Unveiling the protective potential of mirabegron against thioacetamide-induced hepatic encephalopathy in rats: Insights into cAMP/PPAR-γ/p-ERK1/2/p S536 NF-κB p 65 and p-CREB/BDNF/TrkB in parallel with oxidative and apoptotic trajectories

Biochem Pharmacol. 2024 Nov:229:116504. doi: 10.1016/j.bcp.2024.116504. Epub 2024 Aug 22.

Abstract

Hepatic encephalopathy (HE) is one of the most prevalent and severe hepatic and brain disorders in which escalation of the oxidative, inflammatory and apoptotic trajectories pathologically connects acute liver injury with neurological impairment. Mirabegron (Mira) is a beta3 adrenergic receptor agonist with proven antioxidant and anti-inflammatory activities. The current research pointed to exploring Mira's hepato-and neuroprotective impacts against thioacetamide (TAA)-induced HE in rats. Rats were distributed into three experimental groups: the normal control group, the TAA group, received TAA (200 mg/kg/day for three consecutive days) and the Mira-treated group received Mira (10 mg/kg/day; oral gavage) for 15 consecutive days and intoxicated with TAA from the 13th to the 15th day of the experimental period. Mira counteracted hyperammonemia, enhanced rats' locomotor capability and motor coordination. It attenuated hepatic/neurological injuries by its antioxidant, anti-apoptotic as well as anti-inflammatory potentials. Mira predominantly targeted cyclic adenosine monophosphate (cAMP)/phosphorylated extracellular signal-regulated kinase (p-Erk1/2)/peroxisome proliferator-activated receptor gamma (PPARγ) dependent pathways via downregulation of p S536-nuclear factor kappa B p65 (p S536 NF-κB p 65)/tumor necrosis alpha (TNF-α) axis. Meanwhile, it attenuated nuclear factor erythroid 2-related factor (Nrf2) depletion in parallel with restoring of the neuroprotective defensive pathway by upregulation of cerebral cAMP/PPAR-γ/p-ERK1/2 and p-CREB/BDNF/TrkB besides reduction of GFAP immunoreactivity. Mira showed anti-apoptotic activity through inhibition of Bax immunoreactivity and elevation of Bcl2. To summarize, Mira exhibited a hepato-and neuroprotective effect against TAA-induced HE in rats via shielding antioxidant defense and mitigation of the pathological inflammatory and apoptotic axis besides upregulation of neuroprotective signaling pathways.

Keywords: Apoptosis; Hepatic encephalopathy; Mirabegron; PPARγ/p-Erk1/2; Thioacetamide; p-CREB/BDNF/TrkB.

MeSH terms

  • Acetanilides / pharmacology
  • Acetanilides / therapeutic use
  • Animals
  • Apoptosis* / drug effects
  • Brain-Derived Neurotrophic Factor* / metabolism
  • Cyclic AMP / metabolism
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Hepatic Encephalopathy* / chemically induced
  • Hepatic Encephalopathy* / drug therapy
  • Hepatic Encephalopathy* / metabolism
  • Hepatic Encephalopathy* / prevention & control
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology
  • Male
  • NF-kappa B / metabolism
  • Neuroprotective Agents / pharmacology
  • Neuroprotective Agents / therapeutic use
  • Oxidative Stress* / drug effects
  • PPAR gamma* / metabolism
  • Rats
  • Rats, Wistar
  • Receptor, trkB / metabolism
  • Thiazoles / pharmacology
  • Thiazoles / therapeutic use
  • Thioacetamide* / toxicity
  • Transcription Factor RelA / metabolism

Substances

  • Acetanilides
  • Bdnf protein, rat
  • Brain-Derived Neurotrophic Factor
  • Creb1 protein, rat
  • Cyclic AMP
  • Cyclic AMP Response Element-Binding Protein
  • Neuroprotective Agents
  • NF-kappa B
  • Ntrk2 protein, rat
  • PPAR gamma
  • PPAR gamma, rat
  • Receptor, trkB
  • Rela protein, rat
  • Thiazoles
  • Thioacetamide
  • Transcription Factor RelA