Influences of dietary selenomethionine exposure on tissue accumulation, blood biochemical profiles, gene expression and intestinal microbiota of Carassius auratus

Comp Biochem Physiol C Toxicol Pharmacol. 2019 Apr:218:21-29. doi: 10.1016/j.cbpc.2018.12.001. Epub 2018 Dec 4.

Abstract

A 30-days feeding trail was conducted to determine the sensitivity of Carassius auratus to the toxicological effects of elevated dietary Selenomethionine (Se-Met). C. auratus averaging 23.56 ± 1.82 g were exposed to four Se-Met concentrations (mg Se/kg): 0 (Se-Met0), 5 (Se-Met5), 10 (Se-Met10) and 20 (Se-Met20) to estimate the effects on tissue selenium (Se) accumulation, blood biochemical profiles, transcript expression and intestinal microbiota. Se accumulated in the kidney, liver and muscle in a dose-dependent manner and followed this order: kidney > liver > muscle, the highest accumulation were obtained in kidney of Se-Met20 diet after 30 days of feeding. Serum contents of alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) in fish exposed to Se-Met20 group was significantly highest among Se-Met exposure groups. Hydrogen peroxide (H2O2) concentrations in liver were affected by dietary Se-Met exposures. Liver contents of total antioxidant capacity (TAC), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) in fish exposure to Se-Met5 group was significantly highest among Se-Met exposure groups. Growth hormone receptor (GHR), insulin-like growth factor 1 (IGF-1) and antioxidant enzyme related genes including glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST) expression in liver were down-regulated with the concentration of Se-Met exposure groups. The results of high-throughput sequencing showed that gut microbial communities and hierarchy cluster heatmap analysis were significantly affected by Se-Met exposure. The abundances of Cetobacterium and Vibrio increased while fish exposed to Se-Met20 group. The abundance of Ralstonia increased when the Se-Met exposure dose reached 10 mg Se kg-1. The results suggested that the exposure to elevated dietary Se-Met may result toxic effects in C. auratus.

Keywords: Antioxidant activity; Carassius auratus; Intestinal microbiota; Selenomethionine; Transcript expression.

MeSH terms

  • Animal Feed
  • Animals
  • Antioxidants / metabolism
  • Diet / veterinary
  • Gastrointestinal Microbiome / drug effects*
  • Gene Expression Regulation / drug effects
  • Goldfish / blood*
  • Goldfish / metabolism
  • Goldfish / microbiology
  • Hydrogen Peroxide
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / metabolism
  • Malondialdehyde / metabolism
  • Receptors, Somatotropin / genetics
  • Receptors, Somatotropin / metabolism
  • Selenomethionine / pharmacokinetics*
  • Selenomethionine / pharmacology

Substances

  • Antioxidants
  • Receptors, Somatotropin
  • Malondialdehyde
  • Insulin-Like Growth Factor I
  • Selenomethionine
  • Hydrogen Peroxide