Fucose-containing sulfated polysaccharides from brown macroalgae Lobophora variegata with antioxidant,anti-inflammatory,and antitumoral effects

This study analyzed sulfated polysaccharides, such as fucans, from the brown alga Lobophora variegata to verify their antioxidant activity in vitro, antitumoral effect on human colon adenocarcinoma cell line HT-29, and anti-inflammatory activity. Sulfated polysaccharide fractions containing fucans were obtained after fractionation with increasing volumes (v) of acetone (0.3–2.0 v). The polysaccharide was eluted with 1.5 v of acetone and named F1.5. The results showed that F1.5 contained a high yield. Chemical and structure analyses were performed by infrared spectroscopy, electrophoresis in agarose gel, and chemical dosages (sugar, protein, phenolic compounds, and sulfate). We observed that this sulfated polysaccharide had antioxidant activity and antitumoral effect. Anti-inflammatory activity in vivo of F1.5 was observed in the croton oil mouse-ear model at 75 mg kg^-1. The results were correlated with histopathological analysis.     

Evaluating the possible anticoagulant and antioxidant effects of sulfated polysaccharides from the tropical green alga Caulerpa cupressoides var. flabellata

Seaweeds are a source of several biopolymers widely used in cosmetics, food, and pharmaceuticals. Among them are sulfated polysaccharides, which have several biological/pharmacological activities, such as antioxidant and anticoagulant activities. In the present study, four sulfated polysaccharides, denominated CCB-F0.3, CCB-F0.5, CCB-F1.0, and CCB-F2.0, were obtained from the chlorophyte Caulerpa cupressoides var. flabellata through proteolytic digestion, followed by acetone fractionation and molecular sieving in Sephadex G-100. Chemical analyses showed that CCB-F0.5 had the highest sulfate/sugar ratio (0.73), whereas CCB-F1.0 exhibited the lowest ratio (0.23). Polysaccharides from C. cupressoides displayed a heterogeneous constitution of monosaccharides, with galactose as the main sugar unit (except for CCB-F2.0). The presence of sulfated polysaccharides was confirmed by electrophoretic and infrared analyses. Sulfated polysaccharides showed no activity in superoxide and hydroxyl radical scavenging; however, they did demonstrate total antioxidant capacity and ferrous chelating activity. Caulerpa polysaccharides also exhibited anticoagulant activity in the intrinsic (activated partial thromboplastin time (aPTT) test) and extrinsic pathway (prothrombin time (PT) test). In the aPTT test, all polysaccharides displayed considerable dose-dependent activity. A significant result was the aPTT activity of the polysaccharides CCB-F0.3 and CCB-F0.5, which was similar to that of Clexane?, a commercial low molecular weight heparin. In addition, CCB-F0.3 and CCB-F0.5 showed PT activity. Sulfated polysaccharides from C. cupressoides are therefore promising antioxidant agents in preventing the formation of reactive oxygen species and for their possible use in anticoagulant therapy.     

Designed optimization of a single-step extraction of fucose-containing sulfated polysaccharides from Sargassum sp.

Fucose-containing sulfated polysaccharides can be extracted from the brown seaweed, Sargassum sp. It has been reported that fucose-rich sulfated polysaccharides from brown seaweeds exert different beneficial biological activities including anti-inflammatory, anticoagulant, and anti-viral effects. Classical extraction of fucose-containing sulfated polysaccharides from brown seaweed species typically involves extended, multiple-step, hot acid, or CaCl₂ treatments, each step lasting several hours. In this work, we systematically examined the influence of acid concentration (HCl), time, and temperature on the yield of fucose-containing sulfated polysaccharides (FCSPs) in statistically designed two-step and single-step multifactorial extraction experiments. All extraction factors had significant effects on the fucose-containing sulfated polysaccharides yield, with the temperature and time exerting positive effects, and the acid concentration having a negative effect. The model defined an optimized single-step FCSPs extraction procedure for Sargassum sp. (a brown seaweed). A maximal fucose-containing sulfated polysaccharides yield of ～7% of the Sargassum sp. dry matter was achieved by the optimal extraction procedure of: 0.03?M HCl, 90°C, 4?h. HPAEC-PAD analysis confirmed that fucose, galactose, and glucuronic acid were the major constituents of the polysaccharides obtained by the optimized method. Lower polysaccharide yield, but relatively higher fucose content was obtained with shorter extraction time. The data also revealed that classical multi-step extraction with acid ≥0.2?M HCl at elevated temperature and extended time had a detrimental effect on the FCSPs yield as this treatment apparently disrupted the structural integrity of the polymer and evidently caused degradation of the carbohydrate chains built up of fucose residues.     

Curcumin prevents liver fat accumulation and serum fetuin-A increase in rats fed a high-fat diet

Fetuin-A is synthesized in the liver and is secreted into the bloodstream. Clinical studies suggest involvement of fetuin-A in metabolic disorders such as visceral obesity, insulin resistance, diabetes, and fatty liver. Curcumin is extracted from the rhizome Curcuma longa and has been shown to possess potent antioxidant, anticarcinogenic, anti-inflammatory, and hypoglycemic properties. In this study, we investigated the effect of curcumin treatment on serum fetuin-A levels as well as hepatic lipids and prooxidant–antioxidant status in rats fed a high-fat diet (HFD). Male Sprague–Dawley rats were divided into six groups. Group 1 was fed control diet (10 % of total calories from fat). Groups 2 and 3 were given curcumin (100 and 400 mg/kg bw/day, respectively ) by gavage for 8 weeks and were fed control diet. Group 4 was fed with HFD (60 % of total calories from fat). Groups 5 and 6 received HFD together with the two doses of curcumin, respectively. Curcumin treatment appeared to be effective in reducing liver triglycerides and serum fetuin-A levels. These findings suggest that the reduction of fetuin-A may contribute to the beneficial effects of curcumin in the pathogenesis of obesity.     

Effects of high dietary fibre diets formulated from by-products from vegetable and agricultural industries on plasma metabolites in gestating sows

The aim of the present study was to examine the biochemical influence of feeding high dietary fibre (DF) diets formulated from by-products from the vegetable and agricultural industries to sows during early to mid-gestation. The effect of feeding frequency (once vs. twice daily) on diurnal plasma metabolites patterns was also examined. The study included a total of 48 gestating sows from four blocks (12 gestating sows in each block). The sows were fed four different diets containing varying levels of starch (304–519 g/kg dry matter (DM)) and DF (171–404 g/kg DM) but with equal amounts of net energy. The low-DF diet (control) was based on barley and wheat, and the three high-DF diets formulated by replacing barley and wheat by pectin residue, sugar beet pulp and potato pulp, respectively. The experimental design comprised two periods of 4 weeks each. Half the sows were fed once daily at 08:00 h in the first period and twice daily at 08:00 and 15:00 h during the second period, and vice versa for the other half of the sows. Plasma samples from vena jugularis were collected by venipuncture at 07:00, 09:00, 12:00 and 19:00 h. Feeding high-DF increased plasma short-chain fatty acids (p = 0.02) and non-esterified fatty acids (p < 0.001). However, there was no clear effect of DF on glucose and insulin responses. A negative correlation between amount of DF in the diets and plasma creatine (R ² = 1.00; diet effect: p = 0.02) suggested that plasma creatine concentrations was an indicator for the level of glucose–glycogen interchange. Furthermore, an explorative approach using nuclear magnetic resonance spectroscopy-based metabonomics identified betaine (p < 0.001), dimethyl sulfone (DMSO₂; p < 0.001) and scyllo-inositol (p < 0.001) as biomarkers for the different by-products; pectin residue was related to high plasma levels of DMSO₂, sugar beet pulp to plasma betaine, DMSO₂ and scyllo-inositol, and potato pulp to plasma DMSO₂ and scyllo-inositol. In conclusion, replacing starch by DF affected surprisingly few metabolites in peripheral plasma. No negative effects were found in feeding pectin residue, sugar beet pulp or potato pulp for gestating sows as judged from the minor metabolic changes.     

Antioxidant enzymes gene expression and antihypertensive effects of seaweeds Ulva linza and Lessonia trabeculata in rats fed a high-fat and high-sucrose diet

The objective of this work was to evaluate the antihypertensive and antioxidant effect of seaweeds (Ulva linza and Lessonia trabeculata) in rats which were fed a hypercaloric diet. Seaweed at 400 mg kg^?1 of body weight was administered for 8 weeks to Wistar rats that were fed with a standard diet or a hypercaloric diet. Intra-abdominal fat, insulin resistance, and lipid profile of the rats were determined. Liver was isolated to determine antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)] activity and gene expression. The administration of seaweed to the rats reduced the levels of intra-abdominal fat, arterial blood pressure, insulin resistance, and cholesterol and triglyceride serum levels. U. linza reduced the GPx activity in control animals but increased it in animals with MS, which could be reduced by using L. trabeculata. Both seaweeds diminished the SOD and GPx expression and increased CAT in control group. Both seaweeds reduced the CAT expression in animals with metabolic syndrome. Combined effects of the different compounds found in the seaweeds explain the regulating effect over different antioxidant enzymes and metabolic pathways that protect the animals fed a hypercaloric diet against the development of hypertension, hyperglycemia, and obesity.     

Chemical characteristics,antioxidant and anticancer potential of sulfated polysaccharides from <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis>

The sulfated polysaccharides (SPs) from Chlamydomonas reinhardtii (Cr) were isolated by hot water method using 80% alcohol and semi purified by anion-exchange column chromatography. The chemical analysis of the extract showed 78% carbohydrates, 18% reducing sugars, 60% non-reducing sugars, 2% protein, 33% sulfate, 39% uronic acid, and 4% ash. The elemental analysis of this C. reinhardtii sulfated polysaccharide-enriched extract (Cr-SPs) showed 53% carbon, 8% hydrogen, and 6% nitrogen. FTIR analysis of Cr-SPs showed characteristic bands of sulfated polysaccharides. Further, the Cr-SPs showed significant hydroxyl radical scavenging activity of 22.29–80.9% at 0.01–1 mg mL^?1, 38–77% of DPPH radical scavenging activity at 0.01–1 mg mL^?1, 9.8–81% ABTS radical scavenging activity, 34.5–67.6% of ferrous chelating ability, and 11.62–75% of total antioxidant capacity. Cr-SPs also showed efficient in vitro anticancer activity. Specifically, they inhibited triple-negative breast cancer cell (MDA-MB-231) proliferation with an IC₅₀ of 172 μg mL^?1. Concentration-dependent reduction in the number of colonies formed by MDA-MB-231 cells suggested their potential to inhibit the clonal expansion of the cancer cells. Higher concentrations of crude extract were found to disrupt the microtubule networks in these cells. The cells treated with Cr-SPs eventually underwent apoptosis as evidenced by the formation of characteristic DNA ladder. These results indicate that Cr-SPs find promising opportunities for cancer treatment.     

Prebiotic effect of fructo-oligosaccharides on the inner ear of DBA/2 J mice with early-onset progressive hearing loss

Nutrition and dietary habits contribute to the onset and progression of sensorineural hearing loss (SNHL). Fructo-oligosaccharides (FOS) are non-digestible oligosaccharides and are known as prebiotics, which enhance short-chain fatty acid (SCFA) production and antioxidant activity. Although a substantial number of studies have shown that FOS play a role in the prevention of lifestyle-related diseases as prebiotics, little is known about the effects on the inner ear. The purpose of this study is to investigate the effect of FOS on gene expression and spiral ganglion neuron (SGN) protection in the inner ear of DBA/2 J mice, which is a model for early-onset progressive hearing loss. DBA/2 J mice were fed either control diet or FOS diet contained 10% (w/w) of FOS for 8 weeks. Analysis of mice fed the FOS diet revealed a change in intestinal flora including an inversion of the ratio of Bacteroidetes and Firmicutes, which was followed by a significant increase in SCFAs in the cecum and a decrease in an oxidative stress marker in the serum. In the inner ear, gene expression of neurotrophin, brain-derived neurotrophic factor (BDNF), its receptor, tyrosine kinase receptor b (Trkb), and the SCFA receptor, free fatty acid receptor 3 (FFAR3), were increased by FOS. In addition, the survival rate of SGNs in the inner ear was maintained in FOS-fed mice. Altogether, these results suggest that a compositional variation of the intestinal flora due to a prebiotic effect may be involved in the progression of SNHL.     

The role of resveratrol on skeletal muscle cell differentiation and myotube hypertrophy during glucose restriction

Considering the well-known antioxidant properties of statins, it seems important to assess their impact on major markers of oxidative stress (superoxide anion radical, nitric oxide, and index of lipid peroxidation) to compare the antioxidative potentials of atorvastatin and simvastatin during the different degrees of hyperhomocysteinemia (HHcy) in rats. This study was conducted on adult male Wistar albino rats (n = 90; 4 weeks old; 100 ± 15 g body mass) in which HHcy was achieved by dietary manipulation. For 4 weeks, the animals were fed with one of the following diets: standard rodent chow, diet enriched in methionine with no deficiency in B vitamins (folic acid, B6, and B12), or diet enriched in methionine and deficient in B vitamins (folic acid, B6, and B12). At the same time, animals were treated with atorvastatin at doses of 3 mg/kg/day i.p. or simvastatin at doses of 5 mg/kg/day i.p. Levels of superoxide anion radical and TBARS were significantly decreased by administration of simvastatin in normal and high-homocysteine (Hcy) groups (p < 0.05). At 4 weeks after feeding with purified diets, the concentrations of the GSH, CAT, and SOD antioxidants were significantly affected among all groups (p < 0.05). Our results indicated that statin therapy had variable effects on the redox status in hyperhomocysteinemic rats, and simvastatin demonstrated stronger antioxidant effects than did atorvastatin.     

Use of Sodium Butyrate as an Alternative to Dietary Fiber: Effects on the Embryonic Development and Anti-Oxidative Capacity of Rats

In this study, we evaluated the effect of replacing dietary fiber with sodium butyrate on reproductive performance and antioxidant defense in a high fat diet during pregnancy by using a rat model. Eighty virgin female Sprague Dawley rats were fed one of four diets—(1) control diet (C group), (2) high fat + high fiber diet (HF group), (3) high-fat +5% sodium butyrate diet (SB group), and (4) HF diet + α-cyano-4-hydroxy cinnamic acid (CHC group)—intraperitoneally on days 8, 10, 12, 14, and 16 of gestation. SB and dietary fiber had similar effects on improving fetal number and reducing the abortion rate; however, the anti-oxidant capacity of maternal serum, placenta, and fetus was superior in the HF group than in the SB group. In comparison, CHC injection decreased reproductive performance and antioxidant defense. Both dietary fiber (DF) and SB supplementation had a major but different effect on the expression of anti-oxidant related genes and nutrient transporters genes. In summary, our data indicate that SB and DF showed similar effect on reproductive performance, but SB cannot completely replace the DF towards with respect to redox regulation in high-fat diet; and SB might influence offspring metabolism and health differently to DF.     

Improvement of lipid profile and antioxidant of hypercholesterolemic albino rats by polysaccharides extracted from the green alga Ulva lactuca Linnaeus

Sulfated polysaccharides from Ulva lactuca were extracted in hot water and precipitated by ethanol then orally gavaged to rats fed on a hypercholesterolemic diet for 21 days to evaluate the antihypercholesterolemic and antioxidant actions. Atorvastatine Ca (Lipitor) was used as a reference drug. The intragastric administration of U. lactuca extract to hypercholesterolemic rats caused significant decrease of serum total lipids, triglycerides, total cholesterol, LDL-cholesterol and vLDL-cholesterol levels. Whereas, HDL-cholesterol concentration was markedly increased by 180%. Aqueous extract showed a significant ameliorative action on elevated atherogenic index, creatine kinase and lactate dehydrogenase activities of hypercholesterolemic group. Furthermore, serum activities of transaminases and alkaline phosphatase were also improved. High fat diet intake caused a highly significantly elevated serum urea, creatinine concentration. These effects were reversed by oral administration of U. lactuca extract. Sulfates polysaccharides extract of U. lactuca ameliorate hepatic enzymatic (catalase, glutathione peroxidase and superoxide dismutase), non-enzymatic (reduced glutathione & total thiol) antioxidant defenses and thiobarbituric acid reactive substances. In conclusion, the tested U. lactuca polysaccharides extract has potent hypocholesterolemic and antioxidant effects in experimentally-induced hypercholesterolemic animal model.     

Beneficial effects of hydro-alcoholic extract of Caralluma fimbriata against high-fat diet-induced insulin resistance and oxidative stress in Wistar male rats

The main aim of this study was to investigate the beneficial effects of hydro-alcoholic extract of Caralluma fimbriata (CFE) on the effects of high-fat diet feeding on insulin resistance and oxidative stress in Wistar rats. High-fat diet (60 % of fat) and CFE (200 mg/kg body weight/day) were given concurrently to the rats for a period of 90 days. Feeding with high-fat diet resulted in the development of hyperglycemia, hyperinsulinemia, hyperleptinemia, and hypertriglyceridemia and impaired insulin sensitivity (P?<?0.05). Administration of CFE to high-fat diet-fed rats for 90 days resulted in a significant improvement in plasma glucose, insulin, leptin, and triglycerides. Regarding liver antioxidant status, high-fat fed rats showed higher levels of lipid peroxidation, protein oxidation and lower GSH levels and lower activities of enzymatic antioxidants, while CFE treatment prevented all these observed abnormalities. In conclusion, intake of CFE may be beneficial for the suppression of high-fat diet-induced insulin resistance and oxidative stress.     

Effect of Curcuma kwangsiensis polysaccharides on blood lipid profiles and oxidative stress in high-fat rats

We have investigated the protective effect of polysaccharides from Curcuma kwangsiensis (CKP) against oxidative injury in rats fed high-fat diet. The protective effect of CKP was compared with Lovastatin, a well-known antioxidant. Sixty SD rats were used for the experimental study. Oxidative injury was induced by feeding high-fat diet for 3 weeks. The blood profiles, total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-c) levels during experimental period were significantly increased in untreated model control group, whereas high-density lipoprotein cholesterol (HDL-c) levels and antioxidant enzymes activities significantly decreased in untreated model control group. The levels of TC, TG, LDL-c levels in CKP-treated rats were decreased significantly when compared to the untreated model control group, which were brought down to near normal in CKP-treated group. HDL-c level and antioxidant enzymes activities were found to be significantly increased in serum of CKP-treated group compared to the untreated model control group. The protective effect of CKP against oxidative injury was comparable to that of Lovastatin. Our data suggest that CKP exerts its protective effect by modulating the extent of lipid peroxidation and augmenting antioxidant defense system and thus protects the experimental animals against oxidative injury induced by high-fat diet treatment.     

Enhancement of In Vivo Antioxidant Ability in the Brain of Rats Fed Tannin

The effect of the oral administration of mimosa tannin (MMT) on the rat intra-hippocampal antioxidant ability was examined. Wistar rats at the age of 6 weeks were reared for 8 weeks with the rodent diet (RD) consisting of 0.1 g/kg of MMT (RD–MMT). The antioxidant ability of rat brain was evaluated from the decay of a brain–blood-barrier permeable stable nitroxide, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) measured by the microdialysis-electron spin resonance system under a freely moving state. The decay rate of PCAM in the brain of rats fed RD–MMT was significantly larger than that of rats fed control rodent diet, which indicates the increase of the antioxidant ability in the brain of rats fed RD–MMT. In vitro study showed that MMT did not reduce PCAM directly but enhanced the reduction of PCAM by ascorbic acid. These results indicate that MMT is a potent antioxidant in vitro and in vivo.     

Palm tocotrienol-rich fraction reduced plasma homocysteine and heart oxidative stress in rats fed with a high-methionine diet

Oxidative stress contributes to cardiovascular diseases. We aimed to study the effects of palm tocotrienol-rich fraction (TRF) on plasma homocysteine and cardiac oxidative stress in rats fed with a high-methionine diet. Forty-two male Wistar rats were divided into six groups. The first group was the control. Groups 2–6 were fed 1 % methionine diet for 10 weeks. From week 6 onward, folate (8 mg/kg diet) or palm TRF (30, 60 and 150 mg/kg diet) was added into the diet of groups 3, 4, 5 and 6. The rats were then killed. Palm TRF at 150 mg/kg and folate supplementation prevented the increase in plasma total homocysteine (4.14?±?0.33 and 4.30?±?0.26 vs 5.49?±?0.25 mmol/L, p?<?0.05) induced by a high-methionine diet. The increased heart thiobarbituric acid reactive substance in rats fed with high-methionine diet was also prevented by the supplementations of palm TRF (60 and 150 mg/kg) and folate. The high-methionine group had a lower glutathione peroxidase activity (49?±?3 vs 69?±?4 pmol/mg protein/min) than the control group. This reduction was reversed by palm TRF at 60 and 150 mg/kg diet (p?<?0.05), but not by folate. Catalase and superoxide dismutase activities were unaffected by both methionine and vitamin supplementations. In conclusion, palm TRF was comparable to folate in reducing high-methionine diet-induced hyperhomocysteinemia and oxidative stress in the rats’ hearts. However, palm TRF was more effective than folate in preserving the heart glutathione peroxidase enzyme activity.     

The effects of oral taurine administration on behavior and hippocampal signal transduction in rats

Taurine, 2-aminoethylsulfonic acid, is one of the most abundant amino acids in the brain. It has various important physiological functions as a neuromodulator and antioxidant. Taurine is expected to be involved in depression; however, knowledge regarding its function in relation to depression is limited. In this study, we attempted to elucidate the effects of oral taurine administration on antidepressant-like behaviors in rats and depression-related signal transduction in the hippocampus. In behavioral tests, rats fed a high taurine (HT: 45.0 mmol/kg taurine) diet for 4 weeks (HT4w) showed decreased immobility in the forced swim test (FS) compared to controls. However, rats fed a low taurine (LT: 22.5 mmol/kg taurine) diet for 4 weeks or an HT diet for 2 weeks (HT2w) did not show a significant difference in FS compared to controls. In biochemical analyses, the expression of glutamic acid decarboxylase (GAD) 65 and GAD67 in the hippocampus was not affected by taurine administration. However, the phosphorylation levels of extracellular signal-regulated kinase1/2 (ERK1/2), protein kinase B (Akt), glycogen synthase kinase3 beta (GSK3β) and cAMP response element-binding protein (CREB) were increased in the hippocampus of HT4w and HT2w rats. Phospho-calcium/calmodulin-dependent protein kinase II (CaMKII) was increased in the hippocampus of HT4w rats only. Moreover, no significant changes in these molecules were observed in the hippocampus of rats fed an HT diet for 1 day. In conclusion, our findings suggest that taurine has an antidepressant-like effect and an ability to change depression-related signaling cascades in the hippocampus.     

Influence of dietary fibre on nutrient digestibility and energy utilisation in growing pigs fed diets varying in soluble and insoluble fibres from co-products

The co-products from the industry are used to reduce costs in pig diets. However, the co-products used in pig diets are limited because of a high fibre content which is not digested by endogenous enzymes and is resistant to degradation in the small and large intestines. The aim of this study was to investigate digestibility of nutrients and energy, and energy utilisation in pigs fed diets with various soluble and insoluble dietary fibre (DF) from co-products. The experiment was performed as a 4 × 4 Latin square design (four diets and four periods) using four growing pigs (66.2 ± 7.8 kg) surgically fitted with a T-cannula in the end of the small intestine. The pigs were fed four experimental diets: low-fibre control (LF), high-fibre control (HF), high-soluble fibre (HFS) and high-insoluble fibre (HFI) diets. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of ash, organic matter, CP, fat, carbohydrates, starch and non-starch polysaccharides (NSP) divided into cellulose and soluble and insoluble non-cellulosic polysaccharide residues were measured using chromic oxide as marker. The recovery of total solid materials, organic matter and total carbohydrates in ileal digesta in pigs fed the HF and HFS diets was higher than in pigs fed LF and HFI, whereas recovery of organic matter and total carbohydrates in faecal materials in the HFS diet was lowest (P < 0.05). AID of organic matter, total carbohydrates and starch was lowest for HFS diet (P < 0.05). ATTD of organic matter and CP was higher for LF diet compared with other diets (P < 0.05), whereas total NSP, cellulose and non-cellulosic polysaccharides residues were highest for HFS diet (P < 0.05). Lactic acid in ileal digesta was influenced by dietary composition (P < 0.05) whereas neither type nor level of DF affected short chain fatty acids. The digestible energy, metabolisable energy, net energy and retained energy intake were similar among diets without influence of DF inclusion (P > 0.05). The metabolisable energy:digestible energy ratio was lower when feeding the HFS diet because of a higher fermentative methane loss. Faecal nitrogen and carbon were positively correlated with DM intake and insoluble DF in the diets (P < 0.05), but nitrogen and carbon (% of intake) were similar among diets. The present findings suggest that high-DF co-products can be used as ingredients of pig diets when features of DF are considered.     

Equine pre-caecal and total tract digestibility of individual carbohydrate fractions and their effect on caecal pH response

The working hypothesis was that a minor postprandial caecal pH decline would affect apparent total tract digestibility (ATTD) of the fibre fraction in horses and, hence, that soluble fibre would amplify fermentation and consequently increase ATTD of fibre. This study was a 4 × 4 Latin Square design with a sequence of 17 days adaptation to the ration followed by 8 sampling days. The feed rations consisted of only timothy hay (Group H), hay plus molassed sugar beet pulp combined with either whole oats (Group OB) or barley (Group BB) and hay plus loose chaff based concentrate (Group M). Four horses fitted with permanent caecal cannulas and collection harnesses were used. A pH electrode with logger was inserted through the cannula and caecal pH was recorded at 1 min intervals for 8 h. The mobile nylon bag technique was used to quantify pre-caecal loss (PCL) of individual feedstuffs. Fibre was analysed as dietary fibre (DF), non-starch polysaccharides, soluble non-cellulosic polysaccharides (S-NCP), insoluble non-cellulosic polysaccharide (I-NCP) and neutral detergent fibre. The ATTD of the S-NCP fraction was above 0.8, which was 60% higher than for the I-NCP fraction. The PCL of starch were 0.98 (oats) and 0.75 (barley). The BB diet lowered (p < 0.001) postprandial caecal pH more than the other diets and a significant correlation was found between the lowest pH and ATTD of I-NCP (r = ?0.66; p = 0.005). In conclusion, this study successfully measured the in vivo digestibility of individual fibre fractions and found that S-NCP was more digestible than the I-NCP, and that a single meal of unprocessed barley was sufficient to decrease caecal pH to such an extent that the fibre digestibility of the whole diet was negatively affected.     

Neuroprotective role of lipoic acid against acute toxicity of N-acetylaspartic acid

N-Acetylaspartic acid (NAA) accumulates in Canavan disease, a severe inherited neurometabolic disorder clinically characterized by mental retardation, hypotonia, macrocephaly, and seizures. The mechanisms of brain damage in this disease remain poorly understood. Recent studies developed by our research group showed that NAA induces oxidative stress in vitro and in vivo in cerebral cortex of rats. Lipoic acid is considered as an efficient antioxidant which can easily cross the blood–brain barrier. Considering the absence of specific treatment to Canavan disease, this study evaluates the possible prevention of the oxidative stress promoted by NAA in vivo by the antioxidant lipoic acid to preliminarily evaluate lipoic acid efficacy against pro-oxidative effects of NAA. Fourteen-day-old Wistar rats received an acute administration of 0.6 mmol NAA/g body weight with or without lipoic acid (40 mg/kg body weight). Catalase (CAT), glutathione peroxidase (GPx), and glucose 6-phosphate dehydrogenase activities, hydrogen peroxide content, thiobarbituric acid-reactive substances (TBA-RS), spontaneous chemiluminescence, protein carbonyl content, total antioxidant potential, and DNA–protein cross-links were assayed in the cerebral cortex of rats. CAT, GPx activities, and total antioxidant potential were significantly reduced, while hydrogen peroxide content, TBA-RS, spontaneous chemiluminescence, and protein carbonyl content were significantly enhanced by acute administration of NAA. Those effects were all prevented by lipoic acid pretreatment. Our results clearly show that lipoic acid may protect against the oxidative stress promoted by NAA. This could represent a new therapeutic approach to the patients affected by Canavan disease.     

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.