Naringin attenuates thioacetamide-induced liver fibrosis in rats through modulation of the PI3K/Akt pathway

Life Sci. 2017 Oct 15:187:50-57. doi: 10.1016/j.lfs.2017.08.019. Epub 2017 Aug 19.

Abstract

Aims: Naringin (NR) is a flavanone glycoside extracted from grapefruits and citrus fruits. The aim of this study is to investigate the antifibrotic efficacy of NR in thioacetamide (TAA)-induced hepatic fibrosis in rats through evaluating NR effect on the PI3K/Akt pathway.

Main methods: Hepatic fibrosis was induced in rats by intraperitoneal injection of TAA (200mg/kg) twice per week for 6weeks. Simultaneously, NR (40mg/kg/day, p.o.) was given along with TAA injection. The ratio of P-Akt/Akt was assessed in hepatic homogenate as well as antioxidant enzymes (catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx)) and lipid peroxidation marker, malondialdehyde (MDA). Serum level of interleukin (IL)-6 were measured using ELISA. Hepatic tissues were examined histopathologically using hematoxylin and eosin (H&E) and Masson trichome staining. Tissue expression of alpha smooth muscle actin (α-SMA), transforming growth factor β1 (TGF-β1), caspase-3 and fibronectin were scored immunohistochemically. Finally, the mRNA level of cytokine genes (IL-1β, IL-6, IL-10, interferon gamma (IFN-γ)), caspase-3, TGF-β1 and fibronectin were quantified using qPCR.

Key findings: NR significantly suppressed Akt phosphorylation associated with increased number of caspase-3 positive cells especially in the fibrotic areas. Liver tissues of treated rats showed restoration of normal liver histology and decrease in collagen and fibronectin deposition. Furthermore, NR treatment ameliorated oxidative stress and inflammatory cytokine production.

Significance: NR alleviated experimental liver fibrosis through inhibition of PI3K/Akt pathway beside its anti-inflammatory and antioxidant effects. Therefore, NR is a promising therapeutic candidate for hepatic fibrosis.

Keywords: Akt; Cytokines; Naringin; Oxidative stress; Thioacetamide.

MeSH terms

  • Animals
  • Antioxidants / metabolism
  • Caspase 3 / metabolism
  • Cytokines / biosynthesis
  • Fibronectins / metabolism
  • Flavanones / pharmacology*
  • Flavanones / therapeutic use*
  • Interleukin-6 / blood
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / drug therapy*
  • Liver Cirrhosis / metabolism
  • Liver Cirrhosis / pathology
  • Male
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Signal Transduction* / drug effects
  • Thioacetamide / toxicity
  • Transforming Growth Factor beta1 / metabolism

Substances

  • Antioxidants
  • Cytokines
  • Fibronectins
  • Flavanones
  • Interleukin-6
  • Transforming Growth Factor beta1
  • Thioacetamide
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Caspase 3
  • naringin