Evaluation of Effect of Ninjin'yoeito on Regional Brain Glucose Metabolism by 18F-FDG Autoradiography With Insulin Loading in Aged Mice

Jingmin Zhao; Ryota Imai; Naoyuki Ukon; Saki Shimoyama; Chengbo Tan; Yuko Maejima; Yuji Omiya; Kazuhiro Takahashi; Guangxian Nan; Songji Zhao; Hiroshi Ito; Kenju Shimomura

doi:10.3389/fnut.2021.657663

Evaluation of Effect of Ninjin'yoeito on Regional Brain Glucose Metabolism by ¹⁸F-FDG Autoradiography With Insulin Loading in Aged Mice

Front Nutr. 2021 May 12:8:657663. doi: 10.3389/fnut.2021.657663. eCollection 2021.

Authors

Jingmin Zhao^{1

2}, Ryota Imai^{3

4}, Naoyuki Ukon⁵, Saki Shimoyama⁵, Chengbo Tan^{5

6}, Yuko Maejima⁴, Yuji Omiya³, Kazuhiro Takahashi⁵, Guangxian Nan¹, Songji Zhao^{5

7}, Hiroshi Ito^{2

5}, Kenju Shimomura⁴

Affiliations

¹ Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China.
² Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima, Japan.
³ Tsumura Kampo Research Laboratories, Kampo Research and Development Division, Tsumura & Co., Ibaraki, Japan.
⁴ Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University, Fukushima, Japan.
⁵ Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, Japan.
⁶ Department of Neurosurgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
⁷ Department of Pathophysiology, Basic Medical College of Jilin University, Changchun, China.

Abstract

Introduction: A recent clinical study revealed that Ninjin'yoeito (NYT) may potentially improve cognitive outcome. However, the mechanism by which NYT exerts its effect on elderly patients remains unclear. The aim of this study is to evaluate the effect of Ninjin'yoeito on regional brain glucose metabolism by ¹⁸F-FDG autoradiography with insulin loading in aged wild-type mice. Materials and Methods: After 12 weeks of feeding NYT, mice were assigned to the control and insulin-loaded groups and received an intraperitoneal injection of human insulin (2 U/kg body weight) 30 min prior to ¹⁸F-FDG injection. Ninety minutes after the injection, brain autoradiography was performed. Results: After insulin loading, the ¹⁸F-FDG accumulation showed negative changes in the cortex, striatum, thalamus, and hippocampus in the control group, whereas positive changes were observed in the NYT-treated group. Conclusions: Ninjin'yoeito may potentially reduce insulin resistance in the brain regions in aged mice, thereby preventing age-related brain diseases.

Keywords: 18F-FDG autoradiography; Ninjin'yoeito; age; glucose metabolism; insulin loading.