scholarly journals Evaluation of the Antioxidant Capacities of Antarctic Macroalgae and Their Use for Nanoparticles Production

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1182
Author(s):  
N. González-Ballesteros ◽  
M. C. Rodríguez-Argüelles ◽  
M. Lastra-Valdor

Macroalgae are sources of bioactive compounds that are interesting from both a chemical and a medical point of view. Although their use in biomedicine has increased significantly in recent years, tests conducted to date have been mostly related to species from temperate latitudes, with the potential application of Antarctic biodiversity being minor. The wide variety of algae species present on Antarctic coastal areas can be a source of new antioxidants. Bearing this in mind, the brown macroalgae Desmarestia antarctica (DA) and the red Iridaea cordata (IC) were selected for the preparation of aqueous extracts with the aim of analyzing their antioxidant activity. This analysis was performed by determining reducing power, total phenolic content, and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. Furthermore, both extracts were employed to synthesize gold and silver nanoparticles. The nanomaterials were fully characterized by means of UV-Visible spectroscopy, transmission electron microscopy, Z potential measurements, and Fourier transform infrared spectroscopy, which confirmed the formation of stable, spherical nanoparticles with mean diameters of 13.7 ± 3.1 and 17.5 ± 3.7 nm for Ag@DA and Ag@IC and 12.6 ± 1.9 and 12.3 ± 1.6 nm for Au@DA and Au@IC. Antioxidant assays were performed after the synthesis of the nanomaterials to evaluate their possible synergistic effect with the extracts. The results suggest that polysaccharides and proteins may play a key role in the process of reduction and stabilization. Finally, for the sake of comparison, the results obtained for the Antarctic macroalgae Desmarestia menziesii and Palmaria decipiens have also been considered in the present work.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shahinuzzaman ◽  
Parul Akhtar ◽  
N. Amin ◽  
Yunus Ahmed ◽  
Farah Hannan Anuar ◽  
...  

AbstractIn this study, the extraction conditions extracted maximize amounts of phenolic and bioactive compounds from the fruit extract of Ficus auriculata by using optimized response surface methodology. The antioxidant capacity was evaluated through the assay of radical scavenging ability on DPPH and ABTS as well as reducing power assays on total phenolic content (TPC). For the extraction purpose, the ultrasonic assisted extraction technique was employed. A second-order polynomial model satisfactorily fitted to the experimental findings concerning antioxidant activity (R2 = 0.968, P < 0.0001) and total phenolic content (R2 = 0.961, P < 0.0001), indicating a significant correlation between the experimental and expected value. The highest DPPH radical scavenging activity was achieved 85.20 ± 0.96% at the optimum extraction parameters of 52.5% ethanol (v/v), 40.0 °C temperature, and 22 min extraction time. Alternatively, the highest yield of total phenolic content was found 31.65 ± 0.94 mg GAE/g DF at the optimum extraction conditions. From the LC–ESI–MS profiling of the optimized extract, 18 bioactive compounds were tentatively identified, which may regulate the antioxidant activity of fruits of F. auriculata.


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.


2017 ◽  
Vol 71 (5) ◽  
pp. 361-370
Author(s):  
Slavica Grujic ◽  
Ana Dzamic ◽  
Violeta Mitic ◽  
Vesna Stankov-Jovanovic ◽  
P.D. Marin ◽  
...  

Antioxidant and free radical scavenging activity of methanol, ethanol, ethyl acetate and chloroform extracts of aerial parts of Lamium purpureum L. was determined by DPPH, ABTS, FRAP and TRP assays. Contents of flavonoids and phenols were also investigated. The total phenolic content in the extracts, determined using Folin?Ciocalteu assay, ranged between 8.57 to 128.00 mg GAE/g d.e. while concentrations of flavonoids in the extracts varied from 24.20 to 39.80 mg QuE/g d.e. The highest phenolic content was found in methanol extract (128.00 mg GAE/g d.e.). The highest content of total flavonoids was identified in the methanol extract (39.80 mg QuE/g d.e.) and the lowest was in the chloroform (24.30 mg QuE/g d.e.). DPPH scavenging of the extracts was determined and obtained IC50 values ranged from 0.12 to 3.12 mg/mL of solution. The values of ABTS radical scavenging activity ranged from 0.35 to 1.80 mg AA/g. The highest ABTS antiradical activity was registered for methanol extract. The FRAP value was found within the range 0.08 to 1.04 ?mol Fe/mg. The best radical scavenger was methanol (1.04 ?mol Fe/mg). In reducing power assay different extracts of L. purpureum showed increasing of activity with increased concentration, and all extracts possessed substantial dose dependent antioxidant activity. The best reducing capacity was obtained with methanol extract of L. purpureum (0.0132 mg AA/mL). The results in this study confirmed that L. purpureum possesses moderate antioxidant properties.


Author(s):  
Khurul Ain Mohamed Mahzir ◽  
Siti Salwa Abdul Gani ◽  
Nor Fadzillah Mokhtar

In this study, the optimal condition for the extraction of antioxidants from the fruit Buah Mahkota Dewa (Phaleria macrocarpa) was determined by using Response Surface Methodology (RSM). The optimization was applied using central composite design (CCD) to investigate the three independent variables, namely extraction temperature (oC), extraction time (minutes) and extraction solvent to-feed ratio (%v/v) on the responses of free radical scavenging activity (DPPH), ferric ion reducing power assay (FRAP), total phenolic content (TPC) and total flavonoid content (TFC).The optimal conditions for the antioxidants extraction were found to be extraction temperature (64oC), extraction time (66 minutes) and solvent to-feed ratio (75 %v/v) with the highest percentage yield of DPPH, FRAP, TPC and TFC were 86.85%, 7.47%, 292.86 mg/g and 3.22 mg/g respectively. Moreover, the data were subjected to response surface methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack of fit, and presented adjusted determination coefficients (R2) above 99%, proving the yield of phenolic, flavonoid and antioxidants activities obtained experimentally were close to the predicted values and the suitability of the model employed in RSM to optimize the extraction conditions. Hence, in this study, the fruit from P.macrocarpa could be considered to have the strong antioxidant ability and can be used in various cosmeceutical or medicinal applications.


2013 ◽  
Vol 11 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Ishrat Nimmi ◽  
Ismet Ara Jahan ◽  
M Hemayet Hossain ◽  
Mohammad Burhan Uddin ◽  
M Sohel Rana ◽  
...  

A comparative study of antioxidant properties on two varieties of Phyllanthus (Phyllanthus niruiri L. & Phyllanthus urinaria L. leaves) growing in Bangladesh was done in the present study. Five complimentary test methods namely DPPH free radical scavenging activity, reducing power assay, total antioxidant capacity, total phenolic and flavonoid contents determination were used for the evaluation of antioxidant properties of two species of Phyllanthus. In the present investigation for the evaluation of antioxidant activities the concentration is expressed by the ratio of crude sample per solvent volume instead of extract weight per solvent volume. Based on these concentrations the investigated P. niruri L. and P. urinaria L. leaves extracts exhibited significant results. At 2 mg/ml concentration DPPH radical scavenging capacity of the methanol extract of both the plants was found to show significant (>90%) activity which is comparable to Ascorbic acid and BHA. In case of reducing power tests for both the extract, the activity of P. urinaria is comparable to that of BHA and AA and that of P. niruiri is comparable to BHA. P. niruiri showed better antioxidant potential than that of P. urinaria based on the observed results of their corresponding methanol extract. DOI: http://dx.doi.org/10.3329/dujps.v11i2.14579 Dhaka Univ. J. Pharm. Sci. 11(2): 191-197, 2012 (December)


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1552
Author(s):  
Muhammad Arslan Ahmad ◽  
Rabia Javed ◽  
Muhammad Adeel ◽  
Muhammad Rizwan ◽  
Yuesuo Yang

This study addresses the favourable effects of drought stress imposed by polyethylene glycol (PEG) 6000 on the micropropagated shoots of Stevia rebaudiana. Various concentrations, i.e., 0, 0.5, 1, 2, and 4% of PEG 6000 were applied to the nodal shoot explants for four weeks, and the influence produced on shoots growth parameters, bioactive steviol glycosides (rebaudioside A and stevioside), and nonenzymatic antioxidant activities (total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), total reducing power (TRP) and 1,1-diphenyl-2-picrylhydrazyl(DPPH)-free radical scavenging activity (FRSA)) was elucidated. The significantly highest yield (92.4% direct shoot organogenesis) and secondary metabolites (2.94% Reb A, 2.52% ST, 95.3% DPPH-FRSA, 15.0% TPC, 13.0 µg/mg TFC, 22.3 µg/mg TAC, and 19.8 µg/mg TRP) production in response to abiotic stress elicitors was obtained in Murashige and Skoog (MS) medium treatment provided with 4% of PEG 6000. The overall trend was significant enhancement of growth dynamics and pharmaceutical compounds from control to 4% of PEG 6000 concentration as a defensive response against reactive oxygen species (ROS) produced in excess by water deficit. This is a very promising study to be employed in bioreactors to get markedly enhanced content of compounds of medicinal importance in the pharmaceutical market.


Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1772 ◽  
Author(s):  
Mi-Hyeon Kim ◽  
Dae-Hun Park ◽  
Min-Suk Bae ◽  
Seung-Hui Song ◽  
Hyung-Ju Seo ◽  
...  

We evaluated the antioxidant and antibacterial activity of hexnane, ethyl acetate, acetone, methanol, ethanol, and water extracts of the Quercus acuta leaf. The antioxidant properties were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power, and total phenolic content. Antibacterial activity was assessed against general infectious pathogens, including antibiotic-resistant clinical isolates. The methanolic extract showed the highest DPPH radical scavenging activity and total phenolic content, while the reducing power was the highest in the water extract. The ethyl acetate extract showed the best antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Additionally, it displayed antibacterial activity against Staphylococcus aureus KCTC1928, Micrococcus luteus ATCC 9341, Salmonella typhimurium KCTC 1925, Escherichia coli KCTC 1923, and eight MRSA strains. These results present basic information for the possible uses of the ethanolic and ethyl acetate extracts from Q. acuta leaf in the treatment of diseases that are caused by oxidative imbalance and antibiotic-resistant bacterial infections. Six active compounds, including vitamin E, which are known to possess antioxidant and antibacterial activity, were identified from the extracts. To the best of our knowledge, this is the first study that reports the chemical profiling and antibacterial effects of the various QA leaf extracts, suggesting their potential use in food therapy or alternative medicine.


Author(s):  
Joseph Adusei Sarkodie ◽  
Sylvia Afriyie Squire ◽  
Emelia Oppong Bekoe ◽  
Charles Yaw Fosu Domozoro ◽  
Irene Awo Kretchy ◽  
...  

Abstract: The leaves of: The total phenolic content, total flavonoids content, radical scavenging activity and reducing power assays were estimated using Folin–Ciocalteu method, aluminium chloride colorimetric assay, Fe: The results showed that: These findings justify the folkloric use of


Author(s):  
Rajendran Raja Priya ◽  
N. Bhadusha ◽  
Veramuthu Manivannan ◽  
Thanthoni Gunasekaran

Objective: To evaluate the preliminary phytochemical content and antioxidant potential of the hydroalcoholic leaf extracts of Hemionitis arifolia. Methods: Total phenolic, flavonoid and alkaloid contents were evaluated using spectrophotometric methods. The free radical scavenging activity of the leaf hydroalcoholic extract were evaluated against DPPH+, ABTS+, Reducing power assay and nitric oxide assay were determined. Results: The hydroalcoholic concentrate of H. arifolia uncovered the most elevated polyphenol content when contrasted and the other phytoconstituents. Absolute phenol content of the hydroalcoholic separate was observed to be 31.78%, flavonoid content is 1.02% and Alkaloid content is 30.40% individually. The Solvent concentrates showed huge cell reinforcement movement, with hydroalcoholic extract. ABTS Assay, DPPH assay, Reducing power assay and Nitric oxide assay where the Inhibition concentration were 667.75µg/ml, 734.25 µg/ml, 791.58 µg/ml and 899.67 µg/ml. Conclusion: This study suggests that hydroalcoholic leaf extracts of H. arifolia could be a potential source of natural antioxidant and justifies its use in ethno-medicine.


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