# Taurine Intake Alleviates Oxidative Damage During Transportation in Culter alburnus

## TL;DR

Adding taurine to the diet of Culter alburnus fish helps reduce stress and damage during transport by boosting their antioxidant and immune systems.

## Contribution

This study reveals how taurine at 2.0 g/kg optimizes antioxidant and immune responses in Culter alburnus during transport stress through transcriptome analysis.

## Key findings

- Taurine supplementation at 2.0 g/kg improved growth and reduced gill tissue damage during transport.
- High taurine doses activated antioxidant enzymes and immune-related genes like TLR5 and Il12b.
- Transcriptome analysis showed taurine enhanced antioxidative stress via Toll-like receptor and cytokine pathways.

## Abstract

In summary, dietary taurine regulated the antioxidant capacity and immune function of Culter alburnus through multiple mechanisms: optimizing nutritional metabolism to promote the growth of juveniles, alleviating gill tissue damage induced by transport stress, activating antioxidant enzyme systems to scavenge reactive oxygen species (ROS), and regulating immune gene networks to balance immune responses. And, the effect was the best when the taurine supplementation was 2.0 g/kg. This study also systematically revealed the transcriptome response characteristics of the gill tissue of C. alburnus under transport stress and clarified the molecular pathway of taurine regulating its anti-stress, which provided basic data and mechanism reference for the transcriptome study of C. alburnus stress physiology.

Live fish transport easily induces severe physiological stress, marked by pronounced oxidative damage and significant mortality, leading to substantial economic losses annually. Here, we evaluated the effects of taurine intake on alleviating stress response during transportation of Culter alburnus. Juvenile fish were fed diets containing 0 (control), 0.5, 1.0, 1.5, or 2.0 g/kg taurine for 8 weeks before undergoing 12 h of simulated transport. The results showed that taurine supplementation significantly improved growth performance in a dose-dependent manner. During transportation, the deterioration of water quality and the damage of gill tissue decreased with the increase in concentration. The determination of catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) showed that 2.0 g/kg taurine improved antioxidant capacity. The high-concentration taurine group enhanced the activities of immune enzymes such as acid phosphatase (ACP) and alkaline phosphatase (AKP), while the activity of total nitric oxide synthase (T-NOS) was inhibited. The antioxidant immune effect of the 0.5 g/kg and 1.0 g/kg concentration groups was not obvious. Transcriptome analysis revealed that 2.0 g/kg taurine enhanced the antioxidative stress capacity of C. alburnus by upregulating the expression of immune-related genes (TLR5, Il12b) and activating the Toll-like receptor signaling pathway as well as the cytokine–cytokine receptor interaction pathway. These findings demonstrated that dietary taurine improved resilience to transport stress in C. alburnus.