Fluorescence quenching of dipyridamole associated to peroxyl radical scavenging: a versatile probe to measure the chain breaking antioxidant activity of biomolecules

2000 ◽  
Vol 1474 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Luigi Iuliano ◽  
Cristina Piccheri ◽  
Ilaria Coppola ◽  
Domenico Praticò ◽  
Fausta Micheletta ◽  
...  
RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38918-38930 ◽  
Author(s):  
Carolina Caicedo ◽  
Cristina Iuga ◽  
Romina Castañeda-Arriaga ◽  
J. Raúl Alvarez-Idaboy

Excellent antioxidantsviaSPLET in aqueous solution, moderate antioxidantsviaHAT in lipid medium.


1990 ◽  
Vol 9 ◽  
pp. 28
Author(s):  
Valerian Kagan ◽  
Elena Serbinova ◽  
Derick Han ◽  
Anna Shvedova ◽  
Lester Packer

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroshi Ueno ◽  
Shizuka Yamakura ◽  
Riya S. Arastoo ◽  
Takumi Oshima ◽  
Ken Kokubo

Antioxidant activity of hydroxylated fullerenes, so-called fullerenols, against lipid peroxyl radical was evaluated byβ-carotene bleaching assay. All samples showed moderate to high antioxidant activity (%AOA), especially for C60(OH)12(70.1) and C60(OH)44(66.0) as compared with 8, 24, 26, and 36 hydroxylated ones (31.7–62.8). The detection of the possible products was conducted in the model reaction of both fullerenols and C60with methyl linoleate by MALDI-TOF-MS. These results suggested that the two possible mechanisms, such as C-addition to double bonds and H-abstraction from –OH groups, are involved in the present radical scavenging reaction.


Author(s):  
Vijaya Jyothi M ◽  
Bhargav E ◽  
Pavan Kumar K ◽  
Praneeth Gowd K ◽  
Ram Pavan S

Nyctanthes arbour-tristis is a shrub belongs to the family Oleaceae. The flowers of this plant are fragrant since the presence of flavonol glycosides. It has also been reported for the presence of β-sitosterol, iridoid glycosides, tannins etc., and known to have immunostimulant, hepatoprotective, antiviral and antifungal activities. In the present study an attempt is made to identify antioxidant capacity and anthelminthic potential of methanolic flower extract of Nyctanthes arbour-tristis. Antioxidant activity was evaluated by total phenolic content assay, total flavonoids content assay, free radical scavenging activity and reducing ability methods. Anthelmintic activity was evaluated on Perithima posthuma using Piperazine citrate as standard drug. The results obtained for the above activities reveals that Nyctanthes arbour-tristis shows considerable antioxidant activity for all the methods and anthelminthic potential at 300 mg/ml. Keywords: arbour-tristis; antioxidant activity; anthelminthic activity; Perithima posthuma; Piperazine citrate.


2019 ◽  
Author(s):  
Chem Int

Verbena officinalis Linn is a traditionally known medicinal plant which is used against a number of diseases including inflammatory conditions. In this study its antioxidant activity (reducing powers, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities), ferric reduction activity potential (FRAP), total flavonoid concentration and antimicrobial activities of 80%, 90%, 100% methanol and chloroform extracts of V. officinalis Linn root and 90% and100% methanol leaf extracts were determined. Its antioxidant activity increases with increase in amount of extract (10% to 40%v/v). Total flavonoid content (TFC) varied from 73.32±0.002 mgQE/100g of dry weight (90% methanol) to 42.39±0.032 mgQE/100g dry weight (chloroform), 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging activity (%) was varied between 87.39% (90% methanol) to 45.57% (chloroform) while Ferric reducing antioxidant power was observed between 372.93±0.04 mgAAE/100 g extract (90% methanol) to 129.41±0.026 mgAAE/100 g chloroform in the root extract. The methanolic extract of the leaf showed less antioxidant activity than the methanolic extract of the root. Crude extracts of V. officinalis root showed various degree of antimicrobial activity towards drug resistance microbial pathogens. Growth inhibition tests against bacterial pathogens demonstrated concentration dependence. Moreover, gram positive bacteria were more susceptible to V. officinalis root extract when compared to gram negative bacteria. In general V. officinalis root and leave extracts possess strong antioxidant and antimicrobial activities.


2019 ◽  
pp. 7-14
Author(s):  
Hai Trieu Ly ◽  
Tuan Anh Vo ◽  
Viet Hong Phong Nguyen ◽  
Thi My Sa Pham ◽  
Bich Thao Lam ◽  
...  

Background: The natural antioxidants have an important role in the prevention of many diseases. The aim of study is to investigate phytochemical components, antioxidant activity and acute oral toxicity of Pomegranate (Punica granatum L.) fruit peel (PFP) extract. Materials and methods: Phytochemicals of PFP were determined by qualitative chemical tests, thin layer chromatography, total polyphenol and flavonoid contents. The PFP extract was evaluated for antioxidant activity by DPPH assay and MDA assay. In vivo acute oral toxicity test was conducted using Karber-Behrens method to determine LD50. Results: Results illustrated that PFP mainly contains flavonoids, alkaloids, tannins, triterpenes, saponins, and coumarins. PFP extract exhibited the total polyphenol and flavonoid contents with 189.97 mg gallic acid equivalent/g dry weight and 9.42 mg quercetin equivalent/g dry weight, respectively. The DPPH free radical scavenging and anti-lipid peroxidation activities of PFP extract were expressed with IC50 value of 4.80 μg/mL and 0.38 μg/ mL, sequentially. Simultaneously, the Dmax (the maximum dose administered to mice that no toxicity was observed) of PFP extract was determined to be 21.28 g/kg, equivalent to 35.64 g dried herb. Conclusion: The PFP extract is relatively safe and revealed high antioxidant activity. Key words: Punica granatum L.; polyphenols; flavonoids; gallic acid; quercetin; antioxidant activity; acute oral toxicity


2011 ◽  
pp. 151-157 ◽  
Author(s):  
Marijana B. Saka ◽  
Julianna F. Gyura ◽  
Aleksandra Mišan ◽  
Zita I. Šereš ◽  
Biljana S. Pajin ◽  
...  

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 °C at pH = 5.7during 60 min) and treatment with hydrogen peroxide (20 g/LH2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 °C), ground and sieved. TF was investigated in comparison with commercially available Fibrex®. The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 ± 1 ºC). The obtained results indicated that substitution of wheat flour with Fibrex® in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex®-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex®-enriched cookies could be attributed to the presence of ferulic acid.


2019 ◽  
Vol 20 (15) ◽  
pp. 1309-1320 ◽  
Author(s):  
Ahmed M. Younis ◽  
Marwa M. Abdel-Aziz ◽  
Mohamed Yosri

Background:: Mushrooms are deemed as a special delicacy in many countries. They are considered an important cuisine due to their bioactive ingredients and possible health benefits. Methods: Herein, we measured selected biological properties of methanol extracts of Pleurotus citrinopileatus and Boletus edulis fruiting bodies including; in vitro antimicrobial activity, anti-α- glucosidase activity, antioxidant activity, anti-lipase activity and cytotoxic activity against different cancer cells and normal cells. Results: B. edulis methanol extracts showed high antimicrobial and anti-α-glucosidase activity. In contrast, P. citrinopileatus methanol extracts showed superior antioxidant activity indicated by (1,1- diphenyl-2-picrylhydrazyl) DPPH radical scavenging with half maximal inhibitory concentration of IC50 37.4 µg/ml, anti-lipase activities with IC50 65.2 µg/ml and high cytotoxicity activity against HepG2 and HeLa cell lines with IC50 22.8 and 36.7 µg/ml, respectively. Flow cytometric analysis of the cell cycle was used to show apoptotic effects of methanol extracts against HepG2 and HeLa cells. Conclusion: P. citrinopileatus and B. edulis methanolic extracts appear to contain biologically active compounds that might be used to treat some common human diseases.


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