جستجوی مقالات مرتبط با کلیدواژه « phenol » در نشریات گروه « پزشکی »

Yarrow is a member of the Asteraceae family, utilized extensively in the field of medical sciences. Among the medicinal plants, one may encounter few specimens like the aforementioned plant, which enjoys widespread distribution across various regions of the globe and boasts a diverse array of uses that contribute to its renown. The aim of the present study was the synthesis of Yarrow extract evaluation of its antibacterial effects on a group of intestinal bacteria and comparing its antibacterial properties with phenol.

In this experimental study, Yarrow plant extract was extracted with the hydroalcoholic method. The aerial parts of Achillea ageratum plant with herbarium number 1753 were prepared from the slopes of Ardabil mountains and after determining the identity, the extract of this plant was extracted by hydroalcoholic method. In this method, after preparing the plant and drying the aerial parts of the plant, 10 g of it was crushed in a sterile mortar, then it was poured into an Erlenmeyer flask, and 50 mL of 100% ethanol was added to it. After 24 hours of mixing in a magnetic stirrer using a Buchner funnel with Whatman filter paper and a vacuum pump, the remaining components of the plant were separated. Then, a certain amount of distilled water (20 ml) was added to the desired solution and placed again in the magnetic stirrer whose temperature was set at 80 degrees Celsius, so that the alcohol was completely removed from the reactor. The Antibacterial effect of yarrow extract was performed by disc diffusion method and micro broth dilution on standard species of Enterobacteriaceae families including the standard bacterial strains of Klebsiella pneumoniae (ATCC:10031), Escherichia coli (ATCC:23591), Shigella dysentery (ATCC:25922) and Enterobacter aerogenes (ATCC:13048). All experiments were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

In the present study, the growth rate of bacteria decreased by increasing the concentration of yarrow extract. The MIC of Yarrow plant extract for Klebsiella pneumonia and Enterobacter aerogenes was obtained in %6.25 and for Shigella dysentery and Escherichia coli was obtained in %12.5 and %25, respectively. Also, the MBC of extract for Shigella dysentery, Klebsiella pneumonia, and Enterobacter aerogenes bacteria was obtained in 25%, and for Escherichia coli it was obtained in 50%. The results of MIC and MBC show that the most sensitive bacteria to yarrow extract among the studied bacteria is Enterobacter aerogenes and the most resistant is Escherichia coli. The diameter of the inhibition zone for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria was obtained at 19, 18, 20, and 23 mm, respectively. In this experiment, Enterobacter aerogenes bacteria were the most sensitive and Escherichia coli was the most resistant among the investigated bacteria. Comparative investigation of the antibacterial properties of yarrow extract with phenol, showed that yarrow extract had a lower killing effect than phenol at 5, 10, and 15-minute contact time. In this test, the most resistant bacteria are Shigella dysentery and the most sensitive bacteria are Escherichia coli and Enterobacter aerogenes. The reason that the type of resistant and sensitive bacteria was slightly different in the method of comparing the antibacterial effect of yarrow extract with phenol with the results of MIC, MBC, and non-growth halo diameter is related to the reduction of contact time of the extract with bacteria.

The results of the present research show that the hydroalcoholic extract of the yarrow plant is very effective in the removal of gram-negative intestinal bacteria. Also, the hydroalcoholic extract of the yarrow plant is more effective in removing gram-negative bacteria than phenol

Milk is a dairy product which is susceptible to contamination by pathogenic and spoilage microorganisms. One way to control the growth of pathogenic bacteria is to use preservatives and antimicrobial compounds. Due to the general concerns about the side effects of chemical preservatives, there is a tendency to consume products that use natural preservatives. Natural products provide unlimited opportunities for novel and suitable additives. The main objective of this study was to evaluate the antioxidant and antimicrobial activities of hydro-ethanolic extract of rosemary (Rosmarinus officinalis L.) against some gram positive (Staphylococcus aureus and Listeria innocua) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and the next stage was to investigate the impact of hydro-ethanolic extract of this plant at 0.25, 0.5 and 0.75% (w/w) concentrations on the shelf life of pasteurized milk.

The present experimental study was conducted in 2022 at Nahavand Higher Education Complex. The total phenolic content of the extract was measured by Folin-ciocalteau method. Antioxidant activity of different concentration of extract were assessed by diphenyl picrylhydrazyl radical-scavenging activity and compared with synthetic antioxidant butylated hydroxyl anisole (BHA). Antibacterial effects of resemary on pathogenic bacteria was determined by well diffusion agar, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Experimental data were analyzed using ANOVA by the SPSS version 20 software and mean comparison were done using Duncan's multiple range test.

The phenolic content of hydro-ethanolic extract weas 96.47±0.35 mg galic acid/g extract. Hydro-ethanolic extract of rosemary had the greatest effect on Staphylococcus aureus. The MIC of rosemary ethanolic extract ranged from 12.5 to 50 mg/ml, depending on the type of bacteria (gram positive or gram negative). Also, the treatments of pasteurized milk with 0.5%, acceptable sensory properties had a significantly lower total microbial count and longer shelf life compared to the control sample.

Therefore, considering that the hydro-ethanolic extract of rosemary had a significant effect on preventing the growth of pathogenic and spoilage microorganisms, as a result, this extract can be used as a natural antibiotic in milk.

The extraction of chemical compounds from plants is influenced by various factors, such as methodology and duration of extraction, sample preparation, and the type and concentration of solvent used. This study was performed to investigate the effect of extraction time and type of solvent on the contents of phenolic compounds, flavonoids, and antioxidant activity of Digitalis purpurea L. plant.

An experiment based on a completely randomized design in a factorial arrangement with three replications was conducted at the Horticulture Laboratory at the University of Zanjan, Zanjan, Iran, in 2021. The experimental treatments included two levels of extraction duration (24 and 48 h) as the main factor, and two levels of methanol, ethanol, and acetone solvents (100% and 80%), compared with the control (distilled water), as sub-factors. Extraction of purple foxglove leaf powder was done by macerating 24 or 48 h using two levels of methanol, ethanol, or acetone as solvents (100%, 80%, and distilled water for the control). Evaluation of phenolic compounds, flavonoids, and antioxidant activity was performed. The resulting data were analyzed in SAS software version 9, and mean comparisons were performed by Duncan's Multi-Range Tests at the 1% and 5% probability levels. To determine the correlation between parameters, Pearson's correlation coefficient was checked using SPSS version 20 software.

The results showed that there was a significant difference between 24 and 48 h of maceration to extract chemical compounds (P<0.01). The highest amounts of total phenol (24.75 mg GAE/g dw) and antioxidant activity (71.36%) were obtained in 80% acetone extract, and the maximum flavonoid content (6.03 mg Q/g dw) was achieved in 80% ethanol and 48 h maceration time. Generally, increasing the maceration time from 24 h to 48 h caused a significant rise in the extraction of phenolic compounds, flavonoids, and antioxidant activity. Moreover, there was a positive correlation between flavonoid content (P=0.86) and phenolic content (P=0.82) with antioxidant activity.

According to the results, increasing the extraction time and also utilizing hydroalcoholic solvents were more effective in extracting these compounds than pure alcohols.

Pomegranate is a plant with an ancient history that has been widely used in medical sciences and its components have many properties. The aim of the present research is to synthesize pomegranate peel extract and investigate its antibacterial effects on a group of bacteria of intestinal bacteria and compare its antibacterial properties with phenol.

In this experimental study, pomegranate peel extract was extracted with the hydro alcoholic method. The Antibacterial effect of pomegranate peel extract was performed via disc diffusion and micro broth dilution methods on standard species of intestinal bacteria. All experiments were performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI). This study has been registered with the ethical code IR.KHALUMS.REC.1402.006 in the Ethics Committee of Khalkhal Faculty of Medical Sciences.

The MIC of pomegranate peel extract for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae and Enterobacter aerogenes bacteria were 12.5%, 12.5%, 25% and 6.25%, respectively. Also, the MBC of pomegranate peel extract for Shigella dysentery, Escherichia coli, Klebsiella pneumonia and Enterobacter aerogenes bacteria were obtained 25%. The zone of inhibition for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae and Enterobacter aerogenes bacteria was 18, 19, 16 and 22, respectively.

The results of this study has been showed that the hydroalcoholic extract of the pomegranate peel is very effective in the removal of intestinal bacteria in vitro. Also extract than phenol in lower contact time cause killing these bacteria.

In the present study, the solvent effect (aqueous and hydroalcoholic) of the extraction on the content of phenol, flavonoid, and the antioxidant activity of six medicinal plants, including Persian oak fruit hull (Quercus brantii), Zataria multiflora, German Matricaria chamomilla, Teucrium polium, Rosa foetida Herrm, and mountain barberry (Berberis integerrima) was investigated.

To measure phenol and flavonoid content, folin ciocaltio and aluminum chloride reagents were used, respectively, and to measure the antioxidant potential, the DPPH method was used. The content of phenol and flavonoid compounds was calculated as mg equivalent of gallic acid and catechin per gram of dry weight of the plant, respectively. The collected data was analyzed in SPSS software (version 14).

According to the obtained results, the amount of phenol and flavonoid in the hydroalcoholic extract of oak fruit hull Quercus brantii, Zataria multiflora, German Matricaria chamomilla, and mountain barberry was more than the aqueous extract, and this difference was statistically significant (P<0.001). The highest content of phenol and flavonoid were related to the hydroalcoholic extract of oak by 310.2 ± 2.5 mg/g and 241.2 ± 1 mg/g, respectively, and the lowest amounts were related to the aqueous extract of Matricaria chamomilla (53.1±1.1 mg/g) and the aqueous extract of acorn (23.9±1.5 mg/g), respectively. The highest antioxidant activity (IC50) was related to oak fruit-hull hydroalcoholic extract (39.1±4.4 µg/ml), and the lowest was related to the aqueous extract of Matricaria chamomilla (315.3±3.3 µg/ml).

The findings of this study showed that the solvent used to extract plants is a significant factor in separation of phenol and flavonoid compounds as well as their antioxidant activity.

Tussilago farfara L. is a perennial forb belonging to the Asteraceae family. The leaves and flowers of this plant have medicinal properties, and its essential oil has been used for the treatment of dry coughs and inflammation of the mouth, throat, and respiratory tract. This study aimed to assess some phytochemical characteristics of Tussilago farfara L. and compare changes in this plant at different altitudes.

To investigate the changes in the amount of the effective substance of the studied plant in the altitude gradient, altitude classes of 1100-2600 meters were considered in Golestan province, Iran, considering the presence and abundance of the species. In each phenological stage (before and after flowering time), plant samples were randomly collected in each altitude class and transferred to the laboratory. Total phenol content and flavonoid content were measured using the Folin-Ciocalteu and aluminum chloride methods, respectively. The antioxidant activity of the methanolic extract was also evaluated using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) reagent.

The results showed that the highest amounts of total phenol content, flavonoids, and antioxidant activity were observed at altitudes above 2200 meters, and there was a significant difference in plants (Tussilago farfara L.) grown in different altitudes in terms of phytochemical properties. Based on the comparison of phytochemical properties of this plant in different phenological stages, the highest content of total phenol and flavonoids were observed in the phonological stage of flowering and the highest (42.08%) antioxidant activity of leaves was observed in the vegetative stage.

The results of this study can help activists in the field of medicinal plants to determine the appropriate height range and phenological stage in harvesting the leaves of this plant to achieve the highest levels of phenol content, flavonoids, and antioxidant activity.

Macroalgae are rich in diverse valuable compounds so they are known as the 21 century medicinal plants. In this study polar to nonpolar extracts of four macroalgae species, Sargassum boveanum, Fucus trinodis, Galaxaura rugos and Laurencia denderoidea were collected from the Persian Gulf coastlines, evaluated for their phenol and flavonoid contents and antioxidant and antibacterial activities.

Phenol and flavonoid contents of species were estimated by Folin-Ciocalteu and Aluminum chloride methods, respectively. Antioxidant activities of extractions were analyzed by total antioxidant activity (TAC) and reducing power of Fe3+ respectively and also antibacterial activity of samples were analyzed by disc diffusion method against two gram positive and two gram negative bacteria.

F. trinodis showed the highest phenolic (1.38 gGA/100gDW.) and flavonoid (0.798 gQE/100gDW.) contents and G. rugosa showed the lowest phenolic (0.240 gGA/100gDW.) and flavonoid (0.094 gQE/100gDW.) contents. Chloroform extract of F. trinodis (2.98 ugASA/mg) and S. boveanum (2.48 nm) showed the maximum level of TAC and reducing power antioxidant activities, respectively. The samples with high content of phenolic and flavonoid contents showed the highest antioxidant activity too. All the three extracts of S. boveanum and F. trinodis showed the considerable antibacterial activity against all the four examined strains of bacteria especially negative gram bacteria.

The studied macroalgal species showed considerable phenolic content and bioactivities suggest that they can be suitable for medical and medicinal applications.