New Emulsifying Oil Powder Extracted from Pacific Krill Protects against Vascular Cognitive Impairment in a Mouse Model of Cerebral Small Vessel Disease

[Background]: Marine n-3 polyunsaturated fatty acids (PUFAs) may be promising for reducing cognitive and functional decline in elderly patients with mild cognitive impairment. We examined the effects of a new emulsifying oil powder including PUFAs extracted from Pacific krill on vascular cognitive impairment in a mouse model of cerebral small vessel disease. [Methods]: Small vessel disease was created using a mouse model of asymmetric common carotid artery stenosis surgery (ACAS). Mice were fed an MF diet (MFD) or MFD supplemented with the new emulsifying Pacific krill oil powder (EPKOP) from 4 weeks before ACAS to 5 weeks after ACAS. Two and/or from 4 to 5 weeks after ACAS, all experiments were performed. [Results]: Cerebral blood flow (CBF) was decreased in MFD-fed ACAS compared with MFD-fed sham-operated mice. CBF was similar between MFD with EPKOP-fed ACAS and MFD-fed sham-operated mice. EPKOP reversed the ACAS-induced decrease in the latency to fall in a rotarod test of ACAS mice. Moreover, it also reversed the ACAS-induced longer escape latencies in the Morris water maze test of ACAS mice. Hematoxylin/eosin staining demonstrated that EPKOP decreased the number of shrunken neurons in the ACAS mouse hippocampus. Interleukin 1β gene expression in the hippocampus was increased in MFD-fed ACAS compared with MFD-fed sham-operated mice. In contrast, its gene expression in the hippocampus was similar between MFD with EPKOP-fed ACAS and MFD-fed sham-operated mice. [Conclusion]: These results suggest that the new emulsifying oil powder extracted from Pacific krill may be effective to prevent vascular cognitive impairment.