Effect of dietary chitosans on trace iron, copper and zinc in mice

Dietary chitosans with different molecular weight M_w and the degree of deacetylation DDA (high molecular weight chitosan HCS with M_w 7.60 × 10⁵ and DDA 85.5%, middle molecular weight chitosan MCS with M_w 3.27 × 10⁴ and DDA 85.2%, chito-oligomer COS with M_w 0.99 × 10³ and DDA 85.7% and water-soluble chitosan WSC with M_w 3.91 × 10⁴ and DDA 52.6%) were used at the 1.05% level to feed mice for 90 days. Afterwards no pathological symptoms, clinical signs or deaths were observed. The body weight of mice in chitosan group and control group showed no significant difference. Although HCS, COS and WSC had no significant effect on the level of Fe, Zn and Cu in the tested mice’s liver, spleen, heart and kidney, MCS significantly increased the level of Fe, Zn and Cu in liver. Therefore dietary ingestion of chitosan did not depress the level of Fe, Zn and Cu in mice.     

Effects of dietary selenite,copper, and zinc on tissue trace mineral levels in chicks

Studies were conducted to determine whether nutritional selenium (Se) status affects the nutritional status of the chick with respect to other trace elements, particularly copper (Cu) and Zinc (Zn). Severe Se deficiency was produced in chicks by the use of diets that contained exceedingly low contents (less than 0.010 ppm) of Se, but contained adequate amounts of all other known essential nutrients. This diet was based upon corn and soybean meal produced in areas of China with endemic Se deficiency of geobotanical origin. A level of at least 0.10 ppm Se was found to be required to maintain normal Se status of chicks fed this diet, and Se deficiency resulted in decreased levels of Cu, Zn, and molybdenum in the pancreas (liver and plasma levels were not affected). High dietary supplementation of Zn nor Cu did not affect the short-term utilization of Se, as indicated by the 18-h responses of Se-dependent glutathione peroxidase in plasma and liver.     

The trace elements iron, copper and zinc in Tanzanian women during pregnancy. Comparative study with a group of Italians

Atomic absorption spectrophotometry was employed in an evaluation of zinc, copper and iron of 57 Tanzanian women during the various phases of pregnancy, till the delivery. The result are compared with those found in a group of Italian women of same age during the same periods of pregnancy. No significant statistic differences seem to exist between the two groups.     

The effect of high dose oral manganese exposure on copper,iron and zinc levels in rats

Manganese is an essential dietary nutrient and trace element with important roles in mammalian development, metabolism, and antioxidant defense. In healthy individuals, gastrointestinal absorption and hepatobiliary excretion are tightly regulated to maintain systemic manganese concentrations at physiologic levels. Interactions of manganese with other essential metals following high dose ingestion are incompletely understood. We previously reported that gavage manganese exposure in rats resulted in higher tissue manganese concentrations when compared with equivalent dietary or drinking water manganese exposures. In this study, we performed follow-up evaluations to determine whether oral manganese exposure perturbs iron, copper, or zinc tissue concentrations. Rats were exposed to a control diet with 10 ppm manganese or dietary, drinking water, or gavage exposure to approximately 11.1?mg manganese/kg body weight/day for 7 or 61 exposure days. While manganese exposure affected levels of all metals, particularly in the frontal cortex and liver, copper levels were most prominently affected. This result suggests an under-appreciated effect of manganese exposure on copper homeostasis which may contribute to our understanding of the pathophysiology of manganese toxicity.     

Serum and hair levels of zinc, selenium, iron, and copper in children with iron-deficiency anemia

In the present study, the serum and hair levels of zinc, selenium, and copper were determined in children with iron-deficiency anemia (IDA). A total of 52 anemic children aged 1–4 yr constituted the study group. Fortysix healthy children acted as controls. The copper and zinc levels were measured with an atomic absorption spectrophometer. Serum and hair selenium was determined by a spectroflourometric method. The serum zinc and selenium concentrations in the IDA group were found to be significantly lower and serum copper significantly higher than those in the controls (p<0.05). Lower iron, zinc, and selenium concentrations (p<0.001) but not copper were found in hair (p>0.05).     

Changes in iron, calcium, magnesium, copper, and zinc levels in different tissues of riboflavin-deficient rats

To clarify the changes of mineral levels in different tissues of riboflavin-deficient rats, Wistar rats were separated into three groups. One group was fed a diet ad libitum that was deficient in riboflavin. The other two were fed either the complete diet that was weight-matched to the riboflavin-deficient group or fed a complete diet ad libitum. In riboflavin-deficient rats, the hemoglobin concentration and riboflavin contents of blood, liver, and kidney were significantly decreased, compared with weight-matched and ad libitum-fed controls. The mineral concentrations of tissues are summarized as follows: The iron (Fe) concentration in the heart, liver, and spleen was decreased in the riboflavin-deficient group compared with the other groups. Calcium (Ca) and magnesium (Mg) concentrations in tibia were decreased in the riboflavin-deficient group compared with the other two groups. Copper (Cu) concentration was increased in the heart and liver when the riboflavin-deficient group was compared with the other groups. Zinc (Zn) concentration was increased in tibia when the riboflavin-deficient group was compared with the other groups.     

Serum and tissue levels of six trace elements and copper/zinc ratio in patients with cervical cancer and uterine myoma

The aim of this study is to investigate the relationship between trace elements and the incidence of cervical cancer. Tissue and serum levels of six elements (Cu, Zn, Fe, Mn, Ca, and Se) and the Cu/Zn ratio in 40 cases of patients with cervical cancer, 30 cases of uterine myoma, and 50 healthy subjects were measured by atomic absorption spectrophotometry; the selenium content was determined by atomic fluorescence spectrometry. The results showed that the tissue contents of Zn, Se, and Ca were significantly lower and the Cu and Fe concentrations and Cu/Zn ratio were significantly higher in cervical cancer tissue than that for paired nonlesion tissue (p<0.02 and p<0.001, respectively). The serum levels of Zn, Se, Ca, and Fe were lower and Cu and Mn levels and Cu/Zn ratio were higher in patients with cervical cancer than in healthy subjects (p<0.01 and p<0.001, respectively) and in the uterine myoma group compared with healthy subjects (p< 0.05–0.001). There are no significant differences in the contents of six elements and the Cu/Zn ratio between uterine myoma tissue and paired nonlesion tissue. The results showed also that the Fe level and Cu/Zn ratio were significantly higher and the Zn and Se levels were significantly lower in cervical cancer tissue than in uterine myoma tissue (p<0.01 and p<0.001, respectively). The serum Cu level and Cu/Zn ratio were significantly higher in the cervical cancer group than the uterine myoma group (p<0.01). Data were also analyzed using multivarate logistic regression. After adjustment for age, occupation, life habit, and other covariates for the development of cervical cancer, the odds ratios were 22.64 (95% confidence interval [CI]: 5.64–90.88, p=0.001) for Cu, 0.11 (95% CI: 0.034–0.373; p=0.005) for Zn, and 0.60 (95% CI: 0.36–0.99, p=0.01) for Se. Thus, the serum and tissue levels of Cu increase and the deficiency of Zn and Se may be risk factors for the development of cervical cancer.     

Antimicrobial and mutagenic activity of some carbono- and thiocarbonohydrazone ligands and their copper(II), iron(II) and zinc(II) complexes.

Several mono- and bis- carbono- and thiocarbonohydrazone ligands have been synthesised and characterised; the X-ray diffraction analysis of bis(phenyl 2-pyridyl ketone) thiocarbonohydrazone is reported. The coordinating properties of the ligands have been studied towards Cu(II), Fe(II), and Zn(II) salts. The ligands and the metal complexes were tested in vitro against Gram positive and Gram negative bacteria, yeasts and moulds. In general, the bisthiocarbonohydrazones possess the best antimicrobial properties and Gram positive bacteria are the most sensitive microorganisms. Bis(ethyl 2-pyridyl ketone) thiocarbonohydrazone, bis(butyl 2-pyridyl ketone)thiocarbonohydrazone and Cu(H2nft)Cl2 (H2nft, bis(5-nitrofuraldehyde)thiocarbonohydrazone) reveal a strong activity with minimum inhibitory concentrations of 0.7 microgram ml-1 against Bacillus subtilis and of 3 micrograms ml-1 against Staphylococcus aureus. Cu(II) complexes are more effective than Fe(II) and Zn(II) ones. All bisthiocarbono- and carbonohydrazones are devoid of mutagenic properties, with the exception of the compounds derived from 5-nitrofuraldehyde. On the contrary a weak mutagenicity, that disappears in the copper complexes, is exhibited by monosubstituted thiocarbonohydrazones.     

Modulation of alcohol dehydrogenase isoenzyme levels in Zymomonas mobilis by iron and zinc.

Zymomonas mobilis is an unusual microorganism which utilizes both iron-containing alcohol dehydrogenase (ADHII) and zinc-containing alcohol dehydrogenase (ADHI) isoenzymes during fermentative growth. This organism is obligately ethanologenic, and alcohol dehydrogenase activity is essential. The activities of ADHI and ADHII were altered by supplementing growth medium with iron or zinc salts and by iron starvation. Growth under iron-limiting conditions (chelators, minimal medium) reduced ADHII activity but did not prevent the synthesis of the ADHII protein. The inactive form of this enzyme appeared quite stable, was not renatured by iron addition, and persisted in the cell. The iron-induced increase in ADHII activity required de novo synthesis which was blocked by antibiotic additions. The ability of Z. mobilis to synthesize ADHII and ADHI may be advantageous in nature.     

Phylogenetic relationship of Kappaphycus Doty and Eucheuma J. Agardh (Solieriaceae, Rhodophyta) in Malaysia

The genera Kappaphycus Doty and Eucheuma J. Agardh are important sources of carrageenan in Malaysia, offering lucrative revenues to the carrageenan industry, economy, and the local community. The extensive range of morphotypes and the lack of distinct morphological characteristics led to the application of molecular systematics in elucidating this taxonomic confusion. Local varieties of Kappaphycus and Eucheuma, identified using putative external morphology, were analyzed using the mitochondrial cox2–3 spacer and plastid RuBisCO spacer molecular markers. Phylogenetic analysis of these and non-local specimens indicate that Kappaphycus and Eucheuma are genetically distinct. Three main genotypes of Kappaphycus alvarezii were identified, of which two are extant in Hawaii. Morphological and color variations are not supported by molecular data, indicating that most of the local names are not genetically based. Both the cox2–3 spacer and RuBisCO spacer generated phylogenetic trees with similar topology except in variation of nodal supports. The two markers showed clear separation between Kappaphycus and Eucheuma and the existence of three Malaysian Kappaphycus cultivars. Cox2–3 spacer data is more variable and provides better resolution than the RuBisCO spacer, showing that Kappaphycus is more diversified with a larger number of genotypes, strains, and species which are unique to Southeast Asia. Kappaphycus sp. “Aring-aring” appeared to be phenotypically and genotypically different from other Kappaphycus congeners, whereas Kappaphycus striatum exhibited two different genotypes. Our data indicate that Eucheuma denticulatum is the dominant species in Malaysian waters and also suggested paraphyly in Eucheuma which will require further studies. The application of molecular taxonomy on Malaysian Kappaphycus and Eucheuma proves useful, offering valuable insights into the taxonomy and distribution of these commercially important Rhodophytes.     

Separate and joint effects of copper and zinc on the intestine carbohydrase activity in vitro in freshwater teleosts

The separate and joint effect of Cu²⁺ and Zn²⁺ of 0.1–25 mg l⁻¹ concentrations on the intestine carbohydrase activity were studied in vitro in 11 freshwater bone fishes. The total amylolytic activity of the fish intestinal mucosa decreased simultaneously with an increase in the Cu and Zn concentration. The maximal inhibitory effect varied from 15 to 46% and depended on the fish species. Copper had a more toxic effect on the amylolytic enzymes than zinc in planktivorous and bottom-feeding fish; the opposite pattern was observed in typical and facultative ichthyophagous species. The sucrase activity also decreased in the presence of Cu²⁺ and Zn²⁺, with minor exceptions; at the same time it increased by 18–50% in bream, ide, and burbot in the presence of Zn. The joint effect of Cu²⁺ and Zn²⁺ (1: 1) on the intestinal carbohydrase hydrolysis activity was significantly lower than when they were separate.     

Blood levels of copper, iron, zinc, and lead in adults in India and Pakistan and the effect of oral zinc supplementation for six weeks

Deficiency in the intake of trace elements, such as copper (Cu), iron (Fe), selenium (Se), and zinc (Zn), is very common in the general population of most developing countries. A preliminary study in India and Pakistan showing the plasma levels of Zn and Fe indicates that approx 50% of the subjects who participated have low levels of both Fe and Zn, suggesting a marginal deficiency. The low plasma levels of these elements are more pronounced in females. The mean levels of Ze, Cu, and Fe in the plasma of 83 subjects were 0.71 ± 0.11, 0.96 ± 0.10, and 0.80 ± 0.12 mg/L, respectively. The Cu:Zn ratio in the plasma was 1.43 ± 0.16. Three groups of 15 subjects each were given three different levels of oral supplements of Zn (15, 30, and 45 mg of Zn as Zn gluconate) for 6 wk, and blood samples were analyzed during various intervals. Plasma concentration of Zn increased significantly (p < 0.001) in all the groups after 4 wk of supplementation and reached almost normal levels after 6 wk. Along with the increase in Zn, there was a significant decrease(p < 0.001) in plasma Cu levels. There were no changes in the concentration of Fe during the supplementation period. The supplementation was well tolerated by most subjects. The results of this pilot study indicate that Zn supplementation is a practical possibility comparable to that of Fe supplementation in order to prevent marginal Zn deficiency in vulnerable groups in the general population of developing countries.     

Preliminary study of the in vitro antiproliferative effect of a hydroethanolic extract from the subtropical seaweed Turbinaria ornata (Turner) J. Agardh on a human non-small-cell bronchopulmonary carcinoma line (NSCLC-N6)

An unusual sulfated fucan-like polysaccharidecontaining aminosugar constituent was isolated fromthe brown Fucales, Turbinaria ornata. Itsantiproliferative effect on asynchronous cells of ahuman non-small-cell bronchopulmonary carcinoma line(NSCLC-N6) was studied in vitro. The kinetics ofcell growth further to the continuous exposure ofcells to T. ornata extract was investigated andthe changes in the cell cycle were observed usingflow-cytometry. Cell growth appeared to be inhibitedin the G1 phase. Altogether our observations suggesta triggering of the terminal differentiation ofcancerous cells by this fucan-like polysaccharide.     

Effect of calcium,copper, and zinc levels in a rapeseed meal diet on mineral and trace element utilization in the rat

Mineral and trace element interactions were studied in a balance trial with rats. Calcium, copper, and zinc were supplied to a rapeseed meal diet in a factorial design. Animals were fedad libitum, and absorption, excretion, and retention of the elements were evaluated either as fractions of total intake or in relation to nitrogen retention to account for differences in food intake and lean body mass increment. The intrinsic content of minerals and trace elements was sufficient to support growth at a rate that could be expected from the rapeseed protein quality. However, when calcium was included in the diet, the intrinsic dietary level of zinc appeared to be limiting, despite the fact that the zinc level was twice the recommended level. Additional zinc supply reversed growth impairment. This calcium-zinc interaction is believed to be owing to the formation of phytate complexes. Calcium addition influenced the calcium, phosphorus, magnesium, zinc, and iron—but not the copper—balances. The addition of calcium reduced the availability of the intrinsic zinc, whereas no effect was seen in the zinc-fortified groups. The availability of intrinsic copper was in a similar way significantly impaired by addition of dietary zinc, where-as copper-supplied groups were unaffected by zinc addition. Intrinsic iron availability was also dependent upon zinc addition, although in a more ambigouus way. Thus, addition of extrinsic minerals to a diet high in phytate can result in significant impairments of growth and mineral utilization.     

Angiostatic activity and metabolism of cortisol in the chorioallantoic membrane (CAM) of the chick embryo.

There is considerable interest in the discovery of compounds which inhibit angiogenesis dependent (neovascular) diseases. The chick embryo, due to the rapid development of an extensive vascular capillary network in the chorioallantoic membrane (CAM), has been used extensively as a model for studying angiogenesis. Angiostatic steroids are a new class of compounds which inhibit the growth of new capillaries in the chick CAM and in other models of neovascularization. Despite the potential therapeutic importance of these compounds, little is known about the ability of the CAM to metabolize these steroids. We have evaluated the ability of the chick CAM to metabolize cortisol which is both an angiostatic steroid as well as a glucocorticoid. When CAM homogenate was incubated with [3H]cortisol and NADPH at 37 degrees C and pH 7.4, and the reaction products analyzed by reverse phase HPLC, [3H]cortisol was converted exclusively to 20 beta-dihydrocortisol (4-pregnen-11 beta,17 alpha,20 beta,21-tetrol-3-one). The cortisol metabolite, 20 beta-dihydrocortisol, has very little glucocorticoid activity, but shows significant angiostatic activity in the CAM comparable to cortisol. The apparent Km determined for cortisol metabolism was 12 microM and the observed Vmax was 1.4 mumol cortisol/mg protein/min. The majority of the 20 beta-reductase activity was found in the soluble (242,000 g) fraction of CAM homogenate. 20 beta-Reductase activity in chick embryo CAM has not been previously reported.     

Antimicrobial activity of volatile component and various extracts ofEnteromorpha linza (Linnaeus) J. Agardh from the coast of Izmir, Turkey

The methanol, dichloromethane, hexane, chloroform and volatile components ofEnteromorpha linza were testedin vitro for their antimicrobial activity against five Gram-positive, four Gram-negative bacteria andCandida albicans ATCC 10239. GC-MS analysis of the volatile components ofE. linza resulted in the identification of 35 compounds which constituted 84.76% of the total compounds. The volatile components ofE. linza consisted of n-tetratriacontane (8.45%), 1-heptadecanamine (6.65%) and docosane (6.46%) as major components. The methanol and chloroform extracts showed more potent antimicrobial activity than hexane and dichloromethane extracts. The volatile oils of these algae did not remarkably inhibit the growth of tested microorganisms.