Doxycycline-Loaded Calcium Phosphate Nanoparticles with a Pectin Coat Can Ameliorate Lipopolysaccharide-Induced Neuroinflammation Via Enhancing AMPK

J Neuroimmune Pharmacol. 2024 Jan 18;19(1):2. doi: 10.1007/s11481-024-10099-w.

Abstract

Neuroinflammation occurs in response to different injurious triggers to limit their hazardous effects. However, failure to stop this process can end in multiple neurological diseases. Doxycycline (DX) is a tetracycline, with potential antioxidant and anti-inflammatory properties. The current study tested the effects of free DX, DX-loaded calcium phosphate (DX@CaP), and pectin-coated DX@CaP (Pec/DX@CaP) nanoparticles on the lipopolysaccharide (LPS)-induced neuroinflammation in mice and to identify the role of adenosine monophosphate-activated protein kinase (AMPK) in this effect. The present study was conducted on 48 mice, divided into 6 groups, eight mice each. Group 1 (normal control), Group 2 (blank nanoparticles-treated), Group 3 (LPS (untreated)), Groups 4, 5, and 6 received LPS, then Group 4 received free DX, Group 5 received DX-loaded calcium phosphate nanoparticles (DX@CaP), and Group 6 received DX-loaded calcium phosphate nanoparticles with a pectin coat (Pec/DX@CaP). At the end of the experimentation period, behavioral tests were carried out. Then, mice were sacrificed, and brain tissue was extracted and used for histological examination, and assessment of interleukin-6 positive cells in different brain areas, in addition to biochemical measurement of SOD activity, TLR-4, AMPK and Nrf2. LPS can induce prominent neuroinflammation. Treatment with (Pec/DX@CaP) can reverse most behavioral, histopathological, and biochemical changes caused by LPS. The findings of the current study suggest that (Pec/DX@CaP) exerts a significant reverse of LPS-induced neuroinflammation by enhancing SOD activity, AMPK, and Nrf2 expression, in addition to suppression of TLR-4.

Keywords: AMPK; Doxycycline; IL-6; Neuroinflammation; Nrf2; TLR-4.

MeSH terms

  • AMP-Activated Protein Kinases
  • Animals
  • Anti-Bacterial Agents
  • Calcium Phosphates
  • Calcium*
  • Doxycycline*
  • Lipopolysaccharides / toxicity
  • Mice
  • NF-E2-Related Factor 2
  • Neuroinflammatory Diseases
  • Pectins / pharmacology
  • Phosphates
  • Superoxide Dismutase
  • Toll-Like Receptor 4

Substances

  • Doxycycline
  • Calcium
  • Phosphates
  • Lipopolysaccharides
  • AMP-Activated Protein Kinases
  • Pectins
  • NF-E2-Related Factor 2
  • Toll-Like Receptor 4
  • calcium phosphate
  • Calcium Phosphates
  • Anti-Bacterial Agents
  • Superoxide Dismutase