Total Flavonoid Content Of Extracts Research Articles

Antibacterial and antioxidant properties of grape stem extract applied as disinfectant in fresh leafy vegetables.

In the present study total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity and antimicrobial properties of grape (Vitis vinifera var. Red Globe) stem extract is reported. Also, the identification of main phenolic compounds was carried out by UPLC-PAD analysis. TPC and TFC of extract were 37.25gGAEkg-1 and 98.07gQEkg-1, respectively. Extract showed an antioxidant capacity of 132.60 and 317g TEkg-1 for DPPH and ABTS radical scavenging capacity, respectively. The main phenolic compounds identified were rutin, gallic acid, chlorogenic acid, caffeic acid, catechin and ferulic acid. Extract inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Typhimurium, and Escherichia coli O157: H7 at MIC range 16-18gL-1. Extract affected the different phases of bacterial growth. In addition, application of Extract (25g L-1) as a sanitizer was effective to reduce the populations of all bacteria inoculated in lettuce (0.859-1.884 log reduction) and spinach (0.843-2.605 log reduction). This study emphasizes the potential of grape processing byproducts as an emergent and attractive source of bioactive compounds with antioxidant properties and antimicrobial activity against important foodborne pathogens. The study demonstrated that stem extract could be used to control the presence of human pathogenic bacteria in fresh leafy vegetables.

QUANTIFICATION OF TOTAL PHENOLIC AND TOTAL FLAVONOID CONTENT OF EXTRACTS OF TAGETES ERECTA FLOWERS

Objective: Tagetes erecta, marigold, has various ethnomedicinal uses. It has a wide variety of bioactive components such as polyphenols and flavonoids which show different bioactivities. The aim of the present study is to quantitatively estimate total phenolic content (TPC) and total flavonoid content (TFC) of different extracts of T. erecta flowers.Methods: Extraction was done by maceration process, sequentially from non-polar to polar. Chloroform, ethyl acetate, and methanol extracts of T. erecta flowers were subjected to preliminary phytochemical screening. The extracts were analyzed for TPC and TFC using gallic acid and rutin as standard, respectively.Result: Phytochemical screening of different extracts showed the presence of carbohydrates, flavonoids, phenolics, fats, and oils. TPC and TFC in extracts of T. erecta varies with solvents. The study revealed that methanolic extract possesses the highest phenolic content, 49.76±0.29 mg gallic acid equivalents/g extract, and also maximum flavonoid content, 13.43±0.43 mg RE/g extract, among the three extracts.Conclusion: Higher value of phenolics and flavonoid indicates higher antioxidant activity. The present study revealed that methanolic extract has the highest phenolic and flavonoid content. This indicates that the flowers may possess a good antioxidant property and further research could be carried out.

ANTIOXIDANT ACTIVITY ASSESSMENT OF TAMUS COMMUNIS L. ROOTS

<p><strong>Object: </strong>The aim of this study was to evaluate the antioxidant activities of <em>Tamus communis</em> L. (<em>T .communis</em>) roots. This plant is used in folk medicine in the treatment of rheumatism, arthritis and lumbago.</p><p><strong>Methods</strong>: The extraction of polyphenols has been followed by the determination of total polyphenols and flavonoids. The methanol extract (MeOHE) was chromatographied on a silica gel column. The column was eluted with chloroform and then with chloroform /methanol mixtures of increasing polarity, 6 main fractions (FI--FVI)) were collected and grouped according to their TLC (Thin layer chromatography). Several methods were used to evaluate the <em>in vitro</em> antioxidant activity such as DPPH (2,2'-diphenyl-1-picrylhydrazy), bleaching of β-carotene for 24 hours, lipid peroxidation and anti-hemolytic activity. An <em>in vivo</em> approach was carried out on mice treated with CE (crud extract) at a dose of 100 mg / Kg / day for 21 consecutive days, and one group was treated with vitamin C (Vit C 50 mg/kg) as a standard drug. To determine the improvement of antioxidant potential, basic biochemical parameters were used in tissue (liver), plasma and whole blood.</p><p><strong>Results</strong>: The results showed that the highest level of polyphenols was recorded in FII (73.143±0.009<strong> </strong>mg GA-Eq/g extract (Gallic Acid Equivalent)) / g of extract) followed by MeOHE (69.786±0.10 mg GA-Eq/g extract). Total flavonoid contents of extracts / fractions showed that MeOHE contains the highest level. Inhibition of DPPH radical showed that MeOHE (0.1187 ± 0.025 mg / ml) and CE (0.2363 ± 0.019 mg / ml) have the most efficient antioxidant activity. All the extracts were capable of inhibiting the bleaching of β-carotene by scavenging linoleate derived free radicals, and all the studied extracts have a very important antihemolytic activity (p<0.001) and revealed an extension of hemolysis half time from 70.34±2.15 min of CTL (AAPH (2,2-azo- bis (2-amidinopropane) dihydrochloride)) and 207 ± 5.65 min for FI. The in vivo assay was</p><p>exhibited a significant decrease (54.09%) of the content of malondialdehyde (MDA) in the liver and increased glutathione (GSH) and catalase (47.30% and 46.87% respectively).</p><p><strong>Conclusion</strong>: These findings suggest that the extract obtained from <em>T. communis</em> have active substances contributing to the increase in natural antioxidant potential.</p>

The antimicrobial activity of Prunella vulgaris extracts

Summary Prunella vulgaris ( Labiatae family) or self-heal is traditionally used for different ailments such as eye pain and inflammation, headache, dizziness, sore throat and wound healing. Total phenolic and total flavonoid contents of extracts (methanol, ethanol and aqueous) were determined by a spectrophotometer. The antimicrobial activity was evaluated by micro broth dilution assay. The total phenolic content of P. vulgaris extracts were higher in aqueous extract (156.5 mg GAC/g) followed by ethanol extract and methanol extract. The TFC content of P. vulgaris methanol extract (82.8 mg QE/g) was higher than ethanol extract (22.7 mg QE/g) and aqueous extract (16.2 mg QE/g). The antimicrobial activity of methanol or ethanol extracts was higher than aqueous extract from P. vulgaris. The sensitivity of microorganisms to different extracts is related to type of pathogens. There is no positive relation between total phenolic content and its antimicrobial activity. Prunella vulgaris ethanolic extract as a source of phenolic and flavonoid contents can be used as an antimicrobial agent.

Effect of Solvents on the Antioxidant Activity of Walnut (<i>Juglans</i><i> </i><i>regia</i> L.) Shell Extracts

Walnut shell is a waste generated in the walnut (<i>Juglans</i><i> </i><i>regia</i> L.) harvest, containing natural compounds with antioxidant properties. In this connection, the effect of the solvent (water, chloroform, methanol, ethanol, ethyl acetate and N-butanol) on the extraction yields, total flavonoids content and antioxidant properties was analyzed. Total flavonoids content of extracts was determined by NaNO2-Al(NO3)3 method. Extract antioxidant activity was measured by hydroxyl, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide anion radical scavenging capacity and the total antioxidant capacity and reducing power assay. The highest extraction yield was achieved with N-butanol (4.54%) and the greatest total flavonoids content shown by the samples extracted with ethyl acetate. The highest ability to scavenging DPPH, hydroxyl and superoxide radicals was ethyl acetate extract (EC50=81.03μg/mL), methanol extract (EC50=131.35 μg/mL) and chloroform extract (EC50=176.35μg/mL) respectively under the concentration of 500 μg/mL. The methanol extract showed the greatest total antioxidant activity and reducing power. The results showed that different solvent had significant effect on total flavonoids content and antioxidant activity. The result obtained demonstrated the potential of walnut shell as a source of antioxidant.

흰민들레의 부위별 건조방법에 따른 영양성분 및 항산화효과 비교

This study compared the nutritional composition and antioxidative activity of different parts of Taraxacum coreanum (aerial parts and roots) according to different drying methods (natural drying and freeze-drying). There were no significant differences in vitamin C content in roots depending on the drying methods. However, vitamin A (P<0.01), E (P<0.001) and C (P<0.001) content of aerial parts, and vitamin A (P<0.001) and E (P<0.05) content of roots were significantly higher after freeze-drying compared to natural drying. For organic acids, the oxalic acid content of the aerial parts and roots were the highest. The total polyphenol and total flavonoid content in extracts from the aerial parts (P<0.01) and roots (P<0.05) were significantly higher after freeze-drying compared to natural drying. In addition, the total polyphenol and flavonoid content, DPPH radical scavenging activity, and antioxidative index from the natural drying and freeze-drying of Taraxacum coreanum extracts were significantly higher in the aerial parts compared to the roots (P<0.05). These results suggest that the nutritional composition and antioxidative activity of Taraxacum coreanum are higher in the aerial parts compared to the roots, and higher after freeze-drying compared to natural drying. Therefore, the aerial parts of Taraxacum coreanum could be suggested as an antioxidative functional food source.

Antioxidant and α-glucosidase inhibitory activities of Murraya koenigii leaf extracts

Medicinal plants are source for a wide variety of natural antioxidants. Dietary antioxidant consumption may be an important approach for inhibiting or delaying the oxidation of susceptible cellular substrates and thus is relevant to disease prevention in many paradigms. Murraya koenigii is one of the important medicinal herb which is used as a food ingredient across India. In this study, we demonstrated the reducing power, total antioxidant potential, radical scavenging capabilities and α-glycosidase inhibitory property of different crude extracts of curry leaves (Murraya koenigii L.). The extracts were evaluated for their radical scavenging activities by means of DPPH, NO, ·OH, 02- and anti-lipid peroxidation assays. In addition, extract of M. koenigii were tested for α-glycosidase inhibitory property. The extracts of M. koenigii scavenged radicals effectively in varied degree. Similarly, the total reducing power of alcohol extract was found higher in both phosphomolybednum and FRAP methods. In vitro assay of α-glucosidase activity of MKA and MKW showed an IC50 of 174.74 and 287.00 μg/ml respectively, while other two extracts did not show any significant effect. Simultaneously, total phenolic and total flavonoid contents of extracts were studied, where values of MKW were found to be higher than that of other extracts. In present study, we found that MKA and MKW extracts contain effective antioxidant and radical scavenging activities as compared to other extracts. Our study provides a proof for the ethno-medical claims and reported biological activities that curry leaves have significant therapeutic potential.

Evaluation of phenolic content and antioxidant activity of Iranian caraway in comparison with clove and BHT using model systems and vegetable oil

SummaryAntioxidant activity (AA) of phenolic compounds in methanolic extract of Iranian caraway was compared with clove. Total phenolic content of caraway and clove extracts determined by the Folin‐Ciocalteu method, were 13.76 and 243.91 mg g−1 dry matter respectively, expressed as tannic acid equivalents, and total flavonoid content of extracts were 2.6 and 5.0 mg g−1 dry matter, respectively, expressed as epicatechin equivalents. The extracts were screened for their potency as antioxidant using various in vitro models, such as β‐carotene–linoleate, ferric thiocyanate, 1,1‐diphenyl‐2‐picryl hydroxyl (DPPH) radical, hydroxyl radical (•OH) and reducing power model systems. AA of BHT was also determined in model systems. AA of methanolic extracts at different concentrations of total phenolic content according to β‐carotene bleaching and ferric thiocyanate methods expressed as AA (per cent inhibition relative to control) ranged from 82% to 96%.The scavenging effect of both extracts on DPPH and •OH radicals were 23–40% and 3.5–12.7%, respectively, which were comparable with BHT as a synthetic antioxidant. Extracts with high content of total phenolic compounds exhibited also good reducing power.

Comparison of the Free Radical Scavenging Activity of Six Iranian Achillea. Species

This study was designed to evaluate and determine the free radical scavenging activity and total flavonoid content of the ethanol extract of six Iranian Achillea. species (A. micrantha. Willd Asteraceae, A. filipendula. Lam., A. millefolium. L., A. tenuifolia. Lam., A. vermicularis. Trin and A. wilhelmsii. C. Koch.) (Asteraceae) and investigate the possible composition-activity relationship. The free radical scavenging activity of the extracts was characterized by the DPPH scavenging test. The total flavonoid content of the extracts was determined using the colorimetric technique by AlCl3 reagent. Two of six extracts [A. micrantha. (IC50 = 32.92 µg/ml) and A. millefolium. (IC50 = 49.43 µg/ml)] revealed a suitable free radical scavenging activity. The strongest activity was found for A. micrantha. (IC50 = 32.92 µg/ml), whereas the activity of A. wilhelmsii. (IC50 = 118.90 µg/ml) was significantly lower than the others. On the other hand, the extracts of A. vermicularis. (58.17 µg/mg) and A. wilhelmsii. (55.96 µg/mg) had very high content of flavonoid, but the lowest content was determined in A. tenuifolia. (35.66 µg/mg). However, a favorable correlation was not found between the scavenging activity and the total flavonoid content of the extracts. The study suggests that A. micrantha. and A. millefolium. are the possible sources of natural radical scavengers.