Changes in lipid composition of calf tissues by excess dietary zinc

Lipidome of plasma lipoproteins and liver is zinc- modulated in High fat diet treated mice

Zinc (Zn) and Zn-transcription Factors regulate the metabolic pathways of lipids and glucose, consequently nutritional zinc deficiency or excess, activates stress pathways and deranges the hepatic metabolism of lipids. High fat diet (HFD) also leads to lipids' profile disorders as well as to intracellular free radicals (FR) accumulation and finally to metabolic stress-syndrome. Study of nutritional Zn effects on the lipidome of plasma lipoproteins and liver, in HFD-mice, was the aim of the present research. Three Zn enriched HF-Diets as follows, 3 mg/kg feed (Zn deficient diet), 30 mg/kg feed (Zn sufficient diet), 300mgZn /kg feed (Zn excess diet) (Mucedola s.r.l Italy-55% cal) were applied respectively to three groups of male wild type (wt) mice (Hybrid F1/F1),C57Bl/6xCBA, one month old, for 10 weeks. Accordingly, mice body weight rate and ¹H-NMR spectrum analysis of liver extracts and plasma HDL and non-HDL lipoproteins were evaluated at the end of the experimental period. It is concluded that Zn sufficient diet (30 mg/Kg Feed) creates a highly protective lipidomic profile on plasma and liver lipoproteins of HFD-mice, related to significantly increased antiatherogenic indicators in lipids' composition, compared to mice in nutritional Zn deficiency or excess.

Acute toxicity of nano- and micro-scale zinc powder in healthy adult mice

The purpose of this study is to evaluate the acute toxicity of oral exposure to nanoscale zinc powder in mice. The healthy adult male and female mice were gastro-intestinally administered at a dose of 5 g/kg body weight with two size particles, nanoscale zinc (N-Zn) and microscale zinc (M-Zn) powder, while one group mice treated with sodium carboxy methyl cellulose was used as the control. The symptoms and mortality after zinc powder treatment were recorded. The effects of particles on the blood-element, the serum biochemical level and the blood coagulation were studied after 2 weeks of administration. The organs were collected for histopathological examination. The N-Zn treated mice showed more severe symptoms of lethargy, vomiting and diarrhea in the beginning days than the M-Zn mice. Deaths of two mice occurred in the N-Zn group after the first week of treatment. The mortalities were confirmed by intestinal obstruction of the nanoscale zinc aggregation. The biochemical liver function tests of serum showed significantly elevated ALT, AST, ALP, and LDH in the M-Zn mice and ALT, ALP, and LDH in the N-Zn mice compared with the controls (P<0.05), which indicated that the liver damage was probably induced by both micro- and nano-scale zinc powders. The clinical changes were observed in the two treated group mice as well. The levels of the above enzymes were generally higher in the M-Zn mice than in the N-Zn mice, which implied that M-Zn powder could induce more severe liver damage than N-Zn. The biochemical renal function tests of serum BUN and CR in the M-Zn mice markedly increased either compared with the N-Zn mice or with the controls (P<0.05), but no significant difference was found between the N-Zn and the control mice. However, severe renal lesions were found by the renal histopathological examination in the N-Zn exposed mice. Therefore, we concluded that severe renal damage could occur in the N-Zn treated mice, though no significant change of blood biochemical levels occurred. Blood-element test showed that in the N-Zn mice, PLT and RDW-CV significantly increased, and HGB and HCT significantly decreased compared to the controls, which indicated that N-Zn powder could cause severe anemia. Besides the pathological lesions in the liver, renal, and heart tissue, only slight stomach and intestinal inflammation was found in all the zinc treated mice, without significant pathological changes in other organs.