Icariside II, a novel phosphodiesterase-5 inhibitor, attenuates streptozotocin-induced cognitive deficits in rats

Caixia Yin, Yuanyuan Deng, Jianmei Gao, Xiaohui Li, Yuangui Liu, Qihai Gong*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


Beta-amyloid (Aβ) deposition and neuroinflammation are involved in Alzheimer's disease (AD)-type neurodegeneration with cognitive deficits. Phosphodiesterase-5 (PDE5) inhibitors have recently been studied as a potential target for cognitive enhancement by reducing inflammatory responses and Aβ levels. The present study was designed to investigate the effects of icariside II (ICS II), a novel PDE5 inhibitor derived from the traditional Chinese herb Epimedium brevicornum, on cognitive deficits, Aβ levels and neuroinflammation induced by intracerebroventricular-streptozotocin (ICV-STZ) in rats. The results demonstrated that ICV-STZ exhibited cognitive deficits and neuronal morphological damage, along with Aβ increase and neuroinflammation in the rat hippocampus. ICS II improved cognitive deficits, attenuated neuronal death, and decreased the levels of Aβ1-40, Aβ1-42 and PDE5 in the hippocampus of STZ rats. Furthermore, administration of ICS II at the dose of 10 mg/kg for 21 days significantly suppressed the expression of beta-amyloid precursor protein (APP), beta-secretase1 (BACE1) and increased the expressions of neprilysin (NEP) together with inhibited interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, cyclooxygenase-2 (COX-2) and transforming growth factor-β1 (TGF-β1) levels. In addition, ICS II exerted a beneficial effect on inhibition of IκB-α degradation and NF-κB activation induced by STZ. Taken together, the present study demonstrated that ICS II was a potential therapeutic agent for AD treatment.

Original languageEnglish
Pages (from-to)69-79
Number of pages11
Publication statusPublished - 22 Jul 2016
Externally publishedYes


  • icariside II
  • Alzheimer's disease
  • streptozotocin
  • phosphodiesterase-5
  • beta-amyloid
  • neuroinflammation


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