Ocoxin as a complement to first line treatments in cancer.

Chemotherapy and radiotherapy are the most frequent treatment for patients suffering from malignant progression of cancer. Even though new treatments are now being implemented, administration of these chemotherapeutic agents remains as the first line option in many tumor types. However, the secondary effects of these compounds represent one of the main reasons cancer patients lose life quality during disease progression. Recent data suggests that Ocoxin, a plant extract and natural compound based nutritional complement rich in antioxidants and anti-inflammatory mediators exerts a positive effect in patients receiving chemotherapy and radiotherapy. This mixture attenuates the chemotherapy and radiotherapy-related side effects such as radiation-induced skin burns and mucositis, chemotherapy-related diarrhea, hepatic toxicity and blood-infection. Moreover, it has been proven to be effective as anticancer agent in different tumor models both in vitro and in vivo, potentiating the cytotoxic effect of several chemotherapy compounds such as Lapatinib, Gemcitabine, Paclitaxel, Sorafenib and Irinotecan. The aim of this review is to put some light on the potential of this nutritional mixture as an anticancer agent and complement for the standard chemotherapy routine.

Zinc supplementation for improving glucose handling in pre-diabetes: A double blind randomized placebo controlled pilot study.

AIMS: There are a number of studies showing that zinc supplementation may improve glucose handling in people with established diabetes. We sought to investigate whether this zinc-dependent improvement in glucose handling could potentially be harnessed to prevent the progression of pre-diabetes to diabetes. In this double-blind randomized placebo-controlled trial, we determined participants' fasting blood glucose levels, (FBG) and Homeostasis Model Assessment (HOMA) parameters (beta cell function, insulin sensitivity and insulin resistance) at baseline and after 6 months of zinc supplementation. METHODS: The Bangladesh Institute of Health Sciences Hospital (BIHS) (Mirpur, Dhaka, Bangladesh) database was used to identify 224 patients with prediabetes, of whom 55 met the inclusion criteria and agreed to participate. The participants were randomized either to the intervention or control group using block randomization. The groups received either 30mg zinc sulphate dispersible tablet or placebo, once daily for six months. RESULTS: After six months, the intervention group significantly improved their FBG concentration compared to the placebo group (5.37±0.20mmol/L vs 5.69±0.26, p<0.001) as well as compared to their own baseline (5.37±0.20mmol/L vs 5.8±0.09, p<0.001). Beta cell function, insulin sensitivity and insulin resistance all showed a statistically significant improvement as well. CONCLUSION: To our knowledge this is the first trial to show an improvement in glucose handling using HOMA parameters in participants with prediabetes. Larger randomized controlled trials are warranted to confirm these findings and to explore clinical endpoints.

Zinc Absorption by Adults Is Similar from Intrinsically Labeled Zinc-Biofortified Rice and from Rice Fortified with Labeled Zinc Sulfate.

BACKGROUND: Biofortification of staple food crops is a promising strategy to combat zinc deficiency, and it is of particular interest for rice and crops that are not consumed as flours and therefore not suitable for postharvest fortification. Because zinc absorption is decreased by phytic acid (PA) and perhaps other dietary components, it is important to measure the absorption of zinc from a biofortified crop before determining its efficacy. OBJECTIVE: In this study, we compared the zinc absorption from zinc-biofortified rice (hydroponically enriched with (70)Zn) with that from a control rice of the same variety fortified with (70)ZnSO4 at point of use to reach the same total zinc content of 1.1 mg/meal. Both rice meals had a PA:Zn molar ratio of 12. METHODS: Fractional absorption of zinc (FAZ) was measured with the use of the double-isotope tracer ratio method in 16 apparently healthy adults [18-45 y old; BMI (in kg/m(2)) 19-25] who consumed 2 single meals at 4-wk intervals in random order in a crossover design. RESULTS: The FAZ from the biofortified rice (mean ± SD: 25.1 ± 8.7%) did not differ significantly from that of the point-of-use fortified rice (mean ± SD: 20.8 ± 7.1%) (P = 0.08). CONCLUSIONS: These results suggest that the native zinc accumulated in the biofortified rice was readily released from the rice matrix and that its absorption by adults was influenced by PA and other food components in a similar way to the inorganic zinc compound added to the rice at point of use. Moreover, rice biofortification is likely to be as good as postharvest zinc fortification as an intervention strategy to combat zinc deficiency. This trial was registered at clinicaltrials.gov as NCT01633450.

Pharmacokinetics and biodistribution of zinc-enriched yeast in rats.

Zinc-enriched yeast (ZnY) and zinc sulfate (ZnSO4) are considered zinc (Zn) supplements currently available. The purpose of the investigation was to compare and evaluate pharmacokinetics and biodistribution of ZnY and ZnSO4 in rats. ZnY or ZnSO4 were orally administered to rats at a single dose of 4 mg Zn/kg and Zn levels in plasma and various tissues were determined using inductively coupled plasma-optical emission spectrometry. Maximum plasma concentration values were 3.87 and 2.81 µg/mL for ZnY and ZnSO4, respectively. Both ZnY and ZnSO4 were slowly eliminated with a half-life of over 7 h and bone had the highest Zn level in all tissues. Compared to ZnSO4, the relative bioavailability of ZnY was 138.4%, indicating that ZnY had a significantly higher bioavailability than ZnSO4.

Biofortification of soybean sprouts with zinc and bioaccessibility of zinc in the sprouts.

BACKGROUND: Soybean sprouts are a very popular vegetable in Southeast Asian countries and regions. Zinc-rich soybean sprouts can help to improve Zn deficiency in humans. The aim of this study was to prepare Zn-enriched soybean sprouts through agronomic biofortification (germination with ZnSO4 solution) in order to provide consumers with a dietary material for Zn supplementation. RESULTS: A suitable Zn concentration in ZnSO4 solution used for cultivation of Zn-enriched soybean sprouts was found to be less than or equal to 20 µg mL(-1) . Upon biofortification with 10 and 20 µg Zn mL(-1) ZnSO4 solutions, Zn content (102 and 163 vs 32 mg kg(-1) dry weight (DW)), bioaccessible Zn content (3.86 and 8.53 vs 1.11 mg kg(-1) DW) and Zn bioaccessibility (3.8 and 5.2 vs 3.5%) in edible portions of Zn-enriched soybean sprouts were significantly enhanced compared with those of water-germinated soybean sprouts. Meanwhile, no significant differences were observed in Fe, Mn and Cu contents of edible portions of soybean sprouts between ZnSO4 solution and water germinations, although soaking leakages of minerals (Fe, Mn and Cu) from soybean seeds to steeping media occurred to some degree. CONCLUSION: Soybean sprouts biofortified with ZnSO4 solution at 10 or 20 µg Zn mL(-1) contained appreciable quantities of Zn and had good Zn bioaccessibility, indicating that Zn-enriched soybean sprouts may serve as a suitable dietary Zn source to improve the Zn intake of Zn-deficient populations.

The bioavailability of different zinc compounds used as human dietary supplements in rat prostate: a comparative study.

The normal human prostate accumulates the highest levels of zinc (Zn) of any soft tissue in the body. The pool of zinc available to the body is known to significantly decrease with age. It is suggested that dietary Zn supplementation protects against oxidative damage and reduces the risk of cancer. Zinc sulfate and zinc gluconate were the most frequently mentioned in per os administration in studies on Zn supplementation. The major aim of the study was to compare the bioavailability of different Zn compounds (sulfate, gluconate and citrate) in the prostate after their daily administration to male rats at three different doses (3.0; 15.0; and 50.0 mg Zn/kg b.w.) for 30 days. The results show that bioavailability in the prostate differs significantly between individual zinc preparations. A significantly elevated Zn concentration in the dorso-lateral lobe of the prostate, compared to controls, was found in the rats supplemented with two compounds only: zinc gluconate and zinc citrate. However, after administration of zinc gluconate, this effect occurred even at the lowest dose. The lowest zinc bioavailability in the prostate was found in the rats administered zinc sulfate: no significant Zn increase was seen in particular zones of the prostate. To sum up, the use of zinc gluconate is worth considering as a possible means of zinc supplementation in men.

Preventive effects of selenium yeast, chromium picolinate, zinc sulfate and their combination on oxidative stress, inflammation, impaired angiogenesis and atherogenesis in myocardial infarction in rats.

PURPOSE: Accumulating evidences suggest a critical role of trace metal dyshemostasis in oxidative stress and cardiac dysfunction after myocardial infarction (MI). This study investigated the cardioprotective effects of selenium yeast (Se), chromium picolinate Cr(pic)3, zinc sulfate (Zn) and their combination on isoproterenol (ISO)-induced MI. METHODS: Rats were divided into six groups: normal control, ISO control, Se-pretreated (0.1 mg/kg), Cr(pic)3-pretreated (400 µg/kg), Zn-pretreated (30 mg/kg) and metal combination-pretreated groups. All metals were administered for 28 days and at the 27th day, MI was induced by subcutaneous injection of ISO (85 mg/kg) once for two consecutive days. RESULTS: ISO control group showed hyperlipidemia, elevation of cardiac biomarkers and lipid peroxidation and increased immunostaining of p47 phox NADPH oxidase subunit in addition to decreased levels of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Cardiac levels of tumor necrosis factor-α (TNF-α) were increased, while vascular endothelial growth factor (VEGF, the major angiogenic factor) was decreased. Pretreatment with Se normalized the cardiac enzymes, lipid peroxidation, GSH, SOD, CAT, GPx, TNF-α and VEGF (P<0.001) and reduced the immunostaining of p47 phox subunit. However, Se failed to correct the dyslipidemia. Cr(pic)3 significantly improved lipid profile (P<0.001) and all other biochemical deviations except for VEGF. Zn, but to lesser extent, reduced the oxidative damage and TNF-α levels and improved both dyslipidemia and angiogenesis. Combination therapy exhibited less prominent protection compared to individual metals. CONCLUSION: Daily supplementation with trace metals is promising for improving myocardial performance via preventing oxidative damage, induction of angiogenesis, anti-inflammatory and/or anti-hyperlipidemic mechanisms.

Bioavailability of zinc sources and their interaction with phytates in broilers and piglets.

Zinc (Zn) is essential for swine and poultry and native Zn concentrations in feedstuffs are too low to meet their Zn requirement. Dietary Zn bioavailability is affected by phytate, phytase and Zn supplemented in organic form is considered as more bioavailable than inorganic sources. A meta-analysis using GLM procedures was processed using broiler and piglet databases to investigate, within the physiological response of Zn, (1) the bioavailability of inorganic and organic Zn sources (Analysis I); (2) the bioavailability of native and inorganic Zn dependent from dietary phytates, vegetal and supplemental phytase activity (Analysis II). Analysis I: the bioavailability of organic Zn relative to inorganic Zn sources ranged, depending on the variable, from 85 to 117 never different from 100 (P > 0.05). The coefficients of determination of the regressions were 0.91 in broilers and above 0.89 in piglets. Analysis II: in broilers, bone Zn was explained by supplemental Zn (linear and quadratic, P < 0.001) and by supplemental phytase (linear, P < 0.001). In piglets, the interaction between dietary Zn and phytates/phytases was investigated by means of a new variable combining dietary phytic phosphorus (PP) and phytase activity. This new variable represents the remaining dietary PP after its hydrolysis in the digestive tract, mainly due to phytase and is called non-hydrolyzed phytic phosphorus (PP(NH)). Bone Zn was increased with native Zn (P < 0.001), but to a lower extent in high PP or low phytase diets (ZN(N) × PP(NH), P < 0.001). In contrast, the increase in bone zinc in response to supplemental Zn (P < 0.001) was not modulated by PP(NH) (P > 0.05). The coefficients of determination of the regressions were 0.92 in broilers and above 0.92 in piglets. The results from the two meta-analyses suggest that (1) broilers and piglets use supplemented Zn, independent from Zn source; (2) broiler use native Zn and the use is slightly enhanced with supplemental phytase; (3) however, piglets are limited in the use of native Zn because of the antagonism of non-hydrolyzed dietary phytate. This explains the higher efficacy of phytase in improving Zn availability in this specie.

The disposition and intestinal absorption of zinc in rats.

The variety of physiologic and biologic functions of zinc is expected to enable the development of zinc-related medicines. In this study, the distribution of endogenous zinc, the disposition after intravenous injection, and the intestinal absorption of zinc were investigated in vivo using rats from the viewpoints of pharmaceutical science and pharmacokinetics. High levels of endogenous zinc were observed in bone, testis, and liver. RT-PCR analysis on the mRNA of metallothionein in tissues clarified that it is significantly correlated with the distribution of zinc, suggesting that zinc is accumulated in tissues as a complex with MT. Following intravenous injection, uptake of zinc was high in liver, spleen, pancreas, kidney, and intestine. Fractional absorptions of zinc after oral administration to fasted rats were greater than those to fed rats, suggesting that some factors in diet inhibit the absorption of zinc. In fasted rats, fractional absorption was slightly decreased in high-dose group, suggesting the involvement of carrier-mediated transport. Study utilizing an in situ closed-loop method also indicated saturable intestinal absorption of zinc. These findings will further the research and development of zinc-related medicines by providing basic and important information on zinc.

Regulatory role of zinc on the biokinetics and biodistribution of (65)Zn during the initiation of experimentally induced colon cancer.

The present study was conducted to evaluate the kinetics of zinc utilization during the formation of colon carcinoma in an animal model of colon carcinogenesis. The rats were segregated into 4 groups: untreated control, 1,2-dimethylhydrazine (DMH) treated, zinc treated, and DMH+zinc treated. Colon carcinogenesis was initiated through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 8 wk. Zinc (in the form of zinc sulphate) was supplemented at a dose level of 227 mg/L in drinking water, ad libitum for the entire duration of study. Whole body (65)Zn kinetics followed two-compartment kinetics, with Tb(1) representing the initial fast component of the biological half-life and Tb(2), the slower component. The Tb(1) component showed a significant elevation while the Tb(2) component was significantly diminished in DMH-treated rats, which, however, got normalized following zinc supplementation. The biodistribution and subcellular distribution of (65)Zn was significantly affected in DMH-treated rats when compared to normal control rats. However, zinc significantly reversed the altered (65)Zn uptake in different organs and various fractions of colon. The present study for the first time demonstrated a faster mobilization of zinc during initiation of experimentally induced colon carcinoma and provides a physiological basis for the role of zinc in colon tumorigenesis.

Bioavailability of zinc from NutriSet zinc tablets compared with aqueous zinc sulfate.

BACKGROUND/OBJECTIVES: The apparent widespread extent of zinc (Zn) deficiency in developing countries and the efficacy of oral Zn supplements as an adjunct to oral rehydration therapy make oral Zn supplementation an increasingly important modality in clinical medicine and public health. In this study we aimed to compare the relative bioavailability of oral doses of 30 mg of Zn in two dosing forms. SUBJECTS/METHODS: In total, 10 healthy male volunteers ingested oral Zn doses with 200 ml plain water at about 0830 hours in the fasting state on two occasions, once as 30 mg of Zn in an aqueous solution of reagent grade zinc sulfate (ZnSO(4)) and another time as 1.5 NutriSet Zn tablets (Nutriset, Malaunay, France); on a third occasion, only plain water was consumed. Venous blood specimens were collected at baseline, 60, 120, 180 and 240 min after ingestion and the plasma Zn was measured for each sample. RESULTS: The relative bioavailability of oral Zn from a commonly used, tableted (NutriSet) form is only about half of that of a reference dose of aqueous ZnSO(4) as indicated by the area under the curve of serial plasma Zn excursion and maximal change in circulating Zn. CONCLUSIONS: Reduced or absent functional outcomes in Zn intervention trials may derive, in part, from a lower than anticipated intestinal uptake of the Zn in the tableted form.

[Efficacy of using zinc oxide nanoparticles in nutrition. Experiments on the laboratory animal].

In experiments on rats there was researched bioavailability of zinc oxide (ZnO) nanoparticles. There were determined the content of Zn in blood serum and tibia, intestinal uptake of macromolecules of egg albumin, some hematological, biochemical and immune indices, liver cells apoptosis. The results obtained show that the uptake of nanoparticles of ZnO enables restoration of this microelement status damaged by zinc deficit diet.

Changing the zinc:iron ratio in a cereal-based nutritional supplement has no effect on percent absorption of iron and zinc in Sri Lankan children.

The Thriposha programme is a community-level nutrition intervention in Sri Lanka that provides a combination of energy, protein and micronutrients as a 'ready-to-eat' cereal-based food. We measured the bioavailability of Fe and Zn from Thriposha formula at two different molar ratios of Zn:Fe in order to determine the effect on Fe and Zn absorption. Children 4-7 years (n 53) were given a meal prepared with 50 g Thriposha containing 1.5 mg Zn as zinc sulphate and either 9 mg (high Fe concentration (HiFe)) or 4.5 mg (low Fe concentration (LoFe)) Fe as ferrous fumarate. Zn and Fe percent absorption were measured using stable isotopes by tracer:tracee ratio and by incorporation of erythrocytes, respectively. Percent Fe absorption from the two meals was similar (6.6 % (4.8) v. 4.8 % (2.6); P = 0.15), but total Fe absorption was significantly higher from the HiFe meal (0.59 (0.43) mg) than the LoFe meal (0.20 (0.12) mg; P = 0.01). There was no significant difference between the two groups in Zn absorption (10.7 % (0.9) v. 8.8 % (1.4), P = 0.13, respectively). Decreasing the amount of Fe in Thriposha did not cause a significant change in the percent absorption of Fe and Zn, but significantly lowered the total amount of absorbed Fe. These results demonstrate the utility of maintaining a higher Fe content in this supplement. Further studies to increase Zn content are warranted while maintaining a HiFe.

Effect of parenteral zinc sulfate on colon anastomosis repair in the rat.

BACKGROUND AND AIMS: To prevent colonic anastomotic dehiscence, pharmaceutical interventions should inhibit degradation of existing submucosal collagen fibers and accelerate the synthesis of new collagen molecules. Zinc has multiple functions in collagen metabolism and was recently found beneficial in colonic anastomosis repair. We have investigated the effect of daily intraperitoneal zinc (2 mg/kg) injections on the development of the biomechanical integrity of left colon anastomoses. MATERIALS AND METHODS: Sixty Sprague-Dawley male rats (median 245 g) were allocated to treatment with zinc sulfate in saline (n = 30) or with saline alone (n = 30) starting 1 h before the anastomoses were made. Serum zinc levels and anastomotic breaking strength were determined on postoperative days 3 (n = 30) and 7 (n = 30). The initial breaking strength or suture-binding capacity was determined in additional ten non-treated animals (277 g). RESULTS: The breaking strength of the anastomoses decreased in the two groups combined (n = 30) by 50% (p < 0.001) on day 3 but was regained by postoperative day 7 compared with the initial anastomotic biomechanical strength. Serum zinc levels also increased from day 3 to day 7 in both intervention groups and correlated significantly with breaking strength (r = 0.57, p < 0.001). Although the median serum zinc level was 14% higher (p < 0.01) on day 7 in zinc-treated than in saline-treated animals, the breaking strength did not differ significantly between zinc-treated and saline-treated rats on either day 3 (p = 0.95) or day 7 (p = 0.70). CONCLUSION: In contrast to previous report in rabbits, we failed to demonstrate the beneficial effects of parenteral zinc supplementation on colon anastomosis repair in a rat model.

Zinc sulphate following the administration of iodine-131 on the regulation of thyroid function, in rats.

Hyperthyroidism in men is often treated with high doses of iodine-131 ((131)I), which may induce radiation side effects to patients and their environment. These therapeutic doses of (131)I could be decreased, if the (131)I uptake of the thyroid gland of the patients could be increased. Zinc sulphate has been considered to exercise a protective role by maintaining the cellular integrity of the thyroid under various pathological states. The aim of our study was to study in Wistar rats whether zinc sulphate can after treatment of the thyroid gland with (131)I: a) increase the uptake of (131)I in the thyroid and b) stabilize the function of the follicular cells. If such a stabilization finally exists in men we could have favorable results like fewer cases of hypothyroidism after (131)I treatment of hyperthyroidism. To carry out these investigations, rats were divided into four groups comprising of eight animals each. Group I animals served as normal controls. Group II animals received a dose of 3.7 MBq of (131)I. Group III animals were supplemented with zinc (227 mg/L of drinking water) and animals in Group IV were given (131)I together with zinc sulphate as above. Our results showed that in Group II, serum levels of tetra-iodo-thyronine (T(4)) and tri-iodo-thyronine (T(3)) decreased significantly as a function of time following (131)I treatment. An increase in the levels of serum thyroid stimulating hormone (TSH) was noticed one week after (131)I treatment, becoming less pronounced with time. In Group II, thyroid uptake at 2h and at 24h was significantly decreased. In the same Group biological half life (T(biol)) of (131)I in the thyroid gland, was significantly elevated four weeks after the administration of (131)I and decreased eight weeks after. In Group IV animals, zinc sulfate after four weeks, induced normalization of elevated serum TSH levels and a further increase in the T(biol) of (131)I. After eight weeks in these animals, serum T(3) became normal and TSH remained at normal levels. Thyroid (131)I uptake at 2 and 24 h was increased as compared to Group II. Group III animals showed some increase in the levels of Na(+)K(+)ATPase and type 1,5'-deiodinase (5'-DI) as compared to normal rats of Group I. In conclusion, this study suggests the protective potential of zinc sulphate in the disturbed after (131)I treatment, thyroid function, thyroid hormones and TSH while the (131)I uptake was reduced. Thus, if this result is further confirmed, zinc sulphate may show to be a promising radioprotective agent for the thyroid gland.

Chemopreventive potential of zinc in experimentally induced colon carcinogenesis.

The present study was performed to evaluate the efficacy of zinc treatment on colonic antioxidant defense system and histoarchitecture in 1,2-dimethylhydrazine- (DMH) induced colon carcinogenesis in male Sprague-Dawley rats. The rats were segregated into four groups viz., normal control, DMH treated, zinc treated, DMH+zinc treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 16 weeks. Zinc (in the form of zinc sulphate) was supplemented to rats at a dose level of 227 mg/L in drinking water, ad libitum for the entire duration of the study. Increased tumor incidence, tumor size and number of aberrant crypt foci (ACF) were accompanied by a decrease in lipid peroxidation, glutathione-S-transferase, superoxide dismutase (SOD) and catalase. On the contrary, significantly increased levels of reduced glutathione (GSH) and glutathione reductase (GR) were observed in DMH treated rats. Administration of zinc to DMH treated rats significantly decreased the tumor incidence, tumor size and aberrant crypt foci number with simultaneous enhancement of lipid peroxidation, SOD, catalase and glutathione-S-transferase. Further, the levels of GSH and GR were also decreased following zinc supplementation to DMH treated rats. Well-differentiated signs of dysplasia were evident in colonic tissue sections by DMH administration alone. However, zinc treatment to DMH treated rats greatly restored normalcy in the colonic histoarchitecture, with no apparent signs of neoplasia. EDXRF studies revealed a significant decrease in tissue concentrations of zinc in the colon following DMH treatment, which upon zinc supplementation were recovered to near normal levels. In conclusion, the results of this study suggest that zinc has a positive beneficial effect against chemically induced colonic preneoplastic progression in rats induced by DMH.

Long term excessive Zn-supplementation promotes metabolic syndrome-X in Wistar rats fed sucrose and fat rich semisynthetic diet.

During the last two decades Zinc (Zn) as a micronutrient is being used indiscriminately in agricultural and husbandry practices and also in baby foods and multivitamin supplements with a view that Zn is non-toxic and promotes linear growth and body weight in the consumers. The long-term effect of increasing Zn load in the body has not been worked out so far. In this study, three groups of rats were fed on a semi-synthetic diet containing 20 mg (control, group-I), 40 mg (group-II) and 80 mg Zn /kg (group-III) diet respectively for 6 months. The results revealed that the gain in body weight increased in rats in Zn-concentration dependent manner. The urine examined on weekly basis showed glucosuria in group-II on week 10 and in group-III on week 8 and thereafter. The arterial blood pressure was significantly higher in group-II and III than their control counter parts on monthly basis. Histochemical examination of skin revealed an increase in the number of adipocytes filled with triglycerides making a subcutaneous fatty tissue thicker in group-II and group-III than that of control group. The blood profile after 180 days of dietary treatment, displayed a significant rise in glucose, total lipids, cholesterol, triglycerides, LDL-cholesterol, VLDL-cholesterol, insulin, cortisol and aldosterone whereas HDL-cholesterol, T3, T4 and TSH showed a reduction in their levels in the blood serum. The tissue metal status showed an increase of Zn, Cu and Mg in the serum, a rise in Zn in liver, hair and abdominal muscles and fall in Cu and Mg concentrations in liver, hair and abdominal muscles. This data suggest that Zn in excess in diet when fed for longer periods of time induces metabolic syndrome-X.

Bioavailability of zinc glycinate in comparison with zinc sulphate in the presence of dietary phytate in an animal model with Zn labelled rats.

The objective of this study was to quantify the bioavailability of zinc (Zn) from sulphate and glycinate as representatives of inorganic and organic zinc sources. The semi-synthetic basal diet contained 2 microg/g of native Zn and was fortified with pure sodium-phytate (8 g/kg) in order to simulate conditions of common cereal-based meals. The basal diet was supplemented with either 53 microg/g of Zn from sulphate (control) or 10 microg/g of Zn from either sulphate (ZnSulphate) or glycinate (ZnGly). Twenty-four (65)Zn-labelled, growing rats weighing 133 g were allotted to the three diets (eight animals per treatment) and were kept pair-fed to ZnSulphate for 15 days. Zn contents in blood plasma, femur and whole body, as well as, plasma alkaline phosphatase activities were reduced compared with control indicating a zinc deficiency in ZnSulphate and ZnGly treatment. This allowed their differentiation in zinc bioavailability. True absorption of dietary Zn was significantly higher in ZnGly than in ZnSulphate (51% vs. 44%) while losses of endogenous faecal Zn and urinary Zn were not affected to a quantitatively relevant extent (mean: 17% and 2% of intake). This resulted in a +30% significantly improved Zn retention for ZnGly (33% vs. 25%) and a lower severity on Zn deficiency symptoms compared with ZnSulphate. Metabolic utilization accounted for 95% of absorbed dietary Zn for both Zn sources. Overall, the bioavailability of zinc glycinate was significantly superior by 16% to zinc sulphate (49% vs. 42%), mainly because of a higher absorptive potential at presence of a strong anti-nutritive component (phytate) in the diet.

Effects of organic forms of zinc on growth performance, tissue zinc distribution, and immune response of weanling pigs.

This study was conducted to determine the effect of zinc level and source on growth performance, tissue Zn concentrations, intracellular distribution of Zn, and immune response in weanling pigs. Ninety-six 3-wk-old crossbred weanling pigs (BW = 6.45 +/- 0.17 kg) were assigned to one of six dietary treatments (four pigs per pen, four replicates per treatment) based on weight and litter origin. Treatments consisted of the following: 1) a corn-soybean meal-whey diet (1.2% lysine) with a basal level of 80 ppm of supplemental Zn from ZnSO4 (control; contained 104 ppm total Zn); 2) control + 80 ppm added Zn from ZnSO4; 3) control + 80 ppm added Zn from Zn methionine (ZnMet); 4) control + 80 ppm added Zn from Zn lysine (ZnLys); 5) control + 40 ppm added Zn from ZnMet and 40 ppm added Zn from ZnLys (ZnML); and 6) control + 160 ppm added Zn from ZnSO4. Zinc supplementation of the control diet had no effect on ADG or ADFI. Gain efficiency was less (P < 0.05) for pigs fed 80 ppm of Zn from ZnSO4 than for control pigs and pigs fed 160 ppm of Zn from ZnSO4. Organ weights, Zn concentration, and intracellular distribution of Zn in the liver, pancreas, and spleen were not affected (P = 0.12) by Zn level or source. Skin thickness response to phytohemagglutinin (PHA) was not affected (P = 0.53) by dietary treatment. Lymphocyte proliferation in response to PHA was greater (P < 0.05) in pigs fed ZnLys than in pigs fed the control diet or the ZnML diet; however, when pokeweed mitogen was used, lymphocyte proliferation was greatest (P < 0.05) in pigs fed the ZnMet diet than pigs fed the control, ZnLys, ZnML, or 160 ppm ZnSO4 diets. Antibody response to sheep red blood cells was not affected by dietary treatments. Supplementation of 80 ppm of Zn from ZnSO4 or ZnMet and 160 ppm of Zn from ZnSO4 decreased (P < 0.05) the antibody response to ovalbumin on d 7 compared with control pigs, but not on d 14. Phagocytic capability of peritoneal exudate cells was increased (P < 0.05) when 160 ppm of Zn from ZnSO4 was supplemented to the diet. The number of red blood cells ingested per phagocytic cell was increased (P < 0.05) in pigs fed the diet supplemented with a combination of ZnMet and ZnLys and the diet with 160 ppm of Zn from ZnSO4. Results suggest that the level of Zn recommended by NRC for weanling pigs was sufficient for optimal growth performance and immune responses, although macrophage function may be enhanced at greater levels of Zn. Source of Zn did not alter these measurements.

Bioavailability of zinc in fiber-enriched bread fortified with zinc sulphate.

The present study aimed to reduce the caloric value of bread by substituting a part of wheat flour with artichoke bracts at levels of 5%, 10% and 15% without sacrificing taste, texture or acceptability. Moreover, considerable trials had been made to reduce zinc deficiency in wheat bread and fiber-enriched bread and also to study the effect of fiber on zinc bioavailability. Therefore, zinc sulphate was added to bread at levels of 40, 60, 80, 100 and 120 mg/100 g edible portion. The results from this study show that: (i) The addition of artichoke bracts to wheat flour increased the water absorption, arrival time, development time, and weakening of the dough as the level of artichoke bracts increased, while dough stability decreased. (ii) Mixing wheat flour with increasing amount of artichoke bracts increased the content of protein, fiber and total essential amino acids, also all essential amino acids increased in wheat bread and fiber-enriched bread after fortification with zinc sulphate at a level of 100 mg/100 g edible portion except methionine, threonine and tyrosine. (iii) The best level of zinc sulphate to give the best bioavailability for zinc is 100 mg/100 g edible portion. (iv) Evaluation of fortified wheat bread and fiber-enriched bread with zinc sulphate showed no significant difference by test panel.