主な研究 Study
化粧品原料の探索、作用メカニズム解明 Exploration of cosmetic materials and elucidation of their mechanisms of activity
メラニンはヒトの皮膚や毛髪の色素成分です。メラニン生産が過剰になる事で、シミやソバカスの原因となり、逆に減少することで白髪や白斑の原因となります。また、皮膚の張りを支える脂肪細胞の減少により、しわやたるみの原因となります。私たちは医学部皮膚科学研究室や、化粧品会社と共同研究を行い、でメラニン生産を制御する化合物や、しわやたるみの改善が期待される化合物を発見してきました。
論文：International Journal of Cosmetic Science
Melanin is the pigment component of human skin and hair. Excessive melanin production causes spots and freckles, while a decrease in melanin production causes gray hair and vitiligo. In addition, a decrease in fat cells, which support skin tension, causes wrinkles and sagging. We have discovered compounds that control melanin production and compounds that are expected to improve wrinkles and sagging skin in collaboration with the Dermatology Laboratory of the Faculty of Medicine and cosmetics companies.
タンニンの構造と生理活性解明 Elucidation of the structure and bioactivity of tannins
タンニンは、植物に普遍的に存在している成分です。タンニンはタンパク質凝集作用、酵素阻害活性、抗酸化作用、消臭作用など数多くの活性をもつことが知られていますが、分子が大きく構造も複雑なため、「なぜきくの？」、という疑問に、長年誰も答えられていません。そのため、タンニンの構造解析及び、化学合成を行うことで、明確な構造のタンニンを得て、これを使って活性試験を行う事で、この謎を解き明かそうとしています。私たちは初めてタンニンとタンパク質の相互作用位置を明らかにし、タンパク質凝集モデルの作成に成功しました。
Tannins are universally present in plants. Tannins are known to have numerous activities such as protein aggregation, enzyme inhibitory activity, antioxidant activity, and deodorant activity, but because of their large molecules and complex structure, the question "why are they effective? However, because of their large molecules and complex structures, no one has been able to answer the question, "Why do they work? However, due to its large molecule and complex structure, no one has been able to answer the question, "Why is it effective?" Therefore, we are trying to solve this mystery by analyzing the structure of tannins and chemically synthesizing them to obtain tannins with a clear structure and testing their activity. We have identified the location of tannin-protein interactions for the first time and have successfully created a model of protein aggregation.
https://www.gifu-u.ac.jp/about/publication/press/20230309_1.pdf
熱帯産薬用植物研究 Tropical Medicinal Plant Research
熱帯に生育する植物は、過酷な環境要因（紫外線、微生物、昆虫、動物など）に打ち勝つための自己防衛成分を自ら生合成している。これらの成分は量的に多いばかりでなく、生理活性が高い多彩な化学構造を持ちます。一方熱帯地域には、古来より民間伝承薬が発達しており、その国々で育まれ現在でも重要な意味を持ち利用され続けています。本研究では安全性がすでに実証されている南アジアの国々に生育する薬用植物に着目し、薬効性に起因する成分の探索や新規な生理機能と薬効性を見いだすことを目的としています。特に口腔内細菌（虫歯菌、歯周病菌、ニキビ菌）感染症予防、メラニン色素の生産に及ぼす生理活性、炎症性サイトカインの生産抑制、免疫細胞（NK細胞）活性化効果、さらには神経細胞樹状突起形成促進果など、美容と健康をキーワードにした天然医薬成分の構造および機能について分子レベルで研究しています。
Plants growing in the tropics biosynthesize their own self-defense components to overcome harsh environmental factors (UV rays, microbes, insects, animals, etc.). These components are not only large in quantity, but also have diverse chemical structures that are highly bioactive. On the other hand, in the tropics, folklore medicines have been developed since ancient times, and they continue to be nurtured and used with great importance in those countries even today. In this study, we focus on medicinal plants growing in South Asian countries, which have already been proven to be safe, and aim to search for components that are responsible for their medicinal properties and to discover new physiological functions and medicinal properties. In particular, we are conducting molecular-level research on the structure and function of natural medicinal ingredients with the keywords of beauty and health, such as prevention of oral bacterial infections (caries, periodontal disease, and acne), bioactivity on melanin pigment production, suppression of inflammatory cytokine production, immune cell (NK cell) activation effect, and neuronal dendrite formation promotion effect. We are studying the structure and function of natural pharmaceutical ingredients at the molecular level.
植物香気成分の生理・心理作用に及ぼす効果の解明 Elucidation of the effects of plant odorants on physiological and psychological effects
植物の香り成分は，古代エジプトのミイラの製造に欠かせない没薬や聖徳太子が好んだ香木など神事や神聖な時と場所において不可欠なものであるばかりでなく，伝統的な精神疾患の治療薬として世界の各地域で育まれ今なお発展し続けています。現在ではハーブや果実から抽出した精油を嗅いだり，浴槽に入れたり，体に塗ったりすることで，リラクゼーションやストレスケア，美容，健康維持，疲労回復さらには疾病予防などアロマテラピーとして利用されています。たとえば，ラベンダーは鎮静・鎮痛効果，ペパーミントは胃腸機能改善・収斂効果，ローズはホルモン調節効果などが上げられます。これらの効能は，体温，血圧，保水性などの体内環境恒常性を自動的に制御している自律神経系に作用して働くと考えられています。このように，様々な植物由来の香気成分に関する研究・探索が行われていますが，それらの対象は主に果皮，果実，葉，花由来の精油に関するものがほとんどです。一方、豊富なバイオマス量を持つ高等植物の樹木およびその加工材料の木材に関しては，建築用材やパルプ用材などへの利用は確立されているものの，その精油の利用に関する実用化研究は多くありません。
The fragrant components of plants are not only essential for rituals and sacred times and places, such as myrrh, which was essential for the production of mummies in ancient Egypt, and fragrant wood, which was favored by Prince Shotoku, but they are also nurtured in various regions of the world as traditional remedies for mental disorders, and continue to develop. Today, essential oils extracted from herbs and fruits are used as aromatherapy for relaxation, stress care, beauty care, health maintenance, recovery from fatigue, and disease prevention by smelling them, adding them to baths, or applying them to the body. For example, lavender has sedative and analgesic effects, peppermint improves gastrointestinal functions and has astringent effects, and rose has hormone regulating effects. It is thought that these effects work by acting on the autonomic nervous system, which automatically controls the body's internal environmental homeostasis, such as body temperature, blood pressure, and water retention. Thus, research and exploration on various plant-derived fragrant components have been conducted, but most of them are mainly related to essential oils derived from fruit peel, fruit, leaves, and flowers. On the other hand, as for trees of higher plants with abundant biomass and their processing material, wood, there are not many practical studies on the use of their essential oils, although their use as building materials and pulp materials has been established.
最近，我々はマウスやラットを用いた実験において，ヒノキ科樹木の一種であるホワイトサイプレスの心材に含まれる精油（CEO）の香気成分雰囲気下で飼育したマウスの体重，血清中および肝臓中のトリグリセライドとトータルコレステロールがコントロール群に比べて減少することを見出し，この匂い成分に肥満抑制効果があると考察しました。さらに，麻酔下ラットにCEOおよびその分画物を吸入させたときの肩甲骨間褐色脂肪組織の交感神経活動に及ぼす影響と肥満抑制効果に寄与する成分の特定を試みたところ，興味深い新しい知見を得ることができました。
Recently, we found that the body weight, triglycerides in serum and liver, and total cholesterol of mice raised in the presence of the odor component of the essential oil (CEO) contained in the heartwood of white cypress, a member of the cypress family, decreased compared to the control group in experiments using mice and rats. This finding suggests that the odorant has an obesity-inhibiting effect. Furthermore, we attempted to determine the effects of CEO and its fractions on sympathetic nerve activity in the interscapular brown adipose tissue of anesthetized rats and the components contributing to the obesity-suppressing effect, and obtained interesting new findings.
本研究では、植物の香り成分が生理・心理作用に与える影響とその効果を動物実験を通して神経生理化学的手法により考察し、今後日本社会が直面する高齢化社会に向けた、生活習慣病予防や認知症予防などに対応できる研究を進めています。
In this research, we are examining the effects of plant aroma components on physiological and psychological effects through animal experiments using neurophysiological chemical methods, and are conducting research that can help prevent lifestyle-related diseases and dementia for the aging society that Japanese society will face in the future.
