Neuroprotective Effects of Dammarane Sapogenins Against lipopolysaccharide-induced Cognitive Impairment, Neuroinflammation and Synaptic Dysfunction

Neurochem Res. 2023 Dec;48(12):3525-3537. doi: 10.1007/s11064-023-03997-7. Epub 2023 Jul 25.

Abstract

Neuroinflammation is a critical driver in the pathogenesis and progression of neurodegenerative disorders. Dammarane sapogenins (DS), a deglycosylated product of ginsenoside, possess a variety of potent biological activities. The present study aimed to explore the neuroprotective effects of DS in a rat model of neuroinflammation induced by intracerebroventricular injection of lipopolysaccharide (LPS). Our study revealed that DS pretreatment effectively improved LPS-induced associative learning and memory impairments in the active avoidance response test and spatial learning and memory in Morris water maze test. DS also remarkably inhibited LPS-induced neuroinflammation by suppressing microglia overactivation, pro-inflammatory cytok ine release (TNF-α and IL-1β) and reducing neuronal loss in the CA1 and DG regions of the hippocampus. Importantly, pretreatment with DS reversed LPS-induced upregulation of HMGB1 and TLR4 and inhibited their downstream NF-κB signaling activation, as evidenced by increased IκBα and decreased p-NF-κB p65 levels. Furthermore, DS ameliorated LPS-induced synaptic dysfunction by decreasing MMP-9 and increasing NMDAR1 expression in the hippocampus. Taken together, this study suggests that DS could be a promising treatment for preventing cognitive impairments caused by neuroinflammation.

Keywords: Cognitive impairment; Dammarane sapogenins; Lipopolysaccharide; Neuroinflammation; Synaptic dysfunction.

MeSH terms

  • Animals
  • Cognitive Dysfunction* / chemically induced
  • Cognitive Dysfunction* / drug therapy
  • Cognitive Dysfunction* / prevention & control
  • Dammaranes
  • Hippocampus / metabolism
  • Lipopolysaccharides / toxicity
  • Microglia / metabolism
  • NF-kappa B / metabolism
  • Neuroinflammatory Diseases
  • Neuroprotective Agents* / adverse effects
  • Rats
  • Sapogenins* / adverse effects

Substances

  • Lipopolysaccharides
  • Sapogenins
  • Neuroprotective Agents
  • NF-kappa B