared to the control, CHX had significantly increased expression the of MCP-1 from HGFs. LPS and LPS+VEGA had significantly increased expression of IL-6, IL-8, and MCP-1 from HGFs with no other significant differences found between the control and any other group. CHX caused significantly higher levels of EGF, IL-6, IL-8 and MCP-1 compared to LPS and LPS+VEGA. VEGA also caused significantly higher levels of IL-8 and MCP-1 compared to LPS and LPS+VEGA. Overall, there was no statistically significant difference between cytokine expression from HGFs when exposed to CHX and VEGA. No statistically significant difference was seen between treatments CHX, VEGA, LPS+CHX, LPS+VEGA and any cytokine.
Cytokine expression that was higher than the control included IL-8 and MCP-1 for both CHX and VEGA. CHX appeared to express significantly higher cytokine expression of epithelial growth factor (EGF) and IL-6. EGF is a growth factor seen in cell differentiation and IL-6 is a well-known anti-inflammatory cytokine.

Conclusions: The results of this study demonstrate a lack of distinct differences in cytokine expression when HGFs are exposed to either CHX or VEGA. Further research is necessary to understand the mechanism of VEGA oral care gel and its mechanism of action.

Lead Author's Contributions to the Research Project. : The Lead Author was responsible for the data collection, performing the data analysis and the composition of the abstract.