Biophysical investigation of thymoquinone binding to ‘N’ and ‘B’ isoforms of human serum albumin: exploring the interaction mechanism and radical scavenging activity

RSC Advances ◽  
2015 ◽  
Vol 5 (24) ◽  
pp. 18218-18232 ◽  
Author(s):  
Mohd Ishtikhar ◽  
Gulam Rabbani ◽  
Shawez Khan ◽  
Rizwan Hasan Khan

Thymoquinone more strongly interacts with the ‘N’ isoform in comparison to the ‘B’ isoform of HSA and also increases its thermal stability but the antioxidant activity is significantly higher at the ‘B’ isoform of HSA.

2020 ◽  
Vol 35 (1) ◽  
pp. 147
Author(s):  
Dimas Rahadian Aji Muhammad ◽  
Joel Garcia Juvinal ◽  
Koen Dewettinck

<p>The cinnamon extract-loaded nanoparticles with high phenolic content and antioxidant activity were successfully developed in a previous study. This study aimed to investigate the radical scavenging activity in 2.2-diphenyl-1-picrylhydrazyl system and stability of the nanoparticles under heat treatment. This study is important for directing the application of the nanoparticles in foods in the future. The thermal stability test was conducted using two different methods, which were the combination of relatively lower temperature (20-100°C) with a long time treatment (up to 120 hours) and the combination of relatively higher temperature (110-150°C) with a short time treatment (equal to or less than 2 hours). The results show that the cinnamon extract-loaded nanoparticles exhibited a radical scavenging activity. The higher proportion of cinnamon loading resulted in the higher radical scavenging activity of the nanoparticles. The thermal treatment caused a significant degradation on the phenolic content and antioxidant activity of the nanoparticles. The energy activation (Ea) of the phenolic content and antioxidant activity was found at 35.17 kJ mol<sup>-1</sup> and 27.91 kJ mol<sup>-1</sup>, respectively. This study suggests that the cinnamon extract-loaded nanoparticles might be preferably incorporated into foods minimally involving heat exposure during their manufacture.</p>


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2555
Author(s):  
Sang Koo Park ◽  
Yoon Kyung Lee

Using natural products as antioxidant agents has been beneficial to replace synthetic products. Efforts have been made to profile the antioxidant capacities of natural resources, such as medicinal plants. The polyphenol content of Himalayan rhubarb, Rheum emodi wall, was measured and the antioxidant activity was determined using DPPH and ABTS+ assay, and the oxidative stress was assessed using SOD enzymatic assay. Five different solvent fractions, n-hexane, n-butanol, ethyl acetate, dichloromethane, and water, were used for screening the antioxidant capacity in effort to determine the optimum extraction solvent. The total phenolic contents for R. emodi fractions ranged from 27.76 to 209.21 mg of gallic acid equivalents (GAE)/g of dry weight. DPPH and ABTS+ assay results are presented into IC50 values, ranged from 21.52 to 2448.79 μg/mL and 90.25 to 1718.05 μg/mL, respectively. The ethyl acetate fraction had the highest antioxidant activity among other fractions. Also, n-butanol and water fractions showed significantly lower IC50 values than the positive control in DPPH radical scavenging activity. The IC50 values of SOD assay of fractions ranged from 2.31 to 64.78 μg/mL. A similar result was observed with ethyl acetate fraction showing the highest SOD radical scavenging activity. The study suggests that the ethyl acetate fraction of R. emodi possess the strongest antioxidant activity, thus the most efficient in extracting antioxidant contents. Moreover, a highly significant correlation was shown between total polyphenol content and antioxidant activity screening assays. The compounds related to the antioxidant activity of R. emodi were identified to myricitrin, myricetin 3-galloyl rhamnoside, and myricetin, which have not been reported in studies about R. emodi before.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid

The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55–5.14 fold. The extracts also reduced the fructosamine levels by 47.0–86.5%, increased the thiol group levels by 64.3–83.7%, and inhibited the formation of protein carbonyl by 1.36–1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81–288.04 μg/ml and reducing power activity depicted at 0.02–0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.


2014 ◽  
Vol 9 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Mirjana Marčetić ◽  
Silvana Petrović ◽  
Marina Milenković ◽  
Marjan Niketić

AbstractThe chemical composition, antimicrobial and antioxidant activity of Eryngium palmatum, an endemic plant species from the Balkan Peninsula, were investigated. The flavonoids apigenin (9.5±0.3 mg g−1) and apigenin 7-O-glucoside (2.4±0.1 mg g−1) were determined in a methanol extract of aerial parts using HPLC analysis. The methanol extract of roots contained catechin (5.0±0.1 mg g−1), epicatechin (2.9±0.1 mg g−1), chlorogenic acid (1.6±0.0 mg g−1), gallic acid (0.9±0.0 mg g−1) and rosmarinic acid (0.9±0.2 mg g−1). GC-FID and GCMS analysis of a chloroform extract of aerial parts showed that the main volatile constituents were falcarinol, linoleic acid, hexadecanoic acid and methyl linoleate (comprising 32.6%; 24.4%; 19.9; 13.2% of the volatile fraction, respectively), while octanoic acid, tetradecanol and dodecanol dominated in the chloroform extract of the roots (34.9%; 25.8%; 22.2% of the volatile fraction, respectively). Investigation of antimicrobial activity by broth microdilution showed that the methanol and chloroform extracts of aerial parts and roots exerted a significant effect (MIC 3.5–15.6 μg mL−1) against tested Gram-positive and Gram-negative bacteria. The methanol extracts of aerial parts or roots exerted moderate ferric reducing antioxidant power, DPPH radical scavenging activity and hydroxyl radical scavenging activity.


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
K. Nagendra Prasad ◽  
Jing Hao ◽  
Chun Yi ◽  
Dandan Zhang ◽  
Shengxiang Qiu ◽  
...  

Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.


Author(s):  
Sharmistha Banerjee ◽  
Shuchi Kaushik ◽  
Rajesh Singh Tomar

ABSTRACTObjective: This study was performed to identify the phytochemicals and comparatively evaluate the antioxidant activity of Calotropis procera andAzadirachta indica by detection of total phenolics, hydrogen peroxide radical scavenging activity, and estimation of condensed tannins in differentsolvent systems and at different temperatures.Methods: Leaves of C. procera and A. indica were extracted in water, methanol by soaking dried leaf powder at room temperature and also by boilingthe leaf powder in water for 30 minutes. Phytochemical tests were performed in all of the extracts. The antioxidant activity was determined byhydrogen peroxide radical scavenging activity. Quantitative estimation of total phenolics and hydrolysable tannins was also performed.Results: The total phenolics in both leaf extracts was obtained maximum in boiled extract (40.7±1.20 mg gallic acid equivalent [GAE]/g dry extractin C. procera and 33.66±1.45 mg GAE/g dry extract in A. indica). The amount of hydrolysable tannins in both leaf extracts was found to be highest inmethanol (150±1.88 mg catechin equivalent/g dry extract in C. procera and 144.8±2.63 mg catechin equivalent/g dry extract in A. indica).Conclusion: The study showed promising results indicating that these plants are a good source of antioxidants. The majority of phytochemicals wereextracted in distilled water and methanol acts as a good solvent for extraction of tannins, whereas an increase in temperature leads to poor extractionof tannins.Keywords: Antioxidant, Phytochemicals, Phenolics, Radical, Tannins.© 2017 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.


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