Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND: Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS: Of the lichens tested, P. saxatilis had the highest free radical‐scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L^?1. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL^?1. CONCLUSION: The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents. Copyright © 2012 Society of Chemical Industry     

Antioxidant and antimicrobial activity of Satureja montana L. extracts

BACKGROUND: This study aimed to evaluate the antioxidant and antimicrobial activity of extracts (aqueous, ethanolic and essential oil) from Satureja montana and to characterise the chemical composition of its essential oil. RESULTS: Satureja montana L. essential oil had relatively high antimicrobial activities against the seven species of bacteria tested. In contrast, aqueous extracts did not reveal antibacterial activity, and the ethanol extract was not effective against Salmonella typhimurium. The major volatile constituents of the essential oil were carvacrol (306 g L^?1), thymol (141 g L^?1), and carvacrol methyl ether (63 g L^?1). The strongest antioxidant capacity was obtained with the hot water extracts of S. montana, whereas the plant essential oil revealed the highest phenolic content. CONCLUSION: The findings indicate that the bioactive extracts of S. montana have strong potential for use as natural antimicrobials and antioxidants in the preservation of processed food. Copyright © 2011 Society of Chemical Industry     

Screening of bioactive components in grape and apple vinegars: Antioxidant and antimicrobial potential

Vinegars contain several bioactive compounds that are characterized according to the type of the raw material, such as grape vinegars and apple vinegars. Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry was used for identification and quantification of phenolic compounds. Antioxidant properties of vinegars were determined by 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulphonic acid assays. Antimicrobial activities of vinegars were examined with an agar disc diffusion method with Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa . Gallic acid and chlorogenic acid were found to be the major phenolic acids accounting for the largest proportion of the total phenolic acid contents in grape vinegars and apple vinegars. Within the flavonols, quercetin‐3‐O‐galactoside and quercetin were detected as the major compounds in grape vinegars. Apple vinegars were characterized by phloridzin, phloretin and high chlorogenic acid content. Antimicrobial activity results indicated that grape vinegars exhibited higher antimicrobial activity against tested bacterial strains correlated with their higher antioxidant capacity. Copyright © 2017 The Institute of Brewing & Distilling     

Antioxidant, antihypertensive and antimicrobial properties of ovine milk caseinate hydrolyzed with a microbial protease

BACKGROUND: Bioactive peptides might be released from precursor proteins through enzymatic hydrolysis. These molecules could be potentially employed in health and food products. In this investigation, ovine milk caseinate hydrolysates obtained with a novel microbial protease derived from Bacillus sp. P7 were evaluated for antioxidant, antimicrobial, and angiotensin I‐converting enzyme (ACE)‐inhibitory activities. RESULTS: Antioxidant activity measured by the 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonic acid method increased with hydrolysis time up to 2 h, remaining stable for up to 4 h. Hydrolysates showed low 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging abilities, with higher activity (31%) reached after 1 h of hydrolysis. Fe²⁺‐chelating ability was maximum for 0.5 h hydrolysates (83.3%), decreasing thereafter; and the higher reducing power was observed after 1 h of hydrolysis. ACE‐inhibitory activity was observed to increase up to 2 h of hydrolysis (94% of inhibition), declining afterwards. 3 h hydrolysates were shown to inhibit the growth of Bacillus cereus, Corynebacterium fimi, Aspergillus fumigatus, and Penicillium expansum. CONCLUSION: Ovine caseinate hydrolyzed with Bacillus sp. P7 protease presented antioxidant, antihypertensive, and antimicrobial activities. Hydrolysis time was observed to affect the evaluated bioactivities. Such hydrolysates might have potential applications in the food industry. Copyright © 2011 Society of Chemical Industry     

Antioxidant and antimicrobial activities of Polygonum cognatum Meissn extracts

The antioxidant activities, reducing powers, 2,2‐diphenyl‐l‐picrylhydrazyl (DPPH) radical‐scavenging activities, total phenolic compound contents and antimicrobial activities of ether, ethanol and hot water extracts of Polygonum cognatum Meissn were studied in vitro. The highest antioxidant activity was found in the water extract. However, there were no statistically significant differences among 15 µg ml^?1 extract‐containing samples in linoleic acid emulsion (0.02 M , pH 7.0) during 120 h of incubation (P > 0.05). The reducing power of the water extract was the highest, but its reducing power was markedly lower than that of ascorbic acid. The highest DPPH radical‐scavenging activity was found in the water extract, with 50% DPPH radical scavenging at a concentration of 100 µg ml^?1 dried water extract, while at the same concentration of dried ethanol extract the value was 12%. Surprisingly, no DPPH radical‐scavenging activity was observed in the ether extract. The concentrations of phenolic compounds found were 0.48, 0.50 and 0.01 µg ml^?1 gallic acid equivalent in 10 µg ml^?1 water, ethanol and ether extracts respectively. The ether and ethanol extracts showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis. The water extract did not show antimicrobial activity against the studied micro‐organisms. © 2002 Society of Chemical Industry     

茜草精油抗氧化及抗癌活性研究

以水蒸气蒸馏法提取茜草精油,以天然和合成的抗氧化剂为对照,用4种不同的抗氧化体系(ABTS+·,过氧化氢,FRAP和还原力)检测法估价精油的抗氧化活性。精油呈现出在不同体系中剂量依赖式不同程度的功效。抗癌活性的检测使用人体乳腺癌MCF-7和宫颈癌Hela细胞株,结果发现精油对于2种肿瘤细胞均有较强活性,IC_(50)分别为(1.052±0.396)mg/m L和(0.275±0.026)mg/m L,MTT和LDH检测均表明精油抗癌活性对Hela细胞明显更强;1 g精油中总酚含量为0.220 mg/m L没食子酸当量。研究结果表明茜草精油可作为重要的天然抗氧化剂。     

Antioxidant and antimicrobial potentials of Serbian red wines produced from international Vitis vinifera grape varieties

BACKGROUND: Antioxidant and antimicrobial potentials of Serbian red wines produced from different international Vitis vinifera grape varieties and their correlation with contents of phenolic compounds were studied by spectrophotometric and chromatographic methods. The antioxidant activity of red wines was estimated through their ability to scavenge 2,2′‐diphenyl‐1‐picrylhydrazyl free radical (DPPH^?). The red wines, gallic acid, (+)‐catechin and quercetin were screened in vitro for antimicrobial activity against Gram‐positive and Gram‐negative strains using microdilution and disc diffusion techniques. RESULTS: Excellent correlations between the contents of quercetin‐3‐glucoside (R² = 0.9463) and quercetin (R² = 0.9337) and DPPH^?‐scavenging ability of the red wines were found. Serbian red wines exhibited significant activity against Staphylococcus aureus, Listeria inocua, Micrococcus flavus, Sarcina lutea, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Shigella sonnei strains, which was in correlation with their phenolic composition and antioxidant activity. The compounds gallic acid, quercetin and (+)‐catechin showed high activity against B. subtilis, S. aureus, S. lutea and M. flavus Gram‐positive and S. enteritidis and P. aeruginosa Gram‐negative strains. CONCLUSION: The results show that quercetin‐3‐glucoside and quercetin concentrations can be used as markers for the determination of antioxidant and antimicrobial potentials of red wines. Copyright © 2012 Society of Chemical Industry     

Antioxidant and antimicrobial activities of essential oil and various oleoresins of Elettaria cardamomum (seeds and pods)

BACKGROUND: This paper describes the chemical analysis of the essential oil and various oleoresins of Elettaria cardamomum (seeds and pods) by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) techniques. It also compares the effects of the different extraction solvents used (chloroform, methanol, ethanol and diethyl ether) on the antioxidant and antimicrobial activities of the essential oil and oleoresins. RESULTS: The essential oil was found to contain 71 compounds. The major components were α‐terpinyl acetate (44.3%), 1,8‐cineole (10.7%), α‐terpineol (9.8%) and linalool (8.6%). The chloroform and methanol oleoresins both contained α‐terpinyl acetate (21.8 and 25.9% respectively) as the main component, while 5‐hydroxymethylfurfural (28.9%) was the most abundant compound in the ethanol oleoresin. However, very few components (total 0.61%) were found in the diethyl ether oleoresin. The antioxidant activities of the essential oil and oleoresins, studied in mustard oil by monitoring the peroxide value of the oil substrate, were comparable to those of the synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at 0.02% concentration. The essential oil exhibited strong antibacterial activity against the micro‐organisms Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhi at 3000 ppm by the agar well diffusion method. Antifungal activity was tested against the food‐borne fungi Aspergillus terreus, Penicillium purpurogenum, Fusarium graminearum and Penicillium madriti. The methanol and ethanol oleoresins gave the best results against A. terreus at 3000 ppm by the poison food method. CONCLUSION: This study provides important information about the chemistry and antioxidant and antimicrobial properties of E. cardamomum. Copyright © 2007 Society of Chemical Industry     

枫香叶正丁醇提取物抑菌效果及其抗氧化活性研究

采用打孔法测定抑菌圈大小和试管连续稀释法测定最小抑菌浓度(MIC),研究了枫香叶正丁醇提取物抑菌效果,并测定其对DPPH自由基、超氧阴离子自由基和羟自由基的清除活性。结果表明:枫香叶正丁醇提取物对7种实验菌均有抑制作用,不同浓度间、不同菌种间存在极显著(p<0.01)差异;且对细菌的抑制作用强于真菌,对革兰氏阴性菌的抑菌效果比革兰氏阳性菌好;对大肠杆菌、枯草杆菌、金黄色葡萄球菌、四联球菌、黄曲霉、黑曲霉、青霉的MIC分别为3.1、12.5、12.5、6.25、12.5、25、12.5mg/m L。枫香叶正丁醇提取物具有较强的的抗氧化活性,可作为功能性食品资源开发利用。      

茶多酚-肉桂精油复合保鲜剂抗氧化活性及抑菌作用

为了研究茶多酚-肉桂精油复合保鲜剂抗氧化活性和对金黄色葡萄球菌的抑菌作用。采用体外抗氧化法测定了复合保鲜剂抗氧化能力。通过抑菌圈大小确定抑菌效果和最小抑菌浓度（MIC）,结合抑菌活力、细菌生长曲线、细胞壁完整性和细胞膜通透性,综合评价复合保鲜剂对金黄色葡萄球菌的影响。结果表明,复合保鲜剂清除DPPH自由基、羟基自由基和超氧阴离子自由基的IC50分别为4.02μg/m L、9.15μg/m L、0.61 mg/m L。复合保鲜剂能够有效抑制金黄色葡萄球菌的生长,MIC为0.5 mg/m L,且能够破坏细胞壁和细胞膜。综上所述复合保鲜剂具有很强的抗氧化活性,对金黄色葡萄球菌有很好的抑菌效果,其可能的抑菌机理是破坏细胞壁,影响细胞膜的通透性。      

蓝莓多糖的抗氧化性与抑菌作用

利用水提醇沉法从蓝莓中提取多糖,再经初步纯化后,进行多糖的抗氧化性及抑菌作用实验。结果表明,蓝莓多糖对羟自由基和DPPH 自由基有较强的清除作用,且清除率50% 所对应的质量浓度IC50 分别为2mg/mL 和7mg/mL。但蓝莓多糖对超氧阴离子自由基几乎没有作用效果。蓝莓多糖对枯草芽孢杆菌、大肠杆菌、金黄色葡萄球菌、啤酒酵母均有一定的抑制作用,最小抑制浓度MIC 在50～75mg/mL 之间,对热带假丝酵母、青霉和黑曲霉无抑制作用。     

Antioxidant and Antimicrobial Activity of Commercial Propolis Extract in Beef Patties

The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free‐radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high‐performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid‐reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties.     

不同分子量分布的美拉德产物的呈味特性及抗氧化抗菌活性研究

通过超滤及葡聚糖凝胶色谱技术结合将美拉德产物按分子量大小分级成三个组分,即小于1000u、1000～5000u和大于5000u,并评价其在清汤中的风味特性、清除DPPH自由基的能力及对金黄色葡萄球菌、李斯特菌、大肠杆菌和沙门氏菌的抑制活性。结果显示,1000～5000u的美拉德产物增强风味的效果最显著,其次是小于1000u的产物,这两种产物对DPPH自由基清除率分别达80%和72%,对四种菌的最低抑制浓度达25～75mg/mL。大于5000u的美拉德产物在较低浓度下清除率达90%,对四种菌的最低抑制浓度为6.25～25mg/mL,且对金黄色葡萄球菌的抑制效果最强,最低抑制浓度达6.25mg/mL。     

蜂巢提取物的制备及其抑菌性、抗氧化活性

目的:获得蜂巢提取物的最佳制备方案,并探究蜂巢提取物的抑菌、抗氧化活性.方法:对在不同提取条件下所获得蜂巢提取物中的黄酮、总多酚及氨基酸提取率进行检测,选择蜂巢提取物中黄酮、总多酚及氨基酸提取含量相对较高的制备条件,在最佳蜂巢提取物制备方案的基础上,检测蜂巢提取物的抑菌效果、羟基自由基抑制率和还原能力.结果:研究得到蜂...     

Antioxidant activity and phenolic content of raw and blanched Amaranthus species

The study was aimed to determine the antioxidant activity (total antioxidant and free radical-scavenging activities) and total phenolic content of Amaranthus sp. The effects of different blanching times (10 and 15 min) on antioxidant activity and phenolic content were also studied. Four types of Amaranthus species locally known as spinach, namely ‘bayam putih’ (Amaranthus paniculatus) (BP), ‘bayam merah’ (Amaranthus gangeticus) (BM), ‘bayam itik’ (Amaranthus blitum) (BI) and ‘bayam panjang’ (Amaranthus viridis) (BPG), were selected. Total antioxidant activity of water-soluble components in raw spinach was in the order of BI ≈ BM ≈ BPG > BP, whereas free radical-scavenging activity was in the order of BI > BPG > BM > BP. The total phenolic contents of BM and BP were significantly higher (p < 0.05) than other samples. All the studied spinach species possessed different antioxidant activities and phenolic contents. Antioxidant activities and phenolic contents of all the spinach were in the order of raw > blanched 10 min > blanched 15 min. Blanching up to 15 min may affect losses of antioxidant activity and phenolic content, depending on the species of spinach.