Applying GC-MS analysis to identify chemical composition of Iranian propolis prepared with different solvent and evaluation of its biological activity

Background: Propolis as a natural product has shown beneficial effects on human health. This study was aimed to investigate the chemical compositions and biological activity of three different extracts of propolis from two distinct geographic areas in Iran. Methods: The chemical composition of Iranian propolis extracts that were collected in the Spring of 2016 from two provinces in northern Iran: Ardabil and Polur in Mazandaran Province were measured through gas chromatography-mass spectrometry (GC-MS) methods. In addition, antimicrobial activity and cytotoxicity effect on HN5 and LNCaP cell lines were evaluated. The data were analyzed using one-way ANOVA and p<0.05 was considered as significant. Results: The GC-MS analysis identified the presence of compounds that belonged to the different groups such as aromatics acids and their related esters, flavonoid and flavonoid derivatives and terpenes. Flavanone was the most dominant compound of flavonoids. The maximum growth inhibition was observed against S. aureus of ethanolic extract of propolis (p<0.05). Moreover, cytotoxicity showed that ethanolic and dichloromethane extracts had more inhibitory effects on cell lines than the water extract. Conclusion: The results determined that extracts had the highest percentage of flavonoids. Therefore, it is expected that the synergistic effect of the main components of propolis is related to the increase of biological activity of propolis

Imipenem-resistant Pseudomonas aeruginosa strains carry vim-type metallo-beta-lactamases isolated from intensive care unit, Shahid Beheshti Hospital, North of Iran

Background: Pseudomonas aeruginosa is the causing agent of many hospital infections and metallo-beta-lactamases (MBL) are being reported with increasing frequency. The aim of this study was to determine the frequency of metallo-&beta-lactamases (MBL) and VIM-1 gene in multidrug-resistant strains of P. aeruginosa isolates and to compare the methods of phenotypic and molecular detection. Materials and Methods: In 2011- 2012, 50 samples of non – duplicate P. aeruginosa were isolated from intensive care units and tested for MBL production using phenotypic methods. Minimal Inhibitory concentrations (MICs) were determined by commercial micro dilution panels. The presence of metallo-&beta-lactamase (MBL) genes was established by polymerase chain reaction (PCR) with specific primers targeting the bla (VIM) genes. Results: We used 50 clinical isolates amongst which 18 (%36) were found resistant to imipenem. Productions of MBL were detected in 15 (30%) isolates applying phenotypic method. PCR assay showed that 9 (18%) isolates carried aVIM-1 gene. MBL- producing strains were shown 100% resistant to cefepime, ceftazidime, ceftriaxone, cefotaxime and imipenem. Amikacin and ofloxacin appeared to be the most active antimicrobial agent. Conclusion: These findings demonstrate the emergence of bla (VIM-1) producing P. aeruginosa in North of Iran. VIM metallo-beta-lactamases producing P. aeruginosa strains can cause serious infections that are difficult to treat, therefore, there is a need for rapid identification and the timely implementation of infection control measures in combination with systematic surveillance to monitor its potential clonal spread

Unveiling the Antibacterial Properties of Statins: An In Vitro Study on Helicobacter pylori

Background. Helicobacter pylori (H. pylori), a widespread bacterial pathogen, is associated with various gastrointestinal diseases, including gastric cancer. Statins, widely prescribed cholesterol-lowering agents, have demonstrated pleiotropic effects, including potential antimicrobial properties. This in vitro study investigated the direct antibacterial effects of three clinically approved statins, simvastatin, atorvastatin, and rosuvastatin, against H. pylori isolates. Methods. H. pylori strains were isolated from gastric biopsies of dyspeptic patients and identified by microbiological techniques. The minimum inhibitory concentrations (MICs) of statins were determined using the agar dilution method, and their antimicrobial activity was evaluated by the disc diffusion method using different concentrations of simvastatin, atorvastatin, rosuvastatin, tetracycline, and amoxicillin. Scanning electron microscopy (SEM) was employed to examine the morphology of H. pylori cells. Results. The minimum inhibitory concentration (MIC) values (μg/mL) of atorvastatin, rosuvastatin, simvastatin, tetracycline, and amoxicillin against H. pylori were 240 ± 20, 450 ± 20, 460 ± 15, 155 ± 30, and 140 ± 20, respectively. In the disc diffusion assay, atorvastatin and rosuvastatin produced significantly larger inhibition zones compared to simvastatin at all concentrations tested (p<0.05). The inhibition zone diameters (mm) increased with higher statin concentrations, ranging from 9 ± 1.4 to 13 ± 1.4 for atorvastatin, 8 ± 0.9 to 11 ± 0.6 for rosuvastatin, and 5 ± 1.3 to 6 ± 1.4 for simvastatin at the highest tested concentration (1200 μg/ml). SEM analysis revealed the characteristic spiral morphology of H. pylori cells. Conclusion. Statins demonstrated varying degrees of antibacterial activity against H. pylori isolates, with atorvastatin exhibiting the highest potency. While the observed effects were lower than those of conventional antibiotics, these findings suggest the potential of statins as adjunctive agents or alternative therapeutic options, warranting further investigation through in vivo studies and clinical trials

Oral mucosa and Streptococcus mutans count in the saliva. Does graphene oxide nanoparticle mouthwash have a good effect?

Background: This study aimed to assess the effect of graphene oxide (GO) nanoparticles mouthwash on oral mucosa, Streptococcus mutans (S. mutans) count in the saliva of rats, and human enamel surface microhardness, in comparison with fluoride mouthwash. Methods: This study was conducted in two phases namely an animal study, and an in vitro experimental study. GO mouthwash (0.005), sodium fluoride (NaF) mouthwash (0.05), and a combination of both (0.05 NaF-0.005 GO) were prepared. The oral cavity of 36 rats was inoculated with S. mutans, and they were randomly divided into 4 groups according to the type of mouthwash. The control group received saline mouthwash. Fourteen days after using the mouthwashes, all rats were sacrificed, and the salivary S. mutans count was measured. The buccal and tongue mucosa were also histologically examined for the type and severity of inflammation, number of blood vessels, epithelial thickness, and epithelial keratinization. For microhardness testing, 40 sound extracted human premolars were randomly assigned to four groups (n=10) of culture medium with S. mutans and different mouthwashes. The enamel microhardness was measured at 7 and 14 days, and compared with the baseline value. Results: The mean S. mutans count in the saliva of rats in GO and NaF-GO groups was significantly lower than that in other groups (p&#60;0.001). Enamel microhardness in NaF and NaF-GO groups significantly increased at 7 and 14 days, compared with baseline. Conclusion: Addition of GO nanoparticles improved the antibacterial properties without causing adverse mucosal effects such as ulceration, acute inflammation or atrophy of the epithelium of the oral mucosa, but had no effect on surface hardness of the enamel