scholarly journals Polyphenolic Profile and Antioxidant Activity of Juglans regia L. Leaves and Husk Extracts

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 988 ◽  
Author(s):  
Anna Masek ◽  
Malgorzata Latos-Brozio ◽  
Ewa Chrzescijanska ◽  
Anna Podsedek

The aim of this study is to characterize the antioxidant capacity and establish the profile of polyphenolic compounds in walnut extracts (different extracts prepared from walnut leaf and green husks). The correlation between bioingredients of the product tested and their ability to scavenge free radicals and reduce them by chelating various metal ions were examined. Research technology combining TG (thermogravimetry), FTIR (Fourier-transform infrared spectroscopy), high-performance liquid chromatography system (HPLC) with electrochemical methods (cyclic and differential pulse voltammetry) and spectrophotometric methods (ABTS, FRAP, and DPPH assays) was used to rate the potential oxidation-reduction components of walnut extracts. A high affinity for scavenging free radicals ABTS and DPPH was found for natural substances present in leaves and green husks. The walnut is beneficial to health as it contains alpha-linolenic acid in its lipid fraction and, as demonstrated in this study, its husks are rich in polyphenolics with high antioxidant capacity.

2021 ◽  
Vol 11 (4) ◽  
pp. 1358
Author(s):  
Belma Imamović ◽  
Irmela Ivazović ◽  
Amra Alispahić ◽  
Ervina Bečić ◽  
Mirza Dedić ◽  
...  

Anti-aging cosmetics are often sought after in order to slow down the aging process. Free radicals are one of the main causes of skin aging, and therefore antioxidants are used in anti-aging cosmetics. The aim of this study was to investigate which method is the most suitable for determining the antioxidant capacity of these products. Having samples extracted, the antioxidant capacity of the extracts obtained was determined by the following spectrophotometric methods: DPPH, Folin-Ciocalteu, FRAP, the ABTS method and the ferroion chelation method with ferrosine. The antioxidant capacity of the samples varied depending on the extract type and the method used. DPPH and ferroion chelation measurements with ferrosine were carried out in the part of the spectrum where plant pigments absorb. These pigments are often found in anti-aging products affecting these methods measurement results. The Folin-Ciocalteu method is suitable for researching the antioxidant capacity of hydrophilic extracts, but not lipophilic ones, where turbidity and the formation of a gelled ring occur. The FRAP method revealed similar results for all the samples and proved to be less sensitive than the others. The ABTS method for both types of extracts has proven to be the most suitable and sensitive method for determining the antioxidant capacity of anti-aging products.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 503 ◽  
Author(s):  
Fernanda Pilaquinga ◽  
Dennis Amaguaña ◽  
Jeroni Morey ◽  
Mauricio Moncada-Basualto ◽  
Josué Pozo-Martínez ◽  
...  

The search for sensitive and rapid analytical techniques for the determination of natural antioxidants is an area in constant growth due, among other aspects, to the complexity of plant matrices. In this study, silver nanoparticles prepared with the aqueous extract of Mimosa albida leaves were used to assess their polyphenolic content and antioxidant capacity. Silver nanoparticles were characterized by different techniques. As a result, nanoparticles of 6.5 ± 3.1 nm were obtained. The total phenolic content in the extract was 1320.4 ± 17.6 mg of gallic acid equivalents GAE· 100 g−1 and in the nanoparticles 257.3 ± 5.1 mg GAE· 100 g−1. From the phenolic profile analyzed by ultra high-performance liquid chromatography (UPLC) with a diode-array detector (DAD), the presence of apigenin and luteolin in the plant extract is postulated. The antioxidant capacity measured by oxygen radical absorbance capacity ORAC-fluorescein assay was 86917 ± 6287 and 7563 ± 967 µmol ET g−1 in the extract and nanoparticles respectively. Electrochemical analysis by cyclic voltammetry (CV) confirmed the effective reduction capacity of the Mimosa albida leaves extract to reduce Ag ions to AgNPs and differential pulse voltammetry (DPV) suggested the presence of two main reducing agents in the extract. From this study, it was concluded that the aqueous extract of Mimosa albida contains reducing agents capable of synthesizing silver nanoparticles, which can be used in the phytochemical industry.


2019 ◽  
Vol 22 (7) ◽  
pp. 496-501
Author(s):  
Fatemeh Ahmadi-Motamayel ◽  
Parisa Falsafi ◽  
Hamidreza Abolsamadi ◽  
Mohammad T. Goodarzi ◽  
Jalal Poorolajal

Background: Cigarette smoke free radicals can cause cellular damage and different diseases. All the body fluids have antioxidants which protect against free radicals. Objective: The aim of this study was to evaluate salivary total antioxidant capacity and peroxidase, uric acid and malondialdehyde levels in smokers and a nonsmoking control group. Methods: Unstimulated saliva was collected from 510 males. A total of 259 subjects were current smokers and 251 were non-smokers. The levels of salivary total antioxidant capacity, uric acid, peroxidase and malondialdehyde were measured using standard procedures. Data were analyzed with t test and ANOVA. Results: The smokers were younger and dental hygiene index was higher than healthy nonsmoking controls. The mean total antioxidant capacity in smokers and nonsmokers was 0.13±0.07 and 0.21±011, respectively (P=0.001). Smokers had significantly lower peroxidase and uric acid levels than healthy controls. In addition, the mean malondialdehyde levels in the smokers and nonsmokers were 4.55 ±2.61 and 2.79 ±2.21, respectively (P=0.001). Conclusion: Cigarette smoke produces free radical and oxidative stress, causing many side effects. Salivary antioxidant levels decreased and malondialdehyde levels increased in smokers, indicating the high oxidative stress among smokers compared to nonsmokers. Cigarette smoke had deleterious effects on main salivary antioxidants levels.


2012 ◽  
Vol 1 (10) ◽  
pp. 79 ◽  
Author(s):  
G. Raja* ◽  
Ivvala Anand Shaker ◽  
Inampudi Sailaja ◽  
R. Swaminathan ◽  
S. Saleem Basha ◽  
...  

Natural antioxidants can protect the human body from free radicals and retard the progress of many chronic diseases as well as lipid oxidative rancidity in foods. The role of antioxidants has protected effect against free radical damage that may cause many diseases including cancer. Primary sources of naturally occurring antioxidants are known as whole grains, fruits, and vegetables. Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. The role of antioxidants has attracted much interest with respect to their protective effect against free radical damage that may cause many diseases including cancer. Juglans regia L. (walnut) contains antioxidant compounds, which are thought to contribute to their biological properties. Polyphenols, flavonoids and flavonols concentrations and antioxidant activity of Leaves, Stems and Nuts extract of Juglans regia L. as evaluated using DPPH, ABTS, Nitric acid, hydroxyl and superoxide radical scavenging activity, lipid peroxidation and total oxidation activity were determined. The antioxidant activities of Leaves, Stems and Nuts extract of Juglans regia L. were concentration dependent in different experimental models and it was observed that free radicals were scavenged by the test compounds in all the models.


NIR news ◽  
2019 ◽  
Vol 30 (5-6) ◽  
pp. 35-38
Author(s):  
Verena Wiedemair ◽  
Christian Wolfgang Huck

The use of ever smaller near-infrared instruments is becoming more and more prevalent, since they are cheaper, more versatile and often advertised as high-performance spectrometer. The last claim is rarely verified by independent researchers, which is why the presented work evaluates the performance of three hand-held spectrometers in comparison to a benchtop instrument. Seventy-seven samples comprising buckwheat, millet and oat were investigated for their total antioxidant capacity using Folin–Ciocalteu and near-infrared spectroscopy. Partial least squares regression models were established using cross- and test set validation. Results showed that all instruments were able to predict total antioxidant capacity to some extent. The coefficients of determinations ranged from 0.823 to 0.951 for cross-validated and from 0.849 to 0.952 for test set validated models. Errors for cross-validated models ranged from 1.11 to 2.08 mgGAE/g and for test set validated models from 1.02 to 1.86 mgGAE/g.


2019 ◽  
Vol 97 (2) ◽  
pp. 140-146
Author(s):  
Tian Gan ◽  
Zhikai Wang ◽  
Mengru Chen ◽  
Wanqiu Fu ◽  
Haibo Wang ◽  
...  

In this work, the Ag@Cu particles with yolk–shell nanostructure was prepared by facile solvothermal method, which was modified on glassy carbon electrode (GCE) to fabricate electrochemical sensor for the convenient and fast determination of p-aminobenzoic acid (PABA). The surface morphology and electrochemical properties of the as-prepared Ag@Cu nanocomposite modified electrode were characterized by scanning electron microscopy, transmission electron microscopy, chronocoulometry, and electrochemical impedance spectroscopy. Further, the electrochemical sensing of PABA was performed on the Ag@Cu/GCE using cyclic voltammetry and differential pulse voltammetry techniques, showing high catalytic activity. Under the optimal conditions, the sensor exhibited a wide linear range, high sensitivity, and low detection limit of 0.315 μmol/L for PABA. The developed sensor was also successfully applied for PABA detection in anesthetic and cosmetics with satisfactory results.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Zahra Sayyar ◽  
Alireza Yazdinezhad ◽  
Maryam Hassan ◽  
Iraj Jafari Anarkooli

Formaldehyde, as a frequently used compound in many applications, crosses the blood-brain barrier and leads to hippocampal cell death and memory impairment. This study investigates the effects of ethanolic extract of Matricaria chamomilla (MC) on passive avoidance learning induced by damaged hippocampal cells and evaluates the antioxidant traits of MC. The male Wistar rats were divided into six (6 in each) groups: control (10 mg/kg normal saline), 200 (200 mg/kg MC extract), 500 (500 mg/kg MC extract), F (10 mg/kg formaldehyde), F200 (10 mg/kg formaldehyde and 200 mg/kg MC extract), and F500 (10 mg/kg formaldehyde and 500 mg/kg MC extract). Shuttle box assay was used for evaluation of passive avoidance learning. The apoptosis rate of hippocampal tissue, malondialdehyde (MDA) free radicals, and total antioxidant capacity was evaluated to determine the positive effect of the ethanolic extract of MC. We found that the ethanolic extract of MC reduced the cell death, time spent in a dark room, and MDA free radicals in the hippocampus, leading to increased total antioxidant capacity in this region. In conclusion, the ethanolic extract of MC could ameliorate formaldehyde-induced memory damage through decreasing cell death and MDA activity of the hippocampal region and increasing total antioxidant capacity.


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