Journal of

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Introduction: Nowadays, the treatments of infectious disease are regarded difficult due to increasing antibiotic resistance among pathogenic bacteria, which the reason may be placing of microorganisms in a structure named biofilm. Biofilms are complex structures consisting of surface-attached bacteria. Therefore, it is essential to find new compounds in order to remove and inhibit biofilms. This study aimed to examine the antibacterial activities of alcoholic extracts of Centaurea cyanus on the biofilm structures and planktonic form of six pathogen bacteria(Staphylococcusaureus, Bacilluscereus, Streptococcuspneumoniae, Pseudomonasaeruginosa, Escherichiacoli and Klebsiellapneumonia). Methods: Antimicrobial activities of the alcoholic plant extracts against the planktonic form of bacteria were assessed via using the disc diffusion method. MIC and MBC values were determined by a macrobroth dilution technique and anti-biofilm effects were scrutinized by microtiter plate method. Results: The results of this study confirmed high ability of C.cyanus extracts against the biofilm of the tested bacteria as well as their free-living forms. To inhibit bacterial growth, ethanolic extracts proved to be more effective than methanolic extracts. Anti-biofilm effects of plant extracts were associated with the solvent type and extract concentration. C.cyanus extracts were reported to be most efficient to inhibit biofilm formation of E. coli (84/26%) and S. pneumoniae(83/14%). The greatest eradication of biofilm structures were observed on S. pneumonia biofilm (75.66%), and the highest decrease in metabolic activity was reported in S.aureus biofilms (71/85%). Conclusion: In this study the high capacity of C. cyanus extracts to encounter with whit biofilm was emphasized. Moreover, it was demonstrated that these extracts possess an appropriate potential to become active principles of new drugs.

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Introduction: Investigating efficacy of natural products, especially plant materials in dental caries is of great significance. The present study aimed to evaluate in vitro and in silico anti bacterial effects of methanolic extracts of Prangos ferulacea on single and biofilm structure of streptococcus mutans.

Methods: In this experimental study, after collecting the plants and determining their variety, they were air- dried and powdered. Then, the plants were extracted with methanol by the maceration method. In order to determine antibacterial activity as well as antibiofilm activity of the extracts, disk diffusion and micro titer assay were applied respectively. Regarding in silco analysis, the molecular docking was also preformed by iGemdock 2.1 software between Glucosyltransferases and 20 phytochemicals of the mentioned plants. SPSS software was utilized to statistically analyze the study data applying variance and Duncan’s multiple range test.

Results: The results of the present study showed that studied extracts specially their roots extract up to250-3000 μg/ml have significant antibacterial effects against the single form of becteria, which lead to inhibition of biofilm structures formation of the tested strain, though it can not damage biofilm structures of the bacteria. In addition, MIC and MBC minimum values were determined in 250-1000 μg/ml and 500-3000 μg/ml spectera respectively. Then, silico analysis confirmed that studied phytochemical compounds, especially α-pinen, Pesoralen and Limonene revealed an appropriate interaction to Glucosyltransferases,  which could be regarded as an inhibitor for this enzyme.

Conclusion: According to the results of the current study, P.ferulacea has significant antibacterial effects against single structure of S.mutans. However, it does not produce any significant effects on the biofilms structured from this bacteria.

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