scholarly journals Revisiting DPPH (2,2-diphenyl-1-picrylhydrazyl) assay as a useful tool in antioxidant evaluation: A new IC100 concept to address its limitations

2019 ◽  
Vol 7 ◽  
Author(s):  
JuDong Yeo ◽  
Fereidoon Shahidi

The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay has been widely used in antioxidant evaluation. However, it suffers from certain limitations that are addressed in this contribution. The limitations discussed in this work were the ratio of DPPH radicals to antioxidants and the presence of pigments in the reaction medium which interferes with absorbance readings. To do so, we used eight different concentrations of DPPH solution. The modified DPPH assay proposes a new concept, IC100, that is defined as the amount of DPPH radical required to oxidize all antioxidants present in the reaction medium. The modified DPPH assay does not suffer from an underestimation of antioxidant activity found in the original DPPH procedure due to the decrease in the ratio of DPPH radicals to antioxidants. Moreover, the modified method was not influenced by interference from coexisting pigments in the measurement of radical scavenging potential of extracts. To the best of our knowledge, this is the first attempt to effectively resolve the above-mentioned limitations of the DPPH assay.

2011 ◽  
Vol 233-235 ◽  
pp. 2849-2854
Author(s):  
Jie Bi ◽  
Qing Li Yang ◽  
Li Na Yu ◽  
Jie Sun ◽  
Chu Shu Zhang

In this article, the antioxidant activity of the crude extract from peanut hulls was tested with phosphomolybdenum complex method, the reduction of K3Fe(CN)6 and DPPH assay. The IC50 value for DPPH radical scavenging lied 14.86μg ml-1, and 28 μg mL-1 of PHF exhibited total antioxidant activity and reducing power which were comparable to that of the ascorbic acid standard at 52.41 and 15.41 μg mL-1, respectively.


2019 ◽  
Vol 15 (4) ◽  
pp. 341-351 ◽  
Author(s):  
Ana P. Bettencourt ◽  
Marián Castro ◽  
João P. Silva ◽  
Francisco Fernandes ◽  
Olga P. Coutinho ◽  
...  

Background: Previous publications show that the addition of a phenolic antioxidant to an antifungal agent, considerably enhances the antifungal activity. Objective: Synthesis of novel compounds combining phenolic units with linear or cyclic nitrogencontaining organic molecules with antioxidant/antifungal activity using methodologies previously developed in the group. Methods: Several N- [1,2-dicyano-2- (arylidenamino) vinyl]-O-alkylformamidoximes 3 were synthesized and cyclized to 4,5-dicyano-N- (N´-alcoxyformimidoyl)-2-arylimidazoles 4 upon reflux in DMF, in the presence of manganese dioxide or to 6-cyano-8-arylpurines 5 when the reagent was refluxed in acetonitrile with an excess of triethylamine. These compounds were tested for their antioxidant activity by cyclic voltammetry, DPPH radical (DPPH•) assay and deoxyribose degradation assay. The minimum inhibitory concentration (MIC) of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans, and against bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram negative). Their cytotoxicity was evaluated in fibroblasts. Results: Among the synthetised compounds, five presented higher antioxidant activity than reference antioxidant Trolox and from these compounds, four presented antifungal activity without toxic effects in fibroblasts and bacteria. Conclusion: Four novel compounds presented dual antioxidant/antifungal activity at concentrations that are not toxic to bacteria and fibroblasts. The active molecules can be used as an inspiration for further studies in this area.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1839
Author(s):  
Harlinda Kuspradini ◽  
Indah Wulandari ◽  
Agmi Sinta Putri ◽  
Sabeti Yulis Tiya ◽  
Irawan Wijaya Kusuma

Background: Litsea angulata is a plant species belonging to Lauraceae family that is distributed throughout Indonesia, Malaysia, and New Guinea. The seeds have been traditionally used by local people in Kalimantan, Indonesia for the treatment of boils; however, there is no information about the potency of its branch, bark and leaves yet. This study aimed to determine the antioxidant, antimicrobial activity as well as the phytochemical constituent of Litsea angulata branch, bark, and leaves. Methods: Extraction was performed by successive maceration method using n-hexane, ethyl acetate, and ethanol solvent. Antioxidant activity was evaluated by DPPH radical scavenging assay. The antimicrobial activity using the 96 well-plate microdilution broth method against Staphylococcus aureus and Streptococcus mutans. Results: Based on the phytochemical analysis, it showed that extract of L. angulata contains alkaloids, flavonoids, tannins, terpenoids, and coumarin. The results showed that all extracts of plant samples displayed the ability to inhibit DPPH free radical formation and all tested microorganisms. Conclusions: L. angulata contains secondary metabolites such as alkaloids, flavonoids, tannins, terpenoids, carotenoids, and coumarin. The antioxidant activity on different plant extracts was a range as very strong to weak capacity. All extracts in this study could inhibit the growth of S. aureus and S. mutans.


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.


Author(s):  
Shaista Amin ◽  
Amrita Parle

Objective: To synthesize benzothiazole derivatives, characterize them by 1HNMR and ATIR techniques and evaluate for their antioxidant activity.Methods: In the present study 12 benzothiazole derivatives were synthesized by reacting 2-chloronitro benzene as the primary reactant with different aromatic aldehydes and benzoic acids. Reactions were monitored using thin layer chromatography technique, and the newly synthesized derivatives were characterized by ATIR and 1HNMR techniques. The antioxidant assay was performed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) or ABTS method and 2,2-diphenyl-1-picrylhydrazyl or DPPH method.Results: The antioxidant activity was found to be better in ABTS assay than DPPH assay. The compounds showed comparable activity to ascorbic acid at 100µg/ml.Conclusion: It was found that the synthesized benzothiazole derivatives showed significant radical scavenging potential.


2013 ◽  
Vol 781-784 ◽  
pp. 1294-1297 ◽  
Author(s):  
Ping Liu ◽  
Yun Tao Gao ◽  
Jiao Jiao Yu ◽  
Jia Wei Cha ◽  
Dong Mei Zhao ◽  
...  

The UV-Vis absorption spectrum of kaempferol and DPPH was investigated, the optimum determination wavelength and reaction time for determining the DPPH radical scavenging activity of kaempferol was 517 nm and 30 min, respectively. Kaempferol exhibited strong DPPH radical scavenging activity with a IC50 value of 0.004349 mg·mL-1, which is smaller than that of rutin, indicating that kaempferol has a stronger antioxidant activity than rutin.


Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


2010 ◽  
Vol 9 (3) ◽  
pp. 457-460 ◽  
Author(s):  
M. Taufik Ekaprasada ◽  
Hazli Nurdin ◽  
Sanusi Ibrahim ◽  
Dachriyanus Dachriyanus

An antioxidant compound has been isolated from the leaves of Toona sureni (Blume) Merr. The structure was determined to be methyl 3,4,5-trihydroxybenzoate (methyl gallate), based on UV-vis, FTIR, NMR and MS spectra. The isolated compound exhibited potent antioxidant activity in the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging test, with IC50 value 1.02 μg/mL.   Keywords: antioxidant activity, methyl gallate, Toona sureni


Author(s):  
Jane-Rose I. Oche ◽  
Titilayo O. Johnson ◽  
Augustina O. Akinsanmi ◽  
Kiri H. Jaryum ◽  
Timothy Francis

Aim: The aim of this study was to investigate and compare the antioxidative properties of the mistletoe plant obtained from three different host species namely Psidium guajava, Vernonia amygdalina and Moringa olifera lam. Study Design: Experimental Design Place and Duration of Study: Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences and Department of Biochemistry, College of Health Sciences, University of Jos, Nigeria. Methodology: Crude methanolic leaf extracts were studied for their antioxidative properties; Iron reducing and Iron-chelating activities, Nitric oxide (NO) radical and 2,2-diphenyl 1-picrylhydrazyl (DPPH) radical scavenging activities and the lipid peroxidation and thiobarbituric acid reaction (TBAR) methods. One way ANOVA was used for the result analysis with P<.05 for significant difference. Results: Mistletoes from Psidum guajava (MSPG) had significantly higher reducing property (0.16 – 0.20mg/mL); the chelating property of Mistletoes from Moringa olifera (MSMO) was significantly lower (45.7 – 58.9%); DPPH radical scavenging activity had no significant difference; and Nitric oxide scavenging activity was significantly higher in MSPG (72.1% in 75mg/mL) than the extracts from other hosts. MSPG had significantly higher TBAR inhibition using both FeSO4 (77.8% at 125µg/mL) and Sodium nitroprusside (61.6+1.0% at 125µg/mL) with an IC50 of 30.27µg/mL . Extract of Tapinanthus globiferus leaves from Psidium guajava had more antioxidative activities in the TBARs followed by Tapinanthus globiferus leaf extract from Vernonia amygdalina (MSVA). Conclusion: From the study, mistletoes from Psidium guajava had higher antioxidant activity compared to other hosts, which probably justifies its use for treatment of cancer in traditional medicinal practice.


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