Zinc protects HeLa-tat cells against free radical cytotoxicity induced by glucose

Effects of zinc on interleukins and antioxidant enzyme values in psoriasis-induced mice

The effects of zinc chloride (ZnCl2), disodium zinc ethylenediamine tetraacetate (Zn-EDTA), and zinc gluconate (Zn-GLU) on the antioxidant enzyme activities and levels of interleukins (ILs) in psoriasis-induced mice were studied. One hundred twenty female mice were randomly divided into six groups with 20 mice in each group: the control, positive control (PC), methotrexate (MTX), ZnCl2, Zn-EDTA, and Zn-GLU groups. All animals except the control group were given diethylstilbestrol for three consecutive days. After successfully inducing psoriasis, the control and PC groups were given normal saline (i.g.) daily while the remaining groups were given MTX, ZnCl2, Zn-EDTA, and Zn-GLU, respectively. The results revealed that the zinc supplementation could significantly (p < 0.05) inhibit mitosis in the mouse vaginal epithelium as methotrexate did and the inhibiting efficacy had nothing to do with the zinc forms. After ZnCl2, Zn-EDTA, and Zn-GLU supplementation, the levels of liver superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities increased and the concentration of malondialdehyde (MDA) decreased significantly (p < 0.05) compared to the PC group. The levels of SOD, CAT activity, and MDA level between each zinc supplementation group and MTX group were insignificant (p > 0.05). The zinc treatments also caused a significant (p < 0.05) decrease in the raised IL-2 level of animal serum. The results obtained in the present work indicate the potential for zinc as a complementary pharmaceutical intervention for the treatment of topical psoriasis.

Comparison of the effects of zinc alone and zinc associated with selenium and vitamin E on insulin sensitivity and oxidative stress in high-fructose-fed rats

PURPOSE

In the present study, we investigated the effect of an association of micronutrients (zinc (Zn), selenium (Se) and vitamin E (vit E)) on insulin activity and antioxidant status in an animal model of insulin resistance, the high-fructose-fed rat.

PROCEDURES

Five experimental groups were compared: a control group (C) receiving a standard diet, a high-fructose-fed group (F) where 58% of the diet carbohydrate was fructose, a high-fructose-fed group supplemented with Zn alone (FZn group), a high-fructose-fed group supplemented micronutrients (Zn, Se and vit E) (FMicro group). A fifth group consumed a high-fructose diet and received metformin in the drinking water (200mg/day/rat) (FMet group). Insulin sensitivity was measured using the euglycemic hyperinsulinic glucose clamp technique. Metabolic parameters, trace elements and antioxidant parameters were measured in blood samples from all groups.

RESULTS

High-fructose-fed rats were resistant to insulin as indicated by the lower glucose infusion rate. The insulin sensitivity of FZn, FMicro and FMet groups was higher than that of F group, with the highest insulin sensitivity for the FMicro group. No statistically significant difference in glycemia between the groups was observed. The ratio of reduced to oxidized glutathione was higher in FZn and FMicro groups than in all other groups, as a consequence of decreased oxidized glutathione.

CONCLUSION

Our results provide direct evidence that micronutrients have a beneficial effect on insulin sensitivity and some components of the antioxidant defense system in an animal model of insulin resistance.