Antimicrobial and cytotoxic activity of Ferula gummosa plant essential oil compared to NaOCl and CHX: a preliminary in vitro study

OBJECTIVES: The usage of medicinal plants as natural antimicrobial agents has grown in many fields including dental medicine. The aim of this in vitro study was three-fold: (i) to determine the chemical compositions of the Ferula gummosa essential oil (FGEO), (ii) to compare the antimicrobial efficacy of the oil with sodium hypochlorite (NaOCl) and chlorhexidine (CHX), (iii) to assess the toxic behavior of FGEO in different concentrations compared to 5% NaOCl and 0.2% CHX. MATERIALS AND METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to determine the chemical compositions of the oil. The disk diffusion method and a broth micro-dilution susceptibility assay were exploited to assess the antimicrobial efficacy against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mitis, and Candida albicans. The cytocompatibility of the FGEO was assessed on L929 fibroblasts, and compared to that of NaOCl and CHX. RESULTS: Twenty-seven constituents were recognized in FGEO. The major component of the oil was beta-pinene (51.83%). All three irrigants significantly inhibited the growth of all examined microorganisms compared to the negative control group. FGEO at 50 microg/mL was effective in lower concentration against Enterococcus faecalis than 5% NaOCl and 0.2% CHX, and was also more potent than 0.2% CHX against Candida albicans and Staphylococcus aureus. FGEO was a cytocompatible solution, and had significantly lower toxicity compared to 5% NaOCl and 0.2% CHX. CONCLUSIONS: FGEO showed a promising biological potency as a root canal disinfectant. More investigations are required on the effectiveness of this oil on intracanal bacterial biofilms.

Antibacterial and toxic effect of hydrogen peroxide combined with different concentrations of chlorhexidine in comparison with sodium hypochlorite

Statement of the Problem: Hydrogen peroxide [H[2]O[2]] has been suggested to be used in sequence or in combination with chlorhexidine [CHX] to enhance the antibacterial activity against Enterococcus faecalis, but there is no research in the literature on the safety and effectiveness of this irrigation protocol

Purpose: This study aimed to assess the cytocompatibility and antibacterial activity of different concentrations of CHX combined with H[2]O[2] in comparison with the activity of 5.25 and 2.5% sodium hypochlorite [NaOCl]

Materials and Method: Different concentrations of H[2]O[2] [10, 5, 3 and 1%] were exposed to the PDL cells. Then, the solution with minimal cytotoxicity was selected [3% H[2]O[2]]. The cytocompatibility and antibacterial activity of 0.1, 0.2, 1 and 2% CHX combined with 3% H[2]O[2] were evaluated and compared with 5.25 and 2.5% NaOCl. The differences in the mean viability of PDL cells were evaluated by one-way ANOVA. Kruskal-Wallis and post-hoc Dunn's tests were adopted to compare the antibacterial activity of the solutions against E.faecalis

Results: The viability of PDL cells was lower when treated with 5.25 or 2.5% NaOCl than all combinations of CHX and H[2]O[2]. There was no significant difference in the antibacterial activity of the solutions against E.faecalis, except for the 0.1% CHX + 3% H[2]O[2] combination, which had significantly lower efficacy than other groups

Conclusion: All combinations of CHX and H[2]O[2] [used in this study] except 0.1% CHX + 3% H[2]O[2] were efficient irrigants against planktonic E.faecalis and had a better cytocompatibility with PDL cells than 5.25 and 2.5% NaOCl

Computational analysis of collagenase from different Vibrio, Clostridium and Bacillus strains to find new enzyme sources

Collagenase is one the important enzyme, which is applied in varied fields ranging from tannery, food and cosmetic industries to clinical therapies. Currently, the commercially available collagenase enzyme has been produced by Clostridium histolyticum bacteria. In our study, in order to find new sources of collagenase producer, 30 collagenases from different species of Clostridium, Vibrio and Bacillus were evaluated from the view of phylogenetic relation, domain architecture and physiochemical features. Totally our results indicate that the non-pathogenic C. novyi [NT] with the aliphatic index [80.68], instability index [27], pI [6.54], Mw [112.838 kDa] and two PPC domain could be suggested as a potent bacteria for industrial production of collagenase