Effect of dietary alpha-tocopherol + ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha Walbaum)

Modulatory effects of dietary prickly pear (Opuntia ficus-indica) peel on high salinity tolerance, growth rate, immunity and antioxidant capacity of Nile tilapia (Oreochromis niloticus)

This study evaluated the effects of prickly pear (Opuntia ficus-indica) peel (PPP) on salinity tolerance, growth, feed utilization, digestive enzymes, antioxidant capacity, and immunity of Nile tilapia (Oreochromis niloticus). PPP was incorporated into four iso-nitrogenous (280 g kg-1 protein) and iso-energetic (18.62 MJ kg-1) diets at 0 (PPP0), 1 (PPP1), 2 (PPP2), and 4 (PPP4) g kg-1. Fish (9.69 ± 0.2 g) (mean ± SD) were fed the diets for 75 days. Following the feeding experiment, fish were exposed to a salinity challenge (25‰) for 24 h. Fish survival was not affected by the dietary PPP inclusion either before or after the salinity challenge. Fish fed the PPP-supplemented diets showed lower aspartate aminotransferase, alanine aminotransferase, cortisol, and glucose levels compared to PPP0, with the lowest values being observed in PPP1. Fish fed dietary PPP had higher growth rates and feed utilization than PPP0. Quadratic regression analysis revealed that the best weight gain was obtained at 2.13 g PPP kg-1 diet. The highest activities of protease and lipase enzymes were recorded in PPP1, while the best value of amylase was recorded in PPP2, and all PPP values were higher than PPP0. Similarly, PPP1 showed higher activities of lysozyme, alternative complement, phagocytic cells, respiratory burst, superoxide dismutase, glutathione peroxidase and catalase, and lower activity of malondialdehyde than in PPP0. Further increases in PPP levels above 2 g kg-1 diet led to significant retardation in the immune and antioxidant parameters. Thus, the inclusion of PPP at about 1 to or 2 g kg-1 diet can improve stress tolerance, immunity, and antioxidant capacity in Nile tilapia.

Growth Performance, Antioxidant and Immunity Capacity Were Significantly Affected by Feeding Fermented Soybean Meal in Juvenile Coho Salmon (Oncorhynchus kisutch)

This study aims to investigate the effects of partial dietary replacement of fish meal with unfermented and/or fermented soybean meal (fermented by Bacillus cereus) supplemented on the growth performance, whole-body composition, antioxidant and immunity capacity, and their related gene expression of juvenile coho salmon (Oncorhynchus kisutch). Four groups of juveniles (initial weight 159.63 ± 9.54 g) at 6 months of age in triplicate were fed for 12 weeks on four different iso-nitrogen (about 41% dietary protein) and iso-lipid (about 15% dietary lipid) experimental diets. The main results were: Compared with the control diet, the diet with replaced 10% fish meal protein with fermented soybean meal protein supplementation can significantly (p < 0.05) influence the expression of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, nuclear factor erythroid 2-related factor 2, tumor necrosis factor α and interleukin-6 genes, the growth performance, the serum biochemical indices, and the activity of antioxidant and immunity enzymes. However, there was no significant effect (p > 0.05) on the survival rate (SR) and whole-body composition in the juveniles among the experimental groups. In conclusion, the diet with replaced 10% fish meal protein with fermented soybean meal protein supplementation could significantly increase the growth performance, antioxidant and immunity capacity, and their related gene expression of juveniles.

Dietary supplementations modulate the physiological parameters, fatty acids profile and the growth of red claw crayfish (Cherax quadricarinatus)

An optimal diet is an important factor for the proper growth and health of crustaceans. However, the regulation of antioxidant activity and non-specific immunity related to the consumption of feed additives has not been studied in RC-crayfish. Triplicate groups of 20 crayfish/tank (36.72 ± 0.70 g) fed with a basal diet and sixteen experimental diets that contained five feed additives with four grade levels (40, 160, 240 and 320 mg/kg vitamin E, 2, 4, 6 and 8 g/kg nucleotides, 2, 4, 6 and 8 g/kg Haematococcus pluvialis, 5, 10, 15 and 20 g/kg arachidonic acid and 2.5, 5, 10 and 15 g/kg yeast extract) on physiological parameters, fatty acids profile and growth of Cherax quadricarinatus for a period of 70 days by using orthogonal array method (L16 4⁵ ). The results showed that the antioxidants activity in the haemolymph and hepatopancreas were both higher in crayfish fed with diets NO. 9 to 12 than others. Also, all the diets except diets NO. 13 to 16 showed lower free radicals contents than the control group. Similarly, significantly higher non-specific immune parameters were observed in the hepatopancreas of crayfish supplementations than those fed a control diet. Biochemical parameters related to protein profile in haemolymph increased in diets NO. 9 to 12 and then decreased in control and diets NO. 13 to 16, while the highest biochemical parameters related to lipid profile except HDL-c contents in haemolymph were observed in crayfish fed the control diet. Fatty acid composition in the hepatopancreas, muscle and ovary of RC-crayfish was significantly influenced by using the combination of Vit E, NT, H. pluvialis and YP compared to the control group. Compared to all treatments, RC-crayfish fed with diets NO. 2 and 12 had significantly stimulated higher growth performance and feed utilisation. Overall, our results suggest that diets supplemented with Vit E level of 240 mg/kg, in combination with 8 g/kg NT, 4 g/kg, H. pluvialis, 5 g/kg ARA and 10 g/kg YP are the promising treatments to increase antioxidants activity, non-specific immune response, fatty acids composition and growth of RC-crayfish. However, high dietary supplementations level can reduce antioxidants activity, immunity and inhibit growth.

Developing micro-/nanoparticulate drug delivery systems using "design of experiments"

Of late, micro and nanoparticluate drug delivery systems have been gaining immense importance primarily attributed to their improved drug release controlling and targeting efficiencies. Also, the small particle size and desirable surface charge associated with these delivery systems render them suitable for specific applications like lymphatic uptake, pulmonary uptake, tumor targeting, brain targeting, etc. For decades, micro and nanoparticulate systems have been prepared by the conventional "trial and error" approach of changing One Variable at a Time (OVAT). Using this methodology, the solution of a specific problematic formulation characteristic can certainly be achieved, but attainment of the true optimal composition is never guaranteed. Thus, the present manuscript provides an updated account of the systematic approach "Design of Experiments (DoE)" as applicable to formulation development of microparticles and nanostructured systems. Besides providing a bird's eye view of the various experimental designs and optimization techniques employed for DoE optimization of such systems, the present manuscript also presents a copilation of the major micro/nano-structuctred systems optimized through DoE till date. In a nutshell, the article will act both as a ready reckoner of DoE optimization of micro/nano drug delivery systems and a catalyst in providing an impetus to young pharmaceutical "nano & micro" researchers to venture into the rewarding field of systematic DoE optimization.

Genetic evidence of an evolutionarily conserved role for Nrf2 in the protection against oxidative stress

Transcription factor Nrf2 is considered a master regulator of antioxidant defense in mammals. However, it is unclear whether this concept is applicable to nonmammalian vertebrates, because no animal model other than Nrf2 knockout mice has been generated to examine the effects of Nrf2 deficiency. Here, we characterized a recessive loss-of-function mutant of Nrf2 (nrf2(fh318)) in a lower vertebrate, the zebrafish (Danio rerio). In keeping with the findings in the mouse model, nrf2(fh318) mutants exhibited reduced induction of the Nrf2 target genes in response to oxidative stress and electrophiles but were viable and fertile, and their embryos developed normally. The nrf2(fh318) larvae displayed enhanced sensitivity to oxidative stress and electrophiles, especially peroxides, and pretreatment with an Nrf2-activating compound, sulforaphane, decreased peroxide-induced lethality in the wild type but not nrf2(fh318) mutants, indicating that resistance to oxidative stress is highly dependent on Nrf2 functions. These results reveal an evolutionarily conserved role of vertebrate Nrf2 in protection against oxidative stress. Interestingly, there were no significant differences between wild-type and nrf2(fh318) larvae with regard to their sensitivity to superoxide and singlet oxygen generators, suggesting that the importance of Nrf2 in oxidative stress protection varies based on the type of reactive oxygen species (ROS).

Effects of Haematococcus pluvialis supplementation on antioxidant system and metabolism in rainbow trout (Oncorhynchus mykiss)

Effects of commercial source for astaxanthin (Haematococcus pluvialis) (H.p) on antioxidant power, specific marker enzymes, and some metabolites were examined in rainbow trout (Oncorhynchus mykiss). Fish were fed on diets containing 1, 3, and 10 g microalga kg(-1) feed for 30 days. Serum total antioxidant activity and lipid peroxidation product, indicated by malondialdehyde (MDA), significantly enhanced with different doses of administration, indicating the elevated antioxidant status in all treatment groups. In group fed with high dose of alga, significantly elevated aspartate aminotransferase activity (AST) was noted, indicating damage of normal liver function in this group. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were not affected in all groups. Although serum total protein remained unaffected, serum glucose level was decreased significantly in lower doses of administration. Furthermore, triglyceride and cholesterol levels showed significant decrease in 3 g kg(-1) microalga group by modulation of lipid metabolism in this group. On the other hand, in highest dose, significant increase in lipids was observed, indicating the slight dysfunction in lipid metabolism in this treatment group. The present study suggests that Haematococcus pluvialis especially in dose of 3 g kg(-1) feed administration may effectively enhance the antioxidant system and some biochemical parameters in rainbow trout.