Enhanced Antioxidant Enzyme Research Articles

Hepatoprotective effects of secoiridoid-rich extracts from Gentiana cruciata L. against carbon tetrachloride induced liver damage in rats.

The objective of this work was to investigate the effects of the methanol extracts of Gentiana cruciata L. aerial parts (GCA) and roots (GCR) against carbon tetrachloride-induced liver injury in rats. Pretreatment with GCA and GCR, containing sweroside, swertiamarin and gentiopicrin in high concentrations, dose-dependently and significantly decreased the levels of serum transaminases, alkaline phosphatase and total bilirubin, whereas an increase in the level of total protein was found compared with the CCl4-treated group. Moreover, oral administration of extracts significantly enhanced antioxidant enzyme activities (superoxide dismutase and catalase), increased the content of glutathione and decreased the content of TBARS. Microscopic evaluations of the liver revealed CCl4-induced lesions and related toxic manifestations that were minimal in the liver of rats pretreated with extracts at the dose of 400 mg per kg b.w. The results suggest that the use of G. cruciata extracts has a merit as a potent candidate in protecting the liver against chemical induced toxicity.

Hydroxytyrosol prevents diet-induced metabolic syndrome and attenuates mitochondrial abnormalities in obese mice

A Mediterranean diet rich in olive oil has profound influence on health outcomes including metabolic syndrome. However, the active compound and detailed mechanisms still remain unclear. Hydroxytyrosol (HT), a major polyphenolic compound in virgin olive oil, has received increased attention for its antioxidative activity and regulation of mitochondrial function. Here, we investigated whether HT is the active compound in olive oil exerting a protective effect against metabolic syndrome. In this study, we show that HT could prevent high-fat-diet (HFD)-induced obesity, hyperglycemia, hyperlipidemia, and insulin resistance in C57BL/6J mice after 17 weeks supplementation. Within liver and skeletal muscle tissues, HT could decrease HFD-induced lipid deposits through inhibition of the SREBP-1c/FAS pathway, ameliorate HFD-induced oxidative stress by enhancing antioxidant enzyme activities, normalize expression of mitochondrial complex subunits and mitochondrial fission marker Drp1, and eventually inhibit apoptosis activation. Moreover, in muscle tissue, the levels of mitochondrial carbonyl protein were decreased and mitochondrial complex activities were significantly improved by HT supplementation. In db/db mice, HT significantly decreased fasting glucose, similar to metformin. Notably, HT decreased serum lipid, at which metformin failed. Also, HT was more effective at decreasing the oxidation levels of lipids and proteins in both liver and muscle tissue. Similar to the results in the HFD model, HT decreased muscle mitochondrial carbonyl protein levels and improved mitochondrial complex activities in db/db mice. Our study links the olive oil component HT to diabetes and metabolic disease through changes that are not limited to decreases in oxidative stress, suggesting a potential pharmaceutical or clinical use of HT in metabolic syndrome treatment.

Effect of potassium deficiency on antioxidant status and cadmium toxicity in rice seedlings.

BackgroundCadmium (Cd) is one of the most toxic heavy metals and inhibits physiological processes of plants. Potassium (K) is an essential macronutrient in plants. K deficiency and Cd stress represent two different abiotic stress conditions that occur in the field simultaneously. In this study, effects of K deficiency on antioxidant status and Cd toxicity in rice seedlings were investigated.ResultsK deficiency significantly decreased K concentration in shoots and roots. However, fresh weight and dry weight of rice seedlings were not affected by K deficiency. The activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, glutathione reductase, and catalase) in K-deficient leaves were higher than respective control leaves. However, K deficiency had no effect on the content of antioxidants (ascorbate and glutathione). Cd toxicity was judged by the decrease in biomass production, chlorosis, and induction of oxidative stress. Based on these criteria, we demonstrated that K deficiency protected rice seedling from Cd stress. Moreover, chlorophyll concentration was higher in K-deficient shoots and roots than their respective control shoots and roots.ConclusionsOur results indicated that K deficiency protects rice seedlings from Cd toxicity. This protective effect of K deficiency is mainly due to enhanced antioxidant enzyme activities but not inhibition of Cd uptake.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-54-2) contains supplementary material, which is available to authorized users.

Low‐temperature conditioning induces chilling tolerance in ‘Hayward’ kiwifruit by enhancing antioxidant enzyme activity and regulating en‐dogenous hormones levels

To understand the mechanisms leading to the enhanced chilling tolerance of kiwifruit by low-temperature conditioning (LTC, 12 °C for 3 days), this study investigated the effect of LTC on chilling tolerance and changes in antioxidant enzyme activities and endogenous hormones. LTC significantly alleviated chilling injury in kiwifruit. Fruits treated with LTC maintained lower respiration and ethylene production and higher firmness. Furthermore, this treatment inhibited the accumulation of malondialdehyde, superoxide radicals and hydrogen peroxide and the increase in membrane permeability and increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and peroxidase under chilling stress. The treatment also maintained higher levels of endogenous abscisic acid (ABA), indole-3-acetic acid (IAA) and zeatin riboside (ZR), lower gibberellic acid (GA3) levels and higher ABA/GA3 and ABA/IAA ratios. The results suggested that LTC alleviated chilling injury in kiwifruit by improving antioxidant enzyme activities and maintaining higher levels of endogenous ABA, IAA and ZR, lower GA3 levels and higher ABA/GA3 and ABA/IAA ratios.

Protective role of phosphatidylcholine against cisplatin-induced renal toxicity and oxidative stress in rats

Although cisplatin is widely used in the treatment of cancers, clinical use of cisplatin is limited due to its nephrotoxicity. Pathophysiological mechanism of cisplatin-induced renal toxicity is a complex process and has not been fully understand. Reactive oxygen species (ROS) and oxidative stress have been presumed to be involved in this damage process. Phosphatidylcholine (PC) has antioxidant effect and prevents oxidative stress. Therefore, the present study aimed to investigate potential protective effects of PC on cisplatin-induced renal damage in rat. We examined the protective effects of PC on cisplatin-induced renal damage by assessment of serum creatinine, BUN, lipid peroxidation, total glutathione, glutathione peroxidase activity, catalase activity, superoxide dismutase activity and histophathological changes. PC ameliorated cisplatin-induced increases in serum creatinine, urea and oxidative stress. PC also decreased tubular degeneration and hypertrophy of glomeruli. PC may have a protective effect against cisplatin-induced nephrotoxicity in rats via enhancing antioxidant enzyme activity.

Protective effect of Cnestis ferruginea and its active constituent on scopolamine-induced memory impairment in mice: A behavioral and biochemical study

Context: Cnestis ferruginea Vahl ex DC (Connaraceae) (CF) is used in traditional African medicine in the management of CNS disorders. The degeneration and dysfunction of cholinergic neurons is closely associated with the cognitive deficits of Alzheimer’s disease (AD) and oxidative stress has been implicated in its pathogenesis. However, the influence of C. ferruginea on the cholinergic system and oxidative stress parameters has not been explored.Objective: The present study investigates the effect of methanol root extract of C. ferruginea and its active constituent amentoflavone (CF-2) on memory, oxidative stress and acetylcholinesterase (AChE) activity in scopolamine-induced amnesia.Materials and methods: Mice were orally treated with CF (25–200 mg/kg), CF-2 (6.25–25 mg/kg) for three days and memory impairment was induced by intraperitoneal injection of scopolamine (3 mg/kg). Memory function was evaluated by passive avoidance and Morris water maze tests. Biochemical parameters of oxidative stress and cholinergic function were estimated in brain after the completion of behavioral studies.Results: Scopolamine caused memory impairment along with increased AChE activity and oxidative stress in mice brain. Oral administration of CF and CF-2 significantly prevented scopolamine-induced memory impairment, inhibited AChE and enhanced antioxidant enzyme activity in the brain following scopolamine injection as compared to vehicle administration in scopolamine (i.p.)-treated mice that were comparable to the effect of tacrine.Discussion and conclusion: The study demonstrated that C. ferruginea and its constituent have significant protective effect against scopolamine-induced memory deficits in mice that can be attributed to their antioxidant and antiAChE activity.

Bioactivity of selenium-enriched exopolysaccharides produced by Enterobacter cloacae Z0206 in broilers

To investigate effects of Se-enriched exopolysaccharides (Se-ECZ-EPS) produced by Enterobacter cloacae Z0206 on growth performance, antioxidant status and immune function, 240 broilers were randomly assigned into five groups: the control group was fed a basal diet supplemented with 0.15mg/kg Se (Na2SeO3), and the other four groups were fed with diets supplemented with Se-ECZ-EPS at 280, 560, 840 and 1120mg/kg, respectively. Administration of Se-ECZ-EPS (840 and 1120mg/kg) significantly increased average daily gain, decreased feed/gain ratio and enhanced antioxidant enzyme activities. Serum cytokine concentrations showed positive responses in birds treated with 560 and 1120mg/kg Se-ECZ-EPS. Serum antibody titers against Newcastle disease virus in birds treated with 840mg/kg Se-ECZ-EPS were significantly increased. These results suggested that Se-ECZ-EPS could enhance antioxidant status and immune function, and could be developed to a potentiator of the immune response in broilers, with the 840mg/kg addition level being the most effective.

Silicon mediates arsenic tolerance in rice (Oryza sativa L.) through lowering of arsenic uptake and improved antioxidant defence system

Arsenic (As) contamination of paddy rice in South and South-East Asia has raised much concern as rice is the subsidence diet for millions. Two contrasting rice (Oryza sativa L.) cultivars i.e. Triguna (As tolerant) and IET-4786 (As sensitive) were grown hydroponically to study the effect of silicon (Si) supplementation on As accumulation, growth, oxidative stress and antioxidative defence system in shoots during arsenite [As(III)] stress. Rice seedlings were exposed to three As(III) levels (0, 10 and 25μM) and three silicic acid levels (0, 0.5 and 1mM Si) in solution culture experiments. Addition of 1mM Si during As(III) exposure significantly lowers shoot As accumulation in both the cultivar, but more prominently in Triguna (P≤0.01) than IET-4786 (P≤0.05). However, addition of Si during As(III) stress had no significant effect on shoot length and dry weight (P<0.01) of both the cultivars, compared to their As(III) treated plants. In contrast to IET-4786 (P≤0.05), Triguna tolerated As induced oxidative stress through elevated level of cysteine, enhanced antioxidant enzymes activities and their isozymes. Upon Si supplementation lower conglomeration of oxidative stress parameters viz., superoxide and peroxide radicals, lipid peroxidation and electrolyte leakage coincides with increased antioxidants activities and enhanced level of thiols, more effectively in shoots of Triguna than IET-4786 during As(III) stress (P≤0.05). In conclusion, 1mM Si addition, significantly ameliorates As induced oxidative stress in Triguna cultivar by lowering the As accumulation and improving antioxidant and thiolic system compared to IET-4786, implying genotypic differences with Triguna being less susceptible to stress dependent membrane lipid peroxidation.

Synergestic Effect of Milk Thistle and Grape Seed Extracts on the Recovery of Fumonisin b1 Toxicity in Rats.

Fumonisin B1 (FB1) is a mold metabolite produced by Fusarium species that is frequently found in corn worldwide. It is toxic to both liver and kidney. Hepatotoxicity was induced in rats by feeding them FB1 contaminated corn. Evidence of hepatotoxicity was observed after 60 days by an increase in the plasma activity of alanine aminotransferase (ALT), where that elevation reached 78 % (p = 0.000), in comparison with the control group. Treatment with milk thistle (S), or grape seeds (G) extracts or both (S+G) was found to return the ALT level back to normal. FB1, drastically depleted glutathione peroxidase (GpX) to 48%, while treatment with S,G, and S+G could elevate the GpX by 76%, 76% and 35% respectively. Lipid peroxidation represented by malondialdehyde was elevated significantly to 137%. On the other hand, the treated groups (S, G, and S+G) have altered the levels down to 47%, 42%, and 29% respectively. In addition to the hepatotoxicity of FB1, the kidney function was investigated too, where the creatinine level was elevated to 65%. The treatment by S, G and S+G lowered the level down to 16%, 15%and 2%. Serum activity of urea was significantly elevated to 30%, the treated group G could significantly reduce it to 23% while the treated groups S and S+G could not reduce that elevation in urea level. Histological examination of liver sections confirmed the serum analysis, where significant improvements were observed in all treated groups in comparison with the liver sections of rats fed on FB1. These improvements might be due to their ability to lower serum total cholesterol and low- density lipoprotein cholesterol levels as well as slowing the lipid peroxidation process by enhancing antioxidant enzyme activity.

The neuroprotective effects of intraperitoneal injection of hydrogen in rabbits with cardiac arrest

ObjectiveThe purpose of this study was to investigate the neuroprotective effects of intraperitoneal injection of hydrogen (H2) in rabbits with cardiac arrest (CA). MethodsA rabbit model of CA was established by the delivery of alternating current between the esophagus and chest wall to induce ventricular fibrillation. Before CA, the animals were randomly divided into four groups: a sham group (no CA), a CA group, a CA+low dose (10ml/kg) H2 group (CA+H2 group 1), and a CA+high dose (20ml/kg) H2 group (CA+H2 group 2). In the first experiment, animals were observed for 72h after the restoration of spontaneous circulation (ROSC). The neurological scores were assessed at 24, 48 and 72h after ROSC. The rabbits that survived until 72h were sacrificed using an overdose of anesthetic, and the brain tissues were collected and Nissl-stained to observe nerve cell damage in the hippocampal CA1 area. In addition, TUNEL assay was performed to detect apoptosis. In the second experiment, animals were observed for 6h after ROSC. Blood samples and brain hippocampal tissues were collected, and differences in oxidative stress indicators were compared among the four groups. ResultsIntraperitoneal injection of H2 improved the 72-h survival rate and neurological scores, reduced neuronal injury and inhibited neuronal apoptosis. Intraperitoneal injection of H2 reduced oxidative stress indicators in the plasma and hippocampal tissues and enhanced antioxidant enzyme activity. No significant difference was observed between the two CA groups treated with different doses of H2. ConclusionsIntraperitoneal injection of H2 is a novel hydrogen administration method and can reduce cerebral ischemia-reperfusion injury and improve the prognosis of cardiopulmonary cerebral resuscitation in a rabbit model of CA.

Hot Air Treatment Improved the Chilling Resistance of Loquat Fruit under Cold Storage

Absract Hot air treatment at 38C for 36 h significantly improved the chilling resistance of loquat during 4C storage for 28 days, appeared as higher extractable juice, lower firmness, internal browning and decay development. This treatment reduced hydrogen peroxide level by improving superoxide dismutase, ascorbate peroxidase, glutathione reductase and catalase activities, then maintained higher unsaturated/saturated fatty acid ratio and lower permeability of membrane at the end of storage. It also reduced phenylalanine ammonia lyase, peroxidase and polyphenol oxidase activities, and total phenolic content to control internal browning and lignin synthesis; the enhanced antioxidant enzyme activities also contribute to control them. Meanwhile, heat-treated fruits showed significantly higher levels of water- and chelator-soluble pectins and lower Na2CO3-soluble pectin than controls at the later of storage. It was suggested that the improved chilling resistance by heat treatment maybe mainly due to the enhanced scavenging capacity of oxygen species and solubilization of cell wall polysaccharides. Practical Applications Loquat fruit is very perishable because of microbial decay and mechanical damage after harvest. Low-temperature storage is an effective method to control pathogenic decay and preserve quality. However, loquat fruit are chilling-sensitive, and chilling injury limits the storage period and shelf-life. This work investigated the effects of hot air treatment on the chilling resistance of loquat fruit. It was found that heat treatment at 38C for 36 h can enhance the chilling resistance, reduce the chilling symptoms and maintain higher quality after storage at 4C for 28 days. The information obtained from this study suggested that this heat treatment may be a suitable method for the commercial application on loquat fruits.

Evaluation of anti-diabetic effect of Trigonella foenum graecum Linn. Leaf extract in streptozotocin induced diabetic rats

Trigonella foenum graecum leaves are widely used as a vegetable throughout India and have a long history of medicinal use in Ayurveda and Chinese medicine. Even though the leaves of this plant are used in diabetes mellitus, there have been no in vivo studies to prove its efficacy. The aim of this study was to know the efficacy of ethanol extract of T. foenum graecum leaves on blood glucose levels, antioxidant enzymes, islets cells of pancreas, creatinine and urea levels in normal and streptozotocin induced diabetic rats. Diabetes was induced by streptozotocin (45 mg/kg b.w. in 0.9 % cold saline). Two doses (250 and 500 mg/kg b.w.) of the extracts were administered in the study. The activity was compared with the reference standard glibenclamide (0.5 mg/kg b.w.) for various biochemical and histopathological parameters. The data was analysed by one way ANOVA followed by Turkey’s post hoc test. The activity of the extract in reducing blood glucose, creatinine and urea levels, in enhancing antioxidant enzyme activity and restoring and regenerating islet cells of pancreas was comparable to glibenclamide. The result suggests that ethanol leaf extract of T. foenum graecum possesses significant antidiabetic property.

Fermentative quality of purple rice (Oryza sativa L.) silage and its effects on digestibility, ruminal fermentation and oxidative status markers in sheep: A preliminary study

AbstractSome anthocyanins have been reported to exhibit antioxidant activity and to enhance antioxidant enzyme activity. The aim of this study was to determine the fermentative quality of purple rice, which is abundant in anthocyanin, and its effects on digestibility, ruminal fermentation and oxidative status markers in sheep. The whole crop silages of purple and control rice were prepared in drum silos after the materials were chopped and lactic acid bacteria was inoculated. These were followed by a feeding trial using eight wethers in a 2 × 2 crossover design. Both the purple and control rice silages showed excellent fermentative qualities. Although the purple rice silage contained abundant anthocyanin, it had inadequate nutritional values in comparison to the control rice silage, including higher levels of fiber fractions, lower nutrient digestibility and lower production of ruminal volatile fatty acids. The feeding of the purple rice silages led to an elevation in plasma activity of superoxide dismutase, which is an important antioxidant enzyme. The results of this study suggest that purple rice may become a source of anthocyanin to improve oxidative status in ruminants. To achieve that, however, a new variety of purple rice with good nutritional value is needed for practical use as a ruminant feed.

Effect of salinity, salicylic acid, silicium and ascorbic acid on lipid peroxidation, antioxidant enzyme activity and fatty acid content of sunflower

In order to study effects of salinity, salicylic acid, silicium and ascorbic acid on lipid peroxidation, antioxidant enzyme activity and fatty acid content of sunflower, a pot culture experiment was conducted under controlled conditions. Sunflower seeds were sown into the pots and irrigated by Hoagland’s solution. Salinity was induced by adding sodium chloride (NaCl) into nutrient solution. In addition, different concentration of salicylic acid, silicium and ascorbic acid were made by dissolving salicylic acid, silicium and ascorbic acid into the solution to reach certain concentrations. Treatments included 0, 100, 200 and 300 mM NaCl, 1 and 2 mM salicylic acid, 2 and 4 mM silicium and 0 and 4 mM ascorbic acid. The results showed that salinity significantly have effect on all assayed traits. Salinity significantly increased malondialdehyde content and antioxidant enzyme activity, but decreased protein content and fatty acid percentage. Similarly, salicylic acid enhanced antioxidant enzyme activity and decreased protein and oleic acid percentage. Among enzymes, only superoxide dismutase was affected by silicium application and its activity increased. Furthermore, silicium application led to a decrease in protein content. Lipid peroxidation and enzyme activity significantly decreased on account of ascorbic acid application. On the other hand, the interaction between salinity and ascorbic acid was significant on malondialdehyde and antioxidant enzymes activity. Ascorbic acid application significantly decreased malondialdehyde production and enzyme activity under salinity stress. In general, we concluded that ascorbic acid application into the nutrient solution can diminish adverse effect of salinity and alleviate enzyme activity via scavenging of reactive oxygen species. Key words: Ascorbic acid, salicylic acid, silicium, salinity, sunflower.

Postharvest application of salicylic acid enhanced antioxidant enzyme activity and maintained quality of peach cv. ‘Flordaking’ fruit during storage

Peach fruit has become very popular among stone fruits in Pakistan with increasing production. The main area of peach production in Pakistan is Swat, in the northern part of the country. Significant fruit losses occur during harvest temporary storing, and transport to market. Objective of this study was to determine the effectiveness of salicylic acid (SA) at different concentrations (0, 0.5, 1.0, 1.5 or 2.0mmolL−1) on postharvest life of peach fruit (cv. ‘Flordaking’). Fruits were treated with SA immediately after harvest and stored at 0°C for 5 weeks. Generally, all of the SA concentrations gave a higher activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) during five weeks of storage. The 2.0mmol SA concentrations showed the highest activity for enzymatic antioxidants. The fruit browning enzyme polyphenol oxidase (PPO) activity decreased in SA treated fruits. SA treated fruits exhibited higher radical scavenging activity (RSA) than control fruits. The SA 2.0mmol concentration resulted in increased fruit weight, firmness, and decreased juice pH. The higher concentration of SA (2.0mmol) proved to be the most effective in keeping peach fruit quality intact along with maintained skin color and delayed fruit surface decay during storage. Conclusively amongst all treatments SA 2.0mmol application exhibited maximum antioxidants enzymatic activities, minimum weight loss, stored firmness and decreased pH during storage period.

Effect of 1-methylcyclopene on senescence and quality maintenance of green bell pepper fruit during storage at 20 °C

The effect of 1-methylcyclopropene (1-MCP) on senescence and quality maintenance of green bell pepper fruit was investigated. To explore the optimum concentration of 1-MCP to delay senescence, pepper fruit were treated with 0.5, 1.0 or 1.5μLL−1 1-MCP and then stored for 10d at 20°C. The results showed that the application of 1-MCP at 1.0μLL−1 was most effective in delaying senescence, manifested as chlorophyll degradation and increase in weight loss. 1-MCP treated peppers had higher levels of chlorophyll, protein and vitamin C and lower respiration rates and ethylene production compared with that in control peppers. In addition, 1-MCP enhanced activities of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase and levels of polyamines including putrescine, spermidine and spermine. These results suggested that the delaying senescence of green bell pepper by 1-MCP treatment is associated with enhanced antioxidant enzyme activities and polyamine contents.

Polysaccharides in Laminaria japonica (LP): Extraction, physicochemical properties and their hypolipidemic activities in diet-induced mouse model of atherosclerosis

► Determine extraction conditions of polysaccharide from Laminaria japonica (LP). ► Reveal the method to remove proteins from LP. ► Determine the precipitation condition of LP by ethanol. ► Investigate physicochemical properties of LP1, LP2 and LP3 fractionated from LP. ► Evaluate the hypolipidemic activity of crude LP. The crude polysaccharides of Laminaria japonica (LP) were extracted with the optimal conditions as follows: raw materials to water 1:50 (w/v), extraction temperature 60 °C and extraction time 60 min. Trypsinase (6 U/ml) in combination with sevag reagent was beneficial to the removal of proteins from crude LP. Three fractions of LP1, LP2 and LP3 were obtained from the crude LP by using a final concentration of 40%, 60% and 80% ethanol to precipitate in turn. The three fractions showed obvious differences in monosaccharide compositions, molecular weight distribution, viscosity, IR spectroscopy and glycosyl linkages. In comparison with the control group, crude LP at a dose of 400 mg/kg/day caused a reduction in total serum cholesterol, triglycerides, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol in serum by 80.6%, 63.4%, 43.8% and 79.8%, respectively. Moreover, crude LP exhibited good potential of enhancing antioxidant enzyme activities in serum of atherosclerosis mice.

Comparative Studies on the Physiobiochemical, Enzymatic, and Ionic Modifications in Salt-tolerant and Salt-sensitive Citrus Rootstocks under NaCl Stress

A study was conducted to investigate the morphological, physiobiochemical, enzymatic, and ionic differences among four cultivated citrus (Citrus sp.) rootstocks with different salt tolerances. Two salt-tolerant rootstocks [Rangpur lime (C. limonia) and Rubidoux (C. trifoliata)] and two salt-sensitive rootstocks [Carrizo citrange (Citrus sinensis × C. trifoliata) and Sanchton citrumello (C. trifoliata × C. paradisi)], were subjected to NaCl stress in greenhouse conditions. The 9-month-old plants were exposed to four different NaCl levels (0, 30, 60, or 90 mm) in sand culture for 3 months. Plant biomass (fresh weight, dry weight, root length, shoot length, and leaf thickness), physiological attributes [number of stomata, stomatal size, number of epidermal cells, photosynthesis rate, stomatal conductance (gS), water use efficiency, and transpiration rate]. and ion content (Na+, K+, Ca+2, Mg+2, and Cl–) were adversely affected by salt stress, but salt-tolerant cultivars were comparatively less affected. Salt stress also enhanced antioxidant enzyme activity (superoxide dismutase, catalase, and peroxidase), particularly in salt-tolerant cultivars. The salt-sensitive cultivars accumulated the greatest content of Na+ and Cl– in their leaves, whereas the salt-tolerant cultivars accumulated the greatest content of Na+ and Cl– in their roots, an adaptation to combat the highly saline conditions. Overall, it was concluded that the salt tolerance of rootstocks is associated with a greater antioxidant enzyme activity and differing accumulation patterns of Na+, K+, Cl–, Mg+2, and Ca+2 in leaves and roots; these can be considered potential indicators of a cultivar's sensitivity to salt stress.

Chronic treatment with long acting phosphodiesterase-5 inhibitor tadalafil alters proteomic changes associated with cytoskeletal rearrangement and redox regulation in Type 2 diabetic hearts

Diabetic patients are prone to metabolic perturbations that progressively contribute to structural, functional and proteomic alterations in the myocardium. Phosphodiesterase-5 (PDE-5) inhibitors exhibit cardioprotective effects against ischemic/reperfusion injury, however the effects of chronic administration of PDE-5 inhibitors, particularly under diabetic conditions, remain unknown. Hence, the present study was designed to identify novel protein targets related to long-acting PDE-5 inhibitor tadalafil-induced cardioprotection in diabetes. Using two-dimensional differential in-gel electrophoresis with 3 CyDye labeling and MALDI-TOF/TOF tandem mass spectrometry we identified alterations in the expressions of cardiac proteins in diabetic db/db mice treated with tadalafil. Tadalafil reversed the coordinated alterations of cytoskeletal/contractile proteins such as myosin light chain (MLY) 2 and 4, myosin heavy chain α and myosin-binding protein C which contributes to contractile dysfunction. The expression of intermediate filament protein vimentin and extra-cellular matrix proteins like cysteine and glycine rich protein-3 and collagen type VI α were upregulated in db/db mice indicating cardiac remodeling in diabetes. These detrimental proteomic alterations were reflected in cardiac function which were reversed in tadalafil treated mice. Tadalafil also enhanced antioxidant enzyme glutathione S-transferase Kappa-1 (GSKT-1) and downregulated redox regulatory chaperones like heat shock protein 8 (HSPA8), and 75kD glucose regulatory protein (75GRP). Furthermore, tadalafil treatment significantly attenuated GSSG/GSH ratio and improved the metabolic status of db/db mice. Chronic treatment with tadalafil in db/db mice modulates proteins involved in cytoskeletal rearrangement and redox signaling of the heart, which may explain the beneficial effects of PDE-5 inhibition in diabetes.

Gallotannin Suppresses Calcium Oxalate Crystal Binding and Oxalate-Induced Oxidative Stress in Renal Epithelial Cells

Calcium oxalate monohydrate (COM) crystals bind avidly to the surface of proliferating and migrating renal endothelial cells, perhaps a key event in kidney stone formation. Oxalate-induced pre-oxidative stress can further promote crystal attachment cells. Natural products including gallotannins found in green teas have been studied as potentially novel treatments to prevent crystal retention and kidney stone formation. Gallotannin significantly inhibited COM crystal growth and binding to Madin-Darby Canine Kidney Cells type I (MDCK I) renal epithelial cells at non-toxic concentrations. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that gallotannin significantly attenuated oxalate-induced mRNA and protein expressions of monocyte chemoattractant protein 1 (MCP-1), osteopontin (OPN), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit p22(phox) and p47(phox) in human primary renal epithelial cells (HRCs). Gallotannin also reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) as well as enhanced antioxidant enzyme superoxide dismutase (SOD) activity in oxalate treated HRCs. Taken together, our findings suggest that gallotannin can contribute to nephrolithiasis prevention via direct effects on renal epithelial cells including suppression of COM binding and MCP-1 and OPN expression, along with augmenting antioxidant activity.