Effect of Artichoke Leaf Extract on Hepatic and Cardiac Oxidative Stress in Rats Fed on High Cholesterol Diet

Hypercholesterolemia and lipid peroxidation play complementary roles in atherosclerosis. Artichoke (Cynara scolymus L., Asteraceae) leaf extract (ALE), rich in antioxidants, has cholesterol-reducing effect. We investigated the effect of ALE on serum and hepatic lipid levels and pro-oxidant–antioxidant balance in the liver and heart of hypercholesterolemic rats. Rats were fed on 4% (w/w) cholesterol and 1% cholic acid (w/w) supplemented diet for 1 month. ALE (1.5 g/kg/day) was given by gavage during the last 2 weeks. High cholesterol (HC) diet caused significant increases in serum and liver cholesterol and triglyceride levels. It increased malondialdehyde (MDA) and diene conjugate (DC) levels in both tissues. Hepatic vitamin E levels and hepatic and cardiac glutathione peroxidase (GSH-Px) activities decreased, but superoxide dismutase and glutathione transferase activities, glutathione, and vitamin C levels remained unchanged due to HC diet. Serum cholesterol and triglyceride levels and ratio of cholesterol to high-density lipoprotein (HDL)-cholesterol decreased in ALE plus HC-treated rats, but liver cholesterol and triglyceride levels remained unchanged. Significant decreases in hepatic and cardiac MDA and DC levels and increases in hepatic vitamin E and GSH-Px activities were observed in ALE-treated hypercholesterolemic rats. Our results indicate that ALE decreases serum lipids and hypercholesterolemia-induced pro-oxidant state in both tissues.     

An investigation on the antioxidant status of the invasive alga Caulerpa racemosa var. cylindracea (Sonder) Verlaque, Huisman, et Boudouresque (Caulerpales, Chlorophyta)

Caulerpa racemosa var. cylindracea is a potential invader of the Mediterranean Sea and 11 Mediterranean countries are under threat from this alga. In the present study, in order to investigate seasonal changes in the antioxidant status of C. racemosa var. cylindracea, antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and lipid peroxidation (LPO) levels were determined in C. racemosa var. cylindracea samples, which were collected in May 2003, September 2003, December 2003, and March 2004 from Turkish coastlines. SOD and CAT activities showed similar trends. These enzymes increased from May to December, then sharp decreases were observed. On the other hand, GSH-Px enzyme activities showed a fluctuation between May 2003 and March 2004. In contrast to increases in SOD and CAT activities up to December 2003, LPO level decreased in this period. No significant correlation was observed between antioxidant status and solar radiation. In conclusion, the antioxidant status of C. racemosa var. cylindracea is strictly not affected by both solar radiation and seawater temperature; however, the growth of epiphytes on fronds may change antioxidant status. Further investigations are strongly warranted to understand the contributions of non-enzyme-based antioxidants such as glutathione, vitamin E, and vitamin C.     

Impact of mycogenic zinc nanoparticles on performance,behavior, immune response,and microbial load in Oreochromis niloticus

This work aims to evaluate the antibacterial activity of biological zinc nanoparticles (BIO-ZnONPs) against pathogenic fish bacteria and assess the effect of BIO-ZnONPs on the performance, behavior, and immune response in Nile tilapia (Oreochromis niloticus) as compared to chemical zinc nanoparticles (CH- ZnONPs). Aspergillus niger TS16 fabricated the BIO-ZnONPs were spherical shape with the average size of 45 nm and net charge of ?27.23 mV. Generally, the results indicate that BIO-ZnONPs were more effective than CH- ZnONPs in enhancing the performance properties of Nile tilapia. Five experimental groups of Nile tilapia (initial body weight of 20.2 g) were treated with two concentrations of 0.5 and 1 mg L^?1 from biological and chemical ZnONPs, while the fifth group was served as a control. After ten weeks of treated water with ZnONPs, the performance, feed efficiency parameters, feeding, and swimming behaviors significantly improved in BIO-ZnONPs treated groups (P < 0.05). The liver function, LYZ activity, and NBT values were significantly enhanced in the 0.5 mg L^?1 BIO-ZnONPS group compared to CH- ZnONPs group and control (P < 0.05). Furthermore, the lowest cortisol and the highest testosterone and growth hormone levels were recorded in 1 mg L^?1 BIO-ZnONPs group. Regarding the antibacterial effects, BIO-ZnONPs displayed the lower total bacterial loads in water and fish tissues (intestine, gills, skin, and muscle) and the maximum antibacterial properties against pathogenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Aeromonas hydrophila). Our study exemplifies novel findings of BIO-ZnONPs in the promotion of fish health and production and its antibacterial properties in Nile tilapia.     

Studies on the protective role of vitamin C and E against polychlorinated biphenyl (Aroclor 1254)—induced oxidative damage in Leydig cells

Free radical production and lipid peroxidation are potentially important mediators in testicular physiology and toxicology. Polychlorinated biphenyls (PCBs) are global environmental contaminants that cause disruption of the endocrine system in human and animals. The present study was conducted to elucidate the protective role of vitamin C and E against Aroclor 1254-induced changes in Leydig cell steroidogenesis and antioxidant system. Adult male rats were dosed for 30 days with daily intraperitoneal (ip) injection of 2 mg/kg Aroclor or vehicle (corn oil). One group of rats was treated with vitamin C (100 mg/kg bw/day) while the other group was treated with vitamin E (50 mg/kg bw/day) orally, simultaneously with Aroclor 1254 for 30 days. One day after the last treatment, animals were euthanized and blood was collected for the assay of serum hormones such as luteinizing hormone (LH), thyroid stimulating hormone (TSH), prolactin (PRL), triiodothyronine (T₃), thyroxine (T₄), testosterone and estradiol. Testes were quickly removed and Leydig cells were isolated in aseptic condition. Purity of Leydig cells was determined by 3β-hydroxysteroid dehydrogenase (3β-HSD) staining method. Purified Leydig cells were used for quantification of cell surface LH receptors and steroidogenic enzymes such as cytochrome P₄₅₀ side chain cleavage enzyme (P₄₅₀scc), 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β- HSD). Leydig cellular enzymatic antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), γ-glutamyl transpeptidase (γ-GT), glutathione-S-transferase (GST) and non-enzymatic antioxidants such as vitamin C and E were assayed. Lipid peroxidation (LPO) and reactive oxygen species (ROS) were also estimated in Leydig cells. Aroclor 1254 treatment significantly reduced the serum LH, TSH, PRL, T₃, T₄, testosterone and estradiol. In addition to this, Leydig cell surface LH receptors, activities of the steroidogenic enzymes such as cytochrome P₄₅₀scc, 3β-HSD, 17β-HSD, antioxidant enzymes SOD, CAT, GPX, GR, γ-GT, GST and non-enzymatic antioxidants such as vitamin C and E were significantly diminished whereas, LPO and ROS were markedly elevated. However, the simultaneous administration of vitamin C and E in Aroclor 1254 exposed rats resulted a significant restoration of all the above-mentioned parameters to the control level. These observations suggest that vitamin C and E have ameliorative role against adverse effects of PCB on Leydig cell steroidogenesis.     

Pathogenicity and oxidative stress in Nile tilapia caused by Aphanomyces laevis and Phoma herbarum isolated from farmed fish

Identified (n = 17) and unidentified (n = 1) fish-pathogenic fungal species from 10 genera of Oomycetes and soil fungi were isolated from 40 infected freshwater fish samples of the species Oreochromis niloticus niloticus (Nile tilapia) and Clarias gariepinus (African catfish). Samples were collected from various fish farms in the Nile Delta, Egypt. Nile tilapia were tested in aquaria for their susceptibility to the commonest Oomycetes species, Aphanomyces laevis and Achlya klebsiana, and also against the 2 most prevalent pathogenic soil fungi, Paecilomyces lilacinus and Phoma herbarum. Two techniques were used: water bath exposure and intramuscular (subcutaneous) injection. Water bath exposure to the 2 species of Oomycetes caused greater mortalities of O. niloticus niloticus than intramuscular injection, but the reverse was true of the soil fungal species. Regardless of the infection method, the 2 Oomycetes species were more potent pathogens than the soil fungal species. In both gills and mytomal muscles of fish infected by A. laevis and P. herbarum, we measured and compared with controls the oxidative stress parameters total peroxide (TP), lipid peroxidation (LPO) and nitric oxide (NO), as well as levels of the antioxidants vitamin E and glutathione (GSH), and superoxide dismutase (SOD) and catalase (CAT) activities. Infection by these 2 fungal species through either spore suspension or spore injection significantly increased oxidative damage in gills and induced marked decrease in most studied antioxidants. In addition, both routes showed similar effects and A. laevis depressed the antioxidants CAT, vitamin E and GSH more than P. herbarum.     

Hematological and biochemical investigations on the effect of vitamin E and C on Oreochromis niloticus exposed to zinc oxide nanoparticles

This study was carried out to determine the LC₅₀ of zinc oxide nanoparticles (ZnONPs) on Oreochromis niloticus and to investigate the effect of vitamin E and C on hematological and biochemical alterations induced by two sublethal concentrations (1 and 2 mg/L) of ZnONPs. One hundred and eighty fish were used for studying the lethal concentrations of ZnONPs. For sublethal study two hundred and twenty-five males of O. niloticus were equally divided into five groups, control, the second and the third were treated with 1 and 2 mg/L ZnONPs respectively. The fourth and fifth were exposed to the same concentrations of ZnONPs plus vitamins E and C. The results revealed that the 96 h LC₅₀ of ZnONPs was 3.1 ± 0.4 mg/L. The sublethal study revealed the presence of normocytic normochromic anemia in groups (2, 3 and 5) along the experiment period. The 4th group showed normocytic normochromic anemia at the 7th day and microcytic hypochromic anemia at the 15th day. Leukocytosis, heterophilia, lymphopenia and monocytopenia were recorded at the 7th day in all treated groups compared with the normal control. At the 15th day heteropenia, lymphopenia and monocytopenia were reported in all treated groups. A significant increase in the serum levels of alkaline phosphatase, aminotransferases, urea, creatinine and erythrocytic nuclear and morphological abnormalities along the experimental periods in all treated groups compared with the normal control. Serum total protein and albumin levels were significantly decreased at the same period in the same groups. Addition of vitamin E and C to the diet (groups 4 and 5) significantly improved all measured parameters compared with groups (2 and 3) which treated with ZnONPs only.     

Antioxidant system in Uromastyx philbyi during hibernation and activity periods

Hibernation is an extreme physiological state characterized by profound decreases in oxidative metabolism and body temperature during bouts of prolonged torpor, interrupted by brief periods of arousal with sudden increases in oxidative metabolism, with alterations in antioxidant defenses. We monitored the activities of antioxidant enzymes and oxidative stress during hibernation and activity in Uromastyx philbyi. 20 animals were used, 10 of which were collected in the hibernation season (group I) and the other 10 collected during the active period (group II). Blood, liver, brown adipose tissue (BAT) and brain samples were used to determine free radical and antioxidant levels. The results indicated a significant decrease of free radicals and increase of vitamin C, especially in serum during hibernation. In contrast, during the active period free radicals, enzymatic antioxidants as glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) and non-enzymatic antioxidants as reduce glutathione (GSH) and vitamin E increased in all studied tissues. It can be concluded that Uromastyx philbyi has a strong antioxidant defense system that protects it from the injurious effects of free radicals either at the periods of arousal or during activity periods.     

The effects of some antioxidant vitamin- and trace element-supplemented diets on activities of SOD, CAT, GSH-Px and LPO levels in chicken tissues

The effect of diets containing antioxidant vitamins and trace elements on chicken tissue activities of SOD, CAT, GSH-Px and of LPO levels was investigated. Chickens, 45 weeks of age were divided into six groups: control group, Cu group (13.2 mg Cu kg(-1) diet); Se group (0.07 mg Se kg(-l) diet); vitamin E group (70 mg DL-alpha-tocopherol acetate kg(-1) diet) and a constant level vitamin C, 200 mg kg(-1) diet); vitamin A group (240 mg retinol acetate kg(-1) diet) and vitamin C group (500 mg ascorbic acid kg(-1) diet). Significant variation of these antioxidant enzyme activities and LPO levels according to gender was demonstrated statistically. In the Cu group, CuZnSOD activity in the liver, erythrocyte, kidney and heart significantly increased by 75, 40, 12, 12% respectively (P<0.05). MnSOD activity in the heart, liver, kidney and brain of the vitamin C and in the heart of Cu group were found to be increased by approximately 15%, while in liver tissue of the Cu group it was reduced by 19% (P<0.05). GSH-Px activities in the Se, vitamin E and C groups were significantly increased, conversely LPO levels decreased (P<0.001). CAT activities in the liver and heart of the vitamin C group were significantly decreased (by 32%), but in kidney tissue only that of the Cu group was increased from 30.2 +/- 4.767 to 144.49 +/- 6.93 U mg(-1) P<0.001. The resistance to stress of the vitamin E and C groups, which had significantly increased activities of antioxidant enzymes and decreased lipid peroxide levels, were determined in 60% moisture medium at 45 degrees C.     

Protective effect of esculin against prooxidant aflatoxin B1-induced nephrotoxicity in mice

The study was designed to investigate the protective effect of esculin against pro-oxidant aflatoxin B₁ (AFB₁)-induced nephrotoxicity in mice. In this study toxicity was developed by oral administration of AFB₁ at a dose of 66.60 μg/kg bw/day for 90 days in male Swiss albino mice. Esculin (150 mg/kg bw/0.2 ml/day) and standard compound ascorbic acid (300 mg/kg bw/0.2 ml/day) was given after 30 min of AFB₁ administration for 90 days. Protective efficacy was assessed by measuring the levels of lipid peroxidation (LPO) and non-enzymatic antioxidants such as reduced glutathione (GSH) and also by measuring activities of enzymatic antioxidants such as glutathione peroxidase (GPX), glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in kidney. Results were analysed at the 30^th, 60^th and 90^th day of the daily treatments, which showed a decrease in the level of LPO and an increase in the levels of enzymatic and non-enzymatic antioxidants. The protective effect of esculin was further proved by histopathological findings as it exhibited regenerative activities in mice renal tubules against AFB₁-induced nephrotoxicity. The results obtained clearly demonstrate that the protective efficacy of esculin against pro-oxidant AFB₁-induced nephrotoxicity in mice might be due to its antioxidants and free radical scavenging properties.     

Melatonin and vitamin C administration ameliorate diazepam-induced oxidative stress and cell proliferation in the liver of rats

Abstract.  Objective : Oxidative stress is a likely molecular mechanism in long-term diazepam administration. The benefits of antioxidants (melatonin and vitamin C) against diazepam-induced cell proliferation, DNA synthesis and oxidative damage were investigated in this study. Materials & methods : Four equal-sized groups of male rats [control, diazepam (3 mg/kg), diazepam plus melatonin (5 mg/kg) and diazepam plus vitamin C (50 mg/kg)] were used. Levels of lipid peroxides (LPO), superoxide dismutase (SOD) activity and glutathione (GSH) concentration were measured in tissue homogenates. Cell proliferation and rate of DNA synthesis were detected by autoradiography. Results : Results documented increased labelling index, ³H-thymidine incorporation (DNA synthesis), LPO plus decrease in GSH levels and SOD activity in livers of diazepam-administered rats versus those of controls. When melatonin and vitamin C were given to diazepam-administered rats, they almost attenuated the increase of labelling index, DNA synthesis and LPO, and restored the levels of GSH and SOD activity. Conclusion : These results suggest long-term hazard in use of drugs such as diazepam; they may be toxic and damage terminates in complex liver damage. Furthermore, melatonin and vitamin C may be useful in combating free radical-induced liver injury resulting from hazard and/or repeated diazepam administration.     

Antiperoxidative and antioxidant effects of Casearia esculenta root extract in streptozotocin-induced diabetic rats

Oxidative stress is currently suggested to play as a pathogenesis in the development of diabetes mellitus. The present study was designed to evaluate the effect of Casearia esculenta root extract on oxidative stress-related parameters in streptozotocin (STZ) -induced diabetic rats. Antidiabetic treatment with C. esculenta root extract (45 days) significantly (p < .05) decreased thiobarbituric acid reactive substances (TBARS) and remarkably improved tissue antioxidants status such as glutathione (GSH), ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) in liver and kidney of STZ-diabetic rats. In diabetics rats, the activities of enzymatic antioxidants such as superoxide dismutase (SOD, EC 1.11.1.1) catalase (CAT, EC 1.11.1.6) were decreased significantly while the activity of glutathione peroxidase (GPx, EC 1.11.1.9) decreased in the liver and increased in the kidney. The treatment of diabetic rats with C. esculenta root extract over a 45-day period returned these levels close to normal. These results suggest that C. esculenta root extracts exhibit antiperoxidative as well as antioxidant effects in STZ-induced diabetic rats.     

Effects of 17β-estradiol and antioxidant administration on oxidative stress and insulin resistance in ovariectomized rats

The prevalence of insulin resistance syndrome increases during menopause with the overproduction of reactive oxygen species and impairment of the free radical scavenger function. Therefore, we investigated the effects of 17β-estradiol (E(2)) and vitamin E, as an antioxidant, on lipid peroxidation and antioxidant levels in the brain cortex and liver of ovariectomized rats as well as on insulin resistance in those rats. Forty female Sprague-Dawley rats, 3?months of age and weighing 231.5?± 9.4 g, were divided into 4 groups: sham, ovariectomized (OVX), OVX treated with E(2) (40 μg/kg subcutaneously), and OVX treated with E(2) and vitamin E (100?mg/kg intraperitoneally). The 4 groups received the appropriate treatment every day for 8?weeks. Levels of glutathione, glutathione peroxidase, superoxide dismutase , catalase, and malondialdehyde in the brain cortex and liver of ovariectomized rats were measured. Also, fasting plasma insulin, glucose, and homeostatis model assessment of insulin resistance (HOMA-IR) were determined. Malondialdehyde increased and antioxidants (glutathione, glutathione peroxidase, catalase, superoxide dismutase) decreased in the brain cortex and liver of OVX rats. Also, fasting glucose, insulin, and HOMA-IR increased in OVX rats. E(2) and E(2) plus vitamin E decreased malondialdehyde and increased antioxidants in the brain cortex and liver of OVX rats. Moreover, they decreased fasting glucose, insulin, and HOMA-IR in ovariectomized rats. This study demonstrates that E(2) and E(2) plus vitamin E supplementation to OVX rats may improve insulin resistance, strengthen the antioxidant system, and reduce lipid peroxidation.     

Effect of <Emphasis Type="Italic">Tridax procumbens</Emphasis> on liver antioxidant defense system during lipopolysaccharide-induced hepatitis in D-galactosamine sensitised rats

The present study was carried out to assess the effect of chloroform insoluble fraction of ethanolic extract of Tridax procumbens (TP) against D-Galactosamine/Lipopolysaccharide (D-GalN/LPS)-induced hepatitis in rats. Induction of rats with D-GalN/LPS (300 mg/kg body weight/30 g/kg body weight) led to a marked increase in lipid peroxidation as measured by thiobarbituric acid reactive substances (TBARS) in liver. Further there was a decline in the activities of enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione s-transferase and the levels of non-enzymic antioxidants namely reduced glutathione, vitamin C and vitamin E. These biochemical alterations were normalised upon pretreatment with TP extract. Thus, the above results suggest that TP (300 mg/kg body weight orally for 10 days) is very effective in allievating the D-GalN/LPS-induced oxidative stress suggesting its antioxidant property. (Mol Cell Biochem 269: 131–136, 2005)     

Ameliorative effect of kaempferol,a flavonoid,on oxidative stress in streptozotocin-induced diabetic rats

Abstract

Objective

The aim of the present study was to evaluate the protective effect of kaempferol against oxidative stress in streptozotocin (STZ)-induced diabetic rats.

Methods

Diabetes was induced in male, adult albino rats of the Wistar strain, by intraperitoneal administration of STZ (40 mg/kg body weight (BW)). Kaempferol (100 mg/kg BW) or glibenclamide (600 µg/kg BW) was administered orally once daily for 45 days to normal and STZ-induced diabetic rats.

Results

The STZ-induced diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes in plasma, liver, kidney, and heart whereas they showed significantly decreased level of plasma insulin. The levels of non-enzymic antioxidants (vitamin C, vitamin E, reduced glutathione) in plasma, liver, kidney, and heart and the activities of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase) in liver, kidney, and heart were significantly decreased in diabetic rats. Administration of kaempferol to diabetic rats was showed brought back in plasma glucose, insulin, lipid peroxidation products, enzymatic, and non-enzymatic antioxidants to near normal.

Conclusion

The present study indicates that kaempferol has a good antioxidant property, as evidenced by its increase of antioxidant status and decrease of lipid peroxidation markers, thus providing protection from the risks of diabetic complications.     

维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物和抗氧化物酶的影响

为研究维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物和抗氧化物酶的影响 ,我们设置了 4个实验组 ,采用 2 4只小鼠 ,饵料中 35 %维生素C多聚磷酸酯的添加量依次为 0、 5 0 0、 2 5 0 0和 5 0 0 0mg/kg ,喂食 4周后取其肝脏 ,用硫代巴比妥酸分光光度测脂质过氧化物的含量 ,用亚硝酸盐形成法测定超氧化物歧化酶的活性 ,用分光光度法测过氧化氢酶和谷胱甘肽过氧化物酶的活性。结果表明 ,维生素C多聚磷酸酯对小鼠肝脏脂质过氧化物没有明显影响 ,但随着维生素C多聚磷酸酯添加量的增加 ,脂质过氧化物有减少的趋势。维生素C多聚磷酸酯添加量为 2 5 0 0和 5 0 0 0mg/kg的两组 ,其超氧化物歧化酶的活性明显高于对照组和维生素C多聚磷酸酯添加量为 5 0 0mg/kg组 ;过氧化氢酶的活性明显高于对照组。维生素C多聚磷酸酯添加量为5 0 0 0mg/kg组 ,其谷胱甘肽过氧化物酶的活性明显高于其它三组。表明高剂量的维生素C多聚磷酸酯能促进小鼠抗氧化物酶的活性 ,但促进不同抗氧化物酶活性所需的维生素C多聚磷酸酯的量不同     

Agaricus blazei Murill as an efficient hepatoprotective and antioxidant agent against CCl4-induced liver injury in rats

Agaricus blazei Murill is one of the very popular edible medicinal mushrooms. The present study investigated the protective effect of this biologically active mushroom on the tissue peroxidative damage and abnormal antioxidant levels in carbon tetrachloride induced hepatotoxicity in male albino rats. Male albino rats of Sprague–Dawley strain weighting (120–150 g) were categorized into five groups. The first group served as the normal control, the second and the third groups were treated with Agaricus blazei Mushroom extract and carbon tetrachloride dose, respectively. Fourth group (protective group) was first treated with Agaricus blazei Mushroom extract followed by carbon tetrachloride treatment and fifth (therapeutic group) with carbon tetrachloride first followed by Agaricus blazei Mushroom treatment. The wet fruiting bodies of mushroom Agaricus blazei Murill, crushed and suspended in distilled water was administered orally to the treated groups of male albino rats. The activities of various enzymes (aspartate and alanine transaminase, lactate dehydrogenase, glutathione reductase), levels of non-enzymatic antioxidants (glutathione, vitamin C, vitamin E) and level of lipid peroxidation (malondialdehyde) were determined in the serum of all the experimental animals. Decrease in all the enzymes and non-enzymatic antioxidant, along with an increase in the lipid peroxidative index (malondialdehyde) was found in all the carbon tetrachloride treated rats as compared with normal controls. Also increase level of non-enzymatic antioxidant along with the decrease level in malondialdehyde was found in all experimental animals which were treated with Agaricus blazei Mushroom extract as compared with normal controls. The findings indicate that the extract of Agaricus blazei Murill can protect the liver against carbon tetrachloride induced oxidative damage in rats and is an efficient hepatoprotective and antioxidant agent against carbon tetrachloride induced liver injury.     

Phytochemical profiles and antioxidant potential of four Arctic vascular plants from Svalbard

Environmental stress in the Arctic region leads to damage in plant membranes as a result of oxidation processes. To withstand these stress conditions, plants are expected to produce antioxidants that differ from phenolics. Here, we investigated the chemical composition and antioxidative activities of four Arctic flowering plant species (Dryas octopetala, Carex rupestris, Silene uralensis and Deschampsia alpina.) through in vitro measurements of the free radical scavenging activities (FRS), inhibition of lipid peroxidation (ILP) and trolox equivalent antioxidant capacities (TEAC). D. octopetala exhibited the highest ILP (76.45?%) and FRS (86.58?%) activities. The TEAC values were higher than those of the Trolox vitamin E standard in all four species. Overall, the antioxidative activity was highest in D. octopetala, followed by C. rupestris, S. uralensis and D. alpina. Electrospray ionization tandem mass spectrometric (ESI–MS/MS) analysis of methanolic extracts of these plants revealed the presence of organoselenides, linear alkylbenzenesulfonates (LAS) and oligosaccharides, some of which are reported as antioxidants in the literature. Hence, it is likely that the antioxidant activities exhibited by these plants are not only related to the production of phenolics. This is the first report of the antioxidant potential of four Arctic flowering plants and the presence of selenides in D. octopetala and S. uralensis, and the production of LAS in C. rupestris. Our findings suggest that these plants can be used as nutraceutical sources of selenium and as biomarkers for environmental pollution.     

Galangin,a dietary flavonoid,improves antioxidant status and reduces hyperglycemia-mediated oxidative stress in streptozotocin-induced diabetic rats

Objective: To examine the effect of galangin on hyperglycemia-mediated oxidative stress in streptozotocin (STZ)-induced diabetic rats.

Methods: Diabetes was induced by intraperitoneal administration of low-dose STZ (40?mg/kg body weight (BW)) into male albino Wistar rats. Galangin (8?mg/kg BW) or glibenclamide (600?µg/kg BW) was given orally, once daily for 45 days to normal and STZ-induced diabetic rats.

Results: Diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes. The levels of insulin and non-enzymatic antioxidants (vitamin C, vitamin E, reduced glutathione) and the activity of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase (GST)) were decreased significantly in diabetic control rats. These altered plasma glucose, insulin, lipid peroxidation products, enzymatic and non-enzymatic antioxidants ions were reverted to near-normal level after the administration of galangin and glibenclamide.

Conclusion: The present study shows that galangin decreased oxidative stress and increased antioxidant status in diabetic rats, which may be due to its antidiabetic and antioxidant potential.     

Silver and zinc oxide nanoparticles induce developmental and physiological changes in the larval and pupal stages of Spodoptera littoralis (Lepidoptera: Noctuidae)

The rapid growth of nanotechnology application in various fields of science led to need of understanding their possible effects on development and physiology of insects before using them as control agents. Instead of feeding on a toxic dose, the impact of silver nanoparticles (AgNPs, 50–60?nm) and zinc oxide nanoparticles (ZnONPs, 10–30?nm) was studied at a nonlethal concentration on the larval stages of Spodoptera littoralis. Late second instar larvae of S. littoralis were treated with water, 10?mg/mL AgNPs and ZnONPs dipped castor leaves for 6?days. Both nanoparticles treated leaves caused reduction in both larval weight gain and pupal weight than water dipped leaves while ZnONPs only caused extended larval period. ZnONPs increased total hemocyte, granular cell and plasmatocyte counts while AgNPs increased plasmatocytes only. ZnONPs decreased the levels of protein, lipids and carbohydrates than control and AgNPs treated larvae. On the contrary, ZnONPs induced significant increase in the activities of amylase, glucose 6 phosphate dehydrogenase (G6PD), lipase as well as two antioxidative enzymes, the catalase and superoxide dismutase. These results clearly show that ZnONPs ingestion interfere with the digestive and immunological physiology as well as the development of S. littoralis.