The Evaluation of Antioxidant Interactions among 4 Common Vegetables using Isobolographic Analysis

Isobolographic analysis was used to assess the antioxidant interactions (synergism, addition, and antagonism) of 4 common vegetables (tomato [T], carrot [C], eggplant [E], and purple potato [P]). The lipophilic (L) extracts of T and C (main carotenoids), the hydrophilic (H) extracts of E and P (main phenolics) were mixed by the certain ratios (1:9, 3:7, 1:1, 7:3, 9:1, w/w) and their antioxidant activities were investigated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2’‐Azinobis‐(3‐ethylbenzthiazoline‐6‐sulphonate) (ABTS) radical scavenging assays, respectively. Most of the binary mixtures (LC‐HE, LC‐HP, HE‐HP, LT‐HE, and LT‐HP combinations) showed the synergistic antioxidant effects. In DPPH assay, the greatest antioxidant activity of vegetable combinations was 1:9 LT‐HP (EC₅₀: 2.45 ± 0.13 mg/mL), followed by 9:1 HE‐HP (EC₅₀: 3.62 ± 0.12 mg/mL) and 1:9 LC‐HE (EC₅₀: 3.74 ± 0.47 mg/mL). In ABTS assay, the greatest antioxidant activity of vegetable combinations was 9:1 HE‐HP (EC₅₀: 4.20 ± 0.10 mg/mL), followed by 7:3 HE‐HP (EC₅₀: 4.41 ± 0.63 mg/mL) and 1:1 HE‐HP (EC₅₀: 5.35 ± 0.85 mg/mL). Among these combinations, 1:1 LC‐HE combination showed the highest synergistic antioxidant effects in DPPH assay (synergistic rate: 87.4%), and 7:3 LC‐HE combination showed the highest synergistic antioxidant effects in ABTS assay (synergistic rate: 87.0%). The mixtures of phenolics and carotenoids with suitable ratios in vegetables effectively enhanced the synergistic antioxidant effects.     

Effects of Various Heat Treatments on Phenolic Profiles and Antioxidant Activities of Pleurotus eryngii Extracts

Free (FP) and bound phenolics (BP) were extracted from freeze dried (FD), oven dried (OD), as well as boiling treated (BT) Pleurotus eryngii samples. Free, bound, total phenolics were quantified using Folin–Ciocalteau assay. Qualitative and quantitative analysis of phenolic compounds were carried out using high‐performance liquid chromatography (HPLC) coupled with diode array detector (DAD), and a total of 8 phenolic compounds were detected. Free phenolic contents followed the order: Freeze‐dried free phenolics (FDFP) > Oven‐dried free phenolics (ODFP) > Boiling‐treated free phenolics (BTFP), and ranged from 95.42 (BTFP) to 442.50 (ODPF) μg gallic acid equivalents (GAE)/g dry weight (DW). Bound and total phenolic contents followed the order: FD > OD > BT, and ranged from 218.33 (BTBP) to 774.17 (FDBP) and 313.75 (BT total phenolics) to 1090.42 (FD total phenolics) μg GAE/g DW. Bound phenolics contributed 49.76% (OD), 69.59% (BT), and 71% (FD) of the total phenolic contents. All free and bound phenolic extracts were investigated for their antioxidant activities by 3 different assays, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide anion radical scavenging activity. FDFP showed strongest DPPH radical scavenging activity (IC₅₀ at 32.61 μg/mL), ODFP showed strongest reducing power (IC₅₀ at 26.31 μg/mL), and BTBP showed strongest superoxide anion radical scavenging activity (IC₅₀ at 14.07 μg/mL).     

Phenolic Compounds and Antioxidant Capacities of 10 Common Edible Flowers from China

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high‐performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging activity, 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) radical‐scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe²⁺ equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC₅₀) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers.     

Optimisation of hydrolysis of purple sea urchin (Strongylocentrotus nudus) gonad by response surface methodology and evaluation of in vitro antioxidant activity of the hydrolysate

BACKGROUND: Hydrolysates prepared from sea urchin (Strongylocentrotus nudus) gonad by enzymatic treatment showed strong 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity and reducing power. RESULTS: Hydrolysis of S. nudus gonad by the commercial protease papain was optimised for maximum degree of hydrolysis (DH) and trichloroacetic acid‐soluble peptide index (TCA‐SPI) using response surface methodology. Results showed that the optimal conditions were the following: temperature of 48.83 °C, pH of 6.92, enzyme‐to‐substrate ratio of 3143 U g^?1, and substrate concentration of 83.5 g L^?1. Under these conditions, a DH of 27.96 ± 0.54% and a TCA‐SPI of 57.32 ± 0.63% were obtained. The hydrolysate prepared in the optimal conditions was fractionated by an ultra‐filtration system and the resultant fraction below 10 kDa was found to effectively scavenge hydroxyl radical (EC₅₀ = 13.29 ± 0.33 mg mL^?1) and hydrogen peroxide (EC₅₀ = 16.40 ± 0.37 mg mL^?1), inhibit lipid peroxidation (EC₅₀ = 11.05 ± 0.62 mg mL^?1), chelate Fe²⁺ (EC₅₀ = 7.26 ± 0.44 mg mL^?1), and protect mice macrophages against death induced by tert‐butyl hydroperoxide. CONCLUSION: Hydrolysates prepared from S. nudus gonad have the potential to be applied as natural antioxidant agents. Copyright © 2012 Society of Chemical Industry     

Phenolic acid composition and antioxidant properties of Malaysian honeys

Abstract: The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) radical‐scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51– 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27– 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97– 363.38 ± 10.57 μM Fe[II]/kg), and high IC₅₀ of DPPH radical‐scavenging activities (5.24 ± 0.40– 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans‐cinnamic, p‐coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical‐scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical‐scavenging activities.     

In vitro antioxidant and antiproliferative activity of three rosemary (Rosmarinus officinalis L.) extract formulations

Antioxidant and antiproliferative activities of three rosemary extract formulations (VivOX 20, VivOX 40 and Inolens 50) with different contents of carnosic acid, carnosol and methylcarnosol were tested in vitro. Electron spin resonance measurements revealed that Inolens 50 extract that contained highest amount of carnosic acid was the most potent scavenger of hydroxyl (concentration of extract where 50% of its maximal scavenging activity is observed, that is, EC₅₀, 109.54 μg mL^?1), superoxide anion (EC₅₀ = 7.94 μg mL^?1) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (EC₅₀ = 27.4 μg mL^?1)‐free radicals. Comparison of the radar charts of standard antioxidants and rosemary extracts showed similarity between antioxidant characteristics of Inolens 50 and chlorogenic and caffeic acids. Tested rosemary extracts exhibited significant (P ≤ 0.01) antiproliferative effect in cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT‐29) cell lines. In both MCF7 and HeLa cell lines, the extracts yielded very low IC₅₀ values (concentration of extract needed to inhibit cell growth by 50%), the most pronounced being for Inolens 50 in MCF7 (IC₅₀ = 9.95 μg mL^?1) and VivOX 20 in HeLa cell line (IC₅₀ = 10.02 μg mL^?1). The obtained results may provide support for the use of tested rosemary extracts as nutraceuticals and phytopharmaceuticals.     

Phenolic composition,antioxidant and antimicrobial activities of free and bound phenolic extracts of Moringa oleifera seed flour

Phenolic compounds, antioxidant and antibacterial activities of defatted Moringa oleifera seed flour (DMF) were investigated. The total phenolic and flavonoid contents were measured using colorimetric methods. Free phenolic acid and flavonoid profiles were analyzed by high performance liquid chromatography, while antioxidant capacities were evaluated using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), ferric reducing antioxidant power and total antioxidant capacity. The results showed that extractability of phenolic compounds was significantly higher (p < 0.05) in bound phenolic extract (4173.00 ± 32.22 mg gallic acid equivalents (GAE)/100 g) than in free phenolic extract (780.00 ± 14.2 mg GAE/100 g) and it showed higher antioxidant and antimicrobial activities. The IC₅₀ value for DPPH radical scavenging activity was 0.9 ± 0.05 and 14.9 ± 0.07 mg/mL for bound phenolic and free phenolic extracts, respectively. Bound phenolic extract was more effective (minimum inhibitory concentration (MIC), 0.06–0.157%) than free phenolic extract (MIC, 0.117–0.191%) against tested bacteria. Ten phenolic compounds (gallic acid, p-coumaric acid, ferulic acid, caffeic acid, protocatechuic acid, cinnamic acid, catechin, epicatechin, vanillin and quercetin) were identified and quantified in both extracts. These natural plant phenolics from Moringa seeds could be a good source of antioxidants and antibacterials for food and pharmaceutical industries.     

Application of Green Technology for the Acquisition of Extracts of Araçá (Psidium grandifolium Mart. ex DC.) Using Supercritical CO2 and Pressurized Ethanol: Characterization and Analysis of Activity

Brazil is home to a wide variety of flora, including several lesser known species, such as araçá that were processed in this study using two green technologies consecutively: supercritical fluid extraction (SFE) for nonpolar fraction and pressurized liquid extraction. For polar fraction, the experiments followed a central composite design involving ethanol as solvent, with temperature and static time in each bath as independent variables. Both extracts were analyzed for antioxidant and antimicrobial activities. Total phenolics content (TPC) was determined for all ethanol extracts. In the araçá essential oil (AEO) obtained by SFE, the extraction yield was 2.33%. The three major compounds of AEO were α‐pinene (20.75%), p‐cymene (20.50%), and o‐cymene (20.05%). In ethanol extracts, the high yield (14.49%) was obtained at 74 °C/6 min and the major TPC (136.95 mg GAE/100 g) at 60 °C/9 min. Ethanol extracts presented good antioxidant activity (EC₅₀ = 6.37 mg/mL) at 74 °C/6 min. AEO was unable to reduce DPPH? concentration by 50%. Both extract types presented an inhibitory effect against Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus, while only the ethanol extracts presented effect against Listeria monocytogenes. This work had the aim to present the innovation of the use of a whole typical Brazilian fruit that gives rise to extracts with excellent properties for employment in both the pharmaceutical and food industries.     

Oregano: chemical analysis and evaluation of its antimalarial, antioxidant, and cytotoxic activities

Abstract: GC‐FID and GC‐MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p‐cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC₅₀= 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC₅₀= 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC₅₀ of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic.     

Porcine Hemoglobin Hydrolysate Prepared with Pepsin: Antioxidant Activities and Their Mechanisms

Different antioxidant assays were employed in order to evaluate antioxidant activities of porcine hemoglobin hydrolysate (PHH) prepared with pepsin and compared with natural and synthetic antioxidants. Molecular weight distributions of PHH polypeptide components were determined. PHH exhibited DPPH/superoxide/hydroxyl radicals scavenging (EC₅₀ 0.95 ± 0.01 mg/ml, 20.34 ± 2.83 mg/ml, 7.90 ± 0.58 mg/ml, respectively); reducing power (EC₅₀ 3.02 ± 0.91 mg/ml); and metal chelating activity (EC₅₀ 2.59 ± 0.05 mg/ml) in a dose-dependent manner. Hydroxyl radicals scavenging activity of PHH was equivalent to ascorbic acid. Relatively less active of PHH exhibited strong synergistic antioxidant activity with α-tocopherol (TOH). Tested combinations (2:1 and 1:1 of PHH:TOH) showed significantly higher antioxidant activities (P < 0.05) compared to combinations with low PHH rates (1:2 and 1:4 of PHH:TOH). The main synergistic antioxidant mechanism could be due to the regeneration of TOH by PHH. Radicals scavenging mechanism, more than metal chelation, could play a major role in the antioxidant process of PHH.     

苦荞麸皮多酚抑制人结肠癌细胞Caco-2增殖活性研究

研究了产自重庆酉阳的苦荞(Fagopyrum tartaricum L.Gaerth,FG1)麸皮和四川西昌的苦荞(Fagopyyrum tartaricum L.Gaerth,FG2)麸皮中酚类化合物的含量、抗氧化和抗增殖活性。结果表明:FG1和FG2 2种苦荞麸皮总酚含量分别为(26.40±0.41)和(27.00±0.72)mg GAE/g DW,且游离态是其酚类化合物的主要存在形式(约占其总酚含量的93%);2种苦荞麸皮酚提取物均表现出一定的抗氧化性,并且FG2的抗氧化能力强于FG1(P0.05),FG1和FG2的DPPH自由基清除能力总IC50值分别为(39.56±2.76)和(24.69±0.33)μg·mL~(-1);还原力总EC_(50)值分别为(97.92±1.4)和(73.18±4.32)μg·mL~(-1);在抗增殖试验中,与对照组相比,FG1和FG2游离酚提取物均能明显抑制人结肠癌细胞Caco-2增殖(P0.05)。然而,在不产生细胞毒性的浓度范围内,其结合酚提取物却表现出极弱的抗增殖作用。     

Antioxidant Properties of Free,Soluble Ester and Insoluble‐Bound Phenolic Compounds in Different Barley Varieties and Corresponding Malts

Ten different barley cultivars and their corresponding malts were used to obtain different fractions. Phenolics extracted belonged to free, soluble esters and insoluble‐bound fractions. Total phenolic content (TPC) of the free fraction, as measured according to the Folin‐Ciocalteu method, ranged from 37.7 to 167.2 mg gallic acid equiv/kg of dried material (GAE/kg_dw) for barley and between 34.1 and 72.3 mg GAE/kg_dw for malt. The bound phenolic content ranged from 210.3 to 320.5 and between 81.1 and 234.9 mg GAE/kg_dw for barley and malt, respectively. The contribution of bound phenolics to the TPC was significantly higher than that of free and esterified fractions. Catechin and ferulic acid, quantified by high performance liquid chromatography with diode array detector (HPLC‐DAD), were the most abundant phenolics in the free and bound fractions, respectively. The p‐coumaric acid content was lower in hulless genotypes, as compared to hulled genotypes, showing that it is mainly concentrated in the hull. The antioxidant activities of the phenolic fractions were investigated using the radical scavenging assay (DPPH) and ferricyanide reducing power. The bound phenolics demonstrated a significantly higher antioxidant capacity compared to the free and esterified phenolics. During the malting process, a significant decrease of the bound phenolics was observed with a corresponding increase of the esterified fraction.     

Evaluation of free radical scavenging of dietary carotenoids by the stable radical 2,2‐diphenyl‐1‐picrylhydrazyl

In order to avoid the interference of compounds with a chromophoric system when the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^·) method is used, a new measure of the decrease in absorbance at 580 nm was performed (correlation coefficient between absorbance and DPPH^· concentration, 0.9979; p < 0.01). The antioxidant effectiveness of dietary carotenes and xanthophylls towards the stable free radical DPPH^· was measured. The antioxidant activity expressed as the amount of antioxidant able to reduce the initial DPPH^· concentration to 50% (EC₅₀), given in terms of moles of antioxidant per mole of DPPH^·, ranged from 0.16 ± 0.01 (lycopene) to 3.29 ± 0.31 (lutein). The parameter antiradical efficiency (AE), which involves the potency (1/EC₅₀) and the time taken to reach the steady state at EC₅₀ (T_EC50), was calculated to discriminate carotenoids with no significant difference between their EC₅₀. Comparison of the structures of the carotenoids tested revealed that the scavenging ability towards DPPH^· was increased by the length of the effective conjugated double‐bond system and was modulated by the addition of chemical groups on the terminal rings (xanthophylls). © 2000 Society of Chemical Industry     

The Impact of Ozone Treatment on Changes in Biologically Active Substances of Cardamom Seeds

The overall objective of this study was to develop a decontamination method against microorganisms in cardamom (Elettaria cardamomum (L.) Maton) seeds using ozone as a decontaminating agent. Ozone treatment was conducted 3 times, at 24‐h intervals, and the parameters of the process were determined assuring the least possible losses of biologically active substances (essential oils and polyphenols): ozone concentration 160 to 165.0 g/m³; flow rate 0.1 L/min; pressure 0.5 atm; time 30 min. After each step of decontamination, the microbiological profile of the cardamom seeds was studied, and the contaminating microflora was identified. Next to the microbiological profile, the total polyphenol content (TPC), composition of essential oils, free radical‐scavenging capacity, total antioxidant capacity, ferric‐reducing antioxidant power (FRAP), and LC–MS polyphenol analysis were determined. This study shows that extract from cardamom seeds after ozone treatment is characterized by a better radical scavenging activity (IC₅₀ = 24.18 ± 0.04 mg/mL) than the control sample (IC₅₀ = 31.94 ± 0.05 mg/mL). The extract from cardamom seeds after ozone treatment showed an improved FRAP activity as well (613.64 ± 49.79 mmol TE/g compared to 480.29 ± 30.91 mmol TE/g of control sample). The TPC and the total antioxidant capacity were negatively affected, respectively, 41.2% and 16.2%, compared to the control sample.     

Amaranth Sprouts: A Potential Health Promoting and Nutritive Natural Food

Amaranth sprouts are an edible food with good nutritional qualities and potential biological activities of their proteins. The chemical composition, angiotensin converting enzyme inhibitory activity and antioxidant activity of the sprouts were determined. Sprouts showed a protein content similar to the seeds’ on a dry basis (16%) and a high fiber content (17%). Amaranth sprout proteins presented a capacity to inhibit angiotensin converting enzyme activity similar to other plant proteins (IC₅₀ = 0.9 ± 0.6 mg/mL). This capacity increased after in vitro gastrointestinal digestion (IC₅₀ = 0.26 ± 0.07 mg/mL). Besides other non protein molecules, the amaranth sprout proteins also presented ABTS^+. scavenging activity (TEAC = 0.32 ± 0.05 μmol/mg) that increased after in vitro gastrointestinal digestion (TEAC = 0.72 ± 0.08 μmol/mg) and oxygen radical antioxidant capacity. According to these results amaranth sprouts are a nutritive food with potential health promoting properties.     

人心果叶不同极性组分的抗氧化与抗菌活性

通过体外DPPH自由基、ABTS自由基清除能力和总抗氧化能力评价人心果叶不同极性萃取物（石油醚相、乙酸乙酯相、正丁醇相、水相）的抗氧化活性,并探究各极性组分对金黄色葡萄球菌、枯草芽孢杆菌和大肠杆菌的抑制能力。结果表明：乙酸乙酯组分的体外抗氧化活性最强,清除DPPH自由基能力IC₅₀值为（0.019±0.010） mg/mL,总抗氧化能力以水溶性维生素E当量（TEAC）表示,值为（5.824±0.234） mmol/g。当质量浓度达到0.50 mg/mL时,乙酸乙酯组分对ABTS自由基清除率就已经超过了50%;且乙酸乙酯组分能够明显抑制金黄色葡萄球菌的生长,最小抑菌浓度（MIC）和最小杀菌浓度（MBC）分别为0.313,0.625 mg/mL。人心果叶乙酸乙酯组分具有显著的抗氧化和抗菌活性,可用于天然抗氧化剂和抗菌剂的开发。     

Characteristics of the leaf parts of some traditional Korean salad plants used for food

BACKGROUND: Total phenolics content, antioxidant activity and cytotoxicity of the methanol extracts from leaf parts of 13 Korean traditional salad plants were investigated in order to determine their properties. RESULTS: The highest phenolics content (mg ferulic acid equivalents kg^?1 dry weight (d.w.), omit one) was found in methanol extracts from Polygonum aviculare, at 293.7 ± 6.0, followed by Euonymus alatus, at 250.7 ± 3.3, Saxifraga stolonifera, at 125.0 ± 8.1 and Ligularia fischeri, at 122.5 ± 5.9. The methanol plant extracts dose‐dependently increased free radical scavenging activity. Methanol extracts of Polygonum aviculare, Euonymus alatus and Saxifraga stolonifera, at 31 mg kg^?1, exhibited the highest 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity (%) by 90.8 ± 4.2, 85.7 ± 3.9 and 64.1 ± 3.2, respectively. According to 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay, the methanol extracts from Portulaca oleracea (IC₅₀ < 25.0 µg mL^?1) showed the highest cytotoxicity against Calu‐6, followed by Plantago asiatica (49.2 µg mL^?1) and Osmunda japonica (89.6 µg mL^?1). CONCLUSION: Total phenolics content of the tested plant extracts was correlated with the DPPH radical scavenging activity, suggesting the phenolics compounds are contributing to the antioxidant properties of Korean salad plants. The leaf parts of the 13 Korean traditional salad plants described here that are currently used as foods may also provide some benefit to human health, and research into their potential benefits as preventative and/or therapeutic agents is warranted. Copyright © 2008 Society of Chemical Industry     

Antioxidant activities of extract and fractions from Tuber indicum Cooke & Massee

The antioxidant activities of ethanolic crude extract (ECE) and its four different solvent sub-fractions (namely, petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butyl alcohol fraction (BAF) and the rest fraction (RF)) from Tuber indicum were investigated using several in vitro antioxidant assays. ECE and four sub-fractions possessed different antioxidant and radical-scavenging activities in different assays. BAF showed the most potent radical-scavenging activity on DPPH radicals, superoxide anion radicals and reducing power, with EC₅₀ values of 1.38, 0.96, 16.0 mg/ml, respectively. EAF exhibited the highest hydroxyl radical-scavenging and ferrous ion chelating activities with EC₅₀ values of 3.31 and 0.70 mg/ml, respectively. The total phenolics (TP) and total flavonoids (TF) were also determined. BAF had the highest TP and TF contents, and the next was EAF. These results showed that the amounts of phenolics and flavonoids were in accordance with higher effectiveness in scavenging radicals and chelating ferrous ions.     

Antioxidant activities of citrus herbal product extracts

Total phenolic content, DPPH free radical-scavenging activity, hydrogen peroxide-scavenging activity, ferrous ion-chelating activity and ferric-reducing antioxidant power (FRAP) of four citrus herbal products, Citri Reticulatae Pericarpium (CRP), Citri Reticulatae Viride Pericarpium (CRVP), Aurantii Immaturus Fructus (AIF) and Aurantii Fructus (AF) extracts were determined. EC₅₀ values of DPPH radical-scavenging activities ranged from 0.1 mg/ml (AF) to 1.59 mg/ml (AIF). EC₅₀ values of hydrogen peroxide-scavenging activities ranged from 0.08 mg/ml (AF) to 0.9 mg/ml (CRP). EC₅₀ values of ferrous ion-chelating activities ranged from 0.8 mg/ml (AF) to 2.08 mg/ml (AIF). The differences in DPPH free radical-scavenging activity, hydrogen peroxide-scavenging activity, and ferrous ion-chelating activity of all citrus herbal product extracts were significant. AF had the highest antioxidant activity. In this study, citrus herbal product extracts did not have good reducing power.     

Assessment of in vitro antioxidant, antibacterial and immune activation potentials of aqueous and ethanol extracts of Phyllanthus niruri

BACKGROUND: Recently much attention has been paid to biologically active plants because of their low production cost and fewer adverse effects compared with chemical drugs. In the present investigation the bioactivity of Phyllanthus niruri ethanol and aqueous extracts was evaluated in vitro. RESULTS: The ethanol extract of P. niruri showed a high level of flavonoid content (123.9 ± 0.002 mg g^?1), while the aqueous extract showed the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH; IC₅₀6.85 ± 1.80 µmol L^?1) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS; 46.44 ± 0.53 µmol L^?1) free radical scavenging activities with high phenol content (376 ± 0.02 mg g^?1) and elevated levels of ferric reducing antioxidant power (FRAP; 23 883 ± 0.019 mmol g^?1) with excellent antibacterial activity against Staphylococcus aureus (20 mm inhibition zone) and Streptococcus agalactiae (12 mm inhibition zone), respectively, in addition to the best immune activation potential of human peripheral blood mononuclear cells (450.5%). CONCLUSIONS: It is clear from our results that both extracts of P. niruri has excellent bioactivity roles via elevated levels of antibacterial, antioxidant and percentage of peripheral blood mononuclear cell proliferation, which could lead to the development of medications for clinical use. Copyright © 2012 Society of Chemical Industry