The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis,Theaceae)

The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis, Theaceae) were investigated with a study of carbon tetrachloride (CCl₄)-induced oxidative stress and hepatic fibrosis in male ICR mice. Oral administration of green tea extract at doses of 125, 625 and 1250 mg/kg for 8 weeks significantly reduced (p < 0.05) the levels of thiobarbituric acid-reactive substances (TBARS) and protein carbonyls in the liver by at least 28% compared with that was induced by CCl₄ (1 mL/kg) in mice. Moreover, green tea extract administration significantly increased (p < 0.05) the activities of catalase, glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver. Our study found that oral administration of green tea extract prevented CCl₄-induced hepatic fibrosis, as evidenced by a decreased hydroxyproline level in the liver and a reduced incidence of hepatic fibrosis by histological observations. These results indicate that green tea exhibits potent protective effects against CCl₄-induced oxidative stress and hepatic fibrosis in mice by inhibiting oxidative damage and increasing antioxidant enzyme activities.     

Hepatoprotection using sweet orange peel and its bioactive compound,hesperidin, for CCl4-induced liver injury in vivo

The hepatoprotective effect of water extracts of sweet orange (Citrus sinensis) peel (WESP) and its biological compound, hesperidin (HD), on oxidative stress in vivo, were investigated. HD was the major compounds among the ten compounds identified using HPLC-DAD and HPLC-MS/MS analysis. Oral administration of WESP to rats at 10 and 100 mg/kg bw for 28 consecutive days before a single dose of CCl₄ (2 ml/kg bw) demonstrates a significant protective effect by lowering the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and by improving the histological architecture of the rat liver. WESP attenuated oxidative stress by increasing the content of hepatic glutathione (GSH), and by a dramatic increase in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). WESP induced a significant CYP2E1 activity, which suggests that WESP may be a substrate of CYP2E1. WESP at a dose of 1.0 mg/kg bw and HD at 0.1 mg/kg bw did not sustain the protective effect against oxidative stress, in vivo. This study demonstrated that citrus peel protects rat liver from CCl₄-induced injury by attenuating hepatic oxidative stress, which suggests that WESP can be used as a therapeutic antihepatotoxic agent for the treatment of hepatic injury.     

Hepatoprotective effect of peptic hydrolysate from salmon pectoral fin protein byproducts on ethanol-induced oxidative stress in Sprague–Dawley rats

Bioactive peptides were generated by pepsin hydrolysis from salmon pectoral fin protein byproduct, and the hepatoprotective effect of the peptic hydrolysate (PH) on ethanol-induced oxidative stress was investigated in Sprague–Dawley rats. Administration of ethanol for 4 weeks significantly (p < 0.05) increased serum markers of liver damage, such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase; however, these activities decreased significantly (p < 0.05) after PH administration. Elevated thiobarbituric acid reactive substance levels in liver tissue and serum decreased significantly (p < 0.05) following administration of PH. Ethanol exposure significantly (p < 0.05) decreased glutathione contents in liver and serum, and hepatic antioxidant enzyme activities such as superoxide dismutase and glutathione peroxidase, while the PH treatment significantly (p < 0.05) increased these altered parameters. These results indicate that the PH had a protective effect against ethanol-induced hepatotoxicity that was comparable to that of silymarin, which was supported by evaluating liver histopathology in the rats.     

Antrodia camphorata ameliorates high-fat-diet induced hepatic steatosis via improving lipid metabolism and antioxidative status

Nonalcoholic fatty liver disease (NAFLD) commonly results from excessive dietary fat intake which characterized by obesity and insulin resistance. Wild fruiting body of Antrodia camphorata (AC) was assayed for alleviative effects on NAFLD. An NAFLD animal model was successfully established in male 7-week-old C57BL/6 mice fed with high-fat diet (HFD) for 36 weeks. The HFD mice exhibited obese and impaired glucose metabolism. After an induction of NAFLD syndrome, AC was given for one week via gavage. Mice with AC treatment showed lowered (p < 0.05) serum TG and TC, lowered (p < 0.05) liver TG content, improved (p < 0.05) oxidative status (TBARS values and GSH levels), and ameliorated (p < 0.05) liver damage (AST, ALT, and LDH values). In addition, AC activated (p < 0.05) gene expressions of PPAR-α with its downstream genes in the liver and caused higher (p < 0.05) rectal temperature, which showed AC attenuates hepatic lipid accumulation by promoting lipid oxidation and further suggests the role of AC in energy expenditure. Overall, our findings revealed that AC possesses alleviative effect on NAFLD.     

High molecular weight persimmon tannin is a potent antioxidant both ex vivo and in vivo

The antioxidant activities of high molecular weight persimmon condensed tannin (HMWPT) were evaluated in an ex vivo tissue system and in vivo. Addition of HMWPT to mouse liver homogenate protected the samples against auto-peroxidation or H₂O₂- or Fe²⁺/ascorbic acid-induced lipid peroxidation. The IC₅₀ values for HMWPT were 4.32 ± 0.20 μg/mL (auto-oxidation), 1.36 ± 0.40 μg/mL (H₂O₂-induced peroxidation) or 0.20 ± 0.09 mg/mL (Fe²⁺/ascorbic acid-induced peroxidation). Mice were oxidatively stressed with bromobenzene to test the antioxidant activity of HMWPT in vivo. An oral dose of HMWPT at 200 or 400 mg/kg HMWPT significantly (P < 0.01) prevented the bromobenzene-induced decrease in serum and liver superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and decreased liver malondialdehyde levels in bromobenzene-treated mice (P < 0.01). The results suggest that dietary HMWPT may provide protection from oxidative damage both ex vivo and in vivo.     

Chemical characterization and chemo-protective activity of cranberry phenolic powders in a model cell culture. Response of the antioxidant defenses and regulation of signaling pathways

Oxidative stress and reactive oxygen species (ROS)-mediated cell damage are implicated in various chronic pathologies. Emerging studies show that polyphenols may act by increasing endogenous antioxidant defense potential. Cranberry has one of the highest polyphenol content among commonly consumed fruits. In this study, the hepato-protective activity of a cranberry juice (CJ) and cranberry extract (CE) powders against oxidative stress was screened using HepG2 cells, looking at ROS production, intracellular non-enzymatic and enzymatic antioxidant defenses by reduced glutathione concentration (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) activity and lipid peroxidation biomarker malondialdehyde (MDA). Involvement of major protein kinase signaling pathways was also evaluated. Both powders in basal conditions did not affect cell viability but decreased ROS production and increased GPx activity, conditions that may place the cells in favorable conditions against oxidative stress. Powder pre-treatment of HepG2 cells for 20 h significantly reduced cell damage induced by 400 μM tert-butylhydroperoxide (t-BOOH) for 2 h. Both powders (5–50 μg/ml) reduced t-BOOH-induced increase of MDA by 20% (CJ) and 25% (CE), and significantly reduced over-activated GPx and GR. CE, with a significantly higher amount of polyphenols than CJ, prevented a reduction in GSH and significantly reduced ROS production. CJ reversed the t-BOOH-induced increase in phospho-c-Jun N-terminal kinase. This study demonstrates that cranberry polyphenols may help protect liver cells against oxidative insult by modulating GSH concentration, ROS and MDA generation, antioxidant enzyme activity and cell signaling pathways.     

Dihydrocaffeic acid,a major microbial metabolite of chlorogenic acids,shows similar protective effect than a yerba mate phenolic extract against oxidative stress in HepG2 cells

The hepatoprotective effect of a yerba mate phenolic extract (YMPE), rich in chlorogenic acids, and its main circulating metabolites dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids were assessed in human hepatoma HepG2 cells subjected to oxidative damage induced by tert-butylhydroperoxide (t-BOOH). Direct treatment of HepG2 cells with realistic concentrations of YMPE (1, 10 and 50 μg/mL), DHCA or DHFA (0.2, 1, 10 μM) for 20 h was not cytotoxic and significantly decreased ROS generation. Pre-treatment with YMPE and DHCA prevented the cytotoxicity and macromolecular damage induced by t-BOOH. Moreover, decreased levels of reduced glutathione (GSH), and increased ROS levels and antioxidant enzyme activity induced by t-BOOH were dose-dependently recovered. DHFA only showed a slight protection against cell cytotoxicity, lipid oxidation and GSH depletion. In conclusion, YMPE and one of its major microbial metabolites, DHCA, confer significant protection against oxidative damage, adding evidences to the beneficial health effects associated with mate intake.     

Study on Dendrobium officinale O-acetyl-glucomannan (Dendronan®): Part VI. Protective effects against oxidative stress in immunosuppressed mice

In this study, the antioxidant activities of Dendrobium officinale and its two polysaccharide fractions (crude and purified, respectively) in cyclophosphamide induced mice were investigated. All samples examined showed protection for the body from oxidative stress, including increase in activities of catalase (CAT), superoxidase dismutase (SOD), and glutathione peroxidase (GSH-Px), and decrease of malondialdehyde (MDA) content in the serum, thymus and liver. The degree of protection was nearly equally found with the administration of both crude material and purified fractions, indicated that polysaccharide was the main bioactive component, as evidenced by the thymus index and liver index. Together with our previous work in structure study, we suppose that β-(1 → 4)-Man linkage and O-acetyl might be the main causes for the purified polysaccharide (Dendronan®) to exhibit the highest values.     

Pinto bean hull extract supplementation favorably affects markers of bone metabolism and bone structure in mice

Hulls from dry edible beans are rich in phenolic compounds recognized as possessing antioxidant activity. The aim of this study was to characterize antioxidant properties of bean hull extract (BHE) and to determine whether BHE supplementation (at 400 or 800 mg/kg for 3 months) affects serum biochemical markers and bone structure in 12-month-old male C57BL/6 mice. Mice supplemented with 800 mg BHE/kg had lower serum tartrate-resistant acid phosphatase and parathyroid hormone concentrations than those on control diet or supplemented with 400 mg BHE/kg. BHE supplementation caused slight decrease in oxidized glutathione concentration in blood (P = 0.07). Compared to the control group, BHE supplementation at 800 mg/kg for 3 months improved bone structural indices, bone mineral density and trabecular thickness in the third lumbar vertebra. These results suggest that BHE supplementation may have beneficial effects on bone health in mice by decreasing bone resorption.     

Myricetin modulates streptozotocin–cadmium induced oxidative stress in long term experimental diabetic nephrotoxic rats

Oxidative stress plays a pivotal role in the development of diabetic nephropathy. The present study was aimed to evaluate the modulatory potential of myricetin on streptozotocin (STZ)–cadmium (Cd) induced oxidative stress in diabetic nephrotoxic rats. Diabetic nephrotoxicity was induced by single intraperitoneal injection of STZ at a dose of (40 mg/kg body weight (b/w)) and Cd as cadmium chloride (CdCl₂) (100 p.p.m.). Myricetin was administered to diabetic nephrotoxic rats by intraperitoneally at 1.0 mg/kg b/w for a period of 12 weeks to assess its effects on fasting plasma glucose, plasma insulin, total haemoglobin, glycosylated haemoglobin, lipid peroxidation products viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyl content (PCO) and non-enzymatic antioxidants namely vitamins C and E and reduced glutathione (GSH) and also enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR). Improvement of antioxidant status in myricetin supplemented diabetic nephrotoxic rats revealed its cellular protective effect. Histopathology of liver and kidney confirmed the protective effects of myricetin in diabetic nephrotoxic rats. The outcome of this study concludes that myricetin could be therapeutic flavonol for regulating oxidative mechanism in STZ–Cd induced diabetic nephrotoxic rats.     

Restoration of arsenite induced hepato-toxicity by crude tannin rich fraction of Theobroma cacao in Sprague Dawley rats

The present study was designed to investigate the protective efficacy of tannin rich cocoa (Theobroma cacao L.) in comparison with its detannified fraction. Arsenic as sodium-m-arsenite at 100 ppm dose was orally administered via drinking water constantly for 28 days to Sprague Dawley female rats. The hepatic cellular thiol levels such as total sulfhydryl content, protein bound sulfhydryl, non-protein bound sulfhydryl content, cellular oxidative stress and damage markers such as reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and the index of nitrite/nitrate (NO_x) levels and a biomarker for arsenic toxicity namely delta-aminolevulinic acid dehydratase (ALAD) were substantially reduced and elevation of thiobarbituric acid reactive substances (TBARS) was observed in arsenic-exposed groups. The supplementation of tannin rich cocoa fraction (TCF) enhanced the levels of cellular thiols, markers of oxidative stress and levels of arsenic biomarkers and decreased the level of oxidative damage in treatment groups. Histopathologically, the liver of arsenic-exposed rats showed some degenerative lesions with few cells showing appearance of apoptosis which was effectively antagonized by tannin rich cocoa feeding. Treatment with detannified cocoa (DCF) was not that protective compared to the tannin rich cocoa (TCF). These results demonstrate that tannin rich cocoa can be considered as a functional food which effectively antagonizes many of the adverse effects of arsenic intoxication.     

Lipopolysaccharide derived from the digestive tract provokes oxidative stress in the liver of dairy cows fed a high-grain diet

The aims of this study were to measure oxidative stress parameters and to investigate the molecular mechanism triggered by grain-induced subacute ruminal acidosis in mid-lactation cows. Twelve Holstein-Friesian cows with an average weight of 455 ± 28 kg were divided into 2 groups and subjected to 2 diets over 18 wk: either a low-grain (forage-to-concentrate ratio = 6:4) or a high-grain (forage-to-concentrate ratio = 4:6) diet based on dry matter. Being fed a long-term high-grain diet resulted in a significant decrease in rumen pH and a significant increase in ruminal lipopolysaccharide (LPS) at 4 h postfeeding in the morning. The increase was also observed in LPS concentrations in the portal vein, hepatic vein, and jugular vein blood plasma as well as reduced milk yield in a high-grain diet. Cows fed a high-grain diet had lower levels of catalase and glutathione peroxidase (GPx) activity and total antioxidant capacity than cows fed a low-grain diet; however, super oxide dismutase (SOD) activity and malondialdehyde (MDA) levels were higher in both the liver and the plasma of high-grain than in low-grain cows. Positive correlations were observed between plasma LPS versus hepatic MDA, plasma MDA, and hepatic SOD activity, whereas hepatic GPx and plasma GPx were negatively correlated with plasma LPS. The relative mRNA abundances of GPX1 and CAT were significantly lower in the liver of cows fed a high-grain diet than those fed a low-grain diet, whereas SOD1 was significantly higher in cows fed a high-grain diet than cows fed a low-grain diet. The expression levels of Nrf2, NQO1, MT1E, UGT1A1, MGST3, and MT1A were downregulated, whereas NF-kB was upregulated, in cows fed a high-grain diet. Furthermore, nuclear factor E2-related factor 2 (Nrf2) total protein and mRNA levels were significantly lower than in low-grains. Our results demonstrate the relationship between the translocated LPS and the suppression of cellular antioxidant defense capacity, which lead to increased oxidative stress and suggests that the Nrf2-dependent antioxidant response may be affected by higher levels of LPS translocated to the bloodstream.     

Consumption of baru seeds [Dipteryx alata Vog.], a Brazilian savanna nut,prevents iron-induced oxidative stress in rats

The protective effect of plant-based foods in human health has been attributed to the presence of bioactive compounds in all parts of the plants. A previous study found a high level of minerals, tannins and phytic acid in the baru nut (Dipteryx alata Vog.), which is a native fruit of the Brazilian savanna. This study investigated the antioxidant activity (AA) of the aqueous and ethyl acetate extracts of the baru nut and the effect of the consumption of this nut on the oxidative status of rats supplemented orally with iron. The AA was evaluated in vitro using the ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid system and free-radical scavenging (DPPH) assays. The total polyphenol concentration was determined spectrophotometrically using the Folin–Ciocalteu reagent. The in vivo study was conducted in male Wistar rats that were fed an AIN-93M diet with or without 10% baru nut or 1% phytic acid and supplemented daily with iron or saline by gavages for 17 days. The liver, heart and spleen were collected for the determination of the malondialdehyde (MDA), carbonyl protein and iron concentrations. The specific activities of catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in these tissues. A T test was used to compare the results among the rats groups and between the different baru nut extracts (p < 0.05). The aqueous extract of the baru nut contained a higher level of phenolic compounds and a higher antioxidant activity, as measured by FRAP and the β-carotene/linoleic system, relative to the EtOAc extract. The iron supplementation reduced the body weight gain, increased the levels of iron and MDA in the liver and the spleen and increased the carbonyl levels in all three tissues. Consumption of the baru nut reduced the carbonyl levels in the liver, heart and spleen of the iron-supplemented rats (p = 0.002, 0.012 and 0.036, respectively) relative to the heart carbonyl level of rats that were fed the control diet (p = 0.000); it also marginally reduced the iron-induced lipid oxidation in the liver (p = 0.117) and the spleen (p = 0.074). Phytic acid reduced the carbonyl level in the spleen (p = 0.020) and marginally reduced the carbonyl level in the liver (p = 0.098) of iron-supplemented rats. These results demonstrated that the consumption of the baru nut protects tissues against iron-induced oxidative stress, and the phytic acid from the baru nut may be partially responsible for this protective effect; however, other compounds such as phenols may also be involved.     

Functional goat milk cheese with feruloyl esterase activity

The aim of this paper was to evaluate the effect of the intake of goat milk cheese manufactured with Lactobacillus fermentum CRL1446 on intestinal feruloyl esterase (FE) activity and oxidative status in Swiss albino mice. This strain was used as single-strain culture (CRL cheese) and in combination with starter culture (Mix cheese). In both cheeses, L. fermentum reached 8–9 log cfu/g and FE activity increased during ripening. Highest activity level was observed in Mix cheese. In vivo studies showed that total intestinal FE activity in mice fed with CRL and Mix cheeses increased 1.5 and 2-fold compared to non-treated mice, respectively. Administration of Mix cheese produced a 2-fold increase in FE activity in small and large intestine mucosa. Mice receiving this cheese also showed an approx. 2-fold decrease in plasmatic thiobarbituric acid-reactive substances (TBARS) levels and an approx. 3-fold increase in glutathione reductase (GR) activity.Goat milk cheese elaborated with FE-producing strain L. fermentum CRL1446 could represent a novel functional food with FE activity, responsible for increasing intestinal FE activity and consequently the bioavailability of antioxidant ferulic acid in the gut, thus enhancing the oxidative status and providing protection against oxidative stress-related disorders.     

Production of chitin oligosaccharides with different molecular weights and their antioxidant effect in RAW 264.7 cells

The purpose of this research is not only to produce two kinds of chitin oligosaccharides or N-acetyl chito-oligosaccharides (NA-COSs) with different molecular weights (MW) from crab chitin hydrolysis solution but also to determine their effect against oxidative stress in live cells. Two kinds of NA-COSs with MW 1–3 kDa (NA-COS 1–3 kDa) and below 1 kDa (NA-COS < 1 kDa) were obtained using an ultrafiltration membrane system. They exhibited an inhibitory effect against DNA and protein oxidation. In addition, in their presence, intracellular glutathione (GSH) level and direct intracellular radical scavenging effect were significantly increased in a time-dependent manner in mouse macrophages (RAW 264.7) and rendered inhibitory effect against cellular oxidative stress. In particular, NA-COS 1–3 kDa was more effective than NA-COS < 1 kDa in protein oxidation and production of intracellular free radicals in live cells. These results suggest that NA-COSs act as a potential scavenger against oxidative stress in cells.     

Intracellular ROS scavenging and antioxidant enzyme regulating capacities of corn gluten meal-derived antioxidant peptides in HepG2 cells

The objective of this study was to investigate the intracellular reactive oxygen species (ROS) scavenging activities and antioxidant enzyme regulating capacities of corn gluten peptide fractions (CPFs) in HepG2 cells. A cellular antioxidant activity (CAA) assay was used to assess their antioxidant activities and revealed that both CPF1 (molecular weight < 1 kDa) and CPF2 (molecular weight between 1 and 3 kDa) exhibited high cellular antioxidant activities with EC₅₀ values of 2.85 ± 0.19 mg/mL and 5.05 ± 0.32 mg/mL, respectively. Both CPFs also exhibited cytoprotective effects and intracellular ROS scavenging activities in HepG2 cells subjected to oxidative stress by oxidation with H₂O₂. In addition, at concentrations of 2.50 mg/mL, the CPFs increased the activity levels of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), as well as the total glutathione (GSH) levels in oxidized HepG2 cells (from 86.54% to 114.14% (CPF1) or 109.72% (CPF2) for SOD activity; from 71.91% to 107.64% (CPF1) or 106.50% (CPF2) for CAT activity; from 70.52% to 103.01% (CPF1) or 104.10% (CPF2) for GR activity; and from 81.39% to 114.00% (CPF1) or 108.82% (CPF2) for total GSH levels). These results suggested that both CPF1 and CPF2 exhibited positive effects on the activities of the intracellular antioxidant enzymes SOD, CAT and GR, as well as on the total GSH levels in HepG2 cells under conditions of oxidative stress. Furthermore, size exclusion gel chromatography and MALDI-TOF/TOF mass spectrometry revealed that the molecular weights of the antioxidant peptides in CPF1 were between 500 Da to 900 Da, and a novel antioxidant peptide consisting of GLLLPH (Gly-Leu-Leu-Leu-Pro-His) was identified in CPF1.     

正膏坊龟苓膏对氧化应激状态的改善作用

目的：研究正膏坊龟苓膏对拘束负荷诱发小鼠应激性肝损伤的保护作用。方法：对于18h 拘束负荷诱发应激性肝损伤的小鼠,分别用赖氏法测定其血浆丙氨酸氨基转移酶(ALT)活性、硫代巴比妥酸法测定肝组织丙二醛(MDA)含量、Griess 化学法测定一氧化氮(NO)含量、荧光酶标仪测定肝组织抗氧化能力指数(ORAC)、HPLC 法测定谷胱甘肽(GSH)含量、比色法测定谷胱甘肽过氧化物酶(GPX)和谷胱甘肽硫转移酶(GST)活性。结果：与拘束应激模型组相比,正膏坊龟苓膏可以明显降低拘束负荷小鼠血浆ALT 活性、肝组织MDA 和NO 含量,有效提高肝组织的ORAC 指数、GSH 含量及GPX 和GST 活性。结论：正膏坊龟苓膏对拘束负荷诱发小鼠应激性肝损伤有一定的保护作用,其作用可能与缓解拘束负荷小鼠的氧化应激水平相关。     

Daily green tea extract supplementation reduces prothrombotic and inflammatory states in dialysis patients

Cardiovascular disease (CVD) remains the most common cause for excess morbidity and mortality in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) under chronic dialysis. ESRD patients have increased oxidative stress and endothelial dysfunction alongside increased levels of inflammation related proteins, which has prompted the exploration of anti-inflammatory and antioxidant treatments to improve outcomes. As green tea is increasingly well recognized for its antioxidant properties, we probed the effect of consumption of 1 capsule daily of green tea as a commercially available, decaffeinated green tea capsule (1 g, catechin content 68 mg) for 6 months on fibrinogen and inflammation in dialysis patients. Chronic hemodialysis patients (N = 25) were recruited and fibrinogen, FDP-D-dimer, high sensitivity (hs) CRP and the mononuclear cell protein expression of p22^phox, were assessed before, i.e. baseline and after 6 months of ingestion of 1 green tea capsule per day. After 6 months of daily green tea capsule ingestion, dialysis patients showed reduced protein expression of p22^phox (p < 0.0001), reduced hsCPR (p = 0.032) and fibrinogen (p = 0.022) levels and increased FDP-D-dimer (p = 0.0019) compared to their values at baseline. These results document lower oxidative stress and inflammation with green tea capsule ingestion and suggest a likely positive impact of green tea treatment on the atherosclerotic process of ESRD patients under dialysis.     

Isolation of antioxidative and ACE inhibitory peptides from protein hydrolysate of skipjack (Katsuwana pelamis) roe

Bioactive peptides from protein hydrolysate of defatted skipjack (Katsuwonus pelamis) roe with 5% degree of hydrolysis (DH) prepared by Alcalase digestion were isolated and characterised. Two active fractions with ABTS radical scavenging activity (973.01–1497.53 μmol TE/mg sample) and chelating activity (0.05–0.07 μmol EE/mg sample) from consecutive purification steps including ultrafiltration, cation exchange column chromatography and reverse phase high performance liquid chromatography (RP-HPLC), were subjected to analysis of amino acid sequence by LC–MS/MS. Seven dominant peptides with 6–11 amino acid residues were identified as DWMKGQ, MLVFAV, MCYPAST, FVSACSVAG, LADGVAAPA, YVNDAATLLPR and DLDLRKDLYAN. These peptides were synthesised and analysed for ACE-inhibitory activity and antioxidative activities. MLVFAV exhibited the highest ACE inhibitory activity (IC₅₀ = 3.07 μM) (p < 0.05) with no antioxidative property, whilst DLDLRKDLYAN showed the highest metal chelating activity, ABTS radical and singlet oxygen scavenging activities. Therefore, peptides prepared from skipjack roe could be further employed as a functional food ingredient.     

Phenolic profile and antioxidant activity of the Algerian ripe date palm fruit (Phoenix dactylifera)

The aim of this study was to determine the phenolic profile of seven different varieties of ripe date palm fruit (Phoenix dactylifera) from Algeria by LC–DAD–MS (ESI+), to investigate their respective antioxidant activities by the DPPH^· method and to estimate their phenolic content using the Folin–Ciocalteu method. The total phenolic content was in the range of 2.49 ± 0.01 to 8.36 ± 0.60 mg gallic acid equivalents (GAE) per 100 g fresh fruit. This fruit was shown to possess an antioxidant activity, giving values of antiradical efficient (AE) from 0.08 ± 0.00 to 0.22 ± 0.00. The phenolic contents and the antiradical efficiencies of the different varieties were highly correlated (R²=0.975). All the varieties were found to contain mainly p-coumaric, ferulic and sinapic acids and some cinnamic acid derivatives. Three different isomers of 5-o-caffeoylshikimic acid were detected. Different types of flavonoids were identified, mainly flavones, flavanones and flavonol glycosides.