Toei Shinyaku Co., Ltd. Obtains Patent for Improvement of Stress-Induced Cognitive Impairment by Intake of King Agaricus KA21

Toei Shinyaku Co., Ltd. (Head office: Mitaka, Tokyo; CEO: Akitomo Motoi) is pleased to announce that, based on joint research conducted with Professor Hirobumi Tada of the Faculty of Health Sciences, Shigakkan University (Obu, Aichi), the company has confirmed that oral intake of its outdoor-cultivated King Agaricus KA21 strain suppresses stress-induced cognitive impairment. Following this research, Toei Shinyaku has been granted a patent for “Compositions for Improving Stress-Induced Cognitive Impairment and Pharmaceuticals, Foods, and Feeds Containing the Same.”

Patent certificate

Overview

Patent Number: Patent No. 7752340

Patent Application Number: 2022-174395

Filing Date: October 31, 2022

Registration Date: October 2, 2025

Inventors: Hirobumi Tada, Akitomo Motoi

Applicants: Toei Shinyaku Co., Ltd., Shigakkan University

Title of the Invention:Compositions for Improving Stress-Induced Cognitive Impairment and Pharmaceuticals, Foods, and Feeds Containing the Same

Technical Field:This invention relates to compositions for improving stress-induced cognitive impairment and to pharmaceuticals, foods, and feeds containing the same.

About Stress-Induced Cognitive Decline

Dementia refers to a decline in cognitive function due to causes such as cerebrovascular disorders or neurodegenerative diseases like Alzheimer’s disease. While many studies are underway to develop drugs that can prevent or improve dementia, it is also known that psychological stress can impair cognitive functions such as memory, judgment, calculation, comprehension, learning, thinking, and language. For example, loneliness-related stress has been reported to increase the risk of developing dementia in the elderly (*1), and social isolation is also recognized as a risk factor for dementia (*2).

The mechanism underlying stress-induced cognitive decline has not yet been fully elucidated. Unlike senile dementia, which is caused by organic damage to the brain due to aging, stress-related cognitive decline may recover when stress factors are alleviated, indicating a different pathological condition.

Therefore, approaches for preventing and improving stress-induced cognitive decline need to differ from those for age-related dementia, and new therapeutic strategies and supplements are attracting increasing attention.

References:

(*1) Wilson et al., Arch. Gen. Psychiatry, 2007

(*2) Livingston et al., The Lancet Commissions, 2017

About Agaricus blazei, brasiliensis, subrufescens

Agaricus blazei is a medicinal mushroom native to Brazil and widely used in complementary and alternative medicine as a health food and dietary supplement. Its properties and composition vary greatly depending on the strain, cultivation environment, and production region, resulting in significant differences in quality among King Agaricus-containing products.

About Toei Shinyaku’s Outdoor-Cultivated King Agaricus KA21

Toei Shinyaku’s King Agaricus KA21 strain—King Agaricus 21 (KA21)—is cultivated outdoors under natural sunlight in Brazil, the mushroom’s country of origin. Compared with typical indoor (dark-room) cultivated Agaricus, the outdoor-grown King Agaricus KA21 mushrooms grow larger and contain higher levels of vitamins and minerals (*3).

(*3) Japan Food Research Laboratories analysis

Outdoor-cultivated King Agaricus KA21 

Size Comparison of Agaricus Mushrooms

Left: Common indoor-cultivated Agaricus

Right: Outdoor-cultivated King Agaricus KA21 

Content of β-glucan, the main component

Difference in vitamins and minerals

Difference in antioxidant activity

About Toei Shinyaku Co., Ltd.

As the manufacturer of the King Agaricus KA21 strain, Toei Shinyaku Co., Ltd. has been conducting research and development on King Agaricus KA21 for over 29 years, publishing 34 international scientific papers — the highest among Agaricus manufacturers — along with obtaining five domestic patents and two U.S. patents.

The company has conducted collaborative research with institutions such as Azabu University (School of Veterinary Medicine), Keio University SFC Research Institute, National Center for Geriatrics and Gerontology, Juntendo University School of Medicine, University of Tokyo Center for Food Safety, Tokyo University of Pharmacy and Life Sciences, and Harvard University (U.S.).

Animal studies have demonstrated that the King Agaricus KA21 strain exerts a wide range of beneficial effects, including antitumor activity, mitigation of chemotherapy side effects, liver protection, improvement of fatty liver, heart protection, reduction of blood glucose levels, promotion of hair growth, improvement of gut microbiota including the proliferation of Akkermansia muciniphila. Clinical studies in humans have confirmed immune enhancement, reduction of fatigue, improvement of hair loss and sleep quality, and alleviation of stress.

Company Information

Company Name: Toei Shinyaku Co., Ltd.

Head Office: 1-11-23 Shimorenjaku, Mitaka, Tokyo 181-0013, Japan

Representative: Akitomo Motoi, CEO

Capital: 10 million yen