Pseudoginsenoside-F11 attenuates cognitive impairment by ameliorating oxidative stress and neuroinflammation in d‑galactose-treated mice.

Oxidative stress and neuroinflammation are thought to be the two key early events during the process of mild cognitive impairment (MCI). Therefore, effective regulation of oxidative stress and neuroinflammation is an important aspect of preventing and improving MCI. We previously found that pseudoginsenoside-F11 (PF11), an ocotillol-type saponin, markedly reduced cognitive impairment in APP/PS1 mice and oAβ _1-42 -injected mice. In the present study, we further evaluate the effect of PF11 on learning and memory dysfunction in d‑galactose (d‑gal)-treated mice model of MCI. C57BL/6 mice received daily subcutaneous injections of d‑gal (100 mg/kg) and oral administration of PF11 (2, 4, 8, 16 mg/kg) for 9 weeks. We observed that PF11 significantly alleviated d‑gal-induced cognitive impairment, attenuated the loss of neuron and the over-activation of microglia in hippocampus of d‑gal-treated mice. The elevated levels of nod-like receptor protein 3 (NLRP3) inflammasome in hippocampus of d‑gal-treated mice were reduced by PF11 through reducing the accumulation of advanced glycation endproducts (AGEs) and the expression of the receptor of advanced glycation endproducts (RAGE). Moreover, PF11 significantly decreased H ₂ O ₂ and malondialdehyde (MDA) levels, improved superoxide dismutase (SOD) activity and increased glutathione (GSH) level in d‑gal-treated mice. Finally, d‑gal treatment reduced the level of nuclear factor erythroid-related factor 2 (Nrf2) and glutathione S-transferase (GST) in hippocampus, which could reverse by PF11. Together, our findings indicated that PF11 exerts a protective effect against MCI-like pathological changes.
(Copyright © 2018. Published by Elsevier B.V.)