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Yuzu (Citrus junos Tanaka) improves cognitive function and glucose homeostasis in β‐amyloid infused rats
Author(s) -
Park Sunmin,
Kim Da Sol,
Yang Hye Jeong,
Hwang Jin Taek
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.861.26
Subject(s) - medicine , endocrinology , insulin resistance , insulin , homeostasis , glucose homeostasis , chemistry
Our preliminary study revealed that dementia induced by β‐amyloid accumulation itself exacerbates peripheral glucose homeostasis in rats. We were interested to study that long‐term oral consumption of Yuzu extract improves cognitive dysfunction and glucose homeostasis in the β‐‐amyloid‐induced rats. Male rats received intracerebralventricular infusions of β‐amyloid (25–35) (AMY) or β‐amyloid (35–25) (RAMY), at a rate of 3.6 nmol/day for 14 days. AMY‐infused rats were divided into two groups: one group received 3% lyophilized 70% ethanol extracts of Yuzu in a high fat diet and the other group received 3% dextrin. After 6 weeks of treatment, AMY increased β‐amyloid deposition in the hippocampus and the accumulation was not detected in RAMY. AMY attenuated hippocampal insulin signaling to induce hyperphosphorylation of tau. Yuzu treatment prevented the attenuation of the hippocampal insulin signaling in AMY‐infused rats and reduced tau phosphorylation. As a result, AMY induced cognitive dysfunction in comparison to RAMY while yuzu reversed cognitive impairment. AMY decreased body weight without lowering visceral fat accumulation by decreasing food intake and yuzu treatment blocked the decrease. However, yuzu treated rats had less visceral fat. AMY did not disrupt glucose tolerance due to increased insulin secretion although AMY exacerbated insulin resistance as indicated by HOMA‐IR and insulin tolerance tests. Yuzu treatment tended to improve the first phase of glucose tolerance and it was related to improved insulin sensitivity since it decreased insulin secretion. In conclusion, yuzu treatment alleviated cognitive dysfunction and impaired energy and glucose homeostasis by improving insulin sensitivity in rats with AMY‐induced cognitive dysfunction.