Astaxanthin Attenuates Early Acute Kidney Injury Following Severe Burns in Rats by Ameliorating Oxidative Stress and Mitochondrial-Related Apoptosis

Early acute kidney injury (AKI) is a devastating complication in critical burn patients, and it is associated with severe morbidity and mortality. The mechanism of AKI is multifactorial. Astaxanthin (ATX) is a natural compound that is widely distributed in marine organisms; it is a strong antioxidant and exhibits other biological effects that have been well studied in various traumatic injuries and diseases. Hence, we attempted to explore the potential protection of ATX against early post burn AKI and its possible mechanisms of action. The classic severe burn rat model was utilized for the histological and biochemical assessments of the therapeutic value and mechanisms of action of ATX. Upon ATX treatment, renal tubular injury and the levels of serum creatinine and neutrophil gelatinase-associated lipocalin were improved. Furthermore, relief of oxidative stress and tubular apoptosis in rat kidneys post burn was also observed. Additionally, ATX administration increased Akt and Bad phosphorylation and further down-regulated the expression of other downstream pro-apoptotic proteins (cytochrome c and caspase-3/9); these effects were reversed by the PI3K inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002. Moreover, the protective effect of ATX presents a dose-dependent enhancement. The data above suggested that ATX protects against early AKI following severe burns in rats, which was attributed to its ability to ameliorate oxidative stress and inhibit apoptosis by modulating the mitochondrial-apoptotic pathway, regarded as the Akt/Bad/Caspases signalling cascade.     

Amelioration of Hexachlorocyclohexane-Induced Oxidative Stress by Amaranth Leaves in Rats

The effect of prefeeding dehydrated amaranth leaves (AL), at 10 and 20% levels on hexachlorocyclohexane (HCH)-induced free radical stress in rat liver was evaluated. The HCH-induced raise in malonadialdehyde (MDA), conjugated dienes and hydroperoxides was diminished by AL. The effect of AL was highly effective with respect to reduction in these cytotoxic products, especially at 20% level. AL intake resulted in a significant increase in hepatic vitamin A and glutathione (GSH). However, the AL consumption reduced hepatic tocopherols. Feeding of AL at 10%level increased the hepatic glucose-6-phosphate dehydrogenase (G-6-PDH) activity while that at 20% level increased the hepatic glutathione reductase (GSSGR) as well, in addition to G-6-PDH. Amaranth leaves at 10 and 20% levels of feeding reduced the hepatic superoxide dismutase and glutathione peroxidase (GSH-Px) activities. The pre-feeding of AL resulted in the reversal of HCH-induced alteration in GSH-Px and G-6-PDH activities. The significant reduction in the level of glutathione S-transferase brought about by HCH was restored to control level by feeding 20% AL. It is concluded that the consumption of AL at 20% level produces reduction in the HCH-induced impairment of antioxidant status in rat liver.     

Astaxanthin Attenuates the Apoptosis of Retinal Ganglion Cells in db/db Mice by Inhibition of Oxidative Stress

Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). It is an ocular manifestation of systemic disease, which affects up to 80% of all patients who have had diabetes for 10 years or more. The genetically diabetic db/db mouse, as a model of type-2 diabetes, shows diabetic retinopathy induced by apoptosis of RGCs. Astaxanthin is a carotenoid with powerful antioxidant properties that exists naturally in various plants, algae and seafood. Here, astaxanthin was shown to reduce the apoptosis of RGCs and improve the levels of oxidative stress markers, including superoxide anion, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity in the retinal tissue of db/db mouse. In addition, astaxanthin attenuated hydrogen peroxide(H₂O₂)-induced apoptosis in the transformed rat retinal ganglion cell line RGC-5. Therefore, astaxanthin may be developed as an antioxidant drug to treat diabetic retinopathy.     

Protective Effect of Potato Peel Powder in Ameliorating Oxidative Stress in Streptozotocin Diabetic Rats

The potential of dietary potato peel (PP) powder in ameliorating oxidative stress (OS) and hyperglycemia was investigated in streptozotocin (STZ)-induced diabetic rats. In a 4-week feeding trial, incorporation of potato peel powder (5 and 10%) in the diet of diabetic rats was found to significantly reduce the plasma glucose level and also reduce drastically the polyuria of STZ diabetic rats. The total food intake was significantly reduced in the diabetic rats fed 10% PP powder compared to the control diabetic rats. However, the body weight gain over 28 days was nearly four times greater in PP powder supplemented diabetic rats (both at 5 and 10%) compared to the control diabetic rats. PP powder in the diet also decreased the elevated activities of serum transaminases (ALT and AST) and nearly normalized the hepatic MDA and GSH levels as well as the activities of specific antioxidant enzymes in liver of diabetic rats. The result of these studies clearly establishes the modulatory propensity of PP against diabetes induced alterations. Considering that potato peels are discarded as waste and not effectively utilized, these results suggest the possibility that PP waste could be effectively used as an ingredient in health and functional food to ameliorate certain disease states such as diabetes.     

Effects of the Consumption of Caffeinated and Decaffeinated Instant Coffee Beverages on Oxidative Stress Induced by Strenuous Exercise in Rats

Many authors attribute the antioxidant activity of brewed coffee to its caffeine content. In addition, caffeine intake has been associated with increased performance during physical exercise. This study analyzed the in vivo effects of drinking caffeinated and decaffeinated instant coffee (8%, w/v) on oxidative stress and antioxidant enzyme activity in the anterior tibialis muscles of rats subjected to intense exercise. It was observed that exercise induced lipid peroxidation (estimated using malondialdehyde) and protein oxidation (evaluated by determining the formation of carbonyl groups) in the muscle (P < 0.05). Decaffeinated instant coffee and caffeine solution did not exhibit antioxidant activity in vivo. Caffeinated instant coffee beverage intake did not induce changes in superoxide dismutase and glutathione peroxidase activities but was able to diminish lipid and protein oxidation in the anterior tibialis muscles of rats after exercise (P < 0.05), contributing to a reduction in the oxidative stress triggered by exercise.     

Influence of the Form of Administration of Chlorogenic Acids on Oxidative Stress Induced by High fat Diet in Rats

Green coffee is one of health-promoting supplements of the diet, applied in the form of either preparations or enriched food products. Its positive impact is manifested by mitigation of the development of certain tumors, e.g., in the colon and liver, and type 2 diabetes. Many studies proved that chlorogenic acids are the main active substances in green coffee. The bioavailability of these compounds depends among others on their interactions with other components of the diet, mainly proteins. When they are used as food ingredients, their bioavailability is additionally decreased because of the decomposition or interactions with other ingredients during food processing. The undesirable changes may be limited among others by microencapsulation, for example with β-cyclodextrin. In this study, rats were fed the pro-oxidative high fat diet, which was supplemented with chlorogenic acids from green coffee that were used in four forms such as: a purified extract, complexes of chlorogenic acids and β-cyclodextrin, and bread supplemented with either the extract or the β-cyclodextrin inclusion complex. Chlorogenic acids added to bread because of the reduced absorption from the crumb in the small intestine and increased passage to the colon, contributed to the beneficial modification of enzymatic activities of intestinal microbiota. When added directly to the diet, they contributed to the improved antioxidant status in the liver and kidneys, lowered glucose level and increased HDL level. A high ratio of reduced to oxidized glutathione in the liver and a high concentration of antioxidants in the blood serum were observed after administration of chlorogenic acids in the form of inclusion complexes with β-cyclodextrin, indicating that microencapsulation increased their bioaccessibility due to the limited interactions with other components of the diet.     

Levo-Carnitine Reduces Oxidative Stress and Improves Contractile Functions of Fast Muscles in Type 2 Diabetic Rats

Background: Metabolic derangements in type 2 diabetes mellitus (T2DM) are likely to affect skeletal muscle contractile functions adversely. Levo-carnitine improves muscle contractile functions in healthy humans and rats and corrects metabolic derangements in T2DM. Therefore, it is likely to improve muscle contractile functions in T2DM as well. This study was designed to determine the effect of levo-carnitine on serum levo-carnitine levels, oxidative stress and contractile parameters of fast muscle in T2DM. Methods: Ninety Sprague-Dawley rats were randomly divided into three equal groups. Healthy rats served as the controls, while T2DM was induced in diabetic and carnitine groups. The carnitine group was administered levo-carnitine 200 mg/kg/day intraperitoneally for 6 days. At 28^th day, extensor digitorum longus muscles were removed and their functions were assessed using iWorx data acquisition unit (AHK/214). Blood obtained by intra-cardiac sampling at 28^th day was used for estimation of serum malondialdehyde (MDA) and levo-carnitine levels. Results: Maximum isometric twitch tension, time-to-peak twitch tension and time-to-relax to 50% of the peak twitch tension were not significantly different amongst the groups. Carnitine group showed significant improvement in maximum fused tetanic tension, maximum fused tetanic tension after fatigue protocol and recovery from fatigue after 5 minutes of rest period compared to the diabetic group. Serum MDA levels were reduced, while serum levo-carnitine levels were elevated significantly in carnitine group as compared to the diabetic group. Conclusion: Levo-carnitine supplementation increases serum levo-carnitine levels which decreases oxidative stress. This action improves contractile force but delays fatigue in fast muscles of diabetic rats. Key Words: Type 2 diabetes mellitus (T2DM), Levo-carnitine, Fast muscles, Contractile functions, Oxidative stress     

大豆异黄酮和皂甙对大鼠肝癌诱发初期肝脏氧化应激的干预作用

利用Solt-Faber法制备大鼠肝癌初期模型,同时以100 mg.kg-1大豆异黄酮和皂甙干预42 d。然后处死动物,制备肝匀浆及肝线粒体提取液。以比色法测定丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)、γ-谷酰胺转肽酶(γ-GT)、谷胱甘肽-S-转移酶(GST)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)活性及丙二醛(MDA)含量。结果表明,大豆异黄酮和皂甙能降低肝癌发生初期大鼠肝脏ALT、AST、γ-GT和GST活性,升高肝脏及肝线粒体SOD、CAT、GSH-PX活性和降低MDA水平。提示,大豆异黄酮和皂甙具有减轻肝癌发生初期大鼠肝细胞损伤,降低其氧化应激的作用。此作用有助于预防肝癌的发生。     

Pelagia noctiluca (Scyphozoa) Crude Venom Injection Elicits Oxidative Stress and Inflammatory Response in Rats

Cnidarian toxins represent a rich source of biologically active compounds. Since they may act via oxidative stress events, the aim of the present study was to verify whether crude venom, extracted from the jellyfish Pelagia noctiluca, elicits inflammation and oxidative stress processes, known to be mediated by Reactive Oxygen Species (ROS) production, in rats. In a first set of experiments, the animals were injected with crude venom (at three different doses 6, 30 and 60 µg/kg, suspended in saline solution, i.v.) to test the mortality and possible blood pressure changes. In a second set of experiments, to confirm that Pelagia noctiluca crude venom enhances ROS formation and may contribute to the pathophysiology of inflammation, crude venom-injected animals (30 µg/kg) were also treated with tempol, a powerful antioxidant (100 mg/kg i.p., 30 and 60 min after crude venom). Administration of tempol after crude venom challenge, caused a significant reduction of each parameter related to inflammation. The potential effect of Pelagia noctiluca crude venom in the systemic inflammation process has been here demonstrated, adding novel information about its biological activity.     

Effects of a Fish Oil Rich in Docosahexaenoic Acid on Cardiometabolic Risk Factors and Oxidative Stress in Healthy Rats

Omega-3 polyunsaturated fatty acids are associated with a lower risk of cardiometabolic diseases. However, docosahexaenoic acid (DHA) is easily oxidized, leading to cellular damage. The present study examined the effects of an increased concentration of DHA in fish oil (80% of total fatty acids) on cardiometabolic risk factors and oxidative stress compared to coconut oil, soybean oil, and fish oil containing eicosapentaenoic acid (EPA) and DHA in a balanced ratio. Forty healthy male Sprague–Dawley rats were supplemented with corresponding oil for 10 weeks. Supplementation with the fish oil containing 80% DHA decreased plasma fat, plasma total cholesterol and muscle fat compared to the coconut oil and the soybean oil. Increasing concentrations of DHA induced incorporation of DHA and EPA in cell membranes and tissues along with a decrease in ω-6 arachidonic acid. The increase in DHA promoted lipid peroxidation, protein carbonylation and antioxidant response. Taken together, the increased concentration of DHA in fish oil reduced fat accumulation compared to the coconut oil and the soybean oil. This benefit was accompanied by high lipid peroxidation and subsequent protein carbonylation in plasma and in liver. In our healthy framework, the slightly higher carbonylation found after receiving fish oil containing 80% DHA might be a protecting mechanism, which fit with the general improvement of antioxidant defense observed in those rats.     

Supplementation with Spirulina platensis Prevents Damage to Rat Erections in a Model of Erectile Dysfunction Promoted by Hypercaloric Diet-Induced Obesity

Erectile dysfunction (ED) is the inability to achieve and/or maintain a penile erection sufficient for sexual satisfaction. Currently, many patients do not respond to the pharmacotherapy. The effects of a supplementation with Spirulina platensis, were evaluated in a model of ED induced by hypercaloric diet consumption. Wistar rats were divided into groups fed with standard diet (SD) or hypercaloric diet (HD) and supplemented with this alga at doses of 25, 50 or 100 mg/kg. Experimental adiposity parameters and erectile function were analyzed. In SD groups, Spirulina platensis reduced food intake, final body mass and adiposity index, and increased the total antioxidant capacity (TAC) of adipose tissue. However, no change was observed in erectile function. In the HD group, without Spirulina supplementation, a decrease in food intake was observed, in addition to an increase of final body mass, weight gain, adipose reserves, and adiposity index. Additionally, reduction in the number and increase in the latency of penile erection and adipose malondialdehyde levels, as well as a reduction in TCA was noted. Furthermore, cavernous contractility was increased, and the relaxing response was decreased. Interestingly, these deleterious effects were prevented by the algae at doses of 25, 50 and/or 100 mg/kg. Therefore, the supplementation with S. platensis prevents damages associated to a hypercaloric diet consumption and emerges as an adjuvant the prevention of ED.     

The Protect Effects of Chitosan Oligosaccharides on Intestinal Integrity by Regulating Oxidative Status and Inflammation under Oxidative Stress

The aim of this study was to evaluate the effects of the dietary supplementation of chitosan oligosaccharides (COS) on intestinal integrity, oxidative status, and the inflammation response with hydrogen peroxide (H₂O₂) challenge. In total, 30 rats were randomly assigned to three groups with 10 replications: CON group, basal diet; AS group, basal diet + 0.1% H₂O₂ in drinking water; ASC group, basal diet + 200 mg/kg COS + 0.1% H₂O₂ in drinking water. The results indicated that COS upregulated (p < 0.05) villus height (VH) of the small intestine, duodenum, and ileum; mucosal glutathione peroxidase activity; jejunum and ileum mucosal total antioxidant capacity; duodenum and ileum mucosal interleukin (IL)-6 level; jejunum mucosal tumor necrosis factor (TNF)-α level; duodenum and ileum mucosal IL-10 level; the mRNA expression level of zonula occludens (ZO)-1 in the jejunum and ileum, claudin in the duodenum, nuclear factor-erythroid 2-like 2 in the jejunum, and heme oxygenase-1 in the duodenum and ileum; and the protein expression of ZO-1 and claudin in jejunum; however, it downregulated (p < 0.05) serum diamine oxidase activity and D-lactate level; small intestine mucosal malondialdehyde content; duodenum and ileum mucosal IL-6 level; jejunum mucosal TNF-α level; and the mRNA expression of IL-6 in the duodenum and jejunum, and TNF-α in the jejunum and ileum. These results suggested COS could maintain intestinal integrity under oxidative stress by modulating the intestinal oxidative status and release of inflammatory cytokines.     

Protective Effects of Restricted Diet and Antioxidants on Testis Tissue in Rats Fed with High-Fat Diet

Background:

A high-fat diet (HFD) promotes the oxidative stress formation, which in turn has hazardous effects on reproductive system and fertility. The present study examines the potential positive effects of a restricted high-fat diet (RHFD) and antioxidants consumption on sperm parameters and testis tissue in rats.

Methods:

Male rats (n = 48) were divided into four groups (12 in each group): control group (Cont), HFD group, RHFD, and RHFD with astaxanthin and vitamins E and C group (RHFDA). After 12 weeks, serum analysis and sperm parameters study were performed. Sections of fixed testes were stained with Hematoxilin and Eosin to study the histological changes. A one-way ANOVA was used to compare the data.

Results:

HFD fed animals presented significant increase in weight load and serum low density lipoprotein (LDL-C) levels (P < 0.05). The sperm count in RHFD was lower than three other groups (P < 0.05) and sperm motility of RHFDA group was significantly higher than HFD and RHFD groups (P < 0.05). The histological study was showed a significant increase in spermatogonium number in RHFDA compared to three other groups (P < 0.05). The number of spermatocyte I and spermatid in RHFD was significantly (P < 0.05) lower than Cont and HFD groups.

Conclusion:

HFD and obesity can affect sperm parameters and spermatogenesis and antioxidants consumption may improve their quality. Although the RHFD is a benefit way in weight loss and decrease of LDL-C of serum, but it is suggested that is not effective on sperm quality improvement.Key Words: Spermatogenesis, high-fat Diet, Restricted fat diet, Antioxidants, Astaxanthin     

Effect of L-arginine Oral Supplementation on Response to Myocardial Infarction in Hypercholesterolemic and Hypertensive Rats

The well known metabolic functions of L-arginine have been recently increased with the discovery of its role as the substrate for the synthesis of nitric oxide (NO), which has emerged as an endogenous signaling molecule with potential therapeutic implications for cardiovascular disease. Steady-state levels of NO are derived in part from dietary sources. It has been reported that supplementation of L-arginine reduces atherosclerosis in rabbits and reduces the arterial pressure in hypertensive rats. Therefore, we investigated the effect of L-arginine supplementation using a group of induced hypercholesterolemic rats and a group of spontaneously hypertensive rats; the infarcted area in cardiac tissue of both groups was measured during the response to myocardial infarction in the ischemia-reperfusion model. Hypercholesterolemic rats supplemented with 170 mg kg⁻¹ of L-arginine showed a significant (P ≤ 0.05) reduction in total cholesterol (25.2%) and LDL (27.8%). Spontaneously hypertensive rats supplemented with L-arginine presented a significant reduction (20.3%) in mean blood pressure (P ≤ 0.05). The index infarcted area / total heart area, in both: hypercholesterolemic and hypertensive rats supplemented with L-arginine, showed a significant 36% and 29% of cardio protection (P ≤ 0.05) effect, respectively. Dietary supplementation with L-arginine may represent a potentially novel nutritional strategy for the treatment of cardiovascular disease.     

Drought Stress Impairs Grain Yield and Quality of Rice Genotypes by Impaired Photosynthetic Attributes and K Nutrition

正Drought is one of the most prevalent abiotic stresses that adversely affect rice productivity(Petrozza et al, 2014). Rice is very sensitive to drought stress and drought can cause 50% reduction in rice production globally(Yang et al, 2008). To meet the food needs for global population, 63% more agricultural production will be required by the year 2050 than     

绿茶多酚对被动吸烟引起小鼠肺氧化应激的干预研究

研究了绿茶多酚（Green tea polyphenol,GTP）对被动吸烟致小鼠肺部氧化应激损伤的干预作用,并探讨其可能机制。将40只KM雌性小鼠随机分成正常对照C组、被动吸烟模型M组、100βmg·kg^-1 GTP1组、200βmg·kg^-1 GTP2组,每组10只。实验12周结束后处死小鼠,测定其肺质量及血清氧化应激炎症水平;采用荧光定量PCR测定白细胞介素6（IL-6）、白细胞介素33（IL-33）、肿瘤坏死因子-α（TNF-α）和白细胞介素1β（IL-1β）基因表达水平。研究结果表明,与M组相比,灌喂GTP后使得小鼠生存质量、肺形态有明显改观,显著提高小鼠血清T-SOD及GSH-Px活力,显著降低MDA、IL-6、TNF-α表达水平,显著抑制IL-6、IL-33、TNF-α及IL-1β炎性相关基因的表达,灌胃200βmg·kg^-1 GTP比100βmg·kg^-1的GTP作用更加显著。研究发现,GTP可能通过抑制炎性细胞因子表达水平、提高抗氧化能力来保护肺部组织形态与结构的完整,保护被动吸烟对肺部的损害。     

Bioavailability of Phenolic Antioxidants Associated with Dietary Fiber: Plasma Antioxidant Capacity After Acute and Long-Term Intake in Humans

Most studies on bioavailability of phenolic antioxidants are focused in foods and beverages in which they may be easily released from the food matrix, reaching a peak in plasma antioxidant capacity 1–2 h after the intake. However, plant foods contain significant amounts of polyphenols associated with dietary fiber. The aim of the present work was to seek the bioavailability of total phenolic antioxidants associated with dietary fiber by measuring plasma antioxidant capacity in human volunteers. An acute intake of 15 g of a dietary fiber rich in associated phenolic antioxidants in healthy volunteers (n = 10) increased antioxidant capacity of plasma in relation to a control group (n = 4), becoming significant 8 h after the intake. This shows that phenolic antioxidants associated with dietary fiber are at least partially bioavailable in humans, although dietary fiber appears to delay their absorption. No significant changes were observed after long-term intake (16 weeks, 34 subjects).     

Effects of Blackcurrant and Dietary Fibers on Large Intestinal Health Biomarkers in Rats

This study examined the effects of anthocyanin-rich blackcurrant extract and dietary fibers individually and their combinations on biomarkers of large intestinal health in rats. After six weeks of feeding, rats fed diets with blackcurrant gained significantly less body weight and reduced their food intake resulting in a lower food efficiency compared with those rats fed control diets. Combining dietary fiber (apple or broccoli) with blackcurrant in the diet was more effective in reducing the body weight gain and food intake. Cecal bacterial populations and short-chain fatty acids differed between the experimental diets. Blackcurrants significantly altered the bacterial populations by increasing the abundance of Bacteroides-Prevotella-Porphyromonas group and Lactobacillus spp., while decreasing the abundance of Bifidobacterium spp. and Clostridium perfringens. Propionic acid concentrations were increased by the diets with blackcurrant. Butyric acid concentrations were increased by dietary fiber supplementation. Dietary fiber increased the number of goblet cells in the colon. Diets with blackcurrant were more effective in altering the biomarkers of large intestinal health than those without blackcurrant.     

Protective Effects of Ulva lactuca Polysaccharide Extract on Oxidative Stress and Kidney Injury Induced by D-Galactose in Mice

Reactive oxygen species (ROS) are the key factors that cause many diseases in the human body. Polysaccharides from seaweed have been shown to have significant antioxidant activity both in vivo and in vitro. The ameliorative effect of Ulva lactuca polysaccharide extract (UPE) on renal injury induced by oxidative stress was analyzed. As shown by hematoxylin–eosin staining results, UPE can significantly improve the kidney injury induced by D-galactose (D-gal). Additionally, the protective mechanism of UPE on the kidney was explored. The results showed that UPE could decrease the levels of serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C (Cys-C), lipid peroxidation, protein carbonylation, and DNA oxidative damage (8-OHdG) and improve kidney glutathione content. Moreover, UPE significantly increased the activities of superoxide dismutase and glutathione peroxidase and total antioxidant activity in mice. UPE also decreased the levels of inflammatory cytokines TNF-α and IL-6. Further investigation into the expression of apoptotic protein caspase-3 showed that UPE decreased the expression of apoptotic protein caspase-3. These results indicate that UPE has a potential therapeutic effect on renal injury caused by oxidative stress, providing a new theoretical basis for the treatment of oxidative damage diseases in the future.