مژگان آزادپور

The aim of this study was to investigate of the chemical composition of the essential oil extracted from Mentha longifolia collected from different regions of Lorestan province (Khorramabad, Aleshtar, Delfan) and to determine the antibacterial activities against three certain bacterial strains (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli). The chemical profiling of the essential oil was performed using gas chromatography-mass spectrometry (GC-MS) analysis. GC-MS analysis revealed that essential oil of M. longifolia from Khorramabad region was constituted by pulegone (54.41%) and 1, 8-cineole (22.05%) as a major component. M. longifolia from Aleshtarwas rich in piperitenone (29.29%), pulegone (17.53%), piperitenone oxide (14.35%), 1, 8-cineole (14.34%) and the main component of M. longifolia from Delfanwas citronelyll acetate (59.93%), aromadrene (5.1%), respectively. A significant correlation between geographical and soil characteristics, except phosphorus and electrical conductivity, with the essential oils components was detected. The results obtained using MIC and MBC showed that the minimum inhibitory concentration of the essential oil of M. longifolia from studied regionwas in the range of 0.03-2 mg/mL. The most effective essential oil in bacterial inhibition for E. coli and S. aureus bacteria was the essential oil from Aleshtar and Delfan, respectively. Two bacteria P. aeruginosa and S. aureus were least susceptible to M. longifolia essential oil from Khorramabad region. The essential oil of M. longifolia from different regions of Lorestan provinc exhibited low to high inhibitory activity against gram-positive and negative bacteria,.which depended to the region of collected plants and studied bacterial strains. In this research, three components citronellyl acetat, citronellal and aromandrene was detected in M. longifolia essential oil for the first time

A green approach by using aqueous extract of Rosmarinus officinalis L. for silver nanoparticles (AgNPs) synthesis was developed and optimized. Parameters affecting the synthesis of AgNPs, such as temperature, extract pH, silver nitrate and extract (ratio of plant mass to extraction solvent volume) concentrations were investigated and optimized. Optimum conditions for the synthesis of silver nanoparticles (AgNPs) are as follows: Ag concentration, 1 mM, extract concentration, 2 g/L, pH=9 and temperature, 45 °C. Biosynthesized silver nanoparticles were characterized using UV Visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). TEM and DLS analyses shown the synthesized AgNPs were predominantly spherical in shape with sizes in the range of 20-40 nm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs were determined for several pathogens include Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus cereus and Staphylococcus aureus. The antibacterial activity of the synthesized AgNPs was compared with several antibiotic drugs as control. This eco friendly and cost-effective synthesis method can be potentially use for large-scale production of silver nanoparticles.

Honey is a natural product of plant secretions collected by bees then after some changes are saved in hive. Honey is rich in enzymatic and non-enzymatic anti-oxidants such as Catalase, ascorbic acid, flavonoids and alkaloids. The important feature of honey is also antimicrobial activity. Also entering some ingredients into bees, diet can increase of effectiveness the nutritional value of honey So the anti-oxidant and anti-microbialactivities of two types of honey by change in bees,diet incomparison with the other honey of the region were studied. Three different types of diet given to bees including apple juice, flowers and root extract of Licorice and region flowers so that three types of honey were produced. The honey affected on standard bacteria and Candida albicans with several antibiotics to evaluate of antimicrobial activity according to agar well diffusion assay. The amount of antioxidant compounds, measured according total phenol test. For measurement of antioxidant effects of honey, three tests of FRAP (ferric reducing antioxidant power), DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABT (3-ethylbenzothiazoline-6-sulphonic acid) were used. In this experiment, Licorice honey had highest antimicrobial activity especially against pseudomonas aeruginosa. The tested honey had a significant difference in total amount of phenol. In all three methods (FRAP, DPPH and ABT), apple honey had the highest antioxidant activity. According to the results of this study, entering some effective and natural materials into bees’ diet can cause a revolution in the honey product industry, as a drug, and health of society.

The D-test is performed by placing clindamycin and erythromycin impregnated disks at a standard distance on the agar plate then looking for the flattening of inhibition zone around the clindamycin disk. A positive D-test indicates clindamycin inducible resistance and also predicts treatment failure possibility of this antibiotic in clinic. Prevalence of staphylococcal inducible resistance to clindamycin through the D-test was the aim of this study. In this descriptive-cross-sectional study، inducible resistance to clindamycin was examined on the 150 isolated Staphylococcus aureus (n=103) and coagulase-negative staphylococci (n=47) collected from nasal employees and clinical samples by using D-test. The statistical analysis was performed using chi-square test. Out of 103 isolated S. aureus، 22 (21. 4%) were methicillin-resistant (MRSA). Among the tested samples، 3 (2%)، 1 (0. 6%) and 2 (1. 3%) had D، D+ and HD phenotypes، respectively. Fifty-four (36%) of isolations exhibited resistance to both clindamycin and erythromycin. Prevalence of resistance to clindamycin and erythromycin between isolated MRSA and methicillin-susceptible S. aureus (MSSA) was statistically significant (p<0. 05). Phenotypical resistance to erythromycin is not always attributable to clindamycin resistance. Therefore، staphylococcus strains resistant to erythromycin and susceptible to clindamycin should be subjected to D-test assay.

In recent years، it has been recommended to use natural materials، instead of chemically synthesized drugs with side effects، in the control and treatment of infections. Increasing use of medicinal plants for medical treatment made for this branch of complementary medicine a unique position. The present research was done to study anti-microbial effect of Medicago sativa exctract in comparison with Ciprofloxacin، Gentamicin and Penicillin antibiotics on clinical strains and phatogenic bacteria such as P. aeruginosa، E. coli، Staphylococcus aureus and Listeria monocytogenes. Experiments were conducted using micro broth dilution and disc diffusion methods، and MIC and MBC of the plant have been evaluatead. MIC Medicago sativa extract was effective on gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes on the 206. 25 and 6600 µg/ml and on the gram-negative bacteria tested in this study had no effect. Based on the research findings، mentioned herbal extract can be a good candidates for laboratory studies to separate active compounds in this plant to achieve effective antimicrobial drugs.