جستجوی مقالات مرتبط با کلیدواژه « ضد میکروبی » در نشریات گروه « پزشکی »

Today, the use of medicinal plants such as T. daenensis as a complementary and effective treatment method to control and inhibit the growth of pathogenic microorganisms is increasing all over the world. This study aimed to investigate the antimicrobial effects of T. daenensis essential oil (EO) and its nanocapsulated against some pathogenic bacteria isolated from aquatic and food samples.

In this experimental research, T. daenensis was collected in June 2023 in Shahrekord City. The EO of the dried aerial part of the plant was obtained by using a Clevenger device (steam distillation). The components in the EO were identified by gas chromatography-mass spectrometry (GC-Mass). T. daenensis EO nanocapsules were prepared using Tween 20, Tween 80 as emulsifier, polyethylene glycol as a co-solvent, acidic chitosan solution (1%), and modified starch (5%) as a coating. Transmission electron microscope (TEM) and dynamic light scattering (DLS) were used to confirm their structure. Antimicrobial properties against Listeria monocytogenes, Escherichia coli, Bacillus cereus, Salmonella typhimurium, Proteus mirabilis, Staphylococcus aureus and Klebsiella pneumoniae isolated from aquatic samples (fish and lobster) and various foods (raw milk, traditional ice cream and mutton, beef, chicken) were investigated by disc diffusion method, determination of minimum inhibitory concentration (MIC) and bactericidal (MBC) by microdilution method. Also, the prevention of biofilm formation was investigated.

The main components of the T. daenensis EO were thymol (75.31 percent), 8 p-Cymene (4.62 percent), carvacrol (4.2 percent), trans-cayophyllene (3.01 percent), terpenine (2.01 percent) and beta- myrcin (1.21 percent), respectively. TEM and DLS methods confirmed the structure of the T. daenensis EO nanocapsules. The size of nanocapsules was between 50 and 90 nm. The MIC amounts for the mentioned bacteria were between 62.5 and 250 μg/ml. The lowest MIC value for P. mirabilis, S. aureus, and K. pneumoniae was reported with a concentration of 62.5 μg/ml of T. daenensis EO nanocapsule. Also, the amounts of MBC for the mentioned bacteria were between 125 and 1000 µg/ml. According to the obtained results, the MIC and MBC levels for all mentioned bacteria against T. daenensis EO nanocapsule were lower than the EO alone (P<0.05). According to the results, with the increase in the concentration of EO, the diameter of the non-growth halo increased, while these results were not the same for T. daenensis EO nanocapsule. In all bacteria except S. aureus, the diameter of the non-growth halo for different concentrations of EO was greater than that of T. daenensis EO nanocapsule. The inhibition percentage of biofilm production was also reported 100% at 125 and 250 μg/ml of T. daenensis EO nanocapsule, except for K. pneumonia. In all concentrations of T. daenensis EO nanocapsule, the percentage of bacteria biofilm reduction was significantly higher than the EO alone (P<0.05).

Based on the findings of the study, the T. daenensis EO nanocapsule had more antibacterial properties than EO alone. It is suggested that future studies for the toxicology of T. daenensis EO nanocapsule on normal and cancerous cells be done iv-vitro. In addition, to apply it in the food industry, experimental studies on food models should also be conducted

Side effects associated with antimicrobial drugs, as well as their high cost, have stimulated the search for inexpensive herbal medicinals with fewer side effects. These substances can be used as a medicinal supplement or to increase the antimicrobial and antifungal effects of drugs. The aim of this study is to investigate the inhibitory effect of oleuropein on fungal and bacterial pathogens isolated from nail infection in laboratory condition.

Antifungal and antibacterial properties of oleuropein by determining the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) of this substance on yeasts Candida albicans, Candida glabrata and Escherichia coli by microbroth dilution method using CLSI protocols were evaluated.

The results showed that the Minimum Inhibitory Concentration (MIC) against all three studied microorganisms was equal to 65 mg/ml and the Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) of oleuropein was equal to 130 mg/ml.

due to the high antifungal and antibacterial activity of oleuropein, the present study introduces oleuropein as a natural antimicrobial drug. This substance can also be used to increase the antimicrobial power of existing antibiotics.

To fight food pathogenic microorganisms, it is necessary to search for new antimicrobial compounds. Marine sponges are potential sources of new antimicrobial agents due to secondary metabolites. This study investigated the antibacterial effect of methanolic extract of H. implexa sea sponge collected from Chabahar.

This study investigated at two concentrations of 3 and 5 mg/ml of the methanolic extract against two foodstuffs bacteria of Escherichia coli and Pseudomonas aeruginosa by disc diffusion sensitivity test, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Statistical analysis was done with One-Way Analysis of Variance and comparison of means with Tukey's test.

According to the results, the highest effects were obtained on concentrations of 5 mg/ml with 11.03±1.7 and 12.033±0.702 mm diameters of non-growth halos for Escherichia coli and Pseudomonas aeruginosa, respectively, and showed significant difference by Gentamycin (p<0.05). The minimum inhibitory concentration of H. impelxa sponge organic extract in Escherichia coli and Pseudomonas aeruginosa was observed at 1 and 3 mg/ml concentration, respectively. Minimum bactericidal concentration observed in Escherichia coli at 3 mg/ml concentration and no effect on Pseudomonas aeruginosa strain observed.  

 Based on the results, H. impelxa sea sponge extract has a good antibacterial effect on pathogenic bacteria of Escherichia coli and Pseudomonas aeruginosa. Therefore, the extract of this sponge can be further studied for use in food packaging.

Medicinal plants contain a high level of antioxidant compounds such as flavonoids, phenolic, carotenoids, and tannins, which can be used to eliminate excess free radicals in the body. This study aimed to determine the total phenolic and flavonoid content and to investigate the antioxidant and antibacterial effects of Berberis integerrima and Graminifolius tragopogon methanolic extracts on some Gram-positive and Gram-negative microorganisms.

In this descriptive-analytical study, methanolic extracts of B. integerrima and G. tragopogon were prepared using 80% methanol. Total phenol and flavonoid contents were determined by Folin–Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant capacity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power methods. The antibacterial activity of the extracts of B. integerrima and G. tragopogon on Escherichia coli, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhimurium were determined by the disk diffusion method. Butylated hydroxytoluene and ciprofloxacin were used as positive controls for antioxidant activity and bacterial strains, respectively.

Total phenol and flavonoid compounds in the extracts of B. integerrima and G. tragopogon were 46.90±0.70 and 22.63±0.59 mg gallic acid per gram of extract and 5.61±0.01 and 46.74±0.81 mg quercetin per gram of extract, respectively. The extracts of B. integerrima and G. tragopogon showed significant antibacterial activity. B. subtilis and S. typhimurium showed the highest sensitivity and resistance to the extracts, respectively. Moreover, the extract of B. integerrima had the most potent inhibitory effect on the examined microorganisms.

B. integerrima extract exhibits higher phenolic content, antioxidant properties, and antimicrobial activity than G. tragopogon extract.

Due to the changes in people's tastes, the producers try to produce newproducts with high nutritional value. Today, using vegetables for flavoring yogurt has becomevery popular among consumers.

In this study, prepared Suaeda aegyptiaca extract was used at theconcentrations of 0.05, 0.1, 2, and 2.5% (w / w) in the formulation of low-fat yogurt. Theantioxidant and antimicrobial properties of the extracts were evaluated, followed byinvestigating the that physical-chemical, microbial, and organoleptic properties of thetreatment during 28 days at 4 ° C.

The result showed that increasing the concentration of the extract was notaccompanied by a significant change in the account of starter cultures and also the content ofstarter culture increased during storage. Moreover, Staphylococcus aureus was significantlyinhibited while Ecoli and Aspergillus niger were inhibited after 14 and 21 days of storage.Furthermore, by increasing the amount of extract, DPPH assay and phenolic compounds werecompound significantly increased and the storage time significantly affected the free radicalscavenging and TPC capacity of the yogurt. During storage, pH decreased while acidity andsyneresis increased and water holding capacity, and viscosity decreased. Color measurementshowed a significant difference in color between different kinds of yogurts. Supplementationwith plant extracts, L*and a* values decreased while b*values increased.

In the case of sensory characteristics of yogurt, samples that have 0.05,0.1 % ofextracts were not significantly different in overall acceptability from plain yogurt.

Today Ginger in fresh and dried form is used as a spice around the world.Ginger with a scientific name of Zingiber officinale, is a herbal medicine. It is widely used inthe traditional medicine and utilised as a dietary supplement. The aim of this study is todetermine the antibacterial and anticancer properties and activities of hydroalcoholic extractof ginger.

The cell lines were grown in RPMI supplemented with 10% FBS,1% penicillin and streptomycin. The cells were allowed to incubate at 37ºC in an atmospherethat contained 5% CO2 and 95% humidity. The extracts were also used with MIC onKlebciella Pneumoniae, E. Coli, Pseudomonas aeroginosa and Staphylococcus aureus. Thestandard MTT assay was performed to estimate cell viability after treatment by Zingiberextracts. We examined cytotoxicity effects of different concentrations the (250, 500, 750,1000, 1250, 1500, 1750, 2000, 1250, 2500, 2750 μg/ml) of Zingiber extracts on AGS celllines were examined.

Based on the findings of this Study, these extracts at different concentrations hadinhibitory effect on Klebciella Pneumoniae, E.Coli, and Staphylococcus aureus. Also Theresults of the MTT assay showed that the Zingiber extracts based on time and concentrationhad anticancer activities.

Based on our results and findings it might be suggested that ginger extract withoptimum concentrations might be employed in food formulations to inhibit pathogenicbacteria and cancer cell lines.

Despite the anti-cancer and antimicrobial effect of licorice extract and lavender essential oil, some factor such as low bioavailability and biodegradable, limit the use of them as a therapeutic treatment. Using of nanoparticles is one of the ways to overcome these limitations. The aim of this study was to investigate the anti-proliferative effects of nanoemulsion containing licorice extract and lavender essential oil against cancer cells and evaluate its antimicrobial properties in the In Vitro environment.

In this experimental study nano-emulsion containing rosemary and peppermint essential oils was synthesized by spontaneous emulsification. The cell toxicity of nanoemulsion was studied using the MTT method against HepG2 and SK-MEL-3 cell lines. The antibacterial activity of nanoemulsion was determined using four bacterial strains (Bacillus subtilis, Stapphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) and minimum inhibitory concentration (MIC) method.

The results of MTT test on HepG2 cells showed that concentrations of 630, 1250 and 2500 μg/ml nanoemulsions caused toxicity to the cell and caused the death of more than 50% of the cells (IC50=401μg/ml ((p<0.05). Evaluation of SK-MEL3 cells showed that with the exception of 75 μg of nanoemulsion, other concentrations caused the death of more than 50% of the cells (IC50=82μg/ml ((p<0.05). The MIC results revealed that the nanoemulsion had a significant antibacterial activity.

the nanoemulsion containing lavender essential oil and licorice extract had antibacterial and anti-proliferative activities against cancer cells. The results of this study indicated that nanoemulsification of lavender essential oil and licorice extract can enhance their biological effect and it can be used as a drug formulation.

Due to the threat to human health with diseases related to oxidative stress and infectious diseases, today the use of natural compounds and changes in them to improve their effectiveness has received much attention. The aim of this study was to evaluate the antioxidant and antimicrobial activity of nanoemulsions prepared from Artemisia aucheri Boiss essential oil (AABEO-NE).

The AABEO-NE was synthesized by ultrasound method and formulated with 9 ml of Tween 80, 1 ml of polyethylene glycol, 3 ml of Artemisia essential oil, and 87 ml of distilled water. The antioxidant activities of nanoemulsions were investigated using various biochemical methods such as DPPH (1,1-diphenyl-2-picryl-hydrazyl) and ABTS (2,2-azinobis (3-ethyl benzothiazoline-6-sulfonic acid). Then, the antibacterial activity of nanoemulsion was evaluated by the disk diffusion (DD) method.

The data obtained from this study showed that nanoemulsions synthesized by Artemisia essential oil have a high potential for inhibiting DPPH radicals (IC50 = 80μg / ml) and ABTS (IC50 = 79μg / ml). The existence of a growth inhibition zone (10mm) in the sample treated with AABEO-NE confirmed the antibacterial effects of AABEO-NE

According to the results, AABEO-NE can be used as a safe, natural, and effective antibiotic for bacterial infections caused by S. aureus and also, this formulation can be used due to its high antioxidant effects in the treatment of diseases related to oxidative stress.

Cold plasma or non-thermal plasma technology is one of the methods of foodprocessing that is used to inactivate pathogen microorganisms and improve food safety. Coldplasma can affect the inactivation of a wide range of microorganisms, without harming thehost and healthy tissues.The aim of this study was to evaluate the effect of cold plasma directly on reducing thenumbers of Salmonella enteritidis on egg shell and also to determine the effect of plasmaexposure time and the composition of the injected gas.

In this study, the effect of cold atmospheric plasma radiation ofargon and argon containing 5% oxygen gas, at the rate of 3 liters / min, and at three differenttimes on inactivation of Salmonella enteritidis was investigated.

The effect of argon gas radiation for 1, 3 and 6 minutes on the reduction ofsalmonella enteritidis numbers being 4.490, 3.948, 0 cfu /ml respectively, was significant at1% probability level. Also, the radiation effect of argon containing 5% oxygen at 1, 3 and 6minutes,on reduction of Salmonella enteritidis numbers was 4.559, 4.226 and 0 cfu /ml,respectively. Both groups of the treatments caused a significant decreasing trend at thestatistical level of 1% as compared to the control sample.

The obtained data indicated that the effects of the gas type, as well as theirradiation time and their interaction on the tested bacterium were statistically significant atp>0/01 as compared to the control.

 Today, despite improved food safety, nearly a quarter of the population is at risk for foodborne diseases. Therefore, the use of lactic acid bacteria and their metabolites due to their potential health benefits, safety and production of natural antimicrobial compounds is an appropriate solution to reduce microbial spoilage of food.

   In this research, lactic isolates were first identified by PCR method and Micro-dilution method was used to evaluate the antimicrobial activity of the Cell Free spent Medium (CFSM).

   The sequencing of PCR products showed that the species identified were Lactobacillus and Enterococcus species. The results of the evaluation of the antibacterial properties of the CFSM on the growth of Gram-positive bacteria showed that all isolates were able to prevent the growth of these pathogens and their inhibitory percentages varied from 86.81 to 38.81 percent. The results of inhibitory effects of lactic isolates on the growth of two gram-negative bacteria of Escherichia coli and Salmonella enterica also showed that the inhibitory levels of the isolates were varied from 2.43 to 36.43 percent and 14.1 to 31.97 percent, respectively. Comparison of the inhibitory effect of lactic isolates on pathogenic bacteria showed that the inhibitory effect of all lactic isolates on gram positive bacteria was significantly (P <0.05) more than their effect on gram negative bacteria.

  The results of this study showed that native dairy lactic acid isolates and their metabolites can be used as biological preservatives or in combination with synthetic preservatives in the food and drug industry.

Since the application of certain methods to minimize the oxidative and microbial spoilage in meat products is economically and hygienically significant, further studies are required to evaluate the antioxidant and antimicrobial activities of plant extracts in meat and meat products.

The aim of the present study was to investigate the antimicrobial effect of sumac extract in ground beef contaminated with multidrug resistance E. coli. Sumac extract was extracted by maceration method. The total phenol content of the extract was measured by Folin-Ciocalteo, and the total flavonoid content was determined by aluminum chloride method. Antioxidant activity was evaluated by iron reduction test (FRAP). The antimicrobial effect of the extract was evaluated using well diffusion method. After the inoculation of the minced meat, the samples were transferred to the refrigerator at 4 ° C, and a six-day storage period for microbial tests including the total count, Pseudomonas, Escherichia coli, mold and yeast started.

The total amount of phenolic compounds was 290.852 mg/g, and the amount of flavonoids was 4.508 mg/g. The antioxidant ability of the extract was reported 380.79-744.04 µmol iron/mg. The results of the antimicrobial tests indicated that the minimum inhibitory and lethal concentrations were 166.66 mg/ml and 333.33 mg/ml, respectively. Adding sumac extract to minced meat samples significantly prevented the growth of all microorganisms. This activity increased with the rise of concentration.

It could be concluded that sumac extract is a remarkable source of antimicrobial and antioxidant compounds and might be used in food products such as meat and meat products.