trolox equivalent
Recently Published Documents

Abstract The present study was conducted to evaluate the chemical composition, antioxidant activity and hypoglycemic effects of whole kumquat (Ku) powder in diabetic rats fed a high-fat-high-cholesterol (HFHC) diet. The antioxidant activities were evaluated using stable 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical scavenging method, 2,2´-azinobis (3-ethyl benzo thiazoline-6-sulphonic acid) radical cation (ABTS) and Ferric reducing antioxidant power (FRAP). Total phenolic content was (51.85 mg GAE/g) and total flavonoid content was (0.24 mg Cateachin Equivalent, CE/g). DPPH and ABTS values were 3.32 and 3.98 mg Trolox equivalent (TE)/g where FRAP value was 3.00 mM Fe2+/kg dry material. A total of 90 albino rats were used in the present study. Rats group were as follows: normal diet; normal treated (2, 4, and 6% Ku.), diabetic rats (non-treated), diabetic + HFHC diet (non-treated), HFHC (non-treated), Diabetic (treated), HFHC (treated) and Diabetic + HFHC (treated). The diets were followed for 8 weeks. Blood samples were collected at the end of the experiment. Serum glucose was recorded and thyroid hormones (T4, Thyroxine and T3, Triiodothyronine) were conducted. Diet supplemented with Kumquat at different concentrations have a hypoglycemic effect and improve the thyroid hormones of both diabetic rats and HFHC diabetic rats.

Kombucha is a popular beverage with various bioactivities (such as antioxidant activity), which can be attributed to its abundant bioactive compounds, especially polyphenols. Kombucha is conventionally prepared by fermentation of a sugared black tea infusion without tea residue. In this study, the effects of black tea residue and green tea residue on kombucha were studied, and its antioxidant activities, total phenolic contents, as well as concentrations of polyphenols at different fermentation stages were evaluated using ferric-reducing antioxidant power, Trolox equivalent antioxidant capacity, Folin-Ciocalteu method and high-performance liquid chromatography with a photodiode array detector. The results showed that fermentation with tea residue could markedly increase antioxidant activities (maximum 3.25 times) as well as polyphenolic concentrations (5.68 times) of kombucha. In addition, green tea residue showed a stronger effect than black tea residue. Overall, it is interesting to find that fermentation with tea residues could be a better strategy to produce polyphenol-rich kombucha beverages.

Introduction. Plant raw materials can be a source of biologically active substances and increase the nutritional value of food products. The present research objective was to determine the content of biologically active substances in powdered viburnum and barberry. Study objects and methods. The study featured viburnum (Viburnum opulus L.) and barberry (Berberis vulgaris L.), dried by convection and crushed into particles of 50 microns. Results and discussion. The total content of phenolic compounds in powdered viburnum was 3114.07 mg/100 g, in powdered barberry – 2272.7 mg/100 g. The content of flavonoids in powdered viburnum was 324.52 mg/100 g, in powdered barberry – 390.00 mg/100 g. The flavonoid profile of the powders included rutin, hyperoside, quercitrin, isoquercintrin, and astralagin. The total content of catechins was 446 mg/100 g for viburnum and 506 mg/100 g for barberry. The catechins included mainly epigallocatechin and catechin. In powdered viburnum, the catechin composition was as follows: epicatechin – 196, catechin – 118, and epigallocatechin – 89 mg/100 g; in powdered barberry: epigallocatechin – 173, catechin – 111, and epicatechin – 74 mg/100 g. The antiradical activity in relation to trolox equivalent was 7560 mg/100 g in powdered viburnum and 9460 mg/100 g in powdered barberry. Conclusion. The obtained viburnum and barberry powders can fortify food with biologically active substances and expand the range of functional products.

Tomato is an economically crucial vegetable/fruit crop globally. Tomato is rich in nutrition and plays an essential role in a healthy human diet. Phenylpropanoid, a critical compound in tomatoes, reduces common degenerative and chronic diseases risk caused by oxidative stress. As an MYB transcription factor, ATMYB12 can increase phenylpropanoid content by activating phenylpropanoid synthesis related genes, such as PAL, C4H, 4CL, CHS. However, the heterologous expression of AtMYB12 in tomatoes can be altered through transgenic technologies, such as unstable expression vectors and promoters with different efficiency. In the current study, the efficiency of other fruit-specific promoters, namely E8S, 2A12, E4, and PG, were compared and screened, and we determined that the expression efficiency of AtMYB12 was driven by the E8S promoter was the highest. As a result, the expression of phenylpropanoid synthesis related genes was regulated by AtMYB12, and the phenylpropanoid accumulation in transgenic tomato fruits increased 16 times. Additionally, the total antioxidant capacity of fruits was measured through Trolox equivalent antioxidant capacity (TEAC) assay, which was increased by 2.4 times in E8S transgenic lines. TEAC was positively correlated with phenylpropanoid content. Since phenylpropanoid plays a crucial role in the human diet, expressing AtMYB12 with stable and effective fruit-specific promoter E8S could improve tomato’s phenylpropanoid and nutrition content and quality. Our results can provide genetic resources for the subsequent improvement of tomato varieties and quality, which is significant for human health.

  This scientific work was aimed to evaluate the antioxidant potential of aromatic plants of Thymus spp. in the East of Ukraine. These plants are known as medicinal and food around the world. All antioxidant parameters were investigated spectrophotometrically: total content of polyphenols (TPC), the total content of phenolic acids (TPAC), the total content of flavonoids (TFC), molybdenum reducing power of extracts (MRP), and antioxidant activity by DPPH method (DPPH). Investigation of ethanolic extracts demonstrated that TPC varied from 57.89 to 123.67 mg/g gallic acid equivalent (GAE) DW for Th. pulegioides, from 61.43 to 168.18 mg GAE/g for Th. serpyllum, and from 47.36 to 115.67 mg GAE/g for Th. vulgaris. TPAC ranged from 27.36 to 50.22 mg/g caffeic acid equivalent (CAE) DW for Th. pulegioides, from 28.58 to 59.62 mg CAE/g for Th. serpyllum, and from 22.95 to 53.82 mg CAE/g for Th. vulgaris. TFC was determined in a range from 29.88 to 61.23 mg/g quercetin equivalent (QE) DW for Th. pulegioides, from 36.0 to 82.43 mg QE/g for Th. serpyllum, and from 24.59 to 55.41 mg QE/g for Th. vulgaris. MRP was detected in the range of 94.65 – 204.76 mg/g Trolox equivalent (TE) DW for Th. pulegioides, 96.06 – 219.0 mg TE/g for Th. serpyllum, and 87.56 – 215.43 mg TE/g for Th. vulgaris. The antioxidant activity of extracts by the DPPH method was 6.34 – 9.23 mg TE/g for Th. pulegioides, 8.11 – 9.21 mg TE/g for Th. serpyllum, and 4.97 – 9.53 mg TE/g for Th. vulgaris. It was established that polyphenol accumulation depended on the growth stage and species. For all species was found a strong correlation between TPC and TFC (r = 0.938, 0.908, and 0.854). Investigated Thymus spp. are a valuable source of antioxidants that can be used in pharmacological studies and the food industry.

This study presents the evaluation of biological activities and chemical profiling of Oenanthe aquatica (L.) Poir. and Oenanthe silaifolia M. Bieb. The phytochemical profile, antioxidant, enzyme inhibitory, cytotoxic and antiviral activities of the methanolic and aqueous extracts were investigated. The aqueous extract of O. aquatica possessing the highest content of phenolics (60.85 mg gallic acid equivalent/g extract), also exhibited the strongest radical scavenging potential against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (79.46 and 148.66 mg Trolox equivalent/g extract, respectively), the highest reducing ability (207.59 and 107.27 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant activity, respectively), metal chelating potential (33.91 mg ethylenediaminetetraacetic acid equivalent/g extract) and total antioxidant ability (1.60 mmol Trolox equivalent/g extract). Liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (LC-ESI-QTOF-MS/MS) permitted tentative identification of compounds from simple organic acids, phenolic acids, coumarins, flavonoids and their glycosides in O. aquatica and O. silaifolia extracts. The methanolic extract of O. aquatica substantially depressed acetylcholinesterase (3.67 mg galantamine equivalent/g extract), tyrosinase (126.66 mg kojic acid equivalent/g extract), and α-amylase (0.83 mmol acarbose equivalent/g extract) enzymes. The methanolic extract of O. silaifolia showed highest enzymatic inhibitory property against butyrylcholinesterase, and its aqueous extract depressed α-glucosidase activity (0.26 mmol acarbose equivalent/g extract). All tested extracts exerted selective toxicity towards cancer cell lines, and the highest anticancer potential was found for O. aquatica aqueous extract on FaDu and HeLa cells with CC50 of 57.36 and 47.16 µg/mL, respectively. Significant antiviral activity against HSV-1 (HHV-1) was found for both aqueous extracts in concentrations of 1000 µg/mL, which inhibited the HSV-1 cytopathic effect (CPE) in virus infected VERO cells and reduced the virus infective titer by more than 3 log (logCCID50/mL). This study has produced critical scientific data on O. aquatica and O. silaifolia, which are potential contenders for the development of novel phyto-pharmaceuticals.

The biocompatible, viscoelastic properties of poly(vinyl alcohol) (PVA) in combination with the antimicrobial and antioxidant natural polyphenolic, tannic acid (TA), and the natural flavonoid and antioxidant curcumin (Cur), were used in the preparation of PVA:TA and PVA:TA:Cur cryogel composites using cryotropic gelation to combine the individually beneficial properties. The effect of TA content on the antioxidant and antimicrobial activities of PVA:TA cryogel composites and the antioxidant activities of PVA:TA:Cur cryogel composites was determined using Trolox equivalent antioxidant capacity (TEAC) and total phenol content (TPC) assays, and were compared. The PVA:TA:Cur cryogel composite showed the highest antioxidant activity, with a TEAC value of 2.10 ± 0.24 and a TPC value of 293 ± 12.00. The antibacterial capacity of the PVA:TA and PVA:TA:Cur 1:1:0.1 cryogel composites was examined against two different species of bacteria, E. coli and S. aureus. It was found that the minimum inhibition concentration (MIC) value of the PVA:TA:Cur 1:1:0.1 cryogel composites varied between 5 and 10 mg/mL based on the type of microorganism, and the minimum bactericidal concentration (MBC) value was 20 mg/mL irrespective of the type of microorganism. Furthermore, the hemocompatibility of the PVA:TA cryogel composites was evaluated by examining their hemolytic and coagulation behaviors. PVA:TA 1:1 cryogels with a value of 95.7% revealed the highest blood clotting index value amongst all of the synthesized cryogels, signifying the potential for blood contacting applications. The release of TA and Cur from the cryogel composites was quantified at different pH conditions, i.e., 1.0, 7.4, and 9.0, and additionally in ethanol (EtOH) and an ethanol–water (EtOH:Wat) mixture. The solution released from the PVA:TA cryogels in PBS was tested for inhibition capability against α-glucosidase (E.C. 3.2.1.20). Concentration-dependent enzyme inhibition was observed, and 70 µL of 83 µg/mL PVA:TA (1:1) cryogel in PBS inhibited α-glucosidase enzyme solution of 0.03 unit/mL in 70 µL by 81.75 ± 0.96%.

Peaches (Prunus persica L.) are a popular and sought-after dessert fruit. This is mainly due to their flavour, aroma, attractive appearance, and high content of substances that play an important role in human nutrition. The present study was carried out to determine some important analytical properties (sugars/sucrose, glucose, fructose and sorbitol), total acid, total phenolics, flavonoids, antioxidant capacity, carotenoids and anthocyanins of 34 selected peach varieties. The analyses are also complemented by colorimetric measurements of peach skin colour using CIELAB and other chromatic parameters. The results show, for example, that all peach varieties are good sources of phenolic compounds (9.43–577 mg gallic acid equivalent (GAE).100 g−1), flavonoids (1.12–95.1 mg catechin equivalent (CAE).100 g−1), and antioxidant capacity (136–462 mg Trolox equivalent (TE).100 g−1).

The production of marine foods is on the rise, and shrimp is one of the most widely consumed. As a result, a considerable amount of shrimp waste is generated, becoming a hazardous problem. Shrimp waste is a rich source of added-value components such as proteins, lipids, chitin, minerals, and carotenoids; however, new bioprocesses are needed to obtain these components. This work aimed to characterize the chemical and nutraceutical constituents from the liquor of shrimp waste recovered during a lactic acid fermentation process using the novel substrate sources whey and molasses. Our results showed that the lyophilized liquor is a rich source of proteins (25.40 ± 0.67%), carbohydrates (38.92 ± 0.19%), minerals (calcium and potassium), saturated fatty acids (palmitic, stearic, myristic and lauric acids), unsaturated fatty acids (oleic acid, linoleic, and palmitoleic acids), and astaxanthin (0.50 ± 0.02 µg astaxanthin/g). Moreover, fermentation is a bioprocess that allowed us to obtain antioxidants such as carotenoids with an antioxidant capacity of 154.43 ± 4.73 µM Trolox equivalent/g evaluated by the ABTS method. Our study showed that liquor from shrimp waste fermentation could be a source of nutraceutical constituents with pharmaceutical applications. However, further studies are needed to separate these added-value components from the liquor matrix.

Abstract Background Saliva is being increasingly used as a sample for measuring biomarkers in several species and shows a high potential of use to detect and monitor stress. The weaning and grouping in dairy calves are a particularly stressful time. Therefore, the objectives of this study were to evaluate a panel of antioxidant and oxidant biomarkers in the saliva of calves on the day of weaning (W0), 2 days after weaning or milk withdrawal (W + 2), and 4 days after grouping (G + 4). In addition, to verify if cortisol and oxytocin concentrations are related to the biomarkers measured. Results Salivary cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of saliva (FRAS), Trolox equivalent antioxidant capacity (TEAC), advanced oxidation protein products (AOPP), and ferrous oxidation-xylenol orange (FOX) were significantly higher (P < 0.02) 4 days after grouping than the day of weaning and 2 days after. The increases were 50 and 54% for CUPRAC, 93 and 116% for FRAS, 117 and 135% for TEAC, 22 and 49% for AOPP and 10 and 5% for FOX in comparison with weaning and 2 days after, respectively. In addition, oxytocin and cortisol showed significant negative and positive correlations (P < 0.05) respectively with the biomarkers of oxidative status. Conclusions Our results showed that calves after grouping show increases in antioxidants and oxidants concentrations, indicating that a balance between these molecules has been tried to maintain during this stressful situation. The dynamic changes of biomarkers of oxidative status should be explored and characterised in other stressful conditions.