Vitamin D3 attenuates lipopolysaccharide-induced cognitive impairment in rats by inhibiting inflammation and oxidative stress

Aims: Vitamin D is a well-known endocrine regulator of calcium/phosphate homeostasis and has been reported as having a wide range of activities that are potentially beneficial for human health. This study aimed to investigate the effects of pretreatment of vitamin D-3 (100, 1000, and 10,000 IU/kg) against lipopolysaccharide (LPS)-induced cognitive impairment in rats. Main methods: Male Wistar rats were divided into five groups. The passive avoidance test and Morris water maze (MWM) test were conducted to evaluate the learning and memory function. Oxidative stress markers including malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), total thiol content as well as interleukin (IL)-6 were evaluated in the hippocampus tissue. Key findings: The intraperitoneal (i.p.) injection of LPS (1 mg/kg) correlates with deficits in passive avoidance and spatial learning in the systemic inflammation model. However, pretreatment with vitamin D-3 improved LPSinduced cognitive impairment. In addition, vitamin D-3 decreased IL-6 and MDA levels, whereas the activities of CAT, SOD, and total thiol content in the hippocampus tissue were significantly increased. Significance: In conclusion, our results suggest that vitamin D-3 plays a protective role against memory dysfunction caused by LPS-induced inflammation through inhibition of oxidative stress and inflammation in the hippocampus. Vitamin D may be a promising potential therapeutic supplement for the treatment or prevention of learning and memory disorders.