Investigation of the Preventive Effects and Mechanisms of Phytoestrogen Intake on Cerebral Aneurysm Rupture

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K17889
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 55060:Emergency medicine-related
• Research Institution: Hamamatsu University School of Medicine
• Principal Investigator: Kimura Tetsuro 浜松医科大学, 医学部, 特任研究員 (00467250)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 脳動脈瘤 / 植物性エストロゲン / 動物モデル / エストロゲン受容体

Outline of Final Research Achievements

Using a cerebral aneurysm model, we investigated the effects of equol, a metabolite of the phytoestrogen daidzein, on the formation and rupture rates of cerebral aneurysms in ovariectomized female mice with low endogenous estrogen levels and sham-operated female mice with circulating estrogen. In the ovariectomized female mice, equol administration resulted in decreased cerebral aneurysm formation and rupture rates, whereas no such effects were observed in the sham-operated female mice.
Using estrogen receptor subtype (ER-β) specific knockout mice, we examined the contribution of estrogen receptor subtypes to the protective effects of estrogen. In ER-β specific female knockout mice administered with either equol or a placebo, there were no differences in cerebral aneurysm formation and rupture rates.

Free Research Field

救急医学

Academic Significance and Societal Importance of the Research Achievements

卵巣摘出した雌マウスの脳動脈瘤において、代表的な植物性エストロゲンであるダイゼインの代謝産物エクオールは脳動脈瘤の形成率と破裂率を低下させた。この効果はER-β受容体欠損雌マウスでは認められなかった。卵巣摘出した雌マウスにおけるエクオールの脳動脈瘤形成、破裂の保護作用にはエストロゲン受容体のサブタイプであるER-β受容体の関与が重要であることが示された。植物性エストロゲンの摂取は、エストロゲンが低下した閉経後女性における脳動脈瘤の形成と破裂に対して保護的に作用する可能性がある。