The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg...The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.展开更多
In this study, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of four different extracts of Adina cordifolia (Roxb.) were determined using spectrophotometric methods. Antioxidant...In this study, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of four different extracts of Adina cordifolia (Roxb.) were determined using spectrophotometric methods. Antioxidant activity of extracts was expressed as percentage of DPPH radicals’ inhibition and IC50 values (μg/ml). IC50 values ranged from 20.39 to 38.96 μg/ml. The total phenolic content ranged from 17.48 to 20.83 mg/g of dry weight of extract, expressed as gallic acid equivalents. The total flavonoid concentrations varied from 17.49 to 22.48 mg/g, expressed as quercetin equivalents. The significant linear correlation was confirmed between the values for the total phenolic content and antioxidant activity of plant extracts. Adina cordifolia (Roxb.) can be regarded as promising candidates for natural plant sources of antioxidants with high value.展开更多
The current interest in the health beneifts of whole wheat grain has prompted breeders to further increase the concentration of antioxidants in wheat. The objective of this study was to investigate the variation in an...The current interest in the health beneifts of whole wheat grain has prompted breeders to further increase the concentration of antioxidants in wheat. The objective of this study was to investigate the variation in antioxidant content among Chinese wheat grains and the relationship between antioxidants and grain color and morphological characteristics. A wide variation was observed in the total phenolic, carotenoid and lfavonoid contents, as well as the antioxidant activity (AOA), of Chinese wheat varieties. Black wheat had the highest mean total phenolic, carotenoid and lfavonoid contents and the highest AOA, followed by red and white wheats. The grain color parameters were signiifcantly negatively correlated with total phenolic, carotenoid and lfavonoid contents and AOA among all of the wheat varieties examined, and grain weight was also signiifcantly negatively correlated with these traits. The same correlation between grain weight and antioxidant traits was also observed within individual groups of wheat, which indicates that grain weight may be used as an index for selecting wheat varieties with high AOA. Landraces had signiifcantly higher lfavonoid content than commercial wheat varieties. The results of this study may be useful for breeding nutrient-rich wheat varieties.展开更多
Objective:To determine the total phenols,total flavonoids and evaluate the antioxidant activity of crude extracts from the leaves of pigeon pea native to Sultanate of Oman by a popular method.Methods:The powdered leav...Objective:To determine the total phenols,total flavonoids and evaluate the antioxidant activity of crude extracts from the leaves of pigeon pea native to Sultanate of Oman by a popular method.Methods:The powdered leaves samples from pigeon pea were used for extraction by maceration method with methanol solvent.The methanol free crude extract by maceration method was suspended in water and successively extracted with different polarities of solvents.The obtained crude extracts with different polarities were used for the determination of total phenols and flavonoids contents by using Folin-Ciocalteu reagent and aluminum chloride methods.The antioxidant activity of six crude extracts from pigeon pea was determined byα,αα-diphenyl-β-picrylhydrazyl method.Results:The different polarities leaves crude extracts showed a significant amount of total phenols content ranging from 97.80 to 256.00 mg of GAE/g of crude extract.The same leaves crude extracts also showed good amount of total flavonoids content ranging from 1.38 to 8.51 mg QE/g plant material.The six crude extracts from the leaves displayed significantα,αα-diphenyl-β-picrylhydrazyl free radical scavenging activity with highest value in chloroform extract followed by methanol,butanol,ethyl acetate,hexane and water crude extracts(98.13%,89.26%,88.82%,86.41%,79.95%and 69.44%,respectively).Conclusions:Leaves crude extracts from pigeon pea have high contents of total phenols and flavonoids.In this regards,it could be used as a medicine for the treatment of different diseases.展开更多
Bunchosia glandulifera belongs to the family Malpighiaceae and is popularly known as “caferana” in the city of Santo Antonio da Patrulha. The fruits have a high economic value and their inclusion in the diet has hea...Bunchosia glandulifera belongs to the family Malpighiaceae and is popularly known as “caferana” in the city of Santo Antonio da Patrulha. The fruits have a high economic value and their inclusion in the diet has health benefits. They are natural sources of antioxidants because of the presence of bioactive compounds. However, their chemical composition can be influenced by the maturation process. This study aims to evaluate the changes in the bioactive antioxidant compounds in the pulp and seeds of B. glandulifera fruit during different stages of ripening. The fruits, were analyzed for caffeine, carotenoids, flavonoids, vitamin C, and total phenolic content as well as for antioxidant activity, at four different stages of ripening. An increase in bioactive compounds was observed from the second maturation stage to the ripened fruit, and the ripened fruit had the highest bioactive compound content. Phenolic compound and carotenoid levels were found to be highest in the pulp. Carotenoid content showed a positive correlation with the antioxidant activity. Colorimetric analysis also showed a high correlation between the levels of carotenoids and color change during the ripening stages.展开更多
Diospyros malabarica (Deshi Gab) belonging to the family “Ebenaceae” grows well in the humid tropical climate of Bangladesh. In order to investigate the phytoconstituents both qualitatively and quantitatively, the s...Diospyros malabarica (Deshi Gab) belonging to the family “Ebenaceae” grows well in the humid tropical climate of Bangladesh. In order to investigate the phytoconstituents both qualitatively and quantitatively, the seed and flesh extracts of D. malabarica were prepared using two polar solvents (i.e., water and 70% ethanol) and a nonpolar solvent (i.e., hexane). The maximum yield was obtained for aqueous and ethanolic seed extracts indicating that most of the phytoconstituents present in D. malabarica fruit are polar. The qualitative phytochemical analysis of the extracts revealed the presence of diverse amount of phytoconstituents in the extracts. On the other hand, the quantitative phytochemical analysis for phenols, tannins, flavonoids, alkaloids, saponin, proteins, reducing sugar and vitamin C revealed that the maximum amount of phenols, tannins, flavonoids and reducing sugar were present in aqueous seed extract. However, the maximum amount of total protein and vitamin C was found in ethanolic seed extract. D. malabarica seed powder contained more amount of alkaloids (i.e., 13.6%) than that of flesh (i.e., 3.4%). However, the content of saponin was more in flesh extract (0.74%) when compared to that of seed extract (0.42%). In vitro antioxidant properties of the extracts were also investigated by DPPH free radical scavenging assay, FRAP assay and reducing power assay. The highest antioxidant activity was observed for aqueous seed extract followed by the ethanolic seed, ethanolic flesh, and aqueous flesh extracts. The lowest antioxidant activity was obtained for hexane flesh extract. Furthermore, the lowest (i.e., 44.70 μg/ml) as well as the highest (2359.66 μg/ml) IC50 values were obtained for aqueous seed and hexane flesh extracts, respectively.展开更多
Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) w...Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane,chloroform,ethy alacetate and methanol.All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts.Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts.Hydrogen peroxide and 1,1 diphenyl-2-picrylhydrazyl were used to determine in vitro antioxidant activity.Results:Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals.Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract,6 in ethyl acetate and 7 compounds in methanolic extract.Methanol extract was found to contain the highest phenolic content and flavonoids.In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid.Conclusions:Results of this study show that the leaves of M.peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.展开更多
Objective:To evaluate the antioxidant and antimicrobial potential of different parts(leaf,stem and pneumatophore)of a mangrove plant Avicennia marina(Forsk.)Vierh(Avicenniaceae).Methods:The extraction was done by cold...Objective:To evaluate the antioxidant and antimicrobial potential of different parts(leaf,stem and pneumatophore)of a mangrove plant Avicennia marina(Forsk.)Vierh(Avicenniaceae).Methods:The extraction was done by cold percolation method using solvents of hexane,ethyl acetate,acetone,methanol and water.Total phenol and flavonoid content were measured by Folin-Ciocalteu’s reagent and aluminium chloride colorimetric method respectively.The antioxidant activity was evaluated using antioxidant assays of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity,superoxide radical scavenging assay,2,2’-azino-bis-(3-ethyl)benzothiazoline-6-sulfonic acid,ferric reducing antioxidant power and reducing capacity assessment.The antibacterial activity was done by agar well diffusion method against four Gram-positive,four Gram-negative bacteria and four fungi.Results:Different antioxidant assays showed different levels of activity in different parts and different solvent extracts.Overall,acetone extract of stem showed the best antioxidant activity.The Gram-positive bacteria were more susceptible than Gram-negative bacteria and fungi.Conclusions:The results indicated extract of Avicennia marina can be used as a promising source of natural antioxidant.展开更多
Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavengi...Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential(2,2-diphenyl-1-picrylhydrazyl)and β-carotene bleaching assay.Total phenolic contents and flavonoid contents were also measured.Antimicrobial activity of these plants was examined against Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans.Results:The values of IC_(50) ranged from 4.30μg/mL to 486.6μg/mL for the DPPH method,while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%.It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay(IC_(50)=4.30μg/mL),while Populus trimula,Origanum glandulosum,Centaurea calcitrapa,Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity in β-carotene/linoleic acid bleaching assay.Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract,respectively.The most interesting antimicrobial activity was obtained from Sysimbrium officinalis,Rhamnus alaternus,Origanum glandulosum,Cupressus sempervirens,Pinus halipensis and Centaurea calcitrapa.Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.展开更多
Objective:To study antioxidant and antimicrobial properties ofTerminalia catappa,Psidium guajava,Alstonia boonei,Morinda lucida (M. lucida) andSpondias mombin leave extracts using ethanol, petroleum-ether and aqueous ...Objective:To study antioxidant and antimicrobial properties ofTerminalia catappa,Psidium guajava,Alstonia boonei,Morinda lucida (M. lucida) andSpondias mombin leave extracts using ethanol, petroleum-ether and aqueous media. <br> Methods: The free radical 2, 2-diphenyl-1-picrylhydroazyl was used to measure scavenging activities of extracts, while phenolic and flavonoid content were estimated by spectrophotometry. Antibacterial screening of extracts was done by determining zone of inhibition using disc diffusion method. Plant extracts were tested against five strains of Gram-positive and Gram-negative bacteria. After sterilization, the discs were loaded with concentrations of broad spectrum ciprofloxacin, and prepared extract solutions of different concentrations were refrigerated for 24 h. Determination of minimum inhibitory concentration of extracts in the screening assay was according to micro-broth dilution, while determination of minimum bactericidal concentration was carried out by agar diffusion. <br> Results: The highest radical scavenging effect was found in petroleum ether extracts of all the plants withM. lucida andPsidium guajava having the highest and lowest values respectively. Aqueous solvent recorded highest phenolic content in all extracts with the exception ofM. lucida. Flavonoid content was extracted better fromAlstonia boonei andM. lucida with ethanol, while aqueous solvent extracted more from the other plants. With exception of extracts from petroleum ether, all others exhibited varying levels of antibacterial activities againstE. coli,Pseudomonas aeruginosa,Salmonella typhi,Vibrio cholera andStaphylococcus aureus. <br> Conclusions:This study proved that all crude extracts showed strong antioxidant and antimicrobial potentials, which qualified them as nutraceuticals in fish feed production.展开更多
基金funded by the Special Funds for Industry System (CARS-03)Science and Technology Support Program (2012BAD04B07-03)
文摘The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.
文摘In this study, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of four different extracts of Adina cordifolia (Roxb.) were determined using spectrophotometric methods. Antioxidant activity of extracts was expressed as percentage of DPPH radicals’ inhibition and IC50 values (μg/ml). IC50 values ranged from 20.39 to 38.96 μg/ml. The total phenolic content ranged from 17.48 to 20.83 mg/g of dry weight of extract, expressed as gallic acid equivalents. The total flavonoid concentrations varied from 17.49 to 22.48 mg/g, expressed as quercetin equivalents. The significant linear correlation was confirmed between the values for the total phenolic content and antioxidant activity of plant extracts. Adina cordifolia (Roxb.) can be regarded as promising candidates for natural plant sources of antioxidants with high value.
基金funded by the Special Funds for AgroScientifc Research in the Public Interest,China (201203031)the Key Technologies R&D Program of China during the 12th Five-Year Plan period (2011BAD16B07-2)the National Agriculture Technology Research System of China (CARS-03)
文摘The current interest in the health beneifts of whole wheat grain has prompted breeders to further increase the concentration of antioxidants in wheat. The objective of this study was to investigate the variation in antioxidant content among Chinese wheat grains and the relationship between antioxidants and grain color and morphological characteristics. A wide variation was observed in the total phenolic, carotenoid and lfavonoid contents, as well as the antioxidant activity (AOA), of Chinese wheat varieties. Black wheat had the highest mean total phenolic, carotenoid and lfavonoid contents and the highest AOA, followed by red and white wheats. The grain color parameters were signiifcantly negatively correlated with total phenolic, carotenoid and lfavonoid contents and AOA among all of the wheat varieties examined, and grain weight was also signiifcantly negatively correlated with these traits. The same correlation between grain weight and antioxidant traits was also observed within individual groups of wheat, which indicates that grain weight may be used as an index for selecting wheat varieties with high AOA. Landraces had signiifcantly higher lfavonoid content than commercial wheat varieties. The results of this study may be useful for breeding nutrient-rich wheat varieties.
基金Supported by the Central Instrument Laboratory,College of Agriculture and Marine Sciences,Sultan Qaboos University,Sultanate of Oman(Grant Ref No.SOP/ADO/72/2014).
文摘Objective:To determine the total phenols,total flavonoids and evaluate the antioxidant activity of crude extracts from the leaves of pigeon pea native to Sultanate of Oman by a popular method.Methods:The powdered leaves samples from pigeon pea were used for extraction by maceration method with methanol solvent.The methanol free crude extract by maceration method was suspended in water and successively extracted with different polarities of solvents.The obtained crude extracts with different polarities were used for the determination of total phenols and flavonoids contents by using Folin-Ciocalteu reagent and aluminum chloride methods.The antioxidant activity of six crude extracts from pigeon pea was determined byα,αα-diphenyl-β-picrylhydrazyl method.Results:The different polarities leaves crude extracts showed a significant amount of total phenols content ranging from 97.80 to 256.00 mg of GAE/g of crude extract.The same leaves crude extracts also showed good amount of total flavonoids content ranging from 1.38 to 8.51 mg QE/g plant material.The six crude extracts from the leaves displayed significantα,αα-diphenyl-β-picrylhydrazyl free radical scavenging activity with highest value in chloroform extract followed by methanol,butanol,ethyl acetate,hexane and water crude extracts(98.13%,89.26%,88.82%,86.41%,79.95%and 69.44%,respectively).Conclusions:Leaves crude extracts from pigeon pea have high contents of total phenols and flavonoids.In this regards,it could be used as a medicine for the treatment of different diseases.
文摘Bunchosia glandulifera belongs to the family Malpighiaceae and is popularly known as “caferana” in the city of Santo Antonio da Patrulha. The fruits have a high economic value and their inclusion in the diet has health benefits. They are natural sources of antioxidants because of the presence of bioactive compounds. However, their chemical composition can be influenced by the maturation process. This study aims to evaluate the changes in the bioactive antioxidant compounds in the pulp and seeds of B. glandulifera fruit during different stages of ripening. The fruits, were analyzed for caffeine, carotenoids, flavonoids, vitamin C, and total phenolic content as well as for antioxidant activity, at four different stages of ripening. An increase in bioactive compounds was observed from the second maturation stage to the ripened fruit, and the ripened fruit had the highest bioactive compound content. Phenolic compound and carotenoid levels were found to be highest in the pulp. Carotenoid content showed a positive correlation with the antioxidant activity. Colorimetric analysis also showed a high correlation between the levels of carotenoids and color change during the ripening stages.
文摘Diospyros malabarica (Deshi Gab) belonging to the family “Ebenaceae” grows well in the humid tropical climate of Bangladesh. In order to investigate the phytoconstituents both qualitatively and quantitatively, the seed and flesh extracts of D. malabarica were prepared using two polar solvents (i.e., water and 70% ethanol) and a nonpolar solvent (i.e., hexane). The maximum yield was obtained for aqueous and ethanolic seed extracts indicating that most of the phytoconstituents present in D. malabarica fruit are polar. The qualitative phytochemical analysis of the extracts revealed the presence of diverse amount of phytoconstituents in the extracts. On the other hand, the quantitative phytochemical analysis for phenols, tannins, flavonoids, alkaloids, saponin, proteins, reducing sugar and vitamin C revealed that the maximum amount of phenols, tannins, flavonoids and reducing sugar were present in aqueous seed extract. However, the maximum amount of total protein and vitamin C was found in ethanolic seed extract. D. malabarica seed powder contained more amount of alkaloids (i.e., 13.6%) than that of flesh (i.e., 3.4%). However, the content of saponin was more in flesh extract (0.74%) when compared to that of seed extract (0.42%). In vitro antioxidant properties of the extracts were also investigated by DPPH free radical scavenging assay, FRAP assay and reducing power assay. The highest antioxidant activity was observed for aqueous seed extract followed by the ethanolic seed, ethanolic flesh, and aqueous flesh extracts. The lowest antioxidant activity was obtained for hexane flesh extract. Furthermore, the lowest (i.e., 44.70 μg/ml) as well as the highest (2359.66 μg/ml) IC50 values were obtained for aqueous seed and hexane flesh extracts, respectively.
基金Supported by the Department of Pharmacy.Oman MedicalCollege.Muscat,Oman(Grant No.OMC-PHAR/425-05/13)
文摘Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane,chloroform,ethy alacetate and methanol.All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts.Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts.Hydrogen peroxide and 1,1 diphenyl-2-picrylhydrazyl were used to determine in vitro antioxidant activity.Results:Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals.Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract,6 in ethyl acetate and 7 compounds in methanolic extract.Methanol extract was found to contain the highest phenolic content and flavonoids.In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid.Conclusions:Results of this study show that the leaves of M.peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.
文摘Objective:To evaluate the antioxidant and antimicrobial potential of different parts(leaf,stem and pneumatophore)of a mangrove plant Avicennia marina(Forsk.)Vierh(Avicenniaceae).Methods:The extraction was done by cold percolation method using solvents of hexane,ethyl acetate,acetone,methanol and water.Total phenol and flavonoid content were measured by Folin-Ciocalteu’s reagent and aluminium chloride colorimetric method respectively.The antioxidant activity was evaluated using antioxidant assays of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity,superoxide radical scavenging assay,2,2’-azino-bis-(3-ethyl)benzothiazoline-6-sulfonic acid,ferric reducing antioxidant power and reducing capacity assessment.The antibacterial activity was done by agar well diffusion method against four Gram-positive,four Gram-negative bacteria and four fungi.Results:Different antioxidant assays showed different levels of activity in different parts and different solvent extracts.Overall,acetone extract of stem showed the best antioxidant activity.The Gram-positive bacteria were more susceptible than Gram-negative bacteria and fungi.Conclusions:The results indicated extract of Avicennia marina can be used as a promising source of natural antioxidant.
基金Supported by Algerian Ministry of Higher Education and Scientific Research.
文摘Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential(2,2-diphenyl-1-picrylhydrazyl)and β-carotene bleaching assay.Total phenolic contents and flavonoid contents were also measured.Antimicrobial activity of these plants was examined against Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans.Results:The values of IC_(50) ranged from 4.30μg/mL to 486.6μg/mL for the DPPH method,while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%.It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay(IC_(50)=4.30μg/mL),while Populus trimula,Origanum glandulosum,Centaurea calcitrapa,Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity in β-carotene/linoleic acid bleaching assay.Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract,respectively.The most interesting antimicrobial activity was obtained from Sysimbrium officinalis,Rhamnus alaternus,Origanum glandulosum,Cupressus sempervirens,Pinus halipensis and Centaurea calcitrapa.Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.
文摘Objective:To study antioxidant and antimicrobial properties ofTerminalia catappa,Psidium guajava,Alstonia boonei,Morinda lucida (M. lucida) andSpondias mombin leave extracts using ethanol, petroleum-ether and aqueous media. <br> Methods: The free radical 2, 2-diphenyl-1-picrylhydroazyl was used to measure scavenging activities of extracts, while phenolic and flavonoid content were estimated by spectrophotometry. Antibacterial screening of extracts was done by determining zone of inhibition using disc diffusion method. Plant extracts were tested against five strains of Gram-positive and Gram-negative bacteria. After sterilization, the discs were loaded with concentrations of broad spectrum ciprofloxacin, and prepared extract solutions of different concentrations were refrigerated for 24 h. Determination of minimum inhibitory concentration of extracts in the screening assay was according to micro-broth dilution, while determination of minimum bactericidal concentration was carried out by agar diffusion. <br> Results: The highest radical scavenging effect was found in petroleum ether extracts of all the plants withM. lucida andPsidium guajava having the highest and lowest values respectively. Aqueous solvent recorded highest phenolic content in all extracts with the exception ofM. lucida. Flavonoid content was extracted better fromAlstonia boonei andM. lucida with ethanol, while aqueous solvent extracted more from the other plants. With exception of extracts from petroleum ether, all others exhibited varying levels of antibacterial activities againstE. coli,Pseudomonas aeruginosa,Salmonella typhi,Vibrio cholera andStaphylococcus aureus. <br> Conclusions:This study proved that all crude extracts showed strong antioxidant and antimicrobial potentials, which qualified them as nutraceuticals in fish feed production.