scholarly journals Total phenolic content of anthocyanin rich berry extracts reduces reactive oxygen species generated from the xanthine:xanthine oxidase reaction

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
David Robert Bell ◽  
Tara Dianne Burt ◽  
Jeremy R Burkett
Author(s):  
Kanya Thongra-ar ◽  
Piyanuch Rojsanga ◽  
Savita Chewchinda ◽  
Supachoke Mangmool ◽  
Pongtip Sithisarn

The objects of this study were to determine the effects to reactive oxygen species and antioxidant enzymes levels in HEK-293 cells and inhibition of α-glucosidases and α-amylase enzymes of extracts from Persicaria odorata or phak phaeo. The ethanol extracts from the leaves and the stems of phak phaeo were investigated for their 2,2-diphenyl-1-picryhydrazyl (DPPH) scavenging activities (IC50 were 7.74 ± 0.47 and 7.91 ± 0.43 µg/mL, respectively). Cellular antioxidant effects in human embryonic kidney-293 (HEK-293) cells with these extracts (0.1 mg/mL) also increased the mRNA expressions of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx-1), catalase and glutathione reductase (GRe). The leaf extract showed the higher efficacies in the induction of the mRNA expressions of Mn-SOD, GPx-1 and GRe while the stem extract exhibited a stronger effect to the induction of catalase. Phak phaeo in vitro inhibitory effects to α-glucosidase enzyme (IC50 values of 9.82 ± 1.64 and 13.99 ± 1.45 µg/mL, respectively and also strong inhibition to α-amylase with IC50 values of 90.66 ± 8.75 and 19.96 ± 5.37 µg/mL, respectively). Lineweaver-Burk plot demonstrated that phak phaeo extracts inhibited α-glucosidase and α- amylase in non-competitive manners. Total phenolic and total flavonoid contents were determined by Folin-Ciocalteu and aluminium chloride methods (the leaf and stem extracts were 22.89 ± 9.16 and 22.27 ± 8.77 g gallic acid equivalent in 100 g extract (g% GAE) and 7.20 ± 3.61 and 4.06 ± 1.73 g quercetin equivalent in 100 g extract (g% QE), respectively). Keywords: Antioxidant enzymes, DPPH, HEK-293, MTT assay, Persicaria odorata, Reactive oxygen species, Total phenolic, Total flavonoid, α-glucosidases, α-amylase


Author(s):  
Sowjanya Pulipati ◽  
P. Srinivasa Babu ◽  
U. Naveena ◽  
S.K. Rafeeka Parveen ◽  
S.K. Sumaya Nausheen ◽  
...  

Free radicals or reactive oxygen species are involved in various pharmacological conditions. As synthetic antioxidants possess numerous adverse health effects, the medicinal plants possessing antioxidant components can be used to prevent harmful effects of reactive oxygen species. In the present study leaves of Amaranthus tricolor Linn were used to prepare chloroform (CEAT), methanolic (MEAT) and aqueous (AEAT) extracts, analyze the presence of phytochemicals and evaluation of in-vitro antioxidant property. Quantitative determination of phenols, tannins and flavonoids in leaves A.tricolor was carried out using spectrophotometric methods. The antioxidant activity was performed by DPPH, p-NDA radical scavenging methods for different extracts of the plant. The plant species showed that methanolic extract (MEAT) on higher concentration possess better antioxidant potential when compared with reference standard ascorbic acid. The plant extracts exhibited strong antioxidant DPPH radical scavenging activity with the IC50 values 290, 657, 830 and 130μg/ml of MEAT, CEAT, AEAT and ASA respectively. In scavenging hydroxyl radical by p-NDA method the MEAT showed maximum activity, CEAT showed moderate and AEAT showed minimum activity. The strongest antioxidant activity of MEAT could be due to the presence of flavonoids and phenols.


2009 ◽  
Vol 4 (6) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Mahassine Amensour ◽  
Esther Sendra ◽  
Jamal Abrini ◽  
Samira Bouhdid ◽  
José Angel Pérez-Alvarez ◽  
...  

The total phenolic content and antioxidant activity of methanolic, ethanolic and aqueous extracts of myrtle ( Myrtus communis) leaves and berries were measured to find new potential sources of natural antioxidants. Total phenolic content was assessed by the Folin-Ciocalteau assay, while the antioxidant activity was evaluated by three methods: diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, the reducing antioxidant power assay and β-carotene linoleic acid assay. The total phenol content of myrtle extracts ranged between 9.0 and 35.6 mg GAE per g extract. For each solvent, leaf extracts contained significantly higher amount of total phenolic compounds than berry extracts. All of the extracts presented antioxidant capacity assessed by the three methods, but at different levels depending on the concentration, the extraction solvent and the part of the plant used. Generally, leaf extracts showed higher antioxidant activities than berry extracts, while the overall antioxidant strength was in the order methanol > water > ethanol in leaf extracts and methanol > ethanol >water in berry extracts. The phenolic content exhibited a positive correlation with the antioxidant activity: DPPH assay showed the highest correlation (r = 0.949), followed by the reducing power assay (r = 0.914) and the lowest for the β-carotene linoleic acid assay (r = 0.722).


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Aderonke Ariyike Olajuyigbe ◽  
Olufunmiso Olusola Olajuyigbe ◽  
Roger Murugas Coopoosamy

With the increased incidence of antibacterial resistance in microorganisms, combining natural products from plants with antibiotics may be considered interesting alternatives for synergy to attain multitarget effects. In this study, the antioxidant activity of the methanol extract of Ziziphus mucronata and its interactions with antibiotics against bacteria of clinical importance were investigated. While its phytochemicals and antioxidant activities were determined by free radical scavenging assays, the antibacterial activities of the extract and its interactions with the antibiotics were determined by macrobroth dilution and the checkerboard methods. From the results, total phenolic content was 29.67 ± 1.90 mg GAE/100 g, total flavonoid content was 8.72 ± 0.08 mg QE/100 g, and total proanthocyanidin content was 1.94 ± 0.00 mg CE/100 g of dry plant material. The inhibition concentration 50% (IC50) of DPPH, BHT, and ascorbic acid was equal to 0.04 ± 0.02 mg/ml, respectively. Those of the ABTS, BHT, and ascorbic acid were equal to 0.02 ± 0.02, 0.04 ± 0.03, and 0.04 ± 0.02 mg/ml, respectively. The checkerboard assay showed that combining the extract with different antibiotics resulted in synergistic (38.75%), indifferent (30%), additive (28.75%), and antagonistic (2.5%) interactions. The interactions between the extract and antibiotics resulting in enhanced antibacterial activities could have resulted from the antioxidant activities of the extract mopping up the ROS generated by the antibiotics or the ability of both extract and antibiotics simultaneously producing reactive oxygen species with deleterious effects resulting in synergistic antibacterial effects.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jigni Mishra ◽  
Anivesh Joshi ◽  
Rakhee Rajput ◽  
Kaushlesh Singh ◽  
Anju Bansal ◽  
...  

Ganoderma lucidum (G. lucidum) fungus (Family Ganodermataceae) is widely used as a traditional medicine in China, Japan, and many Asian countries on account of its numerous medicinal properties such as antioxidant, anticancer, antimicrobial, energy enhancing, and immunostimulatory. This broad spectrum of therapeutic effects exhibited by G. lucidum is ascribed to its abundance in several classes of chemical constituents, namely, carbohydrates, flavonoids, minerals, phenolics, proteins, and steroids which possess substantial bioactivities. The aim of the current study was to prepare phenolic rich fractions (PRFs) from aqueous extract of the Indian variety of G. lucidum mycelium and fruiting body. These fractions were assessed for their antioxidant capacity by TPC (total phenolic content), TFC (total flavonoid content), FRAP (ferric reducing antioxidant power), and ABTS [2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid] assays. Quantification of flavonoids and nucleobases present in the fractions was carried out by high-performance thin layer chromatography (HPTLC). The antibacterial activity of the fractions was evaluated against Escherichia coli, Salmonella typhi, and Staphylococcus aureus. The antibacterial mechanism of action of the PRFs was established to be generation of reactive oxygen species and leakage of proteins within bacterial cells. Additionally, the protective effect of the PRFs in counteracting hypoxia was observed in HEK 293 cell lines.


2015 ◽  
Vol 10 (4) ◽  
pp. 972 ◽  
Author(s):  
Liu-Bing Li ◽  
Subin Lin ◽  
Jun Yan ◽  
Qian-Liang Wang ◽  
Zhi-Ying Fan ◽  
...  

<p>Osteosarcoma shows resistance to chemotherapy and many side effects. The ethyl acetate fraction of ethanolic extract of Chrysophyllum cainito was taken in the present work. The extract was characterized for its phenolic content, antioxidant capacity (ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays), ability to form reactive oxygen species and annexin V assay. The extract contained phenolic content of 30.1 ± 0.2 mg GAE/g extract. Ferric reducing antioxidant power assay and DPPH assay showed 213.2 ± 12.4 mM Fe<sup>2+</sup> equivalent per gram extract and 85.6 ± 4.9 TE/g respectively. For production of reactive oxygen species in the osteosarcoma cells, extract at 50 µg GAE/mLconcentration was statistically equivalent to 100 µM H<sub>2</sub>O<sub>2</sub>. EC<sub>50</sub> of extract was calculated to be 133 µg GAE/mL in cell viability studies.</p>


2009 ◽  
pp. c3 ◽  
Author(s):  
Helena M. Cochemé ◽  
Michael P. Murphy

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.


2001 ◽  
Vol 120 (5) ◽  
pp. A361-A361
Author(s):  
K UCHIKURA ◽  
T WADA ◽  
Z SUN ◽  
S HOSHINO ◽  
G BULKLEY ◽  
...  

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