جستجوی مقالات مرتبط با کلیدواژه « radical scavenging » در نشریات گروه « پزشکی »

In recent years study of medicinal plants in order to discover new pharmaceutical supplies against microbial strains has been considered very much. The main objective of this study was to evaluate the antioxidant and antimicrobial activities of shoot aqueous and ethanolic extracts of purple coneflower against some gram positive and gram negative bacteria.

This experimental study was conducted in 2018 at Bu- Ali Sina University. Maceration method and solvent of water and ethanol at a ratio of 1 to 5 used for extraction. The total phenolic contents of the extracts were measured by Folin-ciocalteau method. Then, the amount of cichoric acid of purple coneflower was determined using by high performance liquid chromatography. Antioxidant activity of different concentration of extracts were assessed by diphenyl picrylhydrazyl radical-scavenging activity and compared with synthetic antioxidant butylated hydroxyl toluene (BHT). The micro-organisms investigated in this study were:  Staphylococcus aureus, Staphylococcus epidermidis, Listeria innocua, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium and Shigella flexneri. The antimicrobial activity of aqueous and ethanolic extracts was tested by pour plate, agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. Also interaction of these extracts was also studied by FICindex determination using modified dilution checkboard method. Experimental data were analyzed using ANOVA by the SPSS version 20 software and mean comparison were done using the t-test and Duncan's multiple range test.

The results showed that the ethanolic extract had the highest total phenolic content and cichoric acid. The ability of purple coneflower aqueous and ethanolic extracts in scavenging free radicals was found to be higher in the ethanolic extract with a concentration of 3000 μg/ml. The aqueous extract of purple coneflower at the concentrations of 25 and 50 mg/ml has no inhibitory effect on gram negative bacteria growth. The maximum diameter of inhibition zone of aqueous or ethanolic extracts of this plant in a concentration of 400 mg/ml pertained to the bacterium Staphylococcus aureus. The minimum zone diameter in this concentration was associated with Pseudomonas aeruginosa. Furthermore, purple coneflower extracts showed greater inhibitory effect on gram positive bacteria in comparison with gram negative bacteria. Also the results showed that ethanolic extract had greater inhibitory effects on the strains studied compared to aqueous extract. The MIC of purple coneflower ethanolic extract ranged from 16 to 256 mg/ml, depending on the type of bacteria (gram positive or gram negative).

These findings showed that ethanolic extract of purple coneflower has antimicrobial effects on gram positive bacteria and can substitute for chemical preservatives.
Key words: Purple coneflower extract, Phenolic compounds, Cichoric acid, Antimicrobial activity, Radical scavenging

Ginger (Zingiber officinale) has been used as medicine and spice in Iran, China, and India since ancient times. Currently ginger is used in many foods, beverages and pharmaceutical agents. The purpose of this research was to evaluate the antibacterial and antifungal activities of ginger essential oil on some pathogenic strains and to determine the chemical compounds, total phenolic content, and antioxidant activity of the ginger essential oil using 2,2-diphenyl-1-picrylhydrazyl. In this experimental study, identification of chemical compounds of the ginger essential oil and their quantitative measurement was performed using gas chromatography and gas chromatography- mass spectrometry devices. The antimicrobial properties were determined by various qualitative and quantitative methods [disc diffusion agar, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC/MFC)]. Measurement of total phenol and antioxidant potential were carried out by Seevers and Daly colorimetric and radical scavenging methods, respectively. The data were analyzed using one-way ANOVA and Tukey test. In this study, the highest and the lowest diameters of the inhibition zone at the concentration of 100mg/ml were observed for Candida albicans and Salmonella typhi, respectively. The MIC of the ginger essential oil was equal to 50, 50, 25, 6.25, 12.5, 12.5, 6.25, and 6.25mg/ml for Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Staphylococcus aureus, Listeria innocua, Bacillus cereus, Candida albicans, and Aspergillus niger, respectively. The MBC/MFC of the essential oil, were higher than MIC. Zingiberene (29.48%) was the major compound in the ginger essential oil, and the antioxidant activity (IC50) and total phenolic content of ginger essential oil were equal to 93.45μg/ml and 76.65 mg GAE/g, respectively. The results of the current study showed that the effect of ginger essential oil on Gram-positive bacteria was higher as compared to Gram-negative bacteria. Therefore, clinical trials are suggested for future researches.

Nowadays given to the fact that a large volume of agricultural waste is produced annually in different parts of industry and agriculture and most of these wastes are abandoned or burned without any change in nature, the need to use and find the application of agricultural waste has become particularly important.   One of the agricultural products with about 40 % of the waste is pistachio. Therefore, in this study, phenolic compounds in pistachio hull were extracted using subcritical water (SCW), and radical scavenging, reduction power and induction period in edible soybean oil for extracts were measured. The extraction process by SCW was carried out in 120–180 °C with 1:20 (sample:solvent) ratio and constant pressure of 30 bar conditions, and the results were compared with the extract obtained by maceration. As a positive control, BHT, ascorbic acid, and alpha-tocopherol antioxidants were used to better compare the results. The results showed that the amount of phenolic compounds increased by increasing from the temperature from 120 to 150°C. The extract obtained from the maceration method had the highest concentration required for the reduction of 50% of trivalent iron ions to bivalent capacity. The extract obtained at 180°C using SCW had the same ability of BHT for stabilizing soybean oil as the synthetic antioxidant. The overall results indicated that the optimum temperature for the extraction of phenolic compounds from pistachio hull by SCW was 150°C, and radical scavenging ability and reduction power of the extracts had a good correlation with the total phenolic compounds.

Scientists have recently focused attention on the properties of natural antioxidants on pathogens and free radicals and their application in the medical and food industries. The present study evaluated the antioxidant properties of the extract of seedless barberries، a popular fruit cultivated in Iran، extracted using subcritical water as a novel technology. The phenolic compounds of the seedless barberry were extracted using subcritical water (SCW) at ratios of 1:10 to 1:30 at 50 bar constant pressure and temperatures of 120 and 180 C. The total phenolic compounds (TPC) were measured using folin ciocalteu reagent and compared with those of maceration extracts. The thermal stability of the soybean oil and the antioxidant extracts was investigated using the Rancimat method at 110C and 20 l/h air flow rate. Radical scavenging and Fe+3 reduction power of the extracts was measured to evaluate the antioxidant characteristics of the SCW extracts and they were then compared the results for ascorbic acid and BHT (300 ppm). The results were evaluated using a factorial design and LSD test at  = 0. 01 using SAS software. The TPC varied from 1729. 76 to 2848. 21 mg/100 g dry material (Gallic acid). The maximum extract yield was produced by the treatment at 120C and a 1:10 ratio. The highest antioxidant power of soybean oil was observed at 180C and a 1:10 ratio. The thermal resistance of the soybean oil with SCW extracts was very similar to that of soybean oil enriched with E vitamin as a natural antioxidant. The extracts obtained by SCW had remarkable antioxidant properties and resistance to increased temperature and reinforced the stability of the soybean oil. Subject to further study، This combination can be recommended as a good alternative frying oil in the food industry.

Background and

Previous investigations have shown that cimetidine (Çi) and ranitidine (Rn) have radioprotective effects against gamma rays. Ïn this study, the radioprotective effects of famotidine (Ft), Which acts like Çi and Rn as histamine H2 – receptor – antagonist, were investigated in male bulb/c mice bone marrow cells by means of the micronucleus test.

Different groups of mice were exposed to different doses of Gamma rays (alone). The other groups received different doses of these drugs two hours before intraperitoneal injection of 2Gy irradiation. Samples were collected 24 hours after irradiation. From the suspension of bone marrow smears were prepared and stained with Granovalt- Gimsa dyes. For each specimen, 1500 poly chromatic erythrocyte (PÇË) and same number of Normo chromatic erythrocyte (NÇË) and poly chromatic erythrocyte Çontaining micro- nuclei (mn PÇË) were counted.

Results indicate that gamma irradiation by itself can lead to abundance of micronuclei and decreases the cell proliferation ratio. Pre- irradiation injection of Ft. of any concentration, effectively reduce the number of Mn PÇË (two folds), but had no effecton PÇË/PÇË+NÇË ratio. Çonclusion: Ïn fact, this drug can reduce the clastogenic effects of gamma rays but is ineffective on gamma cytotoxic properties (P<0.01). The mechanism by which the Ft. can reduce the clastogenic effects of gamma rays is not yet clear and it is probable that the radioprotection brought about by Ft. is due to its antioxidant properties and hydroxyl radical- Scavenging process.