Research Note: Relative bioavailability of zinc in zinc hydroxychloride for chicks.

A chick assay was conducted to determine the effects of Zn source on performance and to establish a Zn relative bioavailability value (RBV) for a new source of Zn hydroxychloride. In the assay, 8-day-old chicks were fed a Zn-deficient soy protein concentrate diet supplemented with 0, 7, and 15 mg Zn/kg from feed grade ZnSO4 monohydrate for 14 d to establish a standard response curve. The same basal diet was supplemented with 3, 7, and 10 mg Zn/kg from a new Zn hydroxychloride (SAMZn). A second source of Zn hydroxychloride (IBZn) was supplemented at 10 mg Zn/kg as a direct comparison to the highest level of SAMZn. Weight gain increased (P < 0.05) with increasing Zn level, regardless of source. Weight gain of chicks fed 7 mg Zn/kg from SAMZn was not different (P > 0.05) from chicks fed 15 mg Zn/kg from ZnSO4. Weight gain was not different (P > 0.05) when comparing the 2 sources of Zn hydroxychloride supplemented at 10 mg Zn/kg. Tibia ash Zn and total tibia Zn were increased (P < 0.05) by all Zn sources and responded linearly (P < 0.05) to Zn supplementation from ZnSO4 and SAMZn. Total tibia Zn concentration was not different (P > 0.05) for chicks fed 10 mg Zn/kg from either source of Zn hydroxychloride. Multiple linear regression of total tibia Zn on supplemental Zn intake (R2 = 0.95) resulted in a RBV of 115% for SAMZn compared with ZnSO4 (set at 100%). The RBV of SAMZn was higher (P < 0.05) than ZnSO4. In conclusion, relative bioavailability of Zn (based on tibia Zn) in Zn hydroxychloride from SAMZn was higher than feed grade ZnSO4 based on multiple regression slope-ratio analysis and was similar to that of IBZn Zn hydroxychloride based on tibia Zn responses to 10 mg/kg supplemental dietary Zn.

Zinc ameliorates human aortic valve calcification through GPR39 mediated ERK1/2 signalling pathway.

AIMS: Calcific aortic valve disease (CAVD) is the most common heart valve disease in the Western world. It has been reported that zinc is accumulated in calcified human aortic valves. However, whether zinc directly regulates CAVD is yet to be elucidated. The present study sought to determine the potential role of zinc in the pathogenesis of CAVD. METHODS AND RESULTS: Using a combination of a human valve interstitial cell (hVIC) calcification model, human aortic valve tissues, and blood samples, we report that 20 µM zinc supplementation attenuates hVIC in vitro calcification, and that this is mediated through inhibition of apoptosis and osteogenic differentiation via the zinc-sensing receptor GPR39-dependent ERK1/2 signalling pathway. Furthermore, we report that GPR39 protein expression is dramatically reduced in calcified human aortic valves, and there is a significant reduction in zinc serum levels in patients with CAVD. Moreover, we reveal that 20 µM zinc treatment prevents the reduction of GPR39 observed in calcified hVICs. We also show that the zinc transporter ZIP13 and ZIP14 are significantly increased in hVICs in response to zinc treatment. Knockdown of ZIP13 or ZIP14 significantly inhibited hVIC in vitro calcification and osteogenic differentiation. CONCLUSIONS: Together, these findings suggest that zinc is a novel inhibitor of CAVD, and report that zinc transporter ZIP13 and ZIP14 are important regulators of hVIC in vitro calcification and osteogenic differentiation. Zinc supplementation may offer a potential therapeutic strategy for CAVD.

Zinc supplementation alleviates endoplasmic reticulum stress during porcine oocyte in vitro maturation by upregulating zinc transporters.

Endoplasmic reticulum (ER) stress is a major contributor to embryonic development failure. Mammalian oocytes have a high risk of exposure to cellular stress during in vitro embryo production. We investigated the effects of zinc supplementation during in vitro maturation under ER stress. We evaluated cumulus expansion, embryonic development derived by parthenogenetic activation, reactive oxygen species, protein expression of X-box binding protein 1 (XBP1), and expression of genes related to ER stress. Supplementation with 1 µg/ml zinc significantly increased the nuclear maturation of oocytes, cleavage and blastocyst formation rates, and total blastocyst cell number (p < .05). Under ER stress, zinc significantly reduced protein expression of XBP1, and increased cleavage and blastocyst rates (p < .05). Concomitantly, zinc supplementation upregulated the expression of zinc transporters (SLC39A14 and SLC39A10), PTGS2, and downregulated ER stress-related genes (sXBP1, uXBP1, ATF4, and PTPN1/PTP1B), and caspase 3. These results suggest that zinc supplementation alleviates ER stress by providing essential metal-ion transporters for oocyte maturation and subsequent embryonic development.

Comparative digestibility of polysaccharide-complexed zinc and zinc sulfate in diets for gestating and lactating sows.

We hypothesized that the digestibility of a zinc polysaccharide complex is greater than zinc sulfate when sows consume high fiber diets containing corn dried distillers grains with solubles (DDGS). Gilts and sows (n = 32) were blocked according to parity and assigned randomly to one of four dietary treatments (n = 8 sows per treatments). Dietary treatments consisted of: 1) Control (ConZnSO4)-corn-soybean meal-based diet + 100 ppm supplemental Zn from ZnSO4; 2) Control PSZn (ConPSZn)-corn-soybean meal-based diet + 100 ppm supplemental Zn from Zn polysaccharide complex; 3) DDGS/ZnSO4-corn-soybean meal-40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from ZnSO4; 4) DDGS/PSZn-corn-soybean meal-40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from Zn polysaccharide complex. A fifth dietary treatment was imposed using a subset of sows (n = 20) to determine basal Zn losses in gestating and lactating sows fed corn-soybean meal-based diets containing no supplemental Zn. Nutrient balance experiments were conducted in both gestation and lactation to evaluate the digestibility of Zn sources of the four dietary treatments and to determine basal Zn losses when no supplemental Zn was provided. The statistical model included fixed effects of diet, Zn source, and their interaction, and random effects of parity. Estimated endogenous losses of Zn were used to adjust apparent total tract digestibility (ATTD) to true total tract digestibility (TTTD) of Zn in the four dietary treatment balance periods. There were no differences in Zn concentrations of urine, plasma, colostrum, or milk samples among treatments at any time of the experiment (P > 0.05). Gestating sows fed DDGS/PSZn had improved (P < 0.05) ATTD, TTTD, and overall retention of Zn compared with both Control treatments, with the DDGS/ZnSO4 treatment responses being intermediate. Lactating sows consuming diets without DDGS and supplemented with Zn polysaccharide complex had the greatest (P < 0.05) ATTD, TTTD, and retention of Zn, which were opposite to responses observed in gestation. Furthermore, ATTD, TTTD, and Zn retention for lactating sows consuming DDGS/PSZn were less (P < 0.05) than all other treatments. Overall, zinc digestibility of ZnSO4 and PSZn appears to be differentially influenced by the stage of the reproductive cycle and presence of dietary fiber from DDGS.

Copper and zinc sources and levels of zinc inclusion influence growth performance, tissue trace mineral content, and carcass yield of broiler chickens.

A 35-d experiment was conducted in broilers to study the effect of supplementation of sulfate or hydroxychloride forms of Zn and Cu at 2 supplemental Zn levels on growth performance, meat yield, and tissue levels of Zn. On day 0, 900 male Ross 308 broiler chicks (45 ± 1.10 g) were allocated to 4 treatments in a randomized complete block design and 2 × 2 factorial arrangement of treatments. The factors were 2 sources (sulfate or hydroxychloride) of Zn and Cu and 2 levels (low or high) of Zn. The Zn sources were zinc sulfate monohydrate (ZSM) or hydroxychloride Zn. Copper sources were copper (II) sulfate pentahydrate or hydroxychloride Cu. Each of the 4 treatments had 15 replicates and 15 birds per replicate. Birds were weighed on days 0, 21, and 35 for growth performance. On day 35, left tibia bone, liver, and blood were collected from 4 randomly selected birds per pen. In addition, 7 birds per pen were used for carcass evaluation. There was no significant source × level interaction on any of the growth performance response. Broiler chickens receiving hydroxychloride Zn and Cu had greater (P < 0.05) gain: feed, whereas broiler chickens receiving lower Zn level had greater (P < 0.01) weight gain. There was no source × level interaction on meat yield. Broiler chickens receiving hydroxychloride Zn and Cu had greater (P < 0.05) % breast yield than those receiving sulfate Zn and Cu. Higher level of Zn, irrespective of source, produced greater (P < 0.01) tibia and plasma Zn levels, whereas liver Cu was greater (P < 0.05) in broiler chickens receiving hydroxychloride Zn and Cu. It was concluded that hydroxychloride Zn and Cu were more efficacious than sulfate Zn and Cu in promoting growth performance and enhancing meat yield in the current study.

Comparison of the Oral Absorption, Distribution, Excretion, and Bioavailability of Zinc Sulfate, Zinc Gluconate, and Zinc-Enriched Yeast in Rats.

SCOPE: The oral absorption, distribution, excretion, and bioavailability of zinc sulfate (ZnS), zinc gluconate (ZnG), and zinc-enriched yeast (ZnY) in rats are fully and systemically compared for the first time. METHODS AND RESULTS: After zinc compounds were orally administered to rats at a single dose of 4 mg Zn kg-1 , blood, tissues, urine, and feces at different time points were collected for the quantification of zinc concentration. Blood was also harvested for the zinc assay in the multiple-dose administration. Plasma zinc levels among three zinc compounds showed no difference, and zinc was widely distributed in various tissues with the level sequence of bone > liver > pancreas > testes. The net Zn balance was 2.993, 5.125, and 7.482% for ZnS, ZnG, and ZnY, respectively. CONCLUSION: ZnS, ZnG, and ZnY show equivalent bioavailability based on plasma and tissues zinc levels, although ZnY was statistically more absorbed and retained than ZnS and ZnG based on the excretion amount.

Effect of feed supplementation with zinc glycine chelate and zinc sulfate on cytokine and immunoglobulin gene expression profiles in chicken intestinal tissue.

The aim of the study was to evaluate the effect of inorganic and organic forms of Zn on the expression of cytokines (IL-2, TNF-α, IFN-γ, IL-12, IL-17, IL-4, IL-10, and TGF-ß) and immunoglobulins (IgA and IgG) in the tissues of the small intestine (jejunum and ileum) of broiler chickens. In the experiment, 90 broiler chickens were divided into 4 experimental groups and a control group, with 18 birds each. The birds received Zn supplements in inorganic form with and without phytase (ZnSO4 and ZnSO4 + F), and in organic form with glycine, with and without phytase (Zn-Gly and Zn-Gly + F). The total rearing period was 42 days. Quantitative real-time (RT)-PCR was used to measure the expression of the cytokines and immunoglobulins. The differences between the results obtained for the control and experimental groups, between the groups receiving ZnSO4 and Zn-Gly, and between groups ZnSO4-F and Zn-Gly-F were analyzed statistically. High relative expression of IL-2 was observed for the chickens in the groups receiving ZnSO4-F, Zn-Gly, and Zn-Gly-F on d 42 in comparison to the control group. High relative expression of TNF-α, IL-12, and IL-17 was noted in the group that received ZnSO4 + F. High expression of IgG, IgA, IL-4, TGF-ß, and IL-10 was noted in the groups of chickens that received feed supplemented with Zn-Gly and Zn-Gly + F chelates on d 42 of the study in comparison to the control group. In conclusion, supplementation with Zn-Gly chelates can ensure Th1 and Th2 balance during the immune response in the gut-associated lymphoid tissue (GALT), and, by increasing IgA and IgG expression, also can stimulate potentiation of the immune response involved in passive protection of the body from infection. In contrast, the use of inorganic forms of Zn, in the form of sulfates, can induce local inflammatory processes in the intestines, which, in the case of long-term supplementation, lead to the development of infections.

Changes in Zn homeostasis during long term culture of primary endothelial cells and effects of Zn on endothelial cell senescence.

Endothelial cell senescence and Zn nutritional status influence cardiovascular disease. The influence of Zn appears dichotomous, hence it is imperative to understand the relationship with cellular senescence to improve knowledge about the molecular and cellular basis of the disease. Here we aimed to determine: 1) the impact of chronic exposure to a moderately high dose of Zn on senescence of endothelial cells; 2) the changes in Zn homeostasis during the lifespan of primary cultured endothelial cells; and 3) the susceptibility of proliferating and senescent endothelial cells to cell death after short term exposure to increasing doses of Zn and of the Zn chelator TPEN. Chronic exposure to Zn accelerated senescence and untreated cells at later passages, where doubling time had increased, displayed relocation of labile Zn and altered expression of genes involved in the response to Zn toxicity, including SLC30A1, SLC39A6, SLC30A5, SLC30A10 and metallothioneins, indicating that senescent cells have altered zinc homeostasis. Most Zn-dependent genes that were expressed differently between early and late passages were correlated with changes in the expression of anti-apoptotic genes. Short-term treatment with a high dose of Zn leads to cell death, but only in the population of cells at both earlier and later passages that had already entered senescence. In contrast, Zn depletion led to death of cells at earlier but not later passages, which suggests that there are sub-populations of senescent cells that are resistant to Zn depletion. This resistant senescent cell population may accumulate under conditions of Zn deficiency and contribute to vascular pathology.

Comparative effects of zinc-nano complexes, zinc-sulphate and zinc-methionine on performance in broiler chickens.

Micronutrients, especially zinc, have an important role in normal metabolism and growth of broilers. Using novel technologies helps to synthesise novel zinc complexes to deliver this micronutrient more efficiently. In the present study, the effects of different zinc complexes and nano complexes on broiler performance were compared. Broilers in 6 groups were given basal diet (without zinc) and basal diet supplemented with zinc-sulphate, zinc-methionine, zinc-nano-sulphate, zinc-nano-methionine and zinc-nano-max (that was synthesised based on nanochelating technology) at a concentration of 80 mg/kg of diet. At 1-42 d of age, dietary zinc-nano-sulphate supplementation decreased weight gain and feed intake. However, feed conversion ratio was not influenced by treatments. Carcass yield (%) of birds in the zinc-nano-sulphate and control groups were dramatically reduced at 42 d of age and abdominal fat (%) increased in these groups. Relative to the control group, the antibody titre, spleen and bursa of Fabricius (%) were significantly higher in groups supplemented with zinc. Heterophil (%) was also significantly higher in the zinc-nano-methionine group in blood on d 42 compared to the control, zinc-sulphate and zinc-nano-sulphate. Compared to the controls, the mean malondialdehyde content in thigh tissue was significantly reduced in groups supplemented with zinc at the time 0, 50, 100 and 150 min after oxidation. Tibia zinc concentration in nanoparticle zinc samples was significantly higher relative to the control and zinc-sulphate groups. Taken together, our data indicate that delivery of zinc in the structure of zinc-nano-methionine and zinc-nano-max at concentrations of 80 mg/kg of diet improves growth performance. However, dietary zinc-nano-sulphate decreased growth performance in broilers.

Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide.

Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P < 0.001). Adding Na2EDTA at an EDTA:zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P < 0.02). The combined inhibitory effect of polyphenols and PA was overcome by EDTA. In conclusion, ZnSO4 was better absorbed than ZnO, phytase used to degrade PA during digestion or during food preparation substantially increased zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

Effect of increasing levels of zinc fortificant on the iron absorption of bread co-fortified with iron and zinc consumed with a black tea.

Iron (Fe) and zinc's (Zn) interaction at the absorptive level can have an effect on the success of co-fortification of wheat flour with both minerals on iron deficiency prevention. The aim of the study was to determine the effect of increasing levels of zinc fortificant on the iron absorption of bread co-fortified with iron and zinc consumed with a black tea. Twelve women aged 33-42 years participated in the study. They received on four different days 200 mL of black tea and 100 g of bread made with wheat flour (70% extraction) fortified with either 30 mg Fe/kg alone, as ferrous sulfate (A), or with the same Fe-fortified flour, but with graded levels of Zn, as zinc sulfate: 30 mg/kg (B), 60 mg/kg (C), or 90 mg/kg (D). Fe radioisotopes ((59)Fe and (55)Fe) of high specific activity were used as tracers, and Fe absorption iron was measured by the incorporation of radioactive Fe into erythrocytes. The geometric mean and range of ±1 SD of Fe absorption were as follows: A = 6.5% (2.2-19.3%), B = 4.6% (1.0-21.0%), C = 2.1% (0.9-4.9%), and D = 2.2% (0.7-6.6%), respectively; ANOVA for repeated measures F = 10.9, p < 0.001 (Scheffè's post hoc test: A vs. C, A vs. D, B vs. C, and B vs. D; p < 0.05). We can conclude that Fe absorption of bread made from low-extraction flour fortified with 30 mg/kg of Fe, as ferrous sulfate, and co-fortified with zinc, as zinc sulfate consumed with black tea is significantly decreased at a zinc fortification level of ≥60 mg/kg flour.

Associations between intestinal mucosal function and changes in plasma zinc concentration following zinc supplementation.

OBJECTIVES: Subclinical environmental enteropathy is associated with malabsorption of fats, carbohydrates, and vitamins A, B12, and folate; however, little information is available on mineral absorption. We therefore investigated the relation between intestinal mucosal function (measured by the lactulose:mannitol permeability test and plasma citrulline concentration), and zinc (Zn) absorption, as estimated by the change in plasma Zn concentration (PZC) following short-term Zn or placebo supplementation. METHODS: We conducted a randomized, partially masked, placebo-controlled trial among 282 apparently healthy children 6 to 23 months of age in Burkina Faso. After completing baseline intestinal function tests, participants received either 5 mg Zn, as zinc sulfate, or placebo, daily for 21 days. RESULTS: At baseline, mean ± standard deviation PZC was 62.9 ± 11.9 µg/dL; median (interquartile range) urinary lactulose:mannitol (L:M) recovery ratio and plasma citrulline concentrations were 0.04 (0.03-0.07) and 11.4 (9.0-15.6) µmol/L, respectively. Change in PZC was significantly greater in the Zn-supplemented versus placebo group (15.6 ± 13.3 vs 0.02 ± 10.9 µg/dL; P < 0.0001), and was negatively associated with initial urinary L:M recovery ratio (-1.1 µg/dL per 50% increase in urinary L:M recovery ratio; P = 0.014); this latter relation did not differ between supplementation groups (P = 0.26). Baseline plasma citrulline concentration was not associated with change in PZC. CONCLUSIONS: Although altered intestinal permeability may reduce dietary Zn absorption, it likely does not undermine the efficacy of Zn supplementation, given the large increases in PZC following short-term Zn supplementation observed in this study, even among those with increased urinary L:M recovery ratios.

Zinc sensitizes prostate cancer cells to sorafenib and regulates the expression of Livin.

In prostate carcinogenesis, normal zinc-accumulating epithelial cells are transformed into malignant cells that do not accumulate zinc. Increased levels of zinc have been shown to induce apoptosis through a caspase-dependent mechanism with down-regulated anti-apoptotic proteins in prostate cancer cells. Our previous study showed that, as a member of the inhibitor of apoptosis proteins (IAPs) family, Livin could play an important role in the initiation of human prostate cancer and promote cell proliferation by altering the G1-S cell cycle transition. In the present study, we measured the apoptosis sensitivity of prostate cancer cells to zinc and sorafenib and found that zinc sensitized prostate cancer cells to sorafenib-induced apoptosis. Surprisingly, we also found that, unlike its counterparts Survivin and cIAP2, Livin was not decreased all the time; instead, it was compensatively increased in zinc-mediated apoptosis at 48 h in prostate cancer cells. Our results offer potential treatment combinations that may augment the effect of sorafenib, and also reveal, for the first time, that increased Livin expression may play a role in the early cell death response of prostate cancer cells to zinc.

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.

Effects of diets supplemented with zinc and manganese on performance and related parameters in laying hens.

Iron is often found to be of excessive concentrations in laying hens' diets, which may cause antagonistic interactions with other minerals. This study was conducted to investigate how to supplement Zn and Mn in the diets without Fe supplementation. In experiment 1, 420 18-week Lohmann Brown layers were fed a basal diet or a basal diet supplemented with 30-0, 65-30 and 100-60 mg/kg of Zn and Mn, respectively. In experiment 2, 360 40-week Lohmann Brown layers were fed a basal diet or a basal diet supplemented with 15-0, 35-0 and 55-15 mg/kg of Mn and Zn, respectively. Minerals were supplemented in the form of sulfate. Egg production was improved by supplementing 30 mg/kg Zn or 65 mg/kg Zn in combination with 30 mg/kg Mn in experiment one. In experiment two, a significant reduction of egg performance occurred with 35 mg/kg Mn supplementation. Mn and/or Zn supplementation increased eggshell thickness in experiment one, and decreased yolk cholesterol in both experiments. Mn and/or Zn supplementation increased Zn and Mn excretion in both experiments. Serum growth hormone (GH), thyroxine (T(4) ), and insulin levels, or alkaline phosphatase (AP) activity were not affected by treatments; serum estrogen (E(2) ) and triiodothyronine (T(3) ) were different but there was no consistency by dietary treatments. This study demonstrates that 30 mg/kg supplemental Zn is necessary to obtain maximal egg production, and there seems to be no need to supply Mn in this type of diet.

Zinc supplementation attenuates high glucose-induced epithelial-to-mesenchymal transition of peritoneal mesothelial cells.

Zinc (Zn) plays an important role in preventing many types of epithelial-to-mesenchymal transition (EMT)-driven fibrosis in vivo. But its function in the EMT of the peritoneal mesothelial cells (PMCs) remains unknown. Here, we studied the Zn effect on the high glucose (HG)-induced EMT in the rat PMCs (RPMCs) and the underlying molecular mechanisms. We found that Zn supplementation significantly inhibited TGF-ß1 and ROS production, and attenuated the HG-induced EMT in the RPMCs, likely through inhibition of MAPK, NF-κB, and TGF-ß/Smad pathways.

Antioxidant and antitumor activities of selenium- and zinc-enriched oyster mushroom in mice.

Selenium and zinc are well-known essential trace elements with potent biological functions. However, the possible health benefits of the combined administration of dietary selenium and zinc have not been studied extensively. In this study, we prepared selenium- and zinc-enriched mushrooms (SZMs) containing increased levels of selenium and zinc. The effects of SZMs on antioxidant and antitumor activities were evaluated. Mice were fed with either a control diet or a diet supplemented with SZMs or sodium selenite and zinc sulfate for 6 weeks. Antioxidant capacity was investigated by measuring the activities of antioxidant enzymes and the levels of lipid peroxide products. Results showed that treatment with SZMs significantly increased the activities of glutathione peroxidase (GPx) and superoxide dismutase and decreased the levels of malondialdehyde and lipofuscin. Furthermore, using a mouse model of lung tumors, we found that SZMs significantly decreased the number of tumor nodes with an increase in the activity of GPx. SZMs had a greater effect on the increase in both antioxidant and antitumor activities than did sodium selenite and zinc sulfate. These findings suggest that SZMs may be effective for improving antioxidant capacity and preventing tumors.

Short-term zinc supplementation with dispersible tablets or zinc sulfate solution yields similar positive effects on plasma zinc concentration of young children in Burkina Faso: a randomized controlled trial.

OBJECTIVE: To assess zinc absorption from dispersible tablets by investigating the effects of short-term zinc supplementation, provided either as zinc (Zn) sulfate dispersible tablets or solution, on changes in plasma Zn concentration in young children. STUDY DESIGN: We conducted a randomized, partially-masked, placebo-controlled trial in 451 children 6 to 23 months of age in Burkina Faso, randomly assigned to receive a dispersible tablet containing 5 mg Zn, a Zn solution containing 5 mg Zn/5 mL, or a placebo solution, daily for 3 weeks. The main outcome measure was change in plasma zinc concentration after supplementation compared with baseline. RESULTS: The mean plus or minus SD change in plasma Zn concentration (µg/dL) was significantly greater in both Zn supplemented groups (tablets: 16.9±13.1µg/dL, liquid: 16.6±14.2 µg/dL), compared with the placebo group (0.2±10.9 µg/dL; P<.001, ANOVA). In both Zn supplemented groups, but not in the placebo group, change in plasma Zn concentration was progressively less with increasing age in months (-0.79 µg/dL/mo and -1.15 µg/dL/mo, respectively; P<.001); this effect did not differ in the Zn supplemented groups (P=.18). CONCLUSIONS: Short-term supplementation results in a large increase in plasma Zn concentration, regardless of whether the additional Zn is provided as a dispersible tablet or solution.

Regulatory role of zinc during aluminium-induced altered carbohydrate metabolism in rat brain.

Aluminium is considered an environmental neurotoxicant and causes many neurological disorders, whereas zinc is vital for many biological functions. The present study was carried out to investigate the role of Zn, if any, in mitigating the adverse effects inflicted by Al on carbohydrate metabolism in rat brain. Male Sprague-Dawley rats weighing 140-160 g were divided into four different groups: normal control, Al-treated (100 mg/kg b.w./day in drinking water via oral gavage), Zn-treated (227mg/liter in drinking water), and combined Al- and Zn-treated rats. All the treatments were continued for 2 months, and their effects on carbohydrate-metabolizing enzymes were studied. Additionally, expressions of the proteins glycogen synthase kinase-3 (GSK3) and protein phosphatase (PP1), which help in regulating carbohydrate energy metabolism, were also studied. Al treatment resulted in increased activities of the glucose-6-phosphatase (G6P), glucose-6-isomerase (G6I), and lactate dehydrogenase (LDH), whereas the activities of hexokinase and succinate dehydrogenase (SDH) and glycogen content were decreased. Moreover, no significant change was observed in the biochemical parameters upon Zn supplementation alone. However, Zn supplementation to Al-treated rats was able to reduce significantly the Al-induced increased activities of G6P, G6I, and LDH, but it elevated the levels of hexokinase, SDH, and glycogen. Furthermore, Al treatment increased the protein expression of GSK3 and decreased the PP1 expression, which were found to be reversed upon Zn administration. Hence, Zn is effective in regulating theAl-induced alterations in carbohydrate metabolism.

Enhanced in vitro regeneration and change in photosynthetic pigments, biomass and proline content in Withania somnifera L. (Dunal) induced by copper and zinc ions.

In the present study the effect of inorganic nutrients (CuSO4 & ZnSO4) on morphogenic and biochemical responses from nodal explants in Withania somnifera L. was investigated. Incorporation of either Copper sulphate (25-200 µM) or Zinc sulphate (50-500 µM) in the optimized Murashige and Skoog (MS) medium highly influenced the shoot bud formation and subsequent elongation, which induced maximum percentage (95%) regeneration, number (61.7 ± 0.25) of shoots with shoot length (5.46 ± 0.16 cm) on CuSO4 (100 µM) and maximum percentage regeneration (100%), number of shoots (66.1 ± 0.96) with shoot length (6.24 ± 0.21 cm) on ZnSO4 (300 µM) after 12 weeks of culture. Healthy growing in vitro microshoots rooted efficiently on ½ MS medium supplemented with NAA (0.5 µM), which induced (16.2 ± 0.12) roots with root length (3.30 ± 0.12 cm) after 4 weeks. Pigment content increased with increasing concentration of Cu and Zn and the maximum Chl. a (0.47), (0.41); Chl. b (0.52), (0.42); total Chl. (0.99), (0.83) and Carotenoid (0.16), (0.16) mg/g FW contents in regenerants were found on CuSO4 (100 µM) and ZnSO4 (300 µM), respectively. Maximum proline content (0.17), (0.16) µg/g FW was observed on high concentrations of CuSO4 (200 µM) and ZnSO4 (500 µM) respectively, in the basal medium. Regenerated plantlets were acclimatized successfully in soilrite with a survival rate of 95%. No morphological variations were detected among the micropropagated plants when compared with seedling raised plants of the same age.