Antioxidant enzyme activities and antioxidant capacity in longissimus muscle from bulls fed diets rich in polyunsaturated fatty acids

The effect of a treatment diet composed of grass silage and concentrate including rapeseed (with/without feeding restriction) was compared with a control diet of maize silage/grass silage (70:30) and concentrate including soybean, on the antioxidant enzyme activities of fresh longissimus muscle from German Simmental bulls. Additionally, the effect of diet on antioxidant capacity (AOC) of hydrophilic and lipophilic antioxidants was evaluated in fresh and stored beef muscle using the FRAP-ferric reducing ability and TEAC – Trolox-equivalent antioxidant capacity assays at different reaction times. Catalase and superoxide dismutase activities were significantly higher in the treatment diet groups, and glutathione peroxidase activity was not different. AOC was not affected by the diet. However, storage affected the values of FRAP and TEAC assays, and the results were time-depending. 30 min were found like a minimum reaction time for both assays. Generally, AOC values of the hydrophilic antioxidants were significantly higher than lipophilic values.     

Evaluation of in vivo antioxidant activities of Ganoderma lucidum polysaccharides in STZ-diabetic rats

Effect of Ganoderma lucidum polysaccharides treatment on blood glucose, serum insulin level, lipid peroxidation, nonenzymic and enzymic antioxidants in the plasma and liver of streptozotocin (STZ)-induced diabetic rats was studied. Adult male rats of Wistar strain, weighing 195 to 250 g, were randomized into control and experimental groups. Experiment group rats were induced diabetes by administration of STZ (45 mg/kg b.wt.) intraperitoneally. The diabetic rats were treated with G. lucidum polysaccharides (60, 120, 180 mg/kg b.wt.) dissolved in 15% dimethyl sulphoxide (DMSO) for 30 days. The normal control rats were treated with 15% DMSO for 30 days. Streptozotocin treatment elevated the levels of lipid peroxidation markers (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes), and reduced nonenzymic antioxidants (vitamin C and reduced glutathione, vitamin E) levels, and enzymic antioxidants (superoxide dismutase, catalase and glutathione peroxidase) activities in the plasma and liver of untreated diabetic control rats. Decreased level of serum insulin and increased level of blood glucose (BG) were observed in the plasma of untreated diabetic control rats. G. lucidum polysaccharides treatment significantly and dose-dependently increased nonenzymic and enzymic antioxidants, serum insulin level and reduced lipid peroxidation, blood glucose levels in STZ-diabetic rats. From the present study, it can be concluded that G. lucidum polysaccharides can be considered as a potent antioxidant.     

Antioxidant from maize and maize fermented by Marasmiellus sp. as stabiliser of lipid-rich foods

Mycelia of Marasmiellus sp. (KUM 50061) were grown on maize for antioxidant production. This formed the mycelial biomass which was then extracted with methanol. Antioxidant activity of methanolic extract was analysed by the TBARS assay, using egg yolk or palm cooking oil as a source of lipid, rather than the conventional rat liver microsomes or linoleic acid. Results showed that at low concentrations of extracts, inhibition of lipid peroxidation in buffered egg yolk was marginal, but significant inhibitory response was evident as the concentrations was increased. The concentration of extract of fermented maize that caused 50% inhibition of lipid peroxidation of buffered egg yolk was 6 mg/ml. Results also indicated a decrease in peroxidation in heated cooking oil supplemented with dried extract compared to unsupplemented cooking oil. The concentration range of dried extract supplementation was 0.2–5 mg/ml. Increasing the extract concentration did not significantly alter the inhibition of peroxidation. The inhibition effect was still evident even at the lowest concentration tested, and was found to be better than catechin and BHA. This pattern of observation was consistent over the 12-day period of observation. Therefore, the possibility of substituting synthetic antioxidants such as BHA and BHT, which are known to be carcinogenic, with antioxidants of natural origin is suggested.     

Concentration‐dependent antioxidant activities of conjugated linoleic acid and α‐tocopherol in corn oil

BACKGROUND: Antioxidants prevent rancidity (lipid peroxidation) and natural antioxidants, e.g., α‐tocopherol, likely provide additional value to oil‐based food products because of their health benefits. Conjugated linoleic acid (CLA) has potential health benefits and may exhibit antioxidant properties. The main aim of this study was to compare the antioxidant efficacy of α‐tocopherol, trans‐10, cis‐12‐CLA and cis‐9, trans‐11‐CLA (in graded concentrations) added to antioxidant‐stripped corn oil. RESULTS: As compared to α‐tocopherol, both CLA isomers displayed significant inhibition of corn oil lipid peroxidation induced by copper. Inhibition of thiobarbituric acid reactive substances (TBARS) were CLA concentration dependent for both isomers but with significant inhibition occurring at 0.1 and 1 ppm of CLA isomers or α‐tocopherol, respectively (P < 0.05). Graded concentrations of α‐tocopherol, and for both CLA isomers and time, had significant effects on TBARS formation (P < 0.0001). There were significant effects in interactions between graded concentrations and time for both CLA isomers (P < 0.0001) but not for α‐tocopherol (P > 0.05). CONCLUSION: CLA compounds could serve as useful food antioxidants and provide additional value because of their potential bioactivity in disease prevention. Copyright © 2007 Society of Chemical Industry     

梨果实后熟衰老过程中温度对活性氧清除的影响

本文以河北水晶梨为试材,研究了贮藏前期和在不同温度下贮藏的梨果实果肉的超氧自由基(O2)产生速率、超氧化物岐化酶(SOD)活性、过氧化氢(H2O2)含量和过氧化氢酶(CAT)活性的变化及温度对它们的影响。结果表明:贮藏前期SOD活性和CAT活性均要低于在20和5条件下贮藏七天的样品,而贮藏前期O2产生速率和H2O2含量则较大,并且在5条件下贮藏七天的样品其果肉SOD活性要高于在20条件下贮藏七天的样品,其果肉的CAT活性也要高于后者;相反地在5条件下贮藏七天的样品其O2产生速率则低于在20条件下贮藏七天的样品的O2产生速率,其H2O2含量也低于后者。     

Effect of muscle and post-mortem rate of pH and temperature fall on antioxidant enzyme activities in beef

The aim of this study was to investigate the effect of muscle, inner and outer Musculus biceps femoris (IBF and OBF respectively) and Musculus longissimus dorsi (LD), on the post-mortem rate of pH and temperature fall, and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) during simulated retail display. At day 0 of display (2 days post-mortem), the CAT and GSH-Px activities were lower in IBF than in OBF and LD (P < 0.001), and the SOD activity was lower in OBF compared to IBF and LD (P < 0.001). At day 10 of display, SOD and CAT activities had decreased in all three muscles compared to day 0 (P < 0.001), whereas the GSH-Px activity did increase with time of display. Across muscles, there were significant relationships between temperature fall, colour, lipid and colour stability and antioxidant enzyme activities.     

The effect of humic and glutamic acids in nutrient solution on the N metabolism in lettuce

BACKGROUND: This paper reports for the first time the influence of partially replacing the nitrogen (N) source of a nutrient solution with amino acids and humic acid on the physiological and antioxidant activities and N metabolism in lettuce. A hydroponic experiment was designed to replace 25 and 50% of the N in nutrient solutions (NSs) with glutamic acid (GA) and humic acid (HA) and evaluate the effects on growth, nitrate (NO₃) assimilation, protein content, nitrate reductase (NR) activity and antioxidant changes in lettuce. RESULTS: The results showed that, when a portion of the N was replaced with GA and HA, the fresh and dry weights of lettuce shoots did not change significantly compared with the full NO₃ treatment. The titratable acidity was not affected by adding HA and/or GA to the NS. The nitrite concentration and NR activity decreased with reductions in the N concentration of the NS and improved with the addition of GA and HA. GA enhanced the NO₃ uptake and protein content more than HA. Changes in the superoxide dismutase (SOD) and peroxidase (POD) activities and malondialdehyde content were inconclusive: SOD and POD activities decreased with decreasing N content of the NS, and HA addition improved the SOD and POD activities. CONCLUSION: When HA and GA were substituted for NO₃ in an NS, the acids effectively adjusted the N metabolism and growth in lettuce and decreased the N consumption of the NS. Copyright © 2012 Society of Chemical Industry     

保鲜盒包装冷鲜牛肉贮藏期间品质及菌相变化

为研究保鲜盒包装冷鲜牛肉贮藏期间的感官品质、新鲜度变化,并初步分析其优势菌相,测定0℃~4℃下贮藏第0、1、3、5、7天时肉样的感官指标、挥发性盐基氮值(total volatile basic nitrogen,TVB-N)、pH值、硫代巴比妥酸反应物值(thiobarbituric acid reactive substances,TBARS)、菌落总数、大肠菌群的变化,以及乳酸菌、假单胞菌、肠杆菌以及热死环丝菌的生长情况。结果表明:保鲜盒包装冷鲜牛肉在0℃~4℃条件下最佳冷藏期为3d,贮藏第5天时为次鲜肉,第7天时已腐败;假单胞菌、乳酸菌、热死环丝菌为其优势腐败菌。     

Effect of the Lycium barbarum polysaccharides administration on blood lipid metabolism and oxidative stress of mice fed high-fat diet in vivo

Epidemiological and experimental studies have suggested that high dietary fat intake of mice is associated with many physically degenerative diseases. Since oxidative stress and abnormal lipid metabolism have been speculated to be critical mechanisms underlying degenerative diseases, we hypothesized that a high-fat (HF) diet might induce oxidative stress or lipid oxidation and subsequently contribute to the high risk of some diseases such as cardiovascular and cerebrovascular ones. To test this hypothesis, male kunming mice were placed on either a HF diet or a normal laboratory diet for 30 consecutive days. This investigation demonstrated that blood fat [low density lipoprotein (LDL), total cholesterol (TC), triacylglycerols (TAG), high density lipoprotein (HDL)], blood sugar (blood glucose and liver glycogen) and oxidative stress (activities of antioxidant enzymes and levels of non-enzymic antioxidants) of mice fed high-fat diet (group II) were significantly increased or decreased (P < 0.05, P < 0.01) when compared with the control group (I). The present study revealed that HF diet induced oxidative stress and provided novel evidence regarding the link between high dietary fat and increased risk of degenerative diseases. The administration of Lycium barbarum polysaccharides did not show any effect on the body weight of the experimental mice, but significantly decreased the levels of LDL, TC, TAG, blood glucose and thiobarbituric acid reactive substances (TBARS) or increased the activities of antioxidant enzymes (P < 0.05, P < 0.01) when compared with mice in HF group (II). These findings were further supported by significantly increased non-enzymic antioxidants levels (P < 0.05, P < 0.01), suggesting that L. barbarum polysaccharides showed a noticeable inhibition against lipid oxidation induced by free radicals caused by HF diet intake (groups III, IV, V) on the basis of their antioxidant activities.     

Evaluation of antioxidant and immune activity of Phellinus ribis glucan in mice

The potential protective effects of Phellinus ribis glucan (PRG) administration against immune injury due to free radical formation were evaluated in mice. The results showed that glucan administration significantly increased thymus and spleen indices, spleen lymphocyte proliferation and NK cells activity, as well as CD8 T cell numbers, and decreased CD4+/CD8+. In accordance with a previous study, glucan administration significantly enhanced plasma glutathione peroxidase, superoxide dismutases activity and reduced plasma thiobarbituric acid reactive species level. In conclusion, our results indicate that glucan administration improve immune function by its free radicals scavenging activity and reducing oxidative stress in mice.     

In vitro and in vivo studies on the antioxidant activities of the aqueous extracts of Douchi (a traditional Chinese salt-fermented soybean food)

The aqueous extracts of Douchi were obtained and evaluated for their antioxidant properties. The isoflavones and peptides contents of extracts were determined. Antioxidant activities in vitro of extracts were conducted by determining the α,α-diphenyl-β-pricrylhydrazyl (DPPH) and 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, and the chelating ability of ferrous ions, of which IC₅₀ values were found to be 0.658, 0.204 and 206 mg/mL, respectively. Antioxidant enzymatic activities of extracts in cholesterol-fed rats and an index of lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) were determined, and hepatic tissue ultramicrostructure was also observed under transmission electron microscope (TEM). These results showed that, in Douchi extracts groups, superoxide dismutase (SOD) activities in liver and kidney, catalase (CAT) activity in liver, and glutathione peroxidase (GSH-Px) activity in kidney increased significantly compared with the negative control group (p < 0.05). TBARS in liver and kidney of extracts groups decreased significantly (p < 0.05). Less fatty degeneration in hepatocytes of extracts groups was found on TEM photos. The percentage of total isoflavones and peptides contents in aqueous extracts were 0.087% and 40.7%, respectively. These results showed that Douchi extracts had excellent antioxidant activities, might affect the activities of antioxidant enzymes and lipid peroxidation, and mitigate the lipidosis of hepatocytes.     

Effects of brown rice, rice bran, and polished rice on colon carcinogenesis in rats

Rice is a nutritious staple food with health-promoting activity. This study investigated the effects of brown rice, rice bran, and polished rice on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. The colons were examined for preneoplastic lesions and the expression of pro-inflammatory proteins. Lipid peroxidation was determined in livers and plasma; antioxidant-associated parameters were determined in livers. The results showed that consumption of medium-level of rice bran significantly reduced the number of aberrant crypt foci (ACF) and altered their distribution. Brown rice and rice bran significantly reduced cyclooxygenase-2 (COX-2) expression of the middle colon. Brown rice, rice bran, and polished rice had no significant effect on plasma and hepatic lipid peroxides and hepatic antioxidant-associated parameters. Thus, rice bran may be one candidate of the active rice fraction that protects the colon against DMH-induced early carcinogenesis in rats and may be a novel dietary supplement for chemoprevention of colon cancer.     

Chemical composition,fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves,sunflower cake and grass hay

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62 ± 0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51 ± 0.19% (93.51 ± 0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95 ± 0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (P < 0.05) higher than other meat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability).     

Effects of diet enriched with restructured meats,containing Himanthalia elongata, on hypercholesterolaemic induction,CYP7A1 expression and antioxidant enzyme activity and expression in growing rats

Meat and pork consumptions are very high in Spain. Seaweeds are rich in fibre, minerals, and bioactive substances. Due to the growing demand for healthier meats, this work studied the effect of diets containing restructured pork (RP) enriched with Himanthalia elongata (Sea Spaghetti) on: (1) cholesterolaemia; (2) liver cytochrome P450 7A1 (CYP7A1) expression; (3) liver antioxidant enzyme activities and gene expression; (4) the liver antioxidant substrate concentrations. Four groups of 10 Wistar rats each were fed a mix of 85% AIN-93 M rodent diet and 15% freeze-dried RM for 35 days. The control group (C) consumed control RP; the Sea Spaghetti (SS) group, RP with 5% Sea Spaghetti. Animals on added cholesterol diets (CholC and CholSS) consumed their basal C and SS diets enriched with cholesterol and cholic acid as hypercholesterolaemic agent. Food intake was significantly affected by the alga × cholesterol interaction and by dietary cholesterol (both p < 0.001). Plasma cholesterol was significantly affected by the cholesterol × alga interaction (p < 0.05). CholC rats showed significantly higher plasma cholesterol (p < 0.001) than did their C counterparts, whilst serum cholesterol of CholSS was significantly lower (p < 0.05) than that of CholC. The glutathione peroxide (GSSG) concentrations and all mRNA expressions were significantly affected by the cholesterol × alga interaction (at least p < 0.05). SS vs C group showed significant (at least p < 0.05) increases in superoxide dismutase (Mn-SOD and Cu,Zn-SOD), glutathione peroxidase (GPx) and decrease of glutathione reductase (GR) expressions, and increased GR activity, GSSG and the redox index. CholSS vs CholC showed significant (at least p < 0.05) increases of CYP7A1, GR and Cu,Zn-SOD expression but decreases in catalase, Mn-SOD and GPx expression, and increase of GR activity. In conclusion, Sea Spaghetti could be widely used in RP design. Its addition to non-cholesterol enriched RP diet reduced oxidation mechanisms. SS-RP partially blocked the effect of the hypercholesterolaemic agent, giving rise to a new balance of the antioxidant enzyme expression.     

Correlation between plasma antioxidant capacity and verbascoside levels in rats after oral administration of lemon verbena extract

Phenylpropanoids are the main class of compounds from lemon verbena which have shown a wide biological activity, verbascoside being the most abundant one. In this work, the composition of a lemon verbena extract was elucidated by HPLC-ESI-MS/MS and one flavone and one methoxylated phenylpropanoid were found in this source for the first time. The antioxidant activity of the lemon verbena extract was fully characterised by several methodologies. Unexpectedly, the extract was especially active in lipophilic environments and lipid peroxidation inhibition assay, as it was found for pure verbascoside. The lemon verbena extract, containing verbascoside as its major bioactive compound, was acutely administered to rats and verbascoside was the only metabolite detected in plasma samples as measured by HPLC mass spectrometry. The correlation between the highest verbascoside concentration in plasma and maximum plasma antioxidant capacity was observed at 20 min as measured by different techniques, i.e. minimum malondialdehyde (MDA) generation, highest ferric-reducing ability of plasma (FRAP value) and maximum superoxide dismutase activity (SOD). Therefore, the in vitro measurements of the antioxidant activity of lemon verbena extract may significantly support the antioxidant activity observed in vivo in this work. Moreover, neither evidence of acute oral toxicity nor adverse effects were observed in mice when the lemon verbena extract containing 25% verbascoside was used at a dosage of 2000 mg/kg.     

Phenolic acids composition and antioxidant activity of canola extracts in cooked beef,chicken and pork

Crude polyphenol extracts (15 or 100 mg gallic acid equivalents (GAE)/kg meat) from canola meal reduced the formation of 2-thiobarbituric acid-reactive substances (TBARS) in pre-cooked beef (66–92%), pork (43–75%) and chicken (36–70%). The canola extract contained sinapic (99.7%), ferulic (0.28%) and p-hydroxybenzoic acids (0.07%).     

Purification and characterisation of a novel antioxidant protein molecule from Phyllanthus niruri

The herb Phyllanthus niruri is known to possess antioxidant activity, but the nature of the responsible active principle(s) is not well defined. The present study reports the purification and characterisation of a 35 kDa antioxidant protein molecule from this herb using a bioassay in which oxidative stress was introduced in hepatocytes with the help of a suitable free radical inducer, tertiary butyl hydroperoxide (TBHP), and the prevention of that stress was monitored using the protein fraction(s) obtained at each step of the purification. Partial amino acid sequence of this protein revealed its unique structural features. The purified protein possesses potent radical-scavenging activity, enhances intracellular antioxidant power and protects the TBHP-induced alterations of the cytoprotective and antioxidant molecules, as well as other parameters used in this particular study. Combining, data suggest that the antioxidant activity of Phyllanthus niruri is at least partly due to this unique protein molecule.     

Isolation,characterization and antioxidant capacity assessment of the bioactive compounds derived from Hypoxis rooperi corm extract (African potato)

The rhizome of the plant Hypoxis rooperi (“African potato”) is known for its traditional and ethnomedical uses in the treatment of benign prostatic hyperplasia and other diseases. We have characterized an extract derived from H. rooperi, isolated its major bioactive compound, hypoxoside, and obtained its aglycone, rooperol, by enzymatic digestion. Absorption, fluorescence emission and bidimensional NMR complete spectral data of these compounds were obtained. The antioxidant capacity of both compounds was fully analyzed through the thiobarbituric acid reactive substances (TBARS) and Trolox equivalent antioxidant capacity (TEAC) assays, and it was compared to catechins and olive biophenolics. Both compounds showed a strong antioxidant capacity, although rooperol exhibited a higher antioxidant activity against lipid peroxidation which correlated to its strong affinity for phospholipid membranes as derived from its extremely high lipid/water partition coefficient (K_p = 3.4 × 10⁴). The study of the lipophilic (EtOH) and hydrophilic (water) TEAC values revealed that more hydrophobic compounds, had greater lipophilic TEAC values than hydrophilic ones, probably indicating that lipophilic TEAC assay may be more reliable for these compounds. The H. rooperi extract also showed higher antioxidant efficacy compared to other strong antioxidant herbal extracts, such as olive leaf or green tea. Moreover, neither evidence of acute oral toxicity nor adverse effects were observed when the H. rooperi commercial extract containing 45% hypoxoside was used at a dosage of 2000 mg/kg. The results obtained in this work may contribute to understanding the biological activity described for these dicatechols and the African potato extract for food and cosmetic applications.     

Modulation of the antioxidant/pro-oxidant balance,cytotoxicity and antiviral actions of grape seed extracts

Grape seed extracts (GSEs) were investigated in yeast cells harbouring defects in their antioxidant system (regarding the cellular growth and growth recovery from H₂O₂ insult). GSEs antioxidant activity was detected in wild-type and mutant strains Δcta1, Δgsh1 and Δoye2glr1, while pro-oxidant activity in Δsod1 cells was seen. Assessment of proliferation of prostate cancer PC3 and HBV-replicating HepG2 2.2.15 cells treated with GSEs has shown higher cytotoxicity of red grape seed extract (RW) than white grape seed extract (WW) subjective to dose and period of administration. No antiviral effect was detected by measuring the secreted virion particles in HepG2 2.2.15 cells treated with GSEs. The GSEs play a dual antioxidant/pro-oxidant role in vivo according with the cellular antioxidant system deficiencies and exhibit cytotoxic properties in PC3 and HepG2 2.2.15 cell lines, but no antiviral action against HBV.     

Phytochemistry, traditional uses and pharmacology of Eugenia jambolana Lam. (black plum): A review

Eugenia jambolana Lam. (syn. Syzigium cumini (L.) SKEELS; S. jambolana DC; Family: Myrtaceae), commonly known as black plum or Jamun is a plant native to India. Annually the trees produce oblong or ellipsoid fruits (berries). They are green when raw and purplish black when fully ripe. The ripe fruits are sweetish sour to taste and are used to prepare health drinks, squashes, juices, jellies and wine. Studies have shown that the berries contain carbohydrates, minerals and the pharmacologically active phytochemicals like flavonoids, terpenes, and anthocyanins. Jamun is a plant with known ethnomedicinal uses. Before the discovery of insulin, Jamun was useful in the treatment of diabetes and is an integral part in the various alternative systems of medicine. Scientific studies have shown that the various extracts of Jamun possess a range of pharmacological properties such as antibacterial, antifungal, antiviral, anti-genotoxic, anti-inflammatory, anti-ulcerogenic, cardioprotective, anti-allergic, anticancer, chemopreventive, radioprotective, free radical scavenging, antioxidant, hepatoprotective, anti-diarrheal, hypoglycemic and antidiabetic effects. The present paper reviews these aspects and also addresses the lacunas in the existing knowledge.