解析桂花释放挥发物与其促进人体健康的生理生化机制

Ornamental plants play an important role in improving urban air quality, maintaining urban ecological balance and beautifying urban landscape. With the support of National Natural Science Foundation of China, we have finished a lot of research on the volatile organic compounds (VOCs) released from Ornamental plants. The aldehydes, released from Osmanthus fragrans 'Thunbergii', O.fragrans 'Odoratus', O.fragrans 'Aurantiacus', and O.fragrans 'Sem-perflorens', can inhibit microbial activity and improve air quality. In this project, in order to further reveal the relationship between t the VOCs released from O. fragrans and human health, we will compare the difference of the VOCs from O. fragrans under the different season, and study on the relationship of the VOCs released from Osmanthus fragrans and the psychological, physiological and biochemical indexes of humans from field and laboratory experiments, and laboratory tests integrated with monomer experiment of zoology. The above results expect to reveal the main compounds of the VOCs released from O. fragrans which are beneficial to human health, to reveal the physiological and biochemical response mechanisms of human health to the VOCs released from O. fragrans, and to provide a scientific basis for arrangement of ornamental plants to construct harmonious healthy living environment.

园林植物在改善城市空气质量、维护城市生态平衡和美化城市景观等方面起着十分重要的作用。申请人在国家自然科学基金资助下，对园林植物释放VOCs开展了大量的研究工作。金桂、银桂、丹桂和四季桂叶片释放醛类化合物能够显著抑制空气中微生物，具有改善空气质量作用。为了进一步研究桂花释放VOCs与人体健康的关系，本项目拟以4个品种的桂花释放VOCs入手，寻找不同生长季节桂花释放VOCs的差异，并分别通过室外和室内试验研究桂花VOCs与人体心理和生理生化指标变化的关系；结合桂花释放VOCs单体的动物实验结果，明确桂花释放VOCs中具有促进人体健康的主要化合物；阐明桂花释放VOCs促进人体健康的生理生化机制。为营造健康和谐居住环境的园林绿化植物配置提供更科学的理论依据。

为了探讨桂花释放挥发物（VOCs）调节人体健康的生理响应机制, 本研究采用动态顶空气体循环采集法和热脱附-气相色谱-质谱对桂花释放VOCs成分进行测定；采用自然沉降法测定了桂花林地空气中细菌、真菌和放线菌的动态变化；采用ELISA法检测嗅闻桂花精油大鼠血清皮质酮（CORT）、脑组织中γ-氨基丁酸（GABA）和多巴胺（DA）的含量；通过人体嗅闻桂花精油和桂花鲜花释放VOCs，测定人体心率、收缩压、舒张压、皮肤温度、血氧含量和皮肤导性人体生理指标。结果表明：金桂、银桂、丹桂和四季桂叶片和鲜花释放的VOCs以萜类化合物为主。金桂和四季桂成分为β-蒎烯、柠檬烯、罗勒烯、芳樟醇氧化物、β-芳樟醇和紫罗兰酮；银桂为β-蒎烯、罗勒烯、芳樟醇氧化物和紫罗兰酮；丹桂为β-蒎烯、柠檬烯、罗勒烯、芳樟醇氧化物、β-芳樟醇；在一天不同时间和一年不同季节桂花释放VOCs的组成及相对含量存在较大差异。金桂、银桂、丹桂和四季桂叶片释放的醛类化合物对空气中细菌和真菌抑制作用极显著，具有明显的改善空气质量作用。桂花精油通过提高大鼠血清CORT含量和降低脑组织中GABA含量，改善高架十字迷宫导致大鼠焦虑的作用。桂花精油和桂花释放的VOCs通过降低人体心率、收缩压和舒张压，使人体处于放松状态，并具有缓解紧张情绪的生理作用。该成果为进一步揭示植物释放VOCs调节人体健康的生理响应机制，以及阐明森林康养对人体健康的生理生化提供理论依据。