Antioxidants, lysosomes and elements status during the life cycle of sea trout Salmo trutta m. trutta L

Biomarkers of oxidative stress, biochemical changes, and the activity of lysosomal enzymes in the livers of rainbow trout (Oncorhynchus mykiss Walbaum) vaccinated against yersiniosis before a Yersinia ruckeri challenge

Introduction

This study aimed to evaluate biomarkers of oxidative stress (2-thiobarbituric acid reactive substances, aldehyde and ketone derivatives of oxidatively modified proteins and total antioxidant capacity), the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase), that of lysosomal enzymes (alanyl aminopeptidase, leucyl aminopeptidase, β-N-acetylglucosaminidase and acid phosphatase) and changes in biochemical parameters (alanine aminotransferase, aspartate aminotransferase, de Ritis ratio, lactate dehydrogenase activity, lactate and pyruvate levels and their ratio) in the liver tissue of fish that were vaccinated against enteric redmouth disease and challenged with its causative agent, the bacterium Yersinia ruckeri.

Material and Methods

The vaccine was administered orally to trout, some of which were challenged with Y. ruckeri 61 days later. For comparison, unvaccinated and unchallenged trout and unvaccinated and challenged trout were also evaluated.

Results

In the unvaccinated fish, infection with Y. ruckeri disrupted the pro-oxidant/antioxidant balance, led to a significant increase in lipid peroxidation and oxidative modification of proteins, decreased total antioxidant capacity and significantly increased the activity of lysosomal enzymes. In vaccinated fish, the Y. ruckeri challenge increased the activity of glutathione-related enzymes and decreased lipid peroxidation, anaerobic metabolism and the activity of lysosomal enzymes in fish livers relative to the unvaccinated and challenged group. In contrast, these parameters increased after the Y. ruckeri challenge in unvaccinated trout relative to those in the untreated group.

Conclusion

Vaccination exerted a protective effect during the Y. ruckeri challenge and had no adverse effect on fish livers.

Effects of Boric Acid on Oxidative Stress Parameters, Growth Performance and Blood Parameters of Rainbow Trout (Oncorhynchus Mykiss)

Rainbow trout (Oncorhynchus mykiss) with a starting weight of 397.28 ± 3.21 g were fed different ratios (G1-0.00%, G2-0.010%, G3-0.025%, and G4-0.050%) of boric acid-supplemented feed for 140 days. The effects of dietary boric acid on oxidative stress parameters, growth performance, haematology and some biochemical parameters were investigated after the feeding period. The addition of boric acid to trout feed positively affected growth performance; the final weights of the groups were 928.15 ± 5.73 g, 955.87 ± 8.67 g, 994.24994,75 ± 7.46 g, and 976.80976,80 ± 6.26 g for the control group and the three experimental groups, respectively. The lowest feed conversation ratio (FCR) was 1.19 (G3) whereas the highest was 1.42 (G1). The lowest protein efficiency ratio was 1.63 (G1), while the highest was 1.95 (G3). In this study, it was observed that boric acid added to the feed changed muscle and blood oxidative stress parameters in rainbow trout, increased the growth performance of rainbow trout, and affected blood and biochemistry values.

Recent Progress in Antioxidant Active Substances from Marine Biota

BACKGROUND

The well-recognized but not fully explored antioxidant activity of marine-biota-derived, biologically active substances has led to interest in their study as substitutes of antibiotics, antiaging agents, anticancer and antiviral drugs, and others. The aim of this review is to present the current state of the art of marine-biota-derived antioxidants to give some ideas for potential industrial applications.

METHODS

This review is an update for the last 5 years on the marine sources of natural antioxidants, different classes antioxidant compounds, and current derivation biotechnologies.

RESULTS

New marine sources of antioxidants, including byproducts and wastes, are presented, along with new antioxidant substances and derivation approaches.

CONCLUSIONS

The interest in high-value antioxidants from marine biota continues. Natural substances combining antioxidant and antimicrobial action are of particular interest because of the increasing microbial resistance to antibiotic treatments. New antioxidant substances are discovered, along with those extracted from marine biota collected in other locations. Byproducts and wastes provide a valuable source of antioxidant substances. The application of optimized non-conventional derivation approaches is expected to allow the intensification of the production and improvement in the quality of the derived substances. The ability to obtain safe, high-value products is of key importance for potential industrialization.