Quercetin mitigates ethanol-induced hepatic steatosis in zebrafish via P2X7R-mediated PI3K/ Keap1/Nrf2 signaling pathway

J Ethnopharmacol. 2021 Mar 25:268:113569. doi: 10.1016/j.jep.2020.113569. Epub 2020 Nov 10.

Abstract

Ethnopharmacological relevanceQuercetin is the active component of the higher content in PCP, which exerts various biological activities such as anti-obesity effect, anti-inflammatory and anti-oxidant activities in alcoholic liver disease (ALD).

Aim of the study: P2X7 receptor (P2X7R) plays an important role in health and disease, which can be activated by extracellular ATP to induce a variety of downstream events, including lipid metabolism, inflammatory molecule release, oxidative stress. However, whether the mechanism of quercetin on ethanol-induced hepatic steatosis via P2X7R-mediated haven't been elucidated.

Material and methods: Zebrafish transgenic (fabp10: EGFP) larvae were treated with 100 μM, 50 μM, 25 μM quercetin for 48 h at 3 days post fertilization (dpf), then soaked in 350 mmol/L ethanol for 32 h, treated with 1 mM ATP (P2X7R activator) for 30min. Serum lipids, liver steatosis, oxidative stress factors were respectively detected. The mRNA levels in the related pathways were measured by quantitative Real-Time PCR (RT-qPCR) to investigate the mechanisms.

Results: Quercetin improved the liver function via decreasing ALT, AST and γ-GT level of zebrafish with acute ethanol-induced hepatic steatosis and attenuated hepatic TG, TC accumulation. Additionally, quercetin significantly reduced the MDA content and suppressed the ethanol-induced reduction of hepatic oxidative stress biomarkers GSH, CAT and SOD and significantly down-regulated the expression of P2X7R, and up-regulated the expression of phosphatidylinositol 3-kinase (PI3K), Kelch like ECH associated protein1 (Keap1), Nuclear Factor E2 related factor 2 (Nrf2). Moreover, ATP stimulation activated P2X7R, which further mediated the mRNA expressions of PI3K, Keap1 and Nrf2.

Conclusion: Quercetin exhibited hepatoprotective capacity in zebrafish model, via regulating P2X7R-mediated PI3K/Keap1/Nrf2 oxidative stress signaling pathway.

Keywords: Ethanol-induced hepatic steatosis; Keap l; Nrf2; P2X7R; PI3K; Quercetin.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Antioxidants / pharmacology
  • Antioxidants / therapeutic use
  • Carrier Proteins / biosynthesis*
  • Dose-Response Relationship, Drug
  • Ethanol / toxicity
  • Fatty Liver / chemically induced
  • Fatty Liver / metabolism*
  • Fatty Liver / prevention & control
  • NF-E2-Related Factor 2 / biosynthesis*
  • Phosphatidylinositol 3-Kinases / biosynthesis*
  • Purinergic P2X Receptor Antagonists
  • Quercetin / pharmacology
  • Quercetin / therapeutic use*
  • Receptors, Purinergic P2X7 / biosynthesis*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Zebrafish
  • Zebrafish Proteins / biosynthesis*

Substances

  • Antioxidants
  • Carrier Proteins
  • Keap1a protein, zebrafish
  • NF-E2-Related Factor 2
  • Purinergic P2X Receptor Antagonists
  • Receptors, Purinergic P2X7
  • Zebrafish Proteins
  • nfe2l2a protein, zebrafish
  • Ethanol
  • Quercetin