Expression of genes related to antioxidant activity in Nile tilapia kept under salinity stress and fed diets containing different levels of vitamin C.

The aim of this study was to examine whether (1) severe changes in salinity produced increased stress, and (2) vitamin C supplementation might reduce the observed damage in Nile tilapia. The parameters measured included condition factor, survival rate, and gene expression of catalase (CAT), heat shock protein 70 (HSP70), glutathione reductase (GSR), glutathione synthase (GSS), and glutathione peroxidase (GPx). The investigation was conducted with 160 Nile tilapia divided into four treatment groups: freshwater; 7 or 21 parts per thousand (‰) salinity, all fed a basal diet; as well as a fourth treatment group consisting of fish kept at 21‰ salinity fed a diet supplemented with vitamin C (1500 mg/kg). For gene expression analysis, liver samples were collected after 24 h or after 14 d. After 24 h, fish raised in 21‰ salinity and fed with the diet supplemented with vitamin C showed similar GPx expression as the control freshwater group. GSS expression in 21‰ salinity was similar to fish exposed to 7‰ salinity. Nile tilapia exposed to 21‰ salinity without vitamin C supplementation exhibited the highest HSP70 gene expression levels after 24 h. After 14-dtreatment, the lowest survival rate was observed in the 21‰ salinity group. After 14 d, the highest expression of GPx and GSR levels was detected in fish in the 21‰ salinity group that received vitamin C. Data indicate that vitamin C supplementation enhanced the expression of genes related to antioxidant capacity in Nile tilapia exposed to higher salinity, thereby increasing protection against the oxidative effects induced by high water salinity..

The role of cinnamon as a modulator of the expression of genes related to antioxidant activity and lipid metabolism of laying quails.

Since cinnamon has vitamins and minerals in addition to antioxidants compounds in its chemical composition studies have shown the potential of cinnamon supplementation on some important characteristics in the performance of birds. Thus, this study was conducted under the hypothesis that the inclusion of cinnamon in the laying quail diet could influence the performance of the birds through the expression of genes related to antioxidant activity and lipid metabolism. To test this hypothesis, 144 Japanese quail (Coturnix japonica) with an initial age of 18 weeks and average weight of 133g were distributed in a completely randomized design with two treatments: no cinnamon supplementation (NCS-control group) and with supplementation of 9g/kg of cinnamon powder (CPS). The experiment lasted for 84 days. At the end of the experimental period, six animals from each treatment were euthanized by cervical dislocation, blood was collected and organs weighed. Liver tissue was collected for gene expression and biochemical analyses. We observed a significant effect of cinnamon inclusion on the weight of the pancreas (P = 0.0418), intestine (P = 0.0209) and ovary (P = 0.0389). Lower weights of the pancreas and intestine, and a higher ovary weight was observed in birds receiving the CPS diet. Quails fed with cinnamon supplementation also had better feed conversion per egg mass (2.426 g /g, P = 0.0126), and higher triglyceride (1516.60 mg/dL, P = 0.0207), uric acid (7.40 mg/dL, P = 0.0003) and VLDL (300.40 mg/dL, P = 0.0252) contents. A decreased content of thiobarbituric acid reactive substances (TBARS) and lower catalase activity was observed in the liver of quails from the CPS diet (0.086 nmoles/mg PTN, and 2.304 H2O2/min/mg PTN, respectively). Quails from the CPS group presented significantly greater expression of FAS (fatty acid synthase, 36,03 AU), ACC (Acetyl-CoA Carboxylase, 31.33 AU), APOAI (apolipoprotein A-I, 803,9 AU), ESR2 (estrogen receptor 2, 0.73 AU) SOD (superoxide dismutase, 4,933.9 AU) and GPx7 (glutathione peroxidase 7, 9.756 AU) than quails from the control group. These results allow us to suggest that cinnamon powder supplementation in the diet of laying quails can promote balance in the metabolism and better performance through the modulation of antioxidant activity and the expression of genes related to lipid metabolism.