scholarly journals Optimising the DPPH Assay for Cell-Free Marine Microorganism Supernatants

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 256
Author(s):  
Yehui Gang ◽  
Tae-Yang Eom ◽  
Svini Dileepa Marasinghe ◽  
Youngdeuk Lee ◽  
Eunyoung Jo ◽  
...  
Keyword(s):  
Water Content ◽  
Antioxidant Activities ◽  
Fermented Foods ◽  
Solution Stability ◽  
Marine Microorganism ◽  
Marine Microorganisms ◽  
Dpph Assay ◽  
Aqueous Methanol ◽  
Potential Applications ◽  
Pseudoalteromonas Rubra

Antioxidants prevent ageing and are usually quantified and screened using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. However, this assay cannot be used for salt-containing samples, such as the cell-free supernatants of marine microorganisms that are aggregated under these conditions. Herein, the DPPH solvent (methanol or ethanol) and its water content were optimized to enable the analysis of salt-containing samples, aggregation was observed for alcohol contents of >70%. The water content of methanol influenced the activities of standard antioxidants but did not significantly affect that of the samples. Based on solution stability considerations, 70% aqueous methanol was chosen as the optimal DPPH solvent. The developed method was successfully applied to the cell-free supernatants of marine bacteria (Pseudoalteromonas rubra and Pseudoalteromonas xiamenensis), revealing their high antioxidant activities. Furthermore, it was concluded that this method would be useful for the screening of marine microorganism–derived antioxidants, which also has numerous potential applications, such as salt-fermented foods.

scholarly journals Evaluation of Pterospermum suberifolium L. Willd Leaves for the Phytochemical Constituents and their in vitro Activities

2020 ◽  
Vol 11 (3) ◽  
pp. 547-553
Author(s):  
Baskar Mohan ◽  
Vadamalai Krishnan K ◽  
Muthuraman K
Keyword(s):  
Leaf Extract ◽  
Antioxidant Activities ◽  
Quantitative Estimation ◽  
Antimicrobial Properties ◽  
Dpph Assay ◽  
Aqueous Methanol ◽  
Leaf Extracts ◽  
High Antioxidant Activity ◽  
Phytochemical Constituents

The present study was intended to investigate the phytochemical constituents present in the leaves of Pterospermum suberifolium L. WILLD and the in vitro  antioxidant and antimicrobial properties of the various extracts prepared by different solvents including aqueous, methanol, ethyl acetate and hexane. The crude extracts were screened for the presence of various phytochemical constituents and the presence of phenols, tannins, flavonoids, saponins and alkaloids were ascertained. The quantitative estimation of phenols and flavonoids were determined. The antioxidant activities of the plant leaf extracts were determined by the DPPH assay, the Phosphomolybdenum assay and the Nitric oxide scavenging assay. It was found that methanolic leaf extract of P. suberifolium possessed high antioxidant activity and found to have potential phytochemical constituents. 

scholarly journals Extraction of Carotenoids from Pumpkin Peel and Pulp: Comparison between Innovative Green Extraction Technologies (Ultrasonic and Microwave-Assisted Extractions Using Corn Oil)

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 787
Author(s):  
Minaxi Sharma ◽  
Rajeev Bhat
Keyword(s):  
Corn Oil ◽  
Antioxidant Activities ◽  
Food Product ◽  
Extraction Techniques ◽  
Protection Factor ◽  
Total Carotenoids ◽  
Green Extraction ◽  
Microwave Assisted ◽  
Potential Applications ◽  
Conventional Extraction

Natural pigments improve aesthetic value as well as antioxidant potential of a food product. This study was designed to determine the effects of green extraction techniques on carotenoids, polyphenols and antioxidant activities of pulp and peel of two varieties of pumpkin (Cucurbita maxima). Innovative green extractions (IGE; Ultrasound and Microwave-Assisted Extractions) synergised with corn oil (used as green solvent) were compared with conventional extraction (CE; hexane/isopropyl alcohol; 60:40, v/v). Results showed total carotenoids to be almost double on employing IGE (PM2-UAE-peel = 38.03 ± 4.21; PM4-UAE-peel = 33.78 ± 1.76 µg/g) when compared to conventional extraction (PM2-CE-peel = 19.21 ± 4.39; PM4-CE-peel = 16.21 ± 2.52 µg/g). Polyphenolic contents ranged between 510.69 ± 5.50 and 588.68 ± 7.26 mg GAE/100 g of extract in IGE, compared with conventional extracts (269.50 ± 2.17 to 318.46 ± 6.60 mg GAE/100 g) and percent inhibition of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) ranging between 88.32 ± 1.51 and 93.53 ± 0.30% in IGE when compared with conventional extraction (50.61 ± 1.44 to 57.79 ± 2.09%). Further, oxidative stability of carotenoids extracts from IGE (protection factor = 1.59 ± 0.01 to 1.81 ± 0.05) were found to be significantly higher (p < 0.05) than conventional extracts. Based on results, this study supports the use of innovative green extraction techniques to obtain bioactive pigments like carotenoids. It is anticipated that results generated will find potential applications in food, pharmaceutical and cosmetic industries.

scholarly journals ANTIOXIDANT EVALUATION AND PHYTOCHEMICAL CONTENT OF VARIOUS RICE BRAN EXTRACTS OF THREE VARIETIES RICE FROM SEMARANG-CENTRAL JAVA, INDONESIA

2017 ◽  
Vol 10 (6) ◽  
pp. 377 ◽  
Author(s):  
Sukrasno Sukrasno ◽  
Slamet Tuty ◽  
Irda Fidrianny
Keyword(s):  
Rice Bran ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Carotenoid Content ◽  
Total Phenolic ◽  
Red Rice ◽  
Black Rice ◽  
Dpph Assay ◽  
Rice Bran Extract ◽  
Dpph Scavenging

Objectives: The objectives of this research were to evaluate antioxidant activity from different polarities rice bran extract of three varieties of rice using two methods of antioxidant testing which were FRAP (Ferric Reducing Antioxidant Power) and DPPH (2,2-diphenyl-1-picrylhydrazyl), and correlation of total phenolic, flavonoid and carotenoid content with their EC50 of FRAP and IC50 of DPPH antioxidant activities. Methods: Extraction was conducted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Determination of total phenolic, flavonoid and carotenoid content, antioxidant activities using FRAP and DPPH assays were performed by UV-visible spectrophotometry and its correlation with EC50 of FRAP capacities and IC50 of DPPH scavenging activities were analyzed by Pearson’s method. Results: Ethanolic rice bran extract of black rice showed the lowest EC50 of FRAP capacity 64.35 µg/ml and IC50 of DPPH scavenging activity 23.92 µg/ml. The highest phenolic content, flavonoid content and carotenoid content were also given by ethanolic rice bran extract of black rice. There were significantly negative correlation between total phenolic content and carotenoid content in rice bran extract of red rice and black rice with their IC50 of DPPH. Conclusions: All of rice bran extracts (except n-hexane rice bran extract of black rice and ethanolic rice bran extract of white rice) were very strong antioxidant, by DPPH assay. Phenolic and carotenoid compounds in rice bran extracts of red rice and black rice were the major contributor in antioxidant activity by DPPH assay. Rice bran extracts of black rice had linear results by FRAP and DPPH assays. 

scholarly journals Fatty acid, mineral content and antioxidant activities of Algerian fat bee pollen

2020 ◽  
Vol 19 (2) ◽  
pp. 208-215
Author(s):  
Bakchiche Boulanouar ◽  
Hadjira Guenane ◽  
Bihter Sahin ◽  
Mehmet Öztürk ◽  
Mosad Ghareeb ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fatty Acid ◽  
Specific Gravity ◽  
Antioxidant Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Total Phenolic ◽  
Dpph Assay ◽  
Bee Pollen ◽  
Iodine Values ◽  
Promising Source

Bee pollen is known for its nutritional value, and therefore it is used in the treatment of some health disorders as food supplements. Herein, the chemical fatty acid profile and mineral contents of two Algerian bee pollen collected from different regions were investigated, along with their physicochemical properties such as specific gravity, refractive index, and acid, saponification, and iodine values. In addition, their total phenolic contents (TPC) were also investigated. Gas chromatography/mass spectrometry (GC/MS) analysis revealed that the bee pollens mainly contained palmitic (17.0 and 26.5 %), oleic (8.5 and 10.1 %), linoleic (15.7 and 12.6 %) and linolenic acids (27.2 and 26.3 %), respectively. The saponification values were 178.54 and 175.73 mg KOH.g-1, while the specific gravity 0.915 and 0.924, the refractive index 1.465 and 1.464, and acid values 22.04, and 10.01 mg KOH.g-1 oil. The iodine values were, however, 44.42 and 32.90 mg I2.g-1 fat, respectively. Potassium and sodium were the main detected elements in both pollen samples with variable percentages. In the DPPH assay, the IC50 was 4.88 and 1.73 mg.mL-1 for samples 1 and 2, respectively, ABTS and phosphomolybdenum assays supported DPPH assay results. It was concluded that the fat part of bee pollen by honeybees (Apis mellifera L.) is a promising source of naturally occurring antioxidants and nutrients.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

scholarly journals Tree Bark Phenols Regulate the Physiological and Biochemical Performance of Gladiolus Flowers

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 71 ◽  
Author(s):  
Hosam O. Elansary
Keyword(s):  
Water Content ◽  
Microbial Growth ◽  
Antioxidant Activities ◽  
Soluble Sugars ◽  
Tree Bark ◽  
Flower Senescence ◽  
Bark Extract ◽  
Plant Residues ◽  
Vase Life ◽  
Gas Exchange Parameters

The postharvest physiology of cut flowers is largely dependent on vase life, which is the maximum number of days before flower senescence. The use of tree bark extracts (major forest plant residues), as an eco-friendly and natural antioxidant preservative in holding solutions, is a novel tool for extending flower longevity. The morphological, physiological, biochemical, and genetic responses of Gladiolus grandiflorus cut spikes to Magnolia acuminata and Taxus cuspidata bark extracts as additives in holding solutions were investigated. G. grandiflorus subjected to bark extracts as well as catechin and protocatechuic acid (main phenols) displayed significant increased longevity (up to 18 days), an increased number of open florets, and increased floret fresh weight. Increases in the relative water content, leaf chlorophyll, carotenoids, soluble sugars, and protein content were observed in addition to a reduction in microbial growth in the cut spikes. Gas exchange parameters were higher in the bark extract treatments than in the controls. Higher antioxidant activities were detected and associated with increased superoxide dismutase and catalase enzyme activities and reduced H2O2 accumulation. The bark extract treatments associated with reduced expression of GgCyP1 (produces cysteine protease) and increased expression of both GgDAD1 (defends against apoptotic activity) and GgEXPA1 (regulates petal expansion). Several mechanisms were implicated in these effects, including maintenance of water content, enhanced management of reactive oxygen species (ROS), increased sugar and protein composition, and control of microbial growth. Thus, bark extracts and isolated phenols could be developed as an eco-friendly, non-toxic, and cost-effective natural preservative for cut gladiolus flowers.

scholarly journals In-vitro Anti-diabetic and Antioxidant Efficacy of Methanolic Extract of Canthium coromandelicum Leaves

2020 ◽  
pp. 12-18
Author(s):  
S. Thiripura Salini ◽  
S. Shankar
Keyword(s):  
Diabetic Complications ◽  
Methanolic Extract ◽  
Antioxidant Activities ◽  
Antidiabetic Activity ◽  
Dpph Radical ◽  
Dpph Assay ◽  
Ic50 Value ◽  
Ic50 Values ◽  
In Vitro Antioxidant Activity

Oxidative stress plays a major role in diabetic complications. The study aim was to investigate the in-vitro antidiabetic and antioxidant activities of methanolic extract of Canthium coromandelicum leaves. The plant material was extracted with methanol and the methanolic extract was screened for in-vitro antioxidant activity using 1, 1-diphenyl-2-picryl hydrazyl (DPPH) assay. The efficiency of the antidiabetic activity of the plant extract was evaluated against α-amylase and α-glucosidase digestive enzymes. The study revealed that the C. coromandelicum extract exhibited significant α-amylase and α-glucosidase inhibitory activities with an IC50 value of 31.52 ± 0.42 and 41.49 ± 0.28 µg/mL respectively and compared with standard acarbose drug. The extract efficiently scavenging DPPH radical with IC50 values of 65.46 ± 0.50 µg/ml. Therefore, the extract could be a promising therapeutic in management of diabetic complications.

scholarly journals NMR metabolomics revealed metabolites and bioactivity variation in Torbangun leaves Plectranthus amboinicus L. with different origins

2018 ◽  
Vol 23 (2) ◽  
pp. 91
Author(s):  
Nancy Dewi Yuliana ◽  
Muhammad Anwari Sugiharto ◽  
Hanifah Nuryani Lioe ◽  
Masao Goto ◽  
Yuko Takano Ishikawa
Keyword(s):  
Comparative Analysis ◽  
Environmental Factors ◽  
Secondary Metabolite ◽  
Antioxidant Activities ◽  
Metabolite Profile ◽  
Total Flavonoids ◽  
Dpph Assay ◽  
Nmr Metabolomics ◽  
Plectranthus Amboinicus ◽  
Different Origins

Plectranthus amboinicus has been reported to have antidiabetic and antioxidant activities. Environmental factors might influence the plant’s secondary metabolite profile and its beneficial properties. NMR-based metabolomics was used to show phytochemical variations between specimens of P. amboinicus grown in Japan and Indonesia. The results showed that flavonoids and triterpenes were among the discriminating factors of the variation between the two groups. Targeted comparative analysis of the concentration of the specific flavonoids of the plants using a validated HPLC-MWD method showed that the Japanese samples contained a higher concentration of total flavonoids compared with the Indonesian samples. The Japanese and Indonesian samples contained 1100.6 ± 5.1 and 532.4 ± 1.8 µg/g luteolin, and 584.5 ± 7.4 and 571.7 ± 11.6 µg/g apigenin, respectively. Eriodyctiol was detected only in the Indonesian samples. Contrarily, more intensive DPPH reduction and α-glucosidase inhibition activities were found in the Indonesian samples (IC50 14.4 ± 1.2 and 24.0 ± 0.3 µg/mL for the DPPH assay, 1181.9 ± 113.5 and 4451.4 ± 290.0 µg/mL for α-glucosidase inhibition, respectively). Thus, flavonoids might not be the only group of compounds related to the aforementioned bioactivities. This should be confirmed by further research targeting other groups of compounds, such as triterpenes.

scholarly journals Lyophilized cell-free supernatants of Lactobacillus isolates exhibited antibiofilm, antioxidant, and reduces nitric oxide activity in lipopolysaccharide-stimulated RAW 264.7 cells

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12586
Author(s):  
Phoomjai Sornsenee ◽  
Moragot Chatatikun ◽  
Watcharapong Mitsuwan ◽  
Kantapich Kongpol ◽  
Nateelak Kooltheat ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Molecular Mechanisms ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Pharmaceutical Products ◽  
Raw 264.7 Cells ◽  
Total Phenolic ◽  
Antibiofilm Activity ◽  
Fermented Foods ◽  
Raw 264.7

Background Probiotics can release bioactive substances known as postbiotics, which can inhibit pathogenic microorganisms, improve immunomodulation, reduce antioxidant production, and modulate the gut microbiota. Methods In this study, we evaluated the in vitro antimicrobial effects, antioxidant activity, and anti-inflammatory potential of 10 lyophilized cell-free supernatants (LCFS) of Lactobacillus isolates. LCFS was obtained via centrifugation and subsequent lyophilization of the supernatant collected from the culture medium ofeach isolate. The antibacterial and antibiofilm activities of the LCFS were determined using broth microdilution. The antioxidant potential was evaluated by measuring the total phenolic and flavonoid contents and 2,2-Diphennyl-1-picrylhydrazyl (DPPH) and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+) radical scavenging activities. Results All the isolates were able to inhibit the four tested pathogens. The isolates exhibited strong antibiofilm activity and eradicated the biofilms formed by Acinetobacter buamannii and Escherichia coli. All the prepared Lactobacillus LCFS contained phenols and flavonoids and exhibited antioxidant activities in the DPPH and ABTS+ radical scavenging assays. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay revealed that LCFS was not cytotoxic to RAW 264.7 cells. In addition, the ten Lactobacillus LCFS decreased the production of nitric oxide. Conclusions All the isolates have beneficial properties. This research sheds light on the role of postbiotics in functional fermented foods and pharmaceutical products. Further research to elucidate the precise molecular mechanisms of action of probiotics is warranted.

scholarly journals Fermented Seeds (“Zgougou”) from Aleppo Pine as a Novel Source of Potentially Probiotic Lactic Acid Bacteria

2019 ◽  
Vol 7 (12) ◽  
pp. 709 ◽  
Author(s):  
Jihen Missaoui ◽  
Dalila Saidane ◽  
Ridha Mzoughi ◽  
Fabio Minervini
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antioxidant Activities ◽  
Fermented Food ◽  
Aleppo Pine ◽  
Fermented Foods ◽  
Probiotic Potential ◽  
Probiotic Lactic Acid Bacteria ◽  
Gastrointestinal Enzymes

Microorganisms inhabiting fermented foods represent the main link between the consumption of this food and human health. Although some fermented food is a reservoir of potentially probiotic microorganisms, several foods are still unexplored. This study aimed at characterizing the probiotic potential of lactic acid bacteria isolated from zgougou, a fermented matrix consisting of a watery mixture of Aleppo pine′s seeds. In vitro methods were used to characterize the safety, survival ability in typical conditions of the gastrointestinal tract, and adherence capacity to surfaces, antimicrobial, and antioxidant activities. Strains belonged to the Lactobacillus plantarum group and Enterococcus faecalis showed no DNase, hemolytic, and gelatinase activities. In addition, their susceptibility to most of the tested antibiotics, satisfied some of the safety prerequisites for their potential use as probiotics. All the strains tolerated low pH, gastrointestinal enzymes, and bile salts. They displayed a good antibacterial activity and antibiofilm formation against 10 reference bacterial pathogens, especially when used as a cell-free supernatant. Furthermore, the lactic acid bacteria (LAB) strains inhibited the growth of Aspergillus flavus and Aspergillus carbonarius. Finally, they had good antioxidant activity, although depending on the strain. Overall, the results of this work highlight that zgougou represents an important reservoir of potentially probiotic LAB. Obviously, future studies should be addressed to confirm the health benefits of the LAB strains.

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