Geraniol protects against cyclosporine A-induced renal injury in rats: Role of Wnt/β-catenin and PPARγ signaling pathways

Life Sci. 2022 Feb 15:291:120259. doi: 10.1016/j.lfs.2021.120259. Epub 2021 Dec 28.

Abstract

Aims: The nephrotoxicity of cyclosporine A (CsA) limits its use as an immunosuppressant. Wnt/β-catenin signaling is involved in the pathogenesis of both acute and chronic kidney disease, and it is inhibited by peroxisome proliferator-activated receptor gamma (PPARγ). We aimed to evaluate if geraniol, which can modulate both PPARγ and Wnt signaling, could protect against CsA-induced nephrotoxicity.

Materials and methods: Rats (6 groups) received the vehicle or a combination of CsA (30 mg/kg) with the vehicle, geraniol (50, 100, or 200 mg/kg), or the PPARγ agonist pioglitazone for 4 weeks. Blood pressure (BP), markers of renal injury (serum urea, serum creatinine, blood urea nitrogen, and urinary NAG), oxidative stress (glutathione peroxidase), inflammation (ICAM-1, IL-18, and NF-κB), apoptosis (caspase-3), extracellular matrix remodeling [matrix metalloproteinase-9 (MMP-9)], and fibrosis (TGF-β1, Smad3, and Smad7) were assessed. Renal histological analysis, Wnt signaling components (Wnt-4/β-catenin and E-cadherin), and PPARγ expression were evaluated.

Key findings: CsA group had renal injury, as well as increased BP, renal oxidative stress, inflammation, and fibrosis. The latter changes were associated with altered renal architecture, active Wnt signaling (higher Wnt-4 and β-catenin expression and E-cadherin down-regulation), and lower PPARγ levels. Geraniol protected against kidney damage and the associated biochemical and histomorphological changes in a dose-dependent manner. The latter effects were comparable or superior to those of pioglitazone.

Significance: The down-regulation of Wnt/β-catenin and the increase in PPARγ by geraniol suggest that both pathways are involved in its renoprotective potential. The study highlights geraniol as a valuable protective asset against chemically induced nephrotoxicity.

Keywords: Cyclosporine A; Geraniol; Nephrotoxicity; PPARγ; Wnt/β-catenin.

MeSH terms

  • Acute Kidney Injury / drug therapy*
  • Acute Kidney Injury / metabolism
  • Acyclic Monoterpenes / metabolism
  • Acyclic Monoterpenes / pharmacology*
  • Animals
  • Apoptosis / drug effects
  • Cyclosporine / adverse effects
  • Inflammation
  • Kidney / metabolism
  • Kidney Diseases / pathology
  • Male
  • NF-kappa B / metabolism
  • PPAR gamma / metabolism
  • Rats
  • Rats, Wistar
  • Wnt Signaling Pathway / drug effects
  • Wnt Signaling Pathway / physiology
  • beta Catenin / metabolism

Substances

  • Acyclic Monoterpenes
  • NF-kappa B
  • PPAR gamma
  • PPAR gamma, rat
  • beta Catenin
  • Cyclosporine
  • geraniol