Effect of dietary chitosans with different viscosity on plasma lipids and lipid peroxidation in rats fed on a diet enriched with cholesterol

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.

Analysis of antioxidant properties of chitosan and its oligomers

Oral treatment with chitosan with a molecular weight approximately 105, but not its oligomer, reduced plasma content of free-radical oxidation products in normal rats and animals treated for the bone marrow form of radiation sickness and stimulated the recovery processes in involved bone marrow and peripheral blood.

Antihyperlipidemic and antioxidant effects of extracts from Pleurotus citrinopileatus

Pleurotus citrinopileatus is a popular edible mushroom which is physiologically active in both humans and animals. In the study we investigate the effects of this mushroom on hyperlipidemic hamster rats. Four dietary forms of the mushroom were created as follows. The powdered dry fruiting body, hot-water extract, and two kinds of elutes were obtained, from ethyl acetate extract and methanol extract, respectively, in different mixed proportion solvents over silica gel column chromatography (referred to as EAE and MOE, respectively). They were tested at different dosages as a supplement to a high-fat diet in hyperlipidemic rats. Serum triglycerides and total cholesterol levels were significantly lower in groups supplemented with the highest dosages of EAE and MOE (0.5 g/kg, body weight daily) as compared with the control groups that received no mushroom additive. High-density lipoprotein levels in these same two experimental groups were also significantly higher than those in the negative control group. The tested rats that were fed with EAE had the highest serum glutathione peroxidase and superoxide dismutase activity, and those with the MOE and EAE had the highest DPPH free radical scavenging activities and ferric-reducing abilities, tested in vitro. The major constituents of MOE and EAE were identified as ergosterol and nicotinic acid, respectively. P. citrinopileatus extracts may have a significant antihyperlipidemia effect. Furthermore, antioxidant activities and antihyperlipidemic effects of MOE and EAE seemed to display similar tendencies.

Lipid lowering activity of hydrosoluble chitosan and association withAloe vera L. andBrassica olearaceae L

The lipid lowering activity of chitosan associated with Aloe vera L. or hydrosoluble chitosan with Brassica olearaceae L. has been studied in rats. In this study, rats were submitted to different treatments with hydrosoluble chitosan alone (4% diet), hydrosoluble chitosan associated with Aloe vera L. or hydrosoluble chitosan with Brassica olearaceae L. (1:4, 4% diet) for 35 days, to identify the formula with the highest hypolipaemic potential. The results showed that all treatments reduced blood lipid levels but that hydrosoluble chitosan associated with Brassica olearaceae L. proved most efficient, because it decreased the levels of total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglycerides in blood serum. The overall results suggest that the hydrosoluble chitosan/Brassica olearaceae L. association is a therapeutic alternative for hyperlipidaemia, and in this way may contribute to the prevention of atherogenic processes.

Study on the synergetic degradation of chitosan with ultraviolet light and hydrogen peroxide

Chitosan was effectively degraded by hydrogen peroxide under irradiation with ultraviolet light. The existence of a synergetic effect on the degradation was demonstrated by means of viscometry. In addition, the optimal conditions of degradation were determined on the basis of orthogonal tests. The structure of the degraded product was characterized by Fourier-transform infrared spectra (FTIR) analysis and diffuse reflectance spectra (DRS) analysis. The mechanism of the degradation of chitosan was correlated with cleavage of the glycosidic bond.

ISSN Exercise & Sport Nutrition Review: Research & Recommendations

Sport nutrition is a constantly evolving field with literally thousands of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper presents a well-referenced overview of the current state of the science related to how to optimize training through nutrition. More specifically, this article discusses: 1.) how to evaluate the scientific merit of nutritional supplements; 2.) general nutritional strategies to optimize performance and enhance recovery; and, 3.) our current understanding of the available science behind weight gain, weight loss, and performance enhancement supplements. Our hope is that ISSN members find this review useful in their daily practice and consultation with their clients.

N-acylated chitosan: hydrophobic matrices for controlled drug release

N-acylation of chitosan with various fatty acid (C(6)-C(16)) chlorides increased its hydrophobic character and made important changes in its structural features. Unmodified chitosan exhibited a low degree of order (DO) and a weak tablet crushing strength. Chitosan acylated with a short chain length (C(6)) possessed similar properties, but exhibited significant swelling. Acylation with longer side chains (C(8)-C(16)) resulted in a higher DO and crushing strength but lower swelling. The best mechanical characteristics and drug release properties were found for palmitoyl chitosan (substitution degree 40-50%) tablets with 20% acetaminophen as a tracer. The high stability of these monolithic tablets appears to be due to hydrophobic interactions between side chains, as shown by a more organized structure. Infrared spectroscopy, X-ray diffractometry and proton nuclear magnetic resonance analyses of palmitoyl chitosan were consistent with a hydrophobic self-assembling model. Drug dissolution kinetics showed longer release times for higher degrees of functionalization, i.e. 30 h (for 47% substitution) and 90 h (for 69% substitution), suggesting palmitoyl chitosan excipients as interesting candidates for oral and subdermal pharmaceutical applications.

Antioxidant activity of water-soluble chitosan derivatives

Water-soluble chitosan derivatives were prepared by graft copolymerization of maleic acid sodium onto hydroxypropyl chitosan and carboxymethyl chitosan sodium. Their scavenging activities against hydroxyl radical *OH were investigated by chemiluminescence technique. They exhibit IC(50) values ranging from 246 to 498 microg/mL, which should be attributed to their different contents of hydroxyl and amino groups and different substituting groups.