Ferric Reducing Ability Of Plasma Assay Research Articles

Antioxidant capacity and total phenol content of beech (Fagus sylvatica L.) bark extracts

Tree bark is mostly regarded as a by-product of log processing but it can be a rich source of antioxidant compounds which are worthwhile to extract and use for industrial purposes (e.g., nutrition supplements, food conservants, wood preservatives). Beech (Fagus sylvatica L.) is a common industrial wood species and the antioxidant properties of its bark have not yet been studied in detail. The main objective of the current study was the assessment of the total phenol content and the comprehensive antioxidant properties of beech bark extracts prepared with different extraction techniques to obtain maximum yield of the active compounds. Three extraction methods were used: sonication, stirring and a microwave assisted technique. For each method we used water, methanol:water 80:20 v/v, and ethanol:water 80:20 v/v solutions. The antioxidant capacity of the extracts was determined with the DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and FRAP (ferric reducing ability of plasma) assays. Total phenol content was measured using the Folin–Ciocâlteu assay. Different antioxidant capacity assays give comprehensive results on the antioxidant properties of the extracts basing on their different selectivity. Ethanol-containing solutions are more efficient for extraction than the respective mixtures with methanol especially at ambient conditions. Under pressurized high temperature conditions, pure water can be as effective as alcohol containing mixtures. Results show that the antioxidant compounds of beech bark can be extracted efficiently using eco-friendly solvents which opens up possibilities for the utilization of beech bark extracts in the future for food industry and wood technology.

Factors Affecting the Quality Attributes of Unripe Grape Functional Food Products

Unripe grapes with sour taste can be processed into various products such as verjuice and sour grape sauce. They have gained popularity because of increasing consumers' demands for natural and functional foods. It was aimed to detect some physicochemical properties and the antioxidant capacity of unripe grape products. Five verjuice and five sour grape sauce samples were analyzed and the mean of the values 2.41 for pH, 0.97 for water activity, 5.63 for soluble solid content, 3.83% for titratable acidity, 6.721 g/L for total sugar content and 473.96 mg/L for total phenol content were obtained. Antioxidant contents of the samples were detected between 0.010–0.231 and 0.035–0.885 μmol TE/mL by FRAP (ferric reducing ability of plasma) and TEAC (Trolox-Equivalent Antioxidant Capacity) assays, respectively. Variation in the result of analysis depends on factors such as varieties, maturation stage, harvesting time, genotypic differences and environmental stress. Unripe grape products could be good alternatives for functional nutrition with their physicochemical and antioxidant properties. Practical Applications The food industry is looking for new, available and low-cost alternatives to supply the demand of the consumers on functional and natural foods. Grapes are a good source of antioxidant-rich food products by making them functional and also extending their shelf life. Unripe grape products such as verjuice and sour grape sauce, used as a flavoring and acidifying agent, could also be considered natural sanitizers. Unripe grape products, directly or as an additive in foods, could contribute to the functional and natural food production.

Anti-inflammatory, antioxidant, and antiparkinsonian effects of adenosine A2A receptor antagonists

The purpose of the study was to examine derivatives of annelated xanthines (imidazo-, pyrimido-, and diazepino-purinediones) for potential anti-inflammatory effects in carrageenan-induced paw edema in mice. Additionally, their antioxidant activity using the FRAP (ferric-reducing ability of plasma) assay and lipid peroxidation in rat brain homogenate were analyzed. All the studied derivatives showed affinity for adenosine A2A receptor. The preliminary assays found that five (KD-114, KD-57, KD-129, KD-50, and KD-358) pyrimidopurinedione derivatives, administered intraperitoneally (i.p.) at a dose of 100mg/kg, had stronger anti-inflammatory effects. At a concentration of 10−5M, three of the derivatives KD-57, KD-114, and KD-129 most influenced the total antioxidant ability. The most efficient anti-inflammatory compound, KD-114, also showed the strongest binding to A2A receptors and when administered at a dose of 5mg/kg (i.p.), effectively reversed haloperidol-induced catalepsy and significantly increased the striatal extracellular dopamine level in the rat striatum. This effect was weaker than the one produced by CSC (1mg/kg i.p.), and only slightly weaker than that produced by ZM 241385 (3mg/kg i.p.) used as reference drugs. From the results of the present studies, it may be concluded that anti-inflammatory and antiparkinsonian effects of the examined compounds correlate with their influence on adenosine A2A receptors, the most probable antagonism to these subtype receptors.

Enhancement of phenolic acid content and antioxidant activity of rice bran fermented with Rhizopus oligosporus and Monascus purpureus

Abstract The effect of solid-state fermentation using several types of fungi on the phenolic acid content and antioxidant activity of rice bran (RB) was determined and compared to the non-fermented counterpart. The substrate was fermented with single and mixed cultures of two types of fungi: Rhizopus oligosporus and Monascus purpureus . The total phenolic content (TPC), determined using the Folin–Ciocalteu method, increased upon fermentation. The antioxidant activity was analyzed using the ferric reducing ability of plasma (FRAP) method, which showed the same trend as TPC; that is, the antioxidant activity improved in all fermented samples. In contrast to the TPC and FRAP assays, the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity of the fermented samples exhibited either an insignificant improvement or reduced activity. The phenolic acid content in methanol extracts of fermented RB, determined using high performance liquid chromatography (HPLC), generally showed a significant increase in ferulic, sinapic, vanillic, caffeic, syringic, and 4-hydroxybenzoic acids. The results of this study prove that the overall antioxidant activity and phenolic acid content of RB can be enhanced by solid-state fermentation using fungi.

Comparative Analysis of Serum (Anti)oxidative Status Parаmeters in Healthy Persons

Five antioxidant and two oxidative stress assays were applied to serum samples of 43 healthy males. The antioxidant tests showed different inter-assay correlations. A very good correlation of 0.807 was observed between the ferric reducing ability of plasma (FRAP) and total antioxidant status (TAS) assay and also a fair correlation of 0.501 between the biological antioxidant potential (BAP) and TAS assay. There was no statistically significant correlation between the BAP and FRAP assay. The anti-oxidant assays have a high correlation with uric acid, especially the TAS (0.922) and FRAP assay (0.869). The BAP assay has a much lower and no statistically significant correlation with uric acid (0.302), which makes BAP more suitable for the antioxidant status. The total thiol assay showed no statistically significant correlation with uric acid (0.114). The total thiol assay, which is based on a completely different principle, showed a good and statistically significant correlation with the BAP assay (0.510) and also to the TAS assay, but to a lower and not significant extent (0.279) and not with the FRAP assay (−0.008). The oxy-adsorbent test (OXY) assay has no correlation with any of the other assays tested. The oxidative stress assays, reactive oxygen metabolites (ROM) and total oxidant status (TOS), based on a different principle, do not show a statistically significant correlation with the serum samples in this study. Both assays showed a negative, but not significant, correlation with the antioxidant assays. In conclusion, the ROM, TOS, BAP and TTP assays are based on different principles and will have an additional value when a combination of these assays will be applied in large-scale population studies.

Evaluation of antinociceptive and antioxidant properties of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one in mice

The aim of this study was to evaluate the influence of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one (LPP1) on nociceptive thresholds in mouse models of persistent pain. Influence of LPP1 on motor coordination and its antioxidant capacity in mouse brain tissue homogenates were also assessed. Pain sensitivity thresholds in animals treated with LPP1 were established using 5 % formalin solution in normoglycemic mice and in streptozotocin (STZ)-treated diabetic mice in the von Frey, hot plate, innocuous, and noxious cold water tests (water at 10 °C and 4 °C, respectively). Motor deficits were assessed in the rotarod test, whereas antioxidant capacities were evaluated using ferric reducing ability of plasma (FRAP) assay, catalase (CAT), and superoxide dismutase (SOD) activities. LPP1was antinociceptive in both phases of the formalin test, in particular, in the late phase (at doses 0.9–30 mg/kg for 66–99 % vs. control normoglycemic mice) and in a statistically significant manner increased nociceptive thresholds in response to mechanical, heat, and noxious cold stimulation in neuropathic mice (at 30 mg/kg for 274, 192, and 316 %, respectively vs. diabetic control). LPP1 did not impair motor coordination of mice in the rotarod revolving at 6 or 18 rpm. In brain tissue homogenates, it demonstrated antioxidant capacity in FRAP assay and increased SOD activity for 63 % (acute administration) and 28 % (chronic administration) vs. control. No influence on CAT activity was observed. LPP1 has significant antinociceptive properties in the formalin model and elevates pain thresholds in neuropathic mice. It has antioxidant capacity and is devoid of negative influence on animals' motor coordination.

Relationship between severity of adult community-acquired pneumonia and impairment of the antioxidant defense system

Oxidant/antioxidant imbalance has been reported in some infectious diseases, including community-acquired pneumonia (CAP). The aim was to assess the antioxidant status in adults with CAP and its relationship with clinical severity at admission. Fifty-nine patients with CAP were enrolled and categorized at admission by the FINE score, from July 2010 to October 2012. In the same period 61 controls were enrolled. Plasma samples were obtained at admission for determination of the ferric reducing ability of plasma (FRAP) and lipid peroxidation (8-isoprostane). Erythrocyte reduced (GSH)/oxidized (GSSG) glutathione, malondialdehyde (MDA) and antioxidant enzyme activity were assessed. Antioxidant status in adults with CAP represented by FRAP and the GSH/GSSG ratio were 16.8% (p=0.03) and 39.7% (p=0.04) lower than control values, respectively. In addition, FRAP values showed a positive correlation with GSH/GSSG ratio (r=0.852; p<0.02; n=59). The CAP group showed greater lipid peroxidation in both plasma and erythrocytes. The FINE score correlated negatively with FRAP (r= -0.718; p<0.05; n=59) and positively with MDA and F2 isoprostane levels (r=0.673; p<0.05; n=59; r=0.892; p<0.01; n=59, respectively). Antioxidant status alterations correlated with clinical severity. The FRAP assay and lipid peroxidation biomarkers may provide a useful parameter for estimating the severity and the clinical outcome of patients with CAP.

Rooperol as an antioxidant and its role in the innate immune system: An in vitro study

Ethnopharmacological relevanceBiologically active rooperol is formed when the glucose subunits of the nontoxic glycoside, hypoxoside, are cleaved by β-glucosidase. Hypoxoside is isolated from Hypoxis, a medicinal plant genus frequently used by the indigenous people of South Africa as an immune system booster. The aim of this study was to investigate rooperol's antioxidant and anti-inflammatory properties using the ferric reducing ability of plasma (FRAP) assay, NO and ROS production, and phagocytosis. Materials and methodsDifferentiation of human promonocytic U937 leukemia cells to monocyte–macrophages was induced using 10–100nM 1,25(OH)2D3 and PMA over 72h. Differentiation was confirmed by light microscopy and flow cytometry. Undifferentiated and/or differentiated cells were treated with DMSO (0.25v/v%, vehicle control), hypoxoside (50μg/mL), rooperol (20μg/mL) or PMA (10/20nM, positive control). ROS production was measured in undifferentiated and differentiated monocyte-macrophages using DCFH-DA and flow cytometry. Phagocytosis of pHrodo™ Escherichia coli BioParticles® was measured using pre-treated monocyte-macrophage differentiated U937 cells. NO production was measured in monocyte–macrophage differentiated U937 cells using DAF-2 DA and flow cytometry. ResultsRooperol was shown to have similar or greater antioxidant potential than ascorbic acid. Differentiation of human promonocytic U937 leukemia cells to monocyte–macrophages were confirmed morphologically (cell attachment, clump- and pseudopodia-formation) and biochemically (CD11b and CD14 cell surface marker expression). Rooperol significantly increased ROS and NO production, and phagocytosis in undifferentiated and/or differentiated human promonocytic U937 leukemia cells. Hypoxoside had no or very little effect on ROS and NO production, and phagocytosis. ConclusionThis study confirms previous reports that hypoxoside has to be converted to rooperol to be biologically active. The FRAP assay confirms the antioxidant capacity of rooperol seen in previous studies, whereas rooperol's induction of ROS and NO production, and phagocytosis constitute novel findings. Possible mode(s) of action for the in vitro anti-inflammatory activities of rooperol may be explained by ROS and NO production, and phagocytosis.

Biological activity assessment and phenolic compounds characterization from the fruit pericarp of Litchi chinensis for cosmetic applications

Context: Litchi chinensis Sonn. (Spindaceae) is an important economic fruit of Thailand. Therapeutic effects of the fruits are contributed by anti-inflammatory phenolics.Objective: To extract the litchi fruit pericarp in order to identify biologically actives substances with potential for cosmetic application.Materials and methods: The litchi pericarp was macerated by 70% ethanol (EtOH) and partitioned using n-hexane and ethyl acetate (EtOAc). In vitro antioxidant activities were assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ABTS and ferric reducing ability of plasma (FRAP) assays including tyrosinase inhibitory effect. Cellular radical scavenging capacity was monitored in a normal human fibroblast cell culture (NHF). Total phenolic content was determined and characterized by HPLC.Results: The EtOAc fraction was a significant antioxidant, stronger than ascorbic acid (p < 0.01), as assessed by ABTS (IC50 = 7.137 ± 0.021 μg/mL), DPPH (IC50 = 2.288 ± 0.063 μg/mL) and FRAP (EC1mMFeSO4 = 8013.183 ± 58.804 μg/mL) assays. It demonstrated an antityrosinase effect (IC50 = 197.860 ± 1.230 μg/mL) and showed no cytotoxic activity toward Vero and NHF cells, at a maximum tested concentration (50 μg/mL), with cellular antioxidant activity. Total phenolic content was highest in the most potent antioxidant fraction. Quercetin, rosmarinic and gallic acids were found. Total phenolic content is highly related to FRAP, antityrosinase, and ABTS activities.Discussion and conclusion: Pericarp from litchi fruit can be obtained abundantly from agricultural waste, and the strong antioxidant activity demonstrated in this report may have application in topical cosmetic products. This ecological antioxidant can be prepared using a feasible method resulting in less waste and increased agro-industrial profitability.

Identification of d-friedoolean-13-en-3-one (Taraxerone) as an antioxidant compound from sedom (Sedum sarmentosum)

A pentacyclic triterpenoid compound was isolated from the ethyl acetate extract of sedum (Sedum sarmentosum) and identified as d-friedoolean-13-en-3-one (taraxerone) by GC-MS and crystallographic analysis. The extraction yield of taraxerone was 74.12±0.57 mg/kg sedum (dry weight). The IC50 values of taraxerone were 102.34±1.53 μM and 1,763.81±12.63 μM/mL (Trolox equivalent) by the DPPH and ferric reducing ability of plasma (FRAP) assays, respectively. Taraxerone exhibited comparable antioxidant capacities with butylated hydroxytoluene (BHT) by the DPPH (p=0.117) and FRAP (p= 0.179) assays. The production of inducible nitric oxide in lipopolysaccharide-stimulated murine macrophage was inhibited by taraxerone (IC50=38.49±3.77 μM) via downregulation of inducible nitric oxide synthase (iNOS) expression at the transcriptional level. The inhibitory effect of taraxerone on nitric oxide generation was significantly more effective than that of caffeic acid and/or gallic acid.

Analysis of the Antioxidant Capacities of Flavonoids under Different Spectrophotometric Assays Using Cyclic Voltammetry and Density Functional Theory

Flavonoids often show inconsistent antioxidant activities (AAs) depending on the assay used. The electrochemical properties of 14 flavonoid standards in cyclic voltammetry [area under anodic wave (Q) and oxidant peak potentials (Epa)] and the structural parameters [bond dissociation enthalpy (BDE) and ionization potential (IP)] were investigated. They were compared with the results of four spectrophotometric assays, namely, diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent (FCR), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), to analyze the chemical reasons for the varying AAs of flavonoids under different assays. Using the cyclic voltammetry method, the AAs of the flavonoids in the DPPH, FCR, and FRAP assays were mainly determined by the ease of charge transferring in the first oxidation step. Meanwhile, the results of TEAC assays were primarily influenced by the amount of charge transfer in the multiple oxidation steps (MOS) of flavonoids. In the theoretical calculation, the BDE values of the selected flavonoids had considerably higher correlations with the results of the DPPH assay (r2=0.89) compared with the other three assays, which indicates that the oxidant-scavenging reaction of the tested flavonoids in the DPPH assay is closer to a hydrogen atom transfer mechanism. Neither the IP values nor BDE values had satisfactory correlation with the AAs of the flavonoids in the TEAC assay (r2=0.57, r2=0.54, respectively), Therefore, complex reaction mechanisms underlie this method and appropriate structural descriptors for reflecting the AAs of flavonoids based on MOS (e.g., TEAC values) need further investigation.

Assessment of antioxidant capacity of sedum (Sedum sarmentosum) as a valuable natural antioxidant source

In order to investigate the antioxidant capacity of sedum (dolnamul, Sedum sarmentosum) and to offer a scientific basis for the medicinal use of it, lyophilized sedum leaves were extracted with n-hexane, n-butanol, ethyl acetate, and methanol, respectively. The methanol extract (ME) showed the highest extraction yield, but no significant differences in the extraction yield were observed. The total polyphenol content (TPC) of the ethyl acetate extract (EAE) and the ME was significantly higher than that of the non-polar solvent extracts. The EAE and ME showed the superior antioxidant activities in the DPPH, oxygen radical absorbance capacity (ORAC), and ferric reducing ability of plasma (FRAP) assays. Lipid peroxidation was efficiently inhibited by the addition of the sedum extracts in the ferric thiocyanate (FTC) and thiobarbituric acid reactive substances (TBARS) assays, but significant differences among the tested extracts were not observed. The ME showed the potent lipid peroxidation inhibitory activity comparable to butylated hydroxytoluene (BHT). The correlations between the TPC and the antioxidant activities based on the DPPH, ORAC, and FRAP assays were highly positive (R 2>0.899).

Validation of a quantitative assay for the total content of lipophilic and hydrophilic antioxidants in foods

One of the main methods used to assess total antioxidant content in foods is the Ferric Reducing Ability of Plasma (FRAP) assay. The FRAP assay has previously not been extensively validated. In the present study, 39 pure compounds, such as different polyphenols, ascorbic acid, tocopherols, tocotrienols and carotenoids dissolved in water/methanol, water/2-propanol and 2-propanol, were tested. Our results demonstrate that the FRAP assay can quantitate satisfactorily most hydrophilic and lipophilic compounds with antioxidant properties. The reaction was followed for 60min. The most extensive reaction occurred within the first 4min for most compounds and foods. The lipophilic tocopherols and tocotrienols were easily quantitated and reached endpoint within 4min while carotenoids were somewhat more demanding due to low solubility and slower reaction kinetics. We conclude that the FRAP assay, with 4min reaction time, is suitable for high-throughput screening of total antioxidant content of edible items.

Evaluation of oxidative stress and antioxidant status of pregnant women suffering from malaria in Cameroon.

Oxidative stress is thought to be involved in the pathophysiology of malaria, especially in pregnancy where natural resistance is markedly reduced. In the present study we investigated oxidative stress in 315 pregnant women out of which 159 had Plasmodium falciparum malaria and 154 controls. We evaluated the level of lipid peroxidation products (MDA level) in the plasma, the activity of erythrocyte antioxidant defense enzymes, superoxide dismutase (SOD, EC: 1.15.1.1) and catalase (Cat, EC: 1.11.1.6) as well as the ability to resist oxidative stress by the FRAP (Ferric Reducing Ability of Plasma) assay. Total erythrocyte protein levels were also examined. For the two groups of patients, several differences between the biochemical parameters tested were found. Median parasitaemia in women with malaria was 25,392 parasites/μl of blood (Range1200-82000), while in controls we had no parasites found in thin and thick smears. Levels of lipid peroxidation products (MDA) were significantly higher in patients with parasitemia than in healthy asymptomatic volunteers (mean: 0.844 ± 0.290 and 0.384 ± 0.129 respectively, p<0.001). This MDA level was higher in primigravidea and also correlates well with parasite density (p<0.001). Catalase activity in erythrocytes of women with malaria did not differ statistically from that of controls. In contrast, SOD activity of patients with malaria was found to be significantly higher than that of controls (mean: 0.7899 ± 0.2777 and 0.4263 ± 0.2629 respectively, p<0.05). FRAP values declined, from parasitemic patients (1.4619 ± 0.6565) compare to controls (2.4396 ± 0.8883, p<0.05), particularly in the first and third trimester of gestation (p<0.05 and p<0.01 respectively). Finally, total erythrocyte protein concentrations of women with malaria did not differ from that of the controls. Our results suggest an imbalance between oxidants and antioxidants in pregnant women suffering from malaria, a situation which could lead to severe damage for either the mother or the fetus. Therefore, further research should be done to assess the potential benefits of antioxidant supplementation for the pregnant women suffering from malaria.

The key role of grape variety for antioxidant capacity of red wines

summary Background & aims: Recent epidemiological studies have supported the idea that food rich in plant bioactive compounds and polyphenols in particular may exert beneficial effects toward human health. One of the foodstuffs widely distributed in the human diet is red wine, a strong antioxidant that contains many bioactive compounds, such as: polyphenols, minerals, and vitamins. The objective of this study was therefore to assess the antioxidant capacity, total phenolics, selected vitamin and mineral content in red wine samples and also to elucidate the existence of a possible relationship between grape variety and all constituents of wines as mentioned above. Methods: The set of 10 red wines, six of Cabernet Sauvignon and four of Merlot was subjected to the study. In all samples total antioxidant capacity was measured by Trolox equivalent antioxidant capacity (TEAC) assay and the Ferric reducing ability of plasma (FRAP) assay simultaneously with total phenolic content, selected minerals and essential vitamins. Results: Both antioxidant capacity and phenolic content were higher in Cabernet Sauvignon wines compared to Merlot. The total antioxidant capacity correlated positively with total phenolic content (r ¼ 0.88, p < 0.001 for TEAC assay and r ¼ 0.89, p < 0.001 for FRAP assay respectively), while a significant relationship among antioxidant capacity, selected minerals and vitamins was not observed. Among the nine minerals analyzed, potassium, zinc and magnesium were the most abundant elements distributed throughout all wine samples. Our results suggest that antioxidant capacity is dependent mainly on total phenolics. Grape variety largely determines such components as phenolic content, antioxidant capacity and mineral content with the exception of vitamins.

C-phycocyanin from Spirulina fussiformis exposed to blue light demonstrates higher efficacy of in vitro antioxidant activity

In this study we made the comparative evaluation of antioxidant activities of C-phycocyanins produced from Spirulina fussiformis exposed to blue light (C-pc (B)) and normal light (C-pc (N)), by various antioxidant assays such as 2,2-azino-bis(3)ethylbenzthiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), super oxide anion (O2−) scavenging, hydroxy radical (OH) scavenging, hypochlorous acid (HOCl) scavenging, ferrous oxidation xylenol orange (FOX), oxygen radical absorbance capacity (ORAC), ferric reducing ability of plasma (FRAP) and reducing power assays. The observed antioxidant activities were compared with that of ascorbic acid, a standard antioxidant. C-pc (B) exhibited significantly (p < 0.05) higher radical scavenging effect than in DPPH, OH, HOCl, ORAC and FRAP assay conditions in a dose-dependent manner. Higher reducing power of C-pc (B) demonstrated a dose-dependent pattern and indicated the presence of free radical scavenger moieties. Furthermore, sequencing of α and β chains of both C-pcs revealed marginal changes in α chains of both kinds of C-pcs and realignment of sequences from 76 to 97 amino position in β chain of C-pc (B) indicating modification of the polypeptide with higher cysteine. In conclusion the present study demonstrated that C-pc (B) showed higher antioxidant activity.

Antioxidant and antimicrobial activities of extract and essential oil of korarima (Aframomum corrorima (Braun) P.C.M. Jansen)

The antioxidant potential of extracts and essential oils of korarima (Aframomum corrorima (Braun) P.C.M. Jansen) were investigated, as well as total phenolics, total ascorbic acid (TAA), condensed tannins (CT) and antifungal potential. Antioxidant capacities of seeds and pods as assayed in methanol extracts, and of essential oils were at moderate levels.The antioxidant activity of seeds (29.59 imol/g dry weight (DW)) was significantly higher than that of pods (14.23 imol/g DW) by FRAP (Ferric Reducing Ability of Plasma) assay. Also the antiradical power of seeds (9.26 imol/g DW) was higher than of pods (3.08 imol/g DW) in the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. Similarly, the antioxidant activity of seeds was higher than of pods in the
-carotene bleaching test. A lower 50% effective concentration (EC50) was achieved with seeds (42.10 mg/mL) as compared to pods (120.50 mg/mL), while EC50 of pod oils (11.9 mg/mL) was lower than seed oils (59.2 mg/mL). The total phenolic content in seeds (3.98 mg/g DW) was significantly higher than in pods (1.32 mg/g DW), while TAA content was significantly lower in seeds (3.49 mg/100 g DW) than in pods (6.25 mg/100 g DW). Differences in CT were non-significant. Antifungal tests exhibited that the extracts from seed were more effective than the control. Based on the present study the consumption of korarima as a spice may be used as source of antioxidants.

Stress Reaction: Ozone and Co-pollutants Linked with Oxidation

Past studies have hinted that several air pollutants can cause oxidative stress in people, suggesting one mechanism behind diseases such as lung cancer, asthma, and increased cardiopulmonary illnesses and deaths. The evidence has gained more support with the discovery that chronic exposure to ambient ozone, nitrogen dioxide, or particulates is strongly linked with lipid peroxidation, an indicator of oxidative stress [EHP 115:1732–1737; Chen et al.]. Moreover, more damage was seen at higher pollutant concentrations. Researchers evaluated two oxidative stress indicators in the blood of 120 University of California, Berkeley, students aged 18 to 22 years. Each student was a lifelong resident of either the Los Angeles or San Francisco area, where they had experienced variable seasonal exposures to pollutants including ozone. To assess lipid peroxidation, the researchers measured 8-iso-prostaglandins-F2α (8-iso-PGF), which has been found in several studies to be a useful indicator. To assess total antioxidant capacity, they measured ferric-reducing ability of plasma (FRAP), which has a more limited history as an indicator. Pollutant concentrations were estimated from data at monitoring stations near where the students lived. The lifelong Los Angeles residents had received much higher average ozone exposure over the course of a lifetime (42.9 ppb versus 26.9 ppb for the San Francisco residents), and 8-iso-PGF was twice as high in these students (195.3 pg/mL versus 97.2 pg/mL). There was also a link between relatively higher ambient ozone concentrations during 2-week and 1-month periods and increased 8-iso-PGF. Neither sex, ethnicity, nor weight affected the results, but there was a wide range in 8-iso-PGF among individuals (17.4–940.7 pg/mL), perhaps due to genetic differences. The researchers also found a significant link between 8-iso-PGF and increased concentration of nitrogen dioxide or particulates, independent of the effects of ozone. The FRAP assay showed no significant difference in antioxidant capacity between the residents of the two cities. However, there was a threefold difference among all study subjects in antioxidant capacity, and males had about 23% more antioxidant capacity than females. Although acknowledging that much more study of other populations and locations needs to be done with more precise measures of personal pollutant exposure, the researchers conclude that each of the three pollutants studied can significantly increase oxidative stress. They also report that 8-iso-PGF is an accurate indicator of oxidative stress, while noting that other indicators, such as cytogenetic damage, may also prove useful.

Antioxidants in some Ugandan fruits

AbstractSeveral studies indicate that a plant‐based diet protects against the development of some serious diseases. It is assumed that the antioxidant content in food is an important reason for this protection. Dietary plants contain several hundred antioxidants, many of which are believed to act in a synergistic way to protect the body against oxidative stress. Berries, fruits, spices and some nuts have proved to be excellent sources of antioxidants. In this preliminary study, many fruits and some seeds from Ugandan plants have been analysed for total antioxidant activity using the FRAP (Ferric reducing ability of plasma) assay. Our results demonstrate that there is a large variation in antioxidant activity between the samples analysed. The plants with highest activity in decreasing order were found to be: African black olive (Canarium sweinfurthii), pomegranate, guava, java plum (Syzygium cuminii), sweet banana, tamarind, mango, orange and passion fruits, with antioxidant values in the range of 47.25 to 0.77 mmol per 100 g fresh weight. We believe that increased awareness of antioxidant activity in food and resulting change in food intake can be of importance for an improved health situation.

Investigation of the Antioxidant Activity of African Potato (Hypoxis hemerocallidea)

African potato (AP) is widely used as an immune booster for the treatment of various ailments. The norlignan glycoside hypoxoside, a major phytoconstituent of AP, its aglycon rooperol, and an aqueous preparation of lyophilized AP corms were screened for in vitro antioxidant activity using the DPPH (1,1-diphenyl-2-picryl hydrazine) and FRAP (ferric reducing ability of plasma) tests. Inhibition of quinolinic acid (QA) induced lipid peroxidation in rat liver tissue was studied in vitro using the thiobarbituric assay (TBA). Superoxide free radical scavenging activity was determined by the nitroblue tetrazolium assay. An isocratic HPLC method was developed to quantitatively determine both hypoxoside and rooperol concurrently. While rooperol and AP extracts reduced QA-induced lipid peroxidation in rat liver homogenates and significantly scavenged the superoxide anion at pharmacological doses, in comparison, hypoxoside was virtually devoid of activity. Since hypoxoside is converted to rooperol in vivo following administration of AP, the results indicate that the hypoxoside component in AP could have value as an antioxidant prodrug.