Vitamin C alleviates LPS-induced cognitive impairment in mice by suppressing neuroinflammation and oxidative stress. - GreenMedInfo Summary

Neuroinflammation is believed to be one of the primary causes of cognitive impairment. Previous studies showed that the antioxidant vitamin C (Vit C) performs many beneficial functions such as immunostimulant and anti-inflammatory actions, but its role in inflammatory cognitive impairment is unclear. In the current study, we investigated the effect and possible mechanism of action of Vit C in lipopolysaccharide (LPS)-induced cognitive impairment. Intracerebroventricular LPS-induced memory impairment was used as the model for neuroinflammatory cognitive dysfunction. Vit C was administered by intracerebroventricular microinjection 30 min prior to LPS exposure. It was found that Vit C significantly protected animals from LPS-induced memory impairment as evidenced by improved performance in the Morris water maze and novel object recognition tests without changes in spontaneous locomotor activity. Vit C pretreatment inhibited the activation of microglia and the production of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Furthermore, Vit C pretreatment markedly decreased the malondialdehyde (MDA) level, increased superoxide dismutase (SOD) activity, and modulated the Bax/Bcl-2 ratio and p-p38 MAPK activation in the hippocampus of LPS-treated mice. Together, these results suggest that vitamin C pretreatment could protect mice from LPS-induced cognitive impairment, possibly through the modulation of oxidative stress and inflammatory responses.