For Ferric Reducing Antioxidant Power Research Articles

Antioxidant activity of yellow dock (Rumex crispus L., Polygonaceae) fruit extract

The methanol extract of ripe Rumex crispus L. fruits was evaluated for its antioxidant potential by assays for ferric-reducing antioxidant power (FRAP), DPPH-free radical scavenging activity (DPPH) and the influence on lipid peroxidation in liposomes (LP). Considerable activity was observed in all test systems (FRAP: 9.9 mmol Fe(2+) /g; DPPH IC(50) : 3.7 μg/mL; LP IC(50) : 4.9 μg/mL), comparable to that of BHT (FRAP: 8.0 μg/mL; DPPH IC(50) : 19.4 μg/mL; LP IC(50) : 3.5 μg/mL), but lower than the activity of ascorbic acid, rutin and quercetin, used as positive control substances. The in vivo effects were evaluated in several hepatic antioxidant systems (activities of LPx, GSH-Px, Px, CAT and XOD, as well as GSH content), after treatment with the studied yellow dock extract in different doses, or in combination with carbon tetrachloride (CCl(4) ). Pretreatment with the R. crispus extract inhibited CCl(4) -induced oxidative stress by decreasing LPx and increasing GSH content in a dose dependent manner, bringing the levels of antioxidant enzymes to near control values.

The effects of a multiflavonoid supplement on blood pressure and oxidative stress

Antioxidant supplementation has been shown to reduce blood pressure. Moderate intensity aerobic exercise also elicits a reduction in blood pressure immediately following exercise, termed post exercise hypotension (PEH). The purpose of this study was to test the effects of a multi‐flavonoid supplement plus exercise on PEH following a 2‐week dosing period.Methods12 normotensive subjects between the ages of 18–24 were randomized into either a placebo or a multiflavonoid supplement. Each subject was studied pre, immediately before and after exercise and at 30 minutes post‐exercise both prior to and following 2 weeks supplementation. Blood was taken both pre and immediately following the exercise sessions and was assayed for ferric reducing antioxidant power (FRAP) and the oxygen radical absorbance capacity (ORAC).ResultsSignificant decreases in systolic blood pressure in the treatment vs. placebo group (−3 ± 0.44 mmHg vs. −0.3 ± 0.56 mmHg, respectively, interaction p = 0.05,) and significant increases in FRAP (742 ± 41 to 956 ± 46 μmol/L vs. 658 ± 41 to 670 ± 46 μmol/L, interaction p=0.024) were found following supplementation and no differences in the control group. ORAC produced no significant differences with supplementation.ConclusionsThese data suggest that Q‐EGCG supplementation increases FRAP in young normotensives which may be a mechanism for the resting blood pressure reduction.

Improvement of quality and antioxidant properties of dried mulberry leaves with combined far-infrared radiation and air convection in Thai tea process

Combined far-infrared radiation with hot-air convection (FIR–HA) drying was used for improving colour and antioxidant properties of mulberry leaf tea. Antioxidant properties and phenolic compounds of FIR–HA dried mulberry tea were determined and compared with the commercial product and with fresh leaves. We found that a smaller decrease in L and b values of the FIR–HA dried tea than those of commercial tea was observed. FIR–HA tea was found to have similar colour to fresh leaf while the commercial tea had darker colour. A significant decrease in total phenolic acid content (TPC) and total flavonoid content (TFC) was found in hot-air (HA) dried commercial tea compared to fresh leaves, while TPC in FIR–HA dried tea was significantly increased. Similar results were found in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical activities. However, the results were different for ferric reducing antioxidant power (FRAP). Both teas had lower FRAP values compared to fresh leaves. Eleven phenolic compounds were identified in fresh leaf and in mulberry tea, namely p-coumaric acid, benzoic acid, (+)-catechin, chlorogenic acid, vanillic acid, syringic acid, sinapic acid, protocatechuic acid, ferulic acid, gallic acid and caffeic acid. The total content of phenolic compounds (TPCC) increased in FIR–HA dried samples compared to those of HA dried tea, except for chlorogenic and syringic acids, which were found in greater amounts in HA dried commercial tea. Our results have demonstrated that FIR–HA should be considered as a suitable drying method for mulberry tea with respect to preserving its antioxidant properties and phenolic compounds.

Antioxidant activity of Filipendula hexapetala flowers

The antioxidant activity of the methanol extract of Filipendula hexapetala flowers was assessed by the assay for ferric-reducing antioxidant power (FRAP), the assay for DPPH free radical scavenging ability (DPPH) and the assay for the influence of lipid peroxidation in liposomes, induced by Fe 2+/ascorbate system and measured by the TBA test (LP). The activity of the investigated extract in all test-systems was found to be significant. The principal constituent responsible for the observed effects was isolated and identified as spiraeoside.

Antioxidant Potential of Various Extracts from Ferula szovitsiana. in Relation to Their Phenolic Content

The objective of this study was to examine the in vitro. and in vivo. antioxidative and radical scavenging potential of organic extracts of the aerial parts and roots of Ferula szovitsiana. DC (Umbelliferae). Extracts were evaluated for ferric-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in vitro.. The influence of the most potent sample was examined in rats for the prevention of plasma and liver lipid peroxidation and activity of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The methanol extract was found as the most active in scavenging DPPH radicals and in FRAP and showed the greatest polyphenol content. The phenolic content of the extracts positively correlated with the FRAP values (r2 = 0.92, p < 0.0001) and DPPH scavenging activity (r2 = 0.96, p < 0.0001) in vitro.. Administration of the methanol extract to rats decreased lipid peroxidation in plasma and liver, whereas FRAP of plasma increased. The activities of CAT and SOD increased in the liver. These results lead to the conclusion that F. szovitsiana. extracts show relevant antioxidant activity both in vitro. and in vivo. by means of scavenging free radicals, reducing cellular lipid peroxidation, increasing the activity of antioxidant enzymes, and total antioxidant power. The higher antioxidant potential of the methanol extract of F. szovitsiana. shown in the current study indicates that most of the active constituents of this plant are polar phenolic components.

Effects of Food Processing on Blueberry Antiproliferation and Antioxidant Activity

ABSTRACTCultivated highbush (Vaccinium corymbosum L.) and wild lowbush (Vaccinium angustifolium Ait.) blueberries are excellent sources of phytochemicals that are believed to have significant biological activity. The objective of this study was to determine whether incorporation of blueberries into food products affects their phenolic content or antioxidant and antiproliferation activity. Several blueberry fruit‐containing products including fresh, individually quick frozen (IQF), freeze‐dried, spray‐dried, heat‐dried, cooked, juice concentrate, pie filling, and jam were fractionated to remove sugars and isolate groups of phytochemicals based on solubility. The fractions were analyzed for total phenolics and assayed for ferric reducing antioxidant power (FRAP) antioxidant activity, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity, and hepa‐1c1c7 antiproliferative activities. For both cultivated and wild berries, fresh and IQF berries had the highest total phenols, antioxidant activity, and antiproliferation activity. Whole freeze‐dried wild blueberries also retained significant antiproliferative activity in 2 fractions eluted with acetone (fraction 4, 4% of control cell growth at 20 (μg/mL) and 50% aqueous acetone (fraction 5, 69% of control cell growth at 20 (μg/mL) and ranked close to the activities recorded for fresh (30% of control cell growth at 20 (μg/mL for fraction 5) and IQF whole fruit (27% of control cell growth at 20 (μg/mL for fraction 5). Products that were heat‐processed retained most of the antioxidant activity and total phenolics found in unprocessed whole fruit. However, the heat‐treated products lacked or had diminished antiproliferation activity, suggesting that although products may be high in phenolic compounds and antioxidant activity, some forms of bioactivity may be compromised by harsh processing methods.