Ferric Reducing Antioxidant Potential Values Research Articles

Evaluation of phenolic and antioxidant profiles of pink Guava peel (Psidium guajava L. cv Arka kiran) during fruit ripening and its in silico Anti SARS-CoV-2 property

Guava (Psidium guajava L.) is a highly nutritious and economically important fruit. Although fruit peel is generally regarded as a waste, researchers believe that the peel of the guava is rich in bioactive constituents, even higher than the fruit's flesh. The present study aimed to estimate phenolic content (total phenolic and total flavonoid) and assess antioxidant properties of guava fruit peel (pink variety, cv Arka kiran) by 2,2-di (4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Ferric Reducing Antioxidant Potential (FRAP) assays at five different ripening stages (stage 1 to 5). The TPC and TFC assays were performed by Folin-Ciocalteu and aluminium chloride (AlCl3) methods, respectively. The molecular docking experiment between the major phenolic of guava peel, Catechin and the spike protein of SARS-CoV-2 was performed by the Dockthor online server. Results showed that the peel had high phenolic (highest TPC and TFC, 7307.3 mg gallic acid equivalent/g dry weight [DW] and 433.9 mg quercetin equivalent/g DW, respectively) and antioxidant values (highest DPPH, ABTS and FRAP values 4784.8, 206.6 and 2451 mg ascorbic acid equivalent/g DW, respectively) throughout all stages, although there was a gradual decline in the activity at the later stages. Furthermore, it was found that catechin had a strong binding affinity (-7.591 kcal mol-1) with the spike protein, in silico when compared with the control drug ceftazidime (-7.250 kcal mol-1). The overall outcome of our experiemnts revealed that guava peel could be explored for future pharmacological applications through in vivo studies, and the ‘green mixed with the yellow’ stage of ripening is optimum for such studies.

Effect of Microwave Power and Time on Total Phenolic Contents and Antioxidant Characteristics of Microwave Assisted Extracts of Watermelon Rind Powder

Watermelon is gaining importance as a functional food due to its therapeutic effect. The therapeutic effect of watermelon has been reported and has been attributed to antioxidant constitutes.The major component in watermelon rind is citrulline that has a strong antioxidant effect which protect body from free-radical damage.Objective:This study was conducted to investigate the effect of microwave powers (150 W, 300 W & 450 W) and time intervals (1,3 & 5 minutes) on total phenolic content (TPC) and total flavonoid content (TFC) and antioxidant characteristics i.e. DPPH and ferric reducing antioxidant potential (FRAP) of microwave assisted extracts of watermelon rind powder.Methods:The extracts collected after Microwave assisted extraction (MAE) of watermelon rind wereanalyzed for their antioxidant potential through different tests including total phenolic contents (TPC), total flavonoid content (TFC), DPPH assayand FRAP.Results:Microwave assisted extraction by using ethanol as a solvent at different microwave powers and various time intervals showed that total antioxidant potential was significantly higher at low microwave power such as TPC ranges obtained at 150W for 1, 3 & 5 minutes of time intervals show ranges (159.84, 160.04 & 169.71 mg GAE/100 g). While TFC ranges at 150W for time 1, 3 & 5 minutes were (21.31, 24.15 & 42.20 mg CEQ/100g) whereas DPPH ranges at 150W for time 1, 3 & 5 minutes were (53.14, 54.87 & 68.17 % ascorbic acid inhibition) and FRAP values at 150W for time 1, 3 & 5 minutes were (201.71, 221.50 & 326.43 mg FE/100g). While high microwave power 450W can result in disruption of some antioxidants at various time intervals.Conclusions:Watermelon rind is a rich source of many antioxidants andmicrowave assisted extraction technique should be implemented in the food and nutraceutical industries and microwave assisted extracts of watermelon rind should be utilize for the development of new functional food to combat many health related problems

Biochemical Characteristics and Antioxidant Properties of Citrus Juice from Lemon (Citrus limon), Lime (Citrus aurantifolia) and Grapefruit (Citrus paradisi) as Influenced by Degree of Ripening

The influence of degree of ripening (unripe, half-ripe and ripe) of citrus fruits (lemon, lime and grapefruit) on the biochemical characteristics and antioxidant potential of their juices was investigated. The juice yield from the citrus fruits was affected by the level of ripening as the highest juice yield was obtained when the fruits were at ripe stage giving 25.2 mL/100 g (lemon), 43.3 mL/100 g (lime), and 21.1 mL/100 g (grapefruit). The biochemical characteristics of the citrus juices revealed that the pH values were generally increasing with an increasing level of ripening particularly for lime and grapefruit while the pH of lemon juice was decreasing with an increase in the degree of ripening. The lowest pH values exhibited by the citrus fruits were 2.87 (ripe lemon), 2.16 (unripe lime), and 3.27 (unripe grapefruits). The total acidity of the citrus juices essentially exhibited an inverse relationship with their corresponding pH values. The highest ascorbic acid contents of the juices were 51.3 g/100mL (unripe lemon), 38.9 g/100mL (unripe lime), and 44.7 g/100mL (unripe grapefruit) while the highest total phenolic contents were 722 µg GAE/mL (unripe lemon), 207 µg GAE/mL (unripe lime), and 646 µg GAE/mL (unripe grapefruit); indicating a significant impact of degree of ripening on the parameters. The antioxidant activity of the citrus juices using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay revealed a significant influence of degree of ripening and juice volume on the activity. The percent inhibition of DPPH free radical by the juices was generally higher at an unripe stage of fruit maturity as well at greater juice volume. The ferric-reducing antioxidant potential (FRAP) of the citrus juices was also influenced by the level of ripening of the fruit. The FRAP values were generally higher at unripe stage which were 3.72 µ mol Fe(II)/g (unripe lemon), 4.98 µ mol Fe(II)/g (unripe lime) and 9.53 µmolFe(II)/g (unripe grapefruit).

Proteolytic activity, antioxidant, and α-Amylase inhibitory activity of yogurt enriched with coriander and cumin seeds

Two types of yogurt (Y) were prepared in the presence of coriander (CO) or cumin seeds (CS) at different concentrations (5, 10, 15, & 20 g/100 mL). The effect of these yogurt samples on post-acidification, proteolysis, α-amylase inhibition activity, total phenolic content, and antioxidant activity (2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant potential (FRAP), and ferrous ion chelating (FIC) ability) was studied during 0,7, and 14 days of refrigerated storage at 4 °C. In addition, sensory evaluation of the yogurt was run during the first day of storage. Both COY and CSY at all concentrations showed significant effects on post-acidification, peptide content, and α-amylase inhibition activity as compared to plain yogurt (control). TPC in COY at all concentrations (42.4–165.4 μg GAE/mL) was higher than in CSY (39.0–75.7 μg GAE/mL) during the entire storage period. The radical scavenging activity increased (p < 0.05) in COY at 20, 15, and 10 g/100 mL concentrations (94 ± 0.01%, 93 ± 0.01%, and 89 ± 0.03%; respectively) on 7 days of storage. FRAP values were higher in CSY at all concentrations than COY during 7 days of storage. Higher (p < 0.05) FIC ability was observed in both types of yogurt than control. The highest overall preference score was shown at a concentration of 15 g/100 mL for both types of yogurt. In conclusion, COY and CSY at all concentrations positively enhanced natural yogurt ability to inhibit α-amylase activity with high antioxidant activity.

Investigation of Antioxidant Properties of Polygonatum orientale Desf and Tilia dasystyla Extracts by Different Methods and Solvents

Background: Free radicals cause many diseases in humans. Antioxidants reduce the risk of cardiovascular disease and stroke by neutralizing free radicals and on the other hand, prevent the progression of cancer. The natural antioxidant enhances the antioxidant properties of plasma to prevent diseases such as heart disease, cancer, and stroke. Secondary metabolites derived from plants have a strong potential for antioxidant activity. Methods: The purpose of this study was to investigate the antioxidant activities of two native plants species, including Polygonatum orientale Desf and Tilia dasystyla extracts, which are obtained with three different solvents (water, ethanol, and methanol) and two extraction methods (sonication and water bath) by DPPH (2,2-Diphenyl-1-Picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Potential) methods. This study is the first research to investigate the antioxidant properties of Polygonatum orientale Desf and Tilia dasystyla. Results: The results showed that methanol solvent had a higher efficiency among the other solvents in extracting of antioxidant compounds. Also, antioxidant level of Tilia dasystyla was higher than Polygonatum oriental Desf. In this regard, the highest FRAP values of Tilia dasystyla belonged to methanol solvent and water bath method with the amount of 2.72 ± 0.36 (mM). Whereas the highest FRAP values of Polygonatum orientae Desf belonged to methanol solvent and sonication method with the amount of 0.147 ± 0.01 (mM). Conclusions: Both plants showed antioxidant properties but Tilia dasystyla had higher antioxidant activities than Polygonatum orientale Desf. Methanol was more effective solvent in extracting antioxidant compounds and also water bath method was generally an effective method for extraction.

Effect of Extraction Solvents and Drying Conditions on Total Phenolic Content and Antioxidant Properties of Watermelon Rind Powder

The objective of the present study was to determine the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant properties, i.e. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferric reducing antioxidant potential (FRAP) assay, of red- and yellow-fleshed watermelon rind powders prepared using different drying conditions (hot-air oven drying at 40 and 60°C and freeze drying). All the samples were subjected to four different solvent extract using water, methanol, ethanol and acetone prior analyses. Water extract from red- and yellow-fleshed watermelon rind powders presented highest value for TPC and TFC. However, methanol extract samples showed highest value for antioxidant properties (DPPH and FRAP) followed by acetone, ethanol and water extract. By comparing the drying conditions, all samples dried using hot-air dryer at 40 and 60°C had significantly higher (p<0.05) in TPC value than the samples dried using freeze dryer. However, samples dried using freeze dryer showed highest in DPPH and FRAP values. The present obtained results would be useful to the food and pharmaceutical industries for developing of functional ingredients.

Nutritional and organoleptic evaluation of functional bread prepared from raw and processed defatted mango kernel flour

The current study aims at highlighting potential use of raw and processed defatted mango kernel flour (DMKF) in the preparation of leavened bread. Straight grade flour (SGF) was replaced with DMKF at 0–25% levels. Biochemical composition, anti-nutritional aspects, and antioxidant potential of DMKF and supplemented bread were investigated. DMKF supplementation resulted in enhanced protein (12.24–13.04%), dietary fiber (0.37–0.54%), and total phenolics concentration (85–128.35 mg GAE/100g) of bread. Likewise, significant improvement (p < .05) was recorded in Ca, K, Fe, and Zn levels of supplemented bread. Processing techniques found to be efficient in reducing anti-nutritional compounds in processed mango kernel flour and supplemented bread. DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant potential) values found to be higher in raw DMKF supplemented bread as compared to the processed DMKF bread. The current study concludes DMKF supplementation improved nutritional profile and antioxidant potential of leavened bread. Practical applications Present investigation examined raw and processed DMKF for their potential to play a pivotal role in nutritional deficiency related maladies and may also be utilized as a novel ingredient in functional food preparation. Sagacious exploitation of this fruit waste as caloric energy anticipating food ingredient might help resolve industrial waste management and food security issues especially in mango producing & processing under developed countries.

Survival and Feeding of Greenlip Abalone (Haliotis laevigata) in Response to a Commercially Available Dietary Additive at High Water Temperature

Elevated mortality, triggered by increased water temperatures (>22°C) and associated factors, is a significant issue for land-based abalone farms in southern Australia. The aim of this study was to test the efficacy of the commercial animal feed product Orego-Stim (OS), containing oregano essential oil in reducing the mortality of 3-y-old greenlip abalone (Haliotis laevigata) exposed to high water temperature (25°C). Inclusion levels of 0.0 (commercial control diet), 0.5%, 1.0%, 2.0%, and 4.0% OS were added into a commercial feed formulation and diets were fed to 3-y-old greenlip abalone (67.98 g, 77.01 mm shell length) at two water temperatures (22°C and 25°C) for 47 days. Survival and immune parameters including phagocytic activity, total hemocyte count (THC), and activities of the enzymes superoxide dismutase (SOD) and catalase (CAT) were measured. Survival was high at 22°C with no significant differences in mortality between treatments. Irrespective of this, exposure to elevated water temperature (25°C) resulted in significantly higher mortalities for all diet treatments (P < 0.05), without any effect of diet. Low ferric reducing antioxidant potential values were observed for all diets. Phagocytic activity remained stable for all temperature and OS treatments (48.82% ± 1.31%). The dietary inclusion of OS and increased water temperature increased the THC compared with the commercial control diet treatment at 22°C. Superoxide dismutase was significantly elevated in greenlip abalone fed the commercial control (0.56 ± 0.08 U mL-1), and CAT was significantly higher when fed the 4.0% OS diet treatment at 25°C (18.93 ± 2.25 nmol min-1 mL-1). Despite failing to increase survival, OS significantly enhanced feed intake at both temperatures at 2.0% and 4.0% compared with the commercial control diet treatment, highlighting its ability as a feeding stimulant (P < 0.05).

ANTIOXIDANT ACTIVITIES OF SOME LESS UTILIZED EDIBLE FRUITS

Objective: The objective of the present study was to evaluate the total phenolic (TPC) and flavonoid content (TFC) of five less utilized fruits such as Aegle marmelos, Spondias pinnata, Limonia acidissima, Averhoa carambola, Crescentia cujete and was compared with Phyllanthus emblica, (Amla) well known for its antioxidant activities. Total phenolic and flavonoid contents of samples were correlated with antioxidant activities like 1,1-Diphenyl-2-Picryl-Hydrazyl (DPPH) free radical scavenging assay, Ferric reducing antioxidant potential (FRAP) assay and total antioxidant capacity (TAC).Methods: The total phenolic of each fruit extract were determined by the Folin-Ciocalteu method with some modifications and the total flavonoids were estimated by Aluminum trichloride colourimetric method. The DPPH antioxidant assay, The FRAP assay and TAC were determined spectrophotometrically.Results: The total phenolics were expressed as mg/100g Gallic acid equivalent (mg GAE/100 gm) and the total flavonoids were expressed as mg/100g Quercetin equivalent (mg QE/100 gm). TPC was found to be maximum in Spondias pinnata with 142.16 mg GAE/100 gm where as TFC was maximum in Phyllanthus emblica with 91.1 mgQE/100 gm. DPPH radical scavenging activity was expressed n percentage(%), FRAP values expressed as mg/100g Ascorbic equivalent (AAE) and the total antioxidant activity was expressed as mg/100g Ascorbic equivalent. Maximum DPPH radical scavenging activity was shown by Spondias pinnata (93.75%), FRAP values were maximum in Phyllanthus emblica with 72.6 mg AAE/100 gm and total antioxidant capacity was found to be highest in Spondias pinnata (50.1 mg AAE/100 gm).Conclusion: Spondias pinnata, an underutilized fruit, was found to be promising with antioxidant activities comparable to Phyllanthus emblica.

Detoxification of Olive Mill Wastewater and Bioconversion of Olive Crop Residues into High-Value-Added Biomass by the Choice Edible Mushroom Hericium erinaceus.

Environmentally acceptable disposal of olive cultivation residues (e.g., olive prunings; olive pruning residues (OLPR)) and olive mill wastes is of paramount importance since they are generated in huge quantities within a short time. Moreover, olive mill wastewater (OMW) or sludge-like effluents ("alperujo"; two-phase olive mill waste (TPOMW)) are highly biotoxic. Hericium erinaceus is a white-rot fungus which produces choice edible mushrooms on substrates rich in lignocellulosics, and its suitability for the treatment of olive by-products was examined for the first time. Fungal growth resulted in a notable reduction of OMW's pollution parameters (i.e., 65% decolorization, 47% total phenolic reduction, and 52% phytotoxicity decrease) and correlated with laccase and manganese peroxidase activities. Solid-state fermentation of various mixtures of OLPR, TPOMW, and beech sawdust (control) by H. erinaceus qualified OLPR in subsequent cultivation experiments, where it exhibited high mushroom yields and biological efficiency (31%). Analyses of proximate composition and bioactive compound content revealed that mushrooms deriving from OLPR substrates showed significantly higher crude fat, total glucan, β-glucan, total phenolics, and ferric-reducing antioxidant potential values than the control. H. erinaceus demonstrated the potential to detoxify OMW and bioconvert OLPR into high-quality biomass, and hence, this fungus could be successfully exploited for the treatment of such by-products.

Comparison of the Antioxidant Activity of Commercial Honeys, Before and After In-Vitro Digestion

Honey is a rich source of antioxidant and antiseptic compounds including Maillard reaction products, vitamins, carotenoids and polyphenols. The objective of the present study was to determine the effect of digestion on the antioxidant activity of a range of honey samples including two economy brands (Tesco and Lidl), a premium Irish brand (Fainne Oir Fine Foods) and a New Zealand Manuka honey. Samples were subjected to an in-vitro digestion which simulates the human gastric and intestinal digestion system. The antioxidant activity of the honey samples before and after digestion was determined by measuring total phenol content (TPC), 2,2-diphenyl-2-picrylhydrazyl hydrate assay (DPPH) radical scavenging and ferric reducing antioxidant potential (FRAP). The ability of the samples to protect against H 2 O 2 -induced DNA damage in the Caco-2 cell line was measured by the Comet assay. The Manuka honey had the highest TPC and the Tesco honey had the highest FRAP and DPPH scavenging activity. TPC was not altered following digestion however there was a signifi cant decrease in the FRAP values for Manuka and Tesco honey and in the DPPH radical scavenging activity for all four of the samples. The Tesco and Manuka honeys demonstrated a signifi cant protective effect against H2O2-induced DNA damage in Caco-2 cells, following digestion. The premium brand honey samples did not demonstrate signifi cantly higher antioxidant activity in comparison with economy brand honey.

ENHANCED BIOLOGICAL ACTIVITIES OF LAMINARIN DEGRADED BY GAMMA-RAY IRRADIATION

ABSTRACT In this study, we investigated the antioxidant and melanin synthesis inhibitory properties of gamma-irradiated laminarin. Antioxidant activities as measured by ferric-reducing antioxidant potential values and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity were found to be greater in irradiated laminarin than in nonirradiated laminarin. However, nonirradiated and irradiated laminarins did not exhibit significant differences in β-carotene bleaching assays. Moreover, inhibitory activity against melanin synthesis in B16BL6 melanoma cells was increased by gamma-irradiated laminarin. The content of reducing sugars in laminarin was found to increase with increased irradiation doses. These results and the molecular weight measured by gel permeation chromatography indicate that laminarin is degraded to a low molecular weight form by the scission of glycosidic bonds. Overall, low molecular weight laminarin may have beneficial biological properties, and gamma irradiation may be an effective method of producing low molecular weight laminarin. PRACTICAL APPLICATIONS Laminarin is a type of storage polysaccharide derived from seaweed. Because of its indigestibility in the upper gastrointestinal tract, laminarin is considered as a dietary fiber. Other beneficial biological properties have been attributed to laminarin, but studies have shown these properties to be ineffective. Therefore, in this study, laminarin was degraded by gamma irradiation to enhance the effects of these biological properties. We observed that gamma-irradiated laminarin had higher antioxidative and melanin synthesis inhibitory activities than nonirradiated laminarin did. The results of this study suggest that laminarin may provide dietary benefits beyond its use as an effective dietary fiber.

Effect of CO(2) enrichment on synthesis of some primary and secondary metabolites in ginger (Zingiber officinale Roscoe).

The effect of two different CO2 concentrations (400 and 800 μmol mol−1) on the photosynthesis rate, primary and secondary metabolite syntheses and the antioxidant activities of the leaves, stems and rhizomes of two Zingiber officinale varieties (Halia Bentong and Halia Bara) were assessed in an effort to compare and validate the medicinal potential of the subterranean part of the young ginger. High photosynthesis rate (10.05 μmol CO2 m−2s−1 in Halia Bara) and plant biomass (83.4 g in Halia Bentong) were observed at 800 μmol mol−1 CO2. Stomatal conductance decreased and water use efficiency increased with elevated CO2 concentration. Total flavonoids (TF), total phenolics (TP), total soluble carbohydrates (TSC), starch and plant biomass increased significantly (P ≤ 0.05) in all parts of the ginger varieties under elevated CO2 (800 μmol mol−1). The order of the TF and TP increment in the parts of the plant was rhizomes > stems > leaves. More specifically, Halia Bara had a greater increase of TF (2.05 mg/g dry weight) and TP (14.31 mg/g dry weight) compared to Halia Bentong (TF: 1.42 mg/g dry weight; TP: 9.11 mg/g dry weight) in average over the whole plant. Furthermore, plants with the highest rate of photosynthesis had the highest TSC and phenolics content. Significant differences between treatments and species were observed for TF and TP production. Correlation coefficient showed that TSC and TP content are positively correlated in both varieties. The antioxidant activity, as determined by the ferric reducing/antioxidant potential (FRAP) activity, increased in young ginger grown under elevated CO2. The FRAP values for the leaves, rhizomes and stems extracts of both varieties grown under two different CO2 concentrations (400 and 800 μmol mol−1) were significantly lower than those of vitamin C (3107.28 μmol Fe (II)/g) and α-tocopherol (953 μmol Fe (II)/g), but higher than that of BHT (74.31 μmol Fe (II)/g). These results indicate that the plant biomass, primary and secondary metabolite synthesis, and following that, antioxidant activities of Malaysian young ginger varieties can be enhanced through controlled environment (CE) and CO2 enrichment.

Physical, biochemical and antioxidant properties of some Indian honeys

The study was intended to characterise the physicochemical and antioxidant properties of some commercial brands of Indian honeys. All the samples showed considerable variations with reference to their level of total phenolics, protein, radical scavenging activity, ascorbic acid equivalent antioxidant content (AEAC) and ferric reducing antioxidant potential (FRAP). Comparative studies of Indian honeys indicated the strong correlation between proline content and AEAC as well as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) scavenging activity whereas phenol content was strongly correlated with FRAP values. Thus, overall antioxidant activity seems to be contributed by proline and phenol contents. Besides these major factors, colour pigments (ABS 460 ) were also found to contribute significantly to the overall observed antioxidant activity.

Inhibition of Protein Glycation by Extracts of Culinary Herbs and Spices

We tested whether polyphenolic substances in extracts of commercial culinary herbs and spices would inhibit fructose-mediated protein glycation. Extracts of 24 herbs and spices from a local supermarket were tested for the ability to inhibit glycation of albumin. Dry samples were ground and extracted with 10 volumes of 50% ethanol, and total phenolic content and ferric reducing antioxidant potential (FRAP) were measured. Aliquots were incubated in triplicate at pH 7.4 with 0.25 M fructose and 10 mg/mL fatty acid-free bovine albumin. Fluorescence at 370 nm/440 nm was used as an index of albumin glycation. In general, spice extracts inhibited glycation more than herb extracts, but inhibition was correlated with total phenolic content (R(2) = 0.89). The most potent inhibitors included extracts of cloves, ground Jamaican allspice, and cinnamon. Potent herbs tested included sage, marjoram, tarragon, and rosemary. Total phenolics were highly correlated with FRAP values (R(2) = 0.93). The concentration of phenolics that inhibited glycation by 50% was typically 4-12 microg/mL. Relative to total phenolic concentration, extracts of powdered ginger and bay leaf were less effective than expected, and black pepper was more effective. Prevention of protein glycation is an example of the antidiabetic potential for bioactive compounds in culinary herbs and spices.

Herb and spice extracts inhibit protein glycation

We hypothesized that substances in herbs and spices may inhibit protein glycation. Extracts of 20 herbs and spices were tested for ability to inhibit glycation of albumin. Dry samples were ground and extracted with 50% ethanol (10% w/v), and total phenolic content and ferric reducing antioxidant potential (FRAP) were measured. Aliquots were incubated in triplicate at 37°C in 0.2 M potassium phosphate buffer, pH.7.4, containing 0.25 M fructose and 10 mg/ml fatty acid-free bovine albumin with final concentrations of total phenolics from 33 to 267 μg/mL. After 4 days, fluorescence was measured at 440 nm as an index of the formation of glycated albumin. In general, the spice extracts inhibited glycation more than the herb extracts. When tested at 267μg/mL total phenolics, the most potent inhibitors included clove (83.5%), ground Jamaican allspice (67.8%), and cinnamon (65.0%). Potent herbs tested included sage (49.1%), tarragon (48.1% ), and rosemary (47.7%). Inhibition of glycation by spice extracts was concentration dependent and correlated with total phenolic and FRAP values (R²=0.66 and R²=0.51, respectively) whereas the inhibition by herb extracts was not highly correlated (R²=0.14 and R²=0.004, respectively). Total phenolics were highly correlated with FRAP (R²=0.93). The evidence shows that compounds found in herb and spice extracts inhibit albumin glycation in vitro. Not all active substances appear to be polyphenolics. (Supported by AES Hatch project GE09622)

Measuring antioxidant potential in corals using the FRAP assay

In this paper, we standardized a method for determining antioxidant potential in corals. This was determined using a simple, reproducible and inexpensive method: the ferric reducing/antioxidant potential (FRAP) assay. This procedure involves the reduction of Fe III-TPTZ to a blue colored Fe II-TPTZ by biological antioxidants and chemical reductants, some of which might have no antioxidant activity in a sample. The FRAP assay compares the change in absorbance at 600 nm of a sample compared with the change in absorbance of a known standard (FeSO 4·7H 2O) to determine antioxidant levels. This assay was used to determine changes in antioxidant potential in the corals Pocillopora damicornis and Pocillopora meandrina exposed to different temperatures (28, 29, 30 and 31 °C) for 3 h. Corals were also incubated at 31 °C for time intervals of a 0.5, 1 and 3 h. Antioxidant potential in the coral host increased with temperature and time, as indicated by FRAP values, compared to control samples at ambient sea surface temperatures (26.5–27 °C). Lower FRAP values could be a response to lower production of reactive oxygen species (ROS) or the result of an increase in ROS that react with the antioxidants. Because of the complex interactions within cells, one test is normally not enough to understand precisely what is going on within the cell. Rather, a broad array of tests is required to determine the different cellular parameters that are occurring within a biological system. To our knowledge, this is the first time that FRAP has been used to determine antioxidant status in a marine organism. The FRAP technique can potentially be a useful and inexpensive tool for marine biologists engaged in ecotoxicological studies.