scholarly journals A Facile Electrochemical Analysis to Determine Antioxidant Activity of Bee Pollen

Author(s):  
Abdelkrim Rebiai ◽  
Touhami Lanez

The aim of this study was to determine the phenolic and flavonoid content, and antioxidant properties of tow samples of bee pollen harvested from Algeria. The content of total polyphenolic compounds, flavonoids, and antioxidant activity by the cyclic voltammetry method were determined. The contents of polyphenolic compounds was 22.68 mg/g for the pollen from Blida and 21,9 mg/g for Tipaza pollen. High antioxidant activities were found for the cyclic voltammetry method, with values that ranged from 22,3 to 27,63 mg of AAE·g–1 pollen. The bee pollen of Blida showed high antioxidant activity probably due to the high content of polyphenolic compounds present in pollen.

2013 ◽  
Vol 12 (06) ◽  
pp. 1350058 ◽  
Author(s):  
DAVOOD FARMANZADEH ◽  
MEYSAM NAJAFI

In this work, the antioxidant properties of the series of 10 aminothiazol hydroxyl coumarin derivatives have been investigated with DFT/B3LYP method. For these antioxidants all reaction enthalpies related to HAT, SPLET, SET-PT mechanisms were calculated in the gas phase and polar solvents. Based on calculated reaction enthalpies (BDE, IP and PA values) the derivations 2, 3 and 4 have the highest antioxidant activity among the studied compounds. Calculated results show that derivations 7, 5 and 6 have the lowest antioxidant activity. The observed theoretical trends for antioxidant activities of studied compounds were similar to trends of previous experimental studies that OH50, TAC50, IC50, CE50 values have been used as a benchmark for measuring the antioxidant properties of these compounds. These results can be useful in synthesis of novel aminothiazol hydroxycoumarin derivatives with high antioxidant activity. Calculated results show that BDE, PA and IP values of studied derivations have linear dependence with structure parameters such as R( O – H ), q( O ) and E HOMO . These observed linear dependences can be useful in synthesis of novel aminothiazol hydroxyl coumarin derivatives with high antioxidant activity. For studied compounds, results indicated that the SPLET and HAT mechanisms represent the thermodynamically preferred mechanism both, in solvent and the gas phase.


Chemistry ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 1-17
Author(s):  
Gopikrishna Agraharam ◽  
Agnishwar Girigoswami ◽  
Koyeli Girigoswami

Flavonoids are natural polyphenolic compounds that mainly possess antioxidant properties due to more hydroxyl groups in their structure and play an important role in combatting many diseases. Myricetin is a flavonoid found in grapes, green tea, fruits, and vegetables and is not only an antioxidant but also is a pro-oxidant. Myricetin is sparingly soluble in water and restricts its properties due to low bioavailability. The present study reports the liposomal nanoformulations of myricetin to improve its bioavailability with reduced pro-oxidant activity. The nanoformulated myricetin was characterized using different photophysical tools, such as dynamic light scattering (DLS), zeta potential, and scanning electron microscopy (SEM). The effect of nanoencapsulated myricetin on the developing zebrafish embryo was studied in terms of microscopic observations, cumulative hatchability, and antioxidant activities, such as catalase, glutathione peroxidase, and superoxide dismutase, after treating the zebrafish embryo with standard oxidant hydrogen peroxide. The results obtained from the cumulative hatchability, developmental studies, and antioxidant assays indicated that the liposomal nanoformulation of myricetin had enhanced antioxidant activity, leading to defense against oxidative stress. The formulation was highly biocompatible, as evidenced by the cumulative hatching studies as well as microscopic observations. The positive effects of liposomal nanoformulation on zebrafish embryos can open an avenue for other researchers to carry out further related research and to check its activities in clinical studies and developmental studies.


Author(s):  
Sergey Sergeevich Kletikov ◽  
Mariya Vasilyevna Tesakova ◽  
Vladislav Ruslanovich Kulagin ◽  
Mitar Lytovac ◽  
Vladimir Ivanovich Parfenyuk

The evaluation of antioxidant activity of porphyrin was carried out on the mutual reaction of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin with a free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). A cyclic voltammetry method was used to research the interaction of porphyrin and DPPH. The results of the electrochemical experiment served as a basis for testing antioxidant qualities of porphyrin on living creatures – chickens of the “Moscow-black” breed. During the duration of the research, no disturbance of physiological condition of the chickens was noticed, as well as any considerable change of body mass or causes of death. The data on blood’s antioxidant activity lets us evaluate the organism’s ability to defend itself from toxic influences of various oxygen-containing compounds. As data shows, the dilution Twin-80 with porphyrin does not lower the blood condition. During the experiment the following was noted: hydroxyl-containing porphyrin with concentrations of 10-4 mole/l lowers the amount of malondialdehyde and increases the amount of ceruloplasmin in blood, which leads to lowering the activity of oxidizing processes in a living organism, and also empowers the protein synthesizing function of the liver.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1688
Author(s):  
Angelica Faith L. Suarez ◽  
April Dawn G. Tirador ◽  
Zenith M. Villorente ◽  
Cathrina F. Bagarinao ◽  
Jan Vincent N. Sollesta ◽  
...  

Honey exhibits antibacterial and antioxidant activities that are ascribed to its diverse secondary metabolites. In the Philippines, the antibacterial and antioxidant activities, as well as the bioactive metabolite contents of the honey, have not been thoroughly described. In this report, we investigated the in vitro antibacterial and antioxidant activities of honey from Apis mellifera and Tetragonula biroi, identified the compound responsible for the antibacterial activity, and compared the observed bioactivities and metabolite profiles to that of Manuka honey, which is recognized for its antibacterial and antioxidant properties. The secondary metabolite contents of honey were extracted using a nonionic polymeric resin followed by antibacterial and antioxidant assays, and then spectroscopic analyses of the phenolic and flavonoid contents. Results showed that honey extracts produced by T. biroi exhibits antibiotic activity against Staphylococcal pathogens as well as high antioxidant activity, which are correlated to its high flavonoid and phenolic content as compared to honey produced by A. mellifera. The bioassay-guided fractionation paired with Liquid Chromatography Mass Spectrometry (LCMS) and tandem MS analyses found the presence of the flavonoid isorhamnetin (3-methylquercetin) in T. biroi honey extract, which was demonstrated as one of the compounds with inhibitory activity against multidrug-resistant Staphylococcus aureus ATCC BAA-44. Our findings suggest that Philippine honey produced by T. biroi is a potential nutraceutical that possesses antibiotic and antioxidant activities.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. S. Prasedya ◽  
A. Frediansyah ◽  
N. W. R. Martyasari ◽  
B. K. Ilhami ◽  
A. S. Abidin ◽  
...  

AbstractSample particle size is an important parameter in the solid–liquid extraction system of natural products for obtaining their bioactive compounds. This study evaluates the effect of sample particle size on the phytochemical composition and antioxidant activity of brown macroalgae Sargassum cristaefolium. The crude ethanol extract was extracted from dried powders of S.cristeafolium with various particle sizes (> 4000 µm, > 250 µm, > 125 µm, > 45 µm, and < 45 µm). The ethanolic extracts of S.cristaefolium were analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), phenolic compound concentration and antioxidant activities. The extract yield and phytochemical composition were more abundant in smaller particle sizes. Furthermore, the TPC (14.19 ± 2.08 mg GAE/g extract to 43.27 ± 2.56 mg GAE/g extract) and TFC (9.6 ± 1.8 mg QE/g extract to 70.27 ± 3.59 mg QE/g extract) values also significantly increased as particle sizes decreased. In addition, phenolic compounds epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and Epigallocatechin gallate (EGCG) concentration were frequently increased in samples of smaller particle sizes based on two-way ANOVA and Tukey’s multiple comparison analysis. These results correlate with the significantly stronger antioxidant activity in samples with smaller particle sizes. The smallest particle size (< 45 µm) demonstrated the strongest antioxidant activity based on DPPH, ABTS, hydroxyl assay and FRAP. In addition, ramp function graph evaluates the desired particle size for maximum phytochemical composition and antioxidant activity is 44 µm. In conclusion, current results show the importance of particle size reduction of macroalgae samples to increase the effectivity of its biological activity.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1262
Author(s):  
Shonisani Eugenia Ramashia ◽  
Felicia Matshepho Mamadisa ◽  
Mpho Edward Mashau

This study investigated the impact of Parinari curatellifolia peel flour on the nutritional, physical and antioxidant properties of formulated biscuits. Biscuits enriched with 5%, 10%, 15% and 20% of Parinari (P). curatellifolia peel flour were formulated and characterised. Thermal, physicochemical, polyphenolic compounds and antioxidant properties of flour and biscuits were determined. The incorporation of P. curatellifolia peel flour significantly increased (p < 0.05) thermal properties (onset, peak and conclusion temperatures) of flour. However, enthalpy of gelatinisation, viscosity and pH of flour samples decreased. Nutritional analysis revealed an increase in ash (0.74% to 2.23%) and crude fibre contents (0.39% to 2.95%) along with an increase of P. curatellifolia peel flour levels. Protein content and carbohydrates decreased while moisture content was insignificantly affected by the addition of P. curatellifolia peel flour. The L*, b* values and whiteness index of formulated biscuits decreased while parameter a* value (10.76 to 21.89) and yellowness index (69.84 to 102.71) decreased. Physical properties such as diameter (3.57 mm to 3.97 mm), spread ratio (2.67 to 3.45) and hardness (1188.13 g to 2432.60 g) increased with the inclusion levels of peel flour while weight and thickness decreased. The inclusion of P. curatellifolia improved the polyphenolic compounds and antioxidant activity of biscuits with values of total flavonoids content ranging from 0.028 to 0.104 mg CE/g, total phenolic content increasing from 20.01 mg to 48.51 mg GAE/g, ferric reducing antioxidant power (FRAP) increasing from 108.33 mg to 162.67 mg GAE/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) from 48.70% to 94.72%. These results lead to the recommendation of the utilisation of P. curatellifolia peel flour to enhance the nutritional value, polyphenolic compounds and antioxidant activity of bakery products such as biscuits.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1127 ◽  
Author(s):  
Beatriz Chamorro ◽  
David García-Vieira ◽  
Daniel Diez-Iriepa ◽  
Estíbaliz Garagarza ◽  
Mourad Chioua ◽  
...  

Herein, we report the neuroprotective and antioxidant activity of 1,1′-biphenyl nitrones (BPNs) 1–5 as α-phenyl-N-tert-butylnitrone analogues prepared from commercially available [1,1′-biphenyl]-4-carbaldehyde and [1,1′-biphenyl]-4,4′-dicarbaldehyde. The neuroprotection of BPNs1-5 has been measured against oligomycin A/rotenone and in an oxygen–glucose deprivation in vitro ischemia model in human neuroblastoma SH-SY5Y cells. Our results indicate that BPNs 1–5 have better neuroprotective and antioxidant properties than α-phenyl-N-tert-butylnitrone (PBN), and they are quite similar to N-acetyl-L-cysteine (NAC), which is a well-known antioxidant agent. Among the nitrones studied, homo-bis-nitrone BPHBN5, bearing two N-tert-Bu radicals at the nitrone motif, has the best neuroprotective capacity (EC50 = 13.16 ± 1.65 and 25.5 ± 3.93 μM, against the reduction in metabolic activity induced by respiratory chain blockers and oxygen–glucose deprivation in an in vitro ischemia model, respectively) as well as anti-necrotic, anti-apoptotic, and antioxidant activities (EC50 = 11.2 ± 3.94 μM), which were measured by its capacity to reduce superoxide production in human neuroblastoma SH-SY5Y cell cultures, followed by mononitrone BPMN3, with one N-Bn radical, and BPMN2, with only one N-tert-Bu substituent. The antioxidant activity of BPNs1-5 has also been analyzed for their capacity to scavenge hydroxyl free radicals (82% at 100 μM), lipoxygenase inhibition, and the inhibition of lipid peroxidation (68% at 100 μM). Results showed that although the number of nitrone groups improves the neuroprotection profile of these BPNs, the final effect is also dependent on the substitutent that is being incorporated. Thus, BPNs bearing N-tert-Bu and N-Bn groups show better neuroprotective and antioxidant properties than those substituted with Me. All these results led us to propose homo-bis-nitrone BPHBN5 as the most balanced and interesting nitrone based on its neuroprotective capacity in different neuronal models of oxidative stress and in vitro ischemia as well as its antioxidant activity.


Author(s):  
M. Suleman Stephen ◽  
E. A. Adelakun ◽  
J. H. Kanus ◽  
Meshack M. Gideon

The presence of natural antioxidant in plants is well known. Plant phenolics constitute one of the major groups of components that act as antioxidant and free radical terminator. Hence, this study focused on investigating the antioxidant activity of Celery plant (Apium graveolens L). The fresh leaves were collected, crushed and extracted with ethanol and acetone by maceration. The radical scavenging properties of the extracts were determined by measuring changes in absorbance of DPPH radical at a wave lenght of 517 nm by UV and ascorbic acid is used as the standard. It showed that the crude ethanolic extract has higher antioxidant activity compared to ascorbic acid and acetone extract with less scavenging activity. The values were (IC50 114.6 µg/mL) for ascorbic acid, (IC50 112 µg/mL) for the crude ethanolic extract and (IC50172 µg/mL) for crude acetone extract. The result shows that Celery plant grown in Jos possess good antioxidant properties which may be linked to the presence of phenolics and flavonoids in the plant, which justifies its use as a medicinal plant. This can be further investigated for the isolation and identification of active compounds of medicinal utilities.


2021 ◽  
Vol 2 (1) ◽  
pp. 028-033
Author(s):  
Hugues Calixte Eyi Ndong ◽  
André Ledoux Njouonkou

Macrolepiota africana is a fungus used as food in Gabon for its culinary properties. However, its nutritional value, mycochemical contents, antioxidant properties and health potential still unknown. The present study investigated the phytochemicals and antioxidant properties of this mushroom species. This chemical screening was followed by a study of the antioxidant activity and a prediction of additional pharmacological activities of M. africana. Using standard methodology, the mycochemical analyses were carried out on aqueous, hydro-ethanolic and ethanolic fungi extracts. The antioxidant activity of the mushroom extracts was determined using DPPH radical scavenging assay. Apart from Digitoxigenine, flavonol and gitoxigenine that were not found in any of the extracts, all other tested mycochemical were found in atleast one of the extracts. Alkaloids, flavonoids, polyphenols, oses and holosides, proanthocyanidins and coumarins were found in all extracts at different intensity. Saponosids, sterols and triterpenes, tannins gallics, reducing sugar, anthracenosides and digitoxine were found in two extracts while tannins catechics, flavone and gitoxine were detected only in one extract. The dosage of phenolic compounds confirmed the richness of this fungus in total polyphenols, its moderate richness in proanthocyanidins, the lack of flavonoids in the aqueous extract and the moderate richness of the hydro-ethanolic and ethanolic extracts in flavonoids. Regarding the antioxidant activities, the results obtained for the DPPH trapping test showed that the different extracts had low to moderate antioxidant activity with antioxidant activity index (IAA) ranged 0.29 to 0.97 respectively in aqueous and ethanolic extracts. The presence of these mycochemical compounds along with the identified antioxidant activities shows that this M. africana have some pharmacological potential.


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