Antioxidant activity of enzymatic extracts from the brown seaweed Undaria pinnatifida by electron spin resonance spectroscopy

Enzyme assisted extraction of Undaria pinnatifida was performed using five proteases (Alcalase, Flavourzyme, Neutrase, Trypsin and Protamex) and six carbohydrases (AMG, Dextrozyme, Maltogenase, Promozyme, Viscozyme and Celluclast) in order to acquire extracts rich in antioxidants. Antioxidant activity of the extracts was investigated using electron spin resonance (ESR) spectroscopy on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals. Extracts exhibited strong radical scavenging activity on DPPH and hydroxyl radical, and activity increased with increasing extract concentration. In contrast to DPPH and hydroxyl radical scavenging activity, extracts showed weak scavenging activity on superoxide radical. Extracts exhibited weak radical scavenging activity compared to vitamin C as a reference compound. However, they are still a good source of antioxidant materials that are safe for consumption and show water-soluble properties.     

Enzymatic extracts from edible red algae, <Emphasis Type="Italic">Porphyra tenera</Emphasis>, and their antioxidant,anti-acetylcholinesterase,and anti-inflammatory activities

Enzymatic extracts from Porphyra tenera were prepared using 4 proteases (Protamex, Neutrase, Flavourzyme, and Alcalase) and 7 carbohydrases (AMG, Celluclast, Dextrozyme, Maltogenase, Termamyl, Promozyme, and Viscozyme), and biological activities of the enzymatic extracts from P. tenera were determined as antioxidant, anti-acetylcholinestrase (AChE), and anti-inflammation. The Alcalase and Maltogenase extracts showed higher 1,1-diphenyl-2-picrylhydrozyl (DPPH) scavenging activities compared to the other extracts. At the 2.5 mg/mL, 94.38% (Alacalase extracts), and 80.13% (Maltogenase extracts) scavenging capacities were observed. The Alcalase and Maltogenase extracts were also showed strong reducing power, ferrous ion chelating, and hydrogen peroxide (H2O2) scavenging capacities. In addition, 2 enzymatic extracts effectively protected hydroxyl radical-induced DNA damage. In the case of AChE inhibition, the Flavourzyme (99.32% inhibition) and Viscozyme extracts (82.68% inhibition) were observed. All enzymatic extracts showed no cytotoxicity in RAW264.7 macrophages, and all enzymatic extracts effectively inhibited lipopolysaccharides (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages. These results suggest that the enzymatic extracts from P. tenera would be useful as an ingredient for functional foods.     

Antioxidant properties of Agaricus blazei, Agrocybe cylindracea, and Boletus edulis

Three mushrooms are currently available in Taiwan, including Agaricus blazei, Agrocybe cylindracea, and Boletus edulis. Their ethanolic and hot water extracts were prepared and antioxidant properties studied. Ethanolic extracts from three mushrooms were more effective than hot water extracts in antioxidant activity using the conjugated diene method and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals whereas hot water extracts were more effective in reducing power, scavenging ability on hydroxyl radials and chelating ability on ferrous ions as evidenced by their lower EC₅₀ values. Overall, for both extracts, B. edulis was more effective among antioxidant properties assayed. Naturally occurring antioxidant components including total tocopherols (3.18-6.18 mg/g) and total phenols (5.67-5.81 mg/g) were found in the extracts and their contents were associated (r=0.636-0.907) with EC₅₀ value of antioxidant properties. Based on the results obtained, both extracts from these three mushrooms were effective in antioxidant properties.     

Antioxidant activity of Nyctanthes arbor-tristis leaf extract

Nyctanthes arbor-tristis (Harsingar) leaf extracts are extensively used in Indian traditional medicine. The acetone-soluble fraction of its ethyl acetate extract showed impressive antioxidant activity as revealed by several in vitro experiments, e.g., DPPH, hydroxyl and superoxide radicals, as well as H₂O₂ scavenging assays. Moreover, its preventive capacity against Fe(II)-induced lipid peroxidation of liposomes and γ-ray-induced DNA damage also confirmed this. The strong reducing power and high phenolics and flavonoids contents could be responsible for the antioxidant activity.     

Oryzadine,a new alkaloid of Oryza sativa cv. Heugjinjubyeo, attenuates oxidative stress-induced cell damage via a radical scavenging effect

The antioxidant properties of oryzadine, a new alkaloid, obtained from Oryza sativa cv. Heugjinjubyeo was investigated by applying various methods based on cell-free and cell experiments. Oryzadine showed scavenging effects on the hydroxyl radical, superoxide radical, and intracellular reactive oxygen species (ROS). Oryzadine inhibited H₂O₂-induced DNA damage, which was demonstrated by DNA tail formation, lipid peroxidation which was demonstrated by the formation of thiobarbituric acid reactive substance (TBARS), and protein oxidation which was demonstrated by protein carbonyl formation. Therefore, oryzadine protected H₂O₂-induced cell damage. Our results show that the cytoprotective effects of oryzadine stem from its ability to inhibit H₂O₂-induced apoptosis, as demonstrated by a decrease in apoptotic body formation and the inhibition of mitochondrial membrane potential (ΔΨ) loss. Taken together, these findings suggest that oryzadine protected cells against H₂O₂-induced cell damage via ROS scavenging effect. Therefore, oryzadine could be considered a significant natural source of antioxidant.     

Antioxidant activity of enzymatic extracts from a brown seaweed Ecklonia cava by electron spin resonance spectrometry and comet assay

The potential antioxidant activity of enzymatic extracts from Ecklonia cava was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and alkyl radical scavenging using a electron spin resonance (ESR) spectrophotometer compared with ESR signal intensity and inhibitory effect of DNA damage on comet assay. E. cava was enzymatically hydrolyzed with five food industrial carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) from Novozyme Nordisk. All the tested extracts exhibited strong radical scavenging activities and the values were dose-dependent. The DPPH and hydroxyl radical scavenging activities of the enzymatic extracts were compatible with the vitamin C, which the alkyl radical scavenging activity was even higher than that of vitamin C. Also in the present study, the enzymatic extracts showed strong inhibitory effect against DNA damage in a dose dependent manner. These results indicated that the E. cava might be valuable natural antioxidative source.     

Phenolic phytochemicals in cabbage inhibit amyloid β protein-induced neurotoxicity

The antioxidative and neuronal protective effects of red and white cabbages were investigated against amyloid β protein (Aβ)-induced cytotoxicity in neuron-like PC12 cells. Red cabbage phenolic phytochemicals showed higher antioxidative effect. In cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), red cabbage showed more protective effect on Aβ-induced neurotoxicity. Since oxidative stress causes membrane breakdown, the protective effect of cabbage phytochemicals was investigated by lactate dehydrogenase and trypan blue exclusion assays. Red cabbages showed more efficient cell protective effects among samples. The overall relative neuronal cell protection activity of red cabbages by three tests was much higher than white cabbages. The degree of neuronal cell protection was closely correlated with their phenolic contents and their antioxidative capacities. Moreover, anthocyanins in cabbage appeared to be the major contributors.     

Antioxidant properties of methanolic extracts from Agaricus blazei with various doses of γ-irradiation

Agaricus blazei Murrill (Agariaceae) was irradiated with gamma rays at doses of 2.5, 5, 10, 15 and 20 kGy and the antioxidant properties of its methanolic extracts were studied. At 7.5 and 10.0 mg/ml, antioxidant activities of methanolic extracts from 2.5 to 20 kGy γ-irradiated A. blazei were significantly higher than those of methanolic extract from the nonirradiated control. At 0.5-7.5 mg/ml, reducing powers of methanolic extracts from A. blazei with 2.5, 10, 15 and 20 kGy of irradiation and without irradiation were comparable. All methanolic extracts showed excellent scavenging abilities of 95.2-100.7% against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at 0.5 mg/ml. With regard to the scavenging ability against hydroxyl radicals, unirradiated and γ-irradiated A. blazei were comparable. Total phenols were the major naturally occurring antioxidant components found in the range of 18.77-21.48 mg/g. All EC₅₀ values were below 10 mg/ml, except values in reducing power, scavenging ability against DPPH radicals and chelating ability against ferrous ions were below 1 mg/ml. That indicates the unirradiated and irradiated A. blazei were good in antioxidant properties. Summarily, up to 20 kGy of irradiation did not remarkably affect the amounts of total antioxidant components in A. blazei.     

The in vitro and in vivo antioxidant properties of seabuckthorn (Hippophae rhamnoides L.) seed oil

The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl₄)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC₅₀ values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77 mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl₄, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent.     

Antioxidant properties of aqueous extracts from Terminalia catappa leaves

Aqueous extracts were prepared from green, yellow fallen and red fallen leaves of Terminalia catappa L. (Combretaceae) and their antioxidant activity, scavenging and chelating abilities were evaluated. Aqueous extracts from three different leaves showed high antioxidant activities and moderate scavenging abilities on hydroxyl radicals at 1 mg/ml. EC₅₀ values in antioxidant activity were 0.549-0.557 mg/ml whereas those in scavenging ability on hydroxyl radicals were 0.631-0.686 mg/ml for aqueous extracts prepared from three leaves with boiling water for 3 min. EC50 values in reducing power were 0.15-0.23 mg/ml. EC50 values in scavenging abilities on superoxide anion and 1,1-diphenyl-2-picrylhydryl radicals were 0.36-0.44 and 10.4-35.3 mg/ml, respectively. EC50 values in chelating abilities on ferrous and cupric ions were 0.41-2.50 and 8.96-9.89 mg/ml, respectively. Based on the results obtained, the aqueous extracts displayed higher antioxidant properties. Six phenolic compounds identified in the aqueous were p-hydroxybenzoic acid, 4-hydroxyphenylpropionic acid, m-coumaric acid, 3,4-dihydroxybenzoic acid, p-coumaric acid and gallic acid. Therefore, the aqueous extracts from three different leaves of T. catappa might be a potential antioxidant supplement for application in food products or as a drink.     

Antioxidative and anti-inflammatory properties of Citrus sulcata extracts

Citrus sulcata was subjected to ultrasound, high-pressure, and Soxhlet extractions. The antioxidant and anti-inflammatory activities of the extracts were evaluated qualitatively and quantitatively. The antioxidant content of the peel extract was twice that of the fruit extract. The quantitative analysis showed that the narirutin and hesperidin contents in the peel extracts were 8.8 and 7.5 mg/100 g, respectively. These extracts had a total phenolic content of 112.22 ± 2.89 gallic acid equivalent (GAE) mg/100 g, a total flavonoid content of 54.09 ± 1.01 rutin equivalent (RE) mg/100 g, DPPH radical scavenging activity of 46%, and antioxidant activity of 213.25 ± 2.82 μM of Trolox equivalents (TEAC). C. sulcata extracts could prevent hydrogen peroxide (H₂O₂)-induced oxidative stress, reduce expression of the inflammatory markers nuclear Factor kappa B (NFκB) and phosphorylated IκBα (p-IκBα) in A549 human lung carcinoma cells, and inhibit Lipopolysaccharide (LPS)-induced THP-1 monocyte differentiation to an extent of 85%.     

Anti-inflammatory effect and modulation of cytochrome P450 activities by Artemisia annua tea infusions in human intestinal Caco-2 cells

In an attempt to understand the beneficial health effects of Artemisia annua other than its anti-malaria properties, extracts from different cultivars prepared as tea infusions were investigated using Caco-2 cells on the intestinal inflammation and cytochrome P450 (CYP) activities. The characterisation of their phenolic compound (PC) profile revealed rosmarinic and chlorogenic acids as the main PCs. The extracts, assayed on Caco-2 cells at a plausible intestinal concentration, significantly decreased the secretion of pro-inflammatory cytokines, IL-8 and IL-6. This effect could be attributable at least to their content in rosmarinic acid, detected as a potent anti-inflammatory compound. The extracts also inhibited the activity of CYP3A4, whose expression was induced by 1,25-dihydroxyvitamin D₃, and of CYP1A1, induced by benzo(a)pyrene. Our results highlight the advantage of drinking A. annua infusions for their potent anti-inflammatory effect, linked to PC content, which could synergise their antimalarial activity.     

Cultured C2C12 cell lines as a model for assessment of bacterial attachment to bovine primary muscle cells

The mechanisms of bacterial attachment to meat tissues need to be understood to enhance meat safety interventions. However, little is known about attachment of foodborne pathogens to meat muscle cells. In this study, attachment of six Escherichia coli and two Salmonella strains to primary bovine muscle cells and a cultured muscle cell line, C₂C₁₂, was measured, including the effect of temperature. At 37 °C, all but one strain (EC623) attached to C₂C₁₂ cells, whereas only five of eight strains (M23Sr, H10407, EC473, Sal1729a and Sal691) attached to primary cells. At 10 °C, two strains (H10407 and EC473) attached to C₂C₁₂ cells, compared to four strains (M23Sr, EC614, H10407 and Sal1729a) of primary cells. Comparing all strains at both temperatures, EC614 displayed the highest CFU per C₂C₁₂ cell (4.60 ± 2.02 CFU/muscle cell at 37 °C), whereas greater numbers of M23Sr attached per primary cell (51.88 ± 39.43 CFU/muscle cell at 37 °C). This study indicates that primary bovine muscle cells may provide a more relevant model system to study bacterial attachment to beef carcasses compared to cell lines such as C₂C₁₂.     

Antioxidant properties of three extracts from Pleurotus citrinopileatus

Pleurotus citrinopileatus Sing. (Lentinaceae) was successfully cultivated and commercially available in Taiwan. The ethanolic, cold and hot water extracts were prepared from P. citrinopileatus fruit bodies, mycelia and fermentation filtrate and their antioxidant properties studied. For three samples, ethanolic extracts exhibited higher antioxidant activities than water extracts. Reducing powers of three extracts from fruit bodies were effective and 1.03-1.10 at 5 mg/ml. With regard to EC₅₀ values of scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals, the effectiveness was in a descending order: ethanolic>hot water>cold water extracts. Scavenging abilities of water extracts from three samples on hydroxyl radicals were 53.4-80.1% at 20 mg/ml. Chelating abilities of cold and hot water extracts on ferrous ions were higher than those of ethanolic extracts. Contents of total phenols were in the descending order: fruit bodies (8.62-12.38 mg/g)>mycelia (5.84-7.85 mg/g)>filtrate (4.80-5.57 mg/g). Overall, three extracts from fruit bodies were more effective in antioxidant properties assayed than those from mycelia and filtrate. Ethanolic extracts were more effective in antioxidant properties assayed, except for scavenging abilities on hydroxyl radicals.     

Intramolecular formation of cyclic ether by dehydration of 20(S)-ginsenoside Rg3

Two new conversion ginsenosides having cyclic ether together with ginsenoside Rg₅, Rk₁, and Rz₁ were isolated from dehydration products of 20(S)-ginsenoside Rg₃. On the basis of NMR spectroscopic analyses and comparison with spectral data of ginsenoside Rg₃ as a starting material, the chemical structures of two new ginsenosides were established as 12β-O-20(S)-ginsenoside Rg₃ and 12β-O-20(R)-ginsenoside Rg₃. The compounds were named as neoginsenoside L₁ and L₂ respectively. The conversion mechanism was expected to be accomplished by the formation of a tertiary carbocation or intramolecular nucleophilic displacement. The two new ginsenosides confirmed the existence from red ginseng extract by liquid chromatography.     

Supercritical CO2 cell breaking extraction of Lycium barbarum seed oil and determination of its chemical composition by HPLC/APCI/MS and antioxidant activity

The extraction parameters for oil extraction from Lycium barbarum seed including extraction pressure, temperature and time were optimized using an orthogonal test design. The optimum conditions for supercritical CO₂ extraction were as follows: extraction pressure, 30 MPa; extraction temperature, 45 °C; dynamic extraction time, 60 min; CO₂ flow, 25 kg/h. The oil yield under the conditions proposed was 19.28 g/100 g. The effect of cell wall breakage pretreatment was investigated by supercritical CO₂ rapid depressurization, and results indicated this pretreatment could result in a rapid and efficient extraction. A sensitive fluorescent reagent 2-(11H-benzo[a]carbazol-11-yl) ethyl 4-methylbenzenesulfonate (BCETS) was utilized as pre-column labeling regent to determine fatty acids (FA) from Lycium barbarum seed oils obtained by different extraction methods. The main FA were: C18:2, C18:1, C16, C20:6, C18:3, and C20. The oil from L. barbarum seed exhibited excellent antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl（DPPH）radical scavenging assay and β-carotene bleaching test, and its antioxidant activity compared well with the references ascorbic acid and α- tocopherol.     

Protective effect of whey protein hydrolysates on H2O2-induced PC12 cells oxidative stress via a mitochondria-mediated pathway

Whey protein hydrolysates (WPHs) were prepared with pepsin and trypsin. A PC12 cell model was built to observe the protective effect of WPHs against H₂O₂-induced oxidative stress. The results indicated that WPHs reduced apoptosis by 14% and increased antioxidant enzyme activities. Flow cytometry was used to assess the accumulation of reactive oxygen species (ROS), Ca²⁺ levels and the mitochondrial membrane potential (MMP). The results showed that WPHs suppressed ROS elevation and Ca²⁺ levels and stabilised MMP by 16%. The anti-apoptosis/pro-apoptosis proteins Bcl-2/Bax and poly (ADP-ribose) polymerase (PARP) were investigated by Western-blot analysis, which indicated that WPHs increased the expression of Bcl-2 while inhibiting the expression of Bax and the degradation of PARP. WPHs also blocked Caspase-3 activation by 62%. The results demonstrate that WPHs can significantly protect PC12 cells against oxidative stress via a mitochondria-mediated pathway. These findings indicate the potential benefits of WPHs as valuable food antioxidative additives.     

Effect of suboptimal temperatures and sublethal CO2 levels on multiplication of Tribolium castaneum (Coleoptera: Tenebrionidae), alone or competing with Cryptolestes ferrugineus (Coleoptera: Cucujidae)

Groups of adults of Tribolium castaneum alone, or in combination with adults of Cryptolestes ferrugineus, were exposed to suboptimal temperatures (15°C, 20°C, and 25°C) and sublethal CO₂ levels (2%, 5%, and 10%) in dry (12%, wet mass basis) and damp (15%, wet mass basis) stored wheat in the laboratory, to investigate effects on population size. The mean adult numbers in single- and mixed-species tests were positively correlated with higher temperature and moisture content and negatively correlated with higher CO₂ levels. Adult numbers in single- and mixed-species tests were lower at sublethal CO₂ levels compared to ambient CO₂ levels at all the test temperatures and decreased in dry grain compared to damp grain. Although, a specific trend was not observed in population inhibition between mixed-species and single-species tests, overall the adult populations of T. castaneum were reduced in the presence of C. ferrugineus. A mathematical model was derived to predict the size of adult populations of T. castaneum alone, or in the presence of C. ferrugineus considering all the variables in this study. The model had an R² value of 0.72 but needs to be validated and refined with field data.     

Superoxide and hydroxyl radical scavenging actions of botanical extracts of Wagatea spicata

Wagatea spicata, candy corn plant, a woody legume shrub, widespread medicinal plant found in Western Ghat of India has significant abilities to scavenge highly reactive free radicals. Shade dried leaf, bark and flower powder of this plant has been extracted with water and fractionated with different solvents. Extracts and their solvent fractions were found to be good scavengers of superoxide and hydroxyl radicals. Free radical scavenging action of W. spicata is due to its rich phenolic and flavonoid contents. Bark and leaf extracts showed significant scavenging action against superoxide radicals, where as flower extracts efficiently inhibited hydroxyl radicals.     

Antioxidant properties of water extracts from Monascus fermented soybeans

Solid-state bioprocessing of soybean by Monascus is a biotechnological strategy to produce Monascus-fermented soybeans (MFS) with more beneficial components. The objective of this study was to evaluate the antioxidant properties of cold and hot water extracts from MFS as compared to uninoculated soybeans. With regard to the EC₅₀ values of antioxidant activities, the effectiveness of cold water extracts was in a descending order: soybeans > MFS-31527 > MFS-31499 whereas that of the hot water extracts: soybeans ∼ MFS-31499 > MFS31527. Cold water extracts showed higher reducing power and lower scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals than hot water extracts. For both extracts, MFS and soybeans showed comparable effective chelating abilities on ferrous ions. Total phenols were the major naturally occurring antioxidant components found. For both extracts, soybeans were more effective in antioxidant activity and scavenging ability on DPPH radicals whereas MFS-31499 and MFS-31527 were more effective in reducing power and scavenging ability on hydroxyl radicals. Based on the results obtained, MFS-31499, MFS-31527 and soybeans were relatively effective in the antioxidant properties assayed and might be potential antioxidants for application in food products.