崭露头角的氢气生物学

氢气（hydrogen gas，H₂）是新发现的生物气体信号分子。自2007年开始，有关H₂的生理调控活性及信号转导功能受到广泛的关注，并逐步形成了研究氢气生物学效应和分子机理的一门新学科--氢气生物学。按照实际运用范围的不同，氢气生物学也可以划分为氢医学和氢农学。在医学方面，通过多种动物模型研究和部分临床试验，发现H2具有抗氧化、抗炎和抗凋亡的作用，而且H₂对缺血/再灌注以及以炎症为基础的急性组织缺血性疾病和慢性退行性疾病（如帕金森病、阿尔茨海默病和动脉粥样硬化等氧化应激相关疾病）均具有较为理想的正面效果。在农学方面，相关报道还发现H₂可以提高苜蓿、水稻和拟南芥对非生物胁迫的耐性，调控黄瓜、番茄、猕猴桃、芽苗菜、黑大麦和食用菌的生长发育和营养品质，延长洋桔梗、玫瑰和百合切花的保鲜以及提高家畜对病原微生物的抗性。本文首先探究了氢气生物学的发展历史，提出氢医学研究思路的源头是电解水，结合H₂测定方法、内源H₂的产生途径以及氢气生物学效应的分子机理和信号转导的研究成果，从给氢方式、生物学效应以及安全性等方面，介绍了氢医学和氢农学的现状，提出选择性抗氧化机制不能完全解释现有的氢生物学效应，反映相关分子机制的复杂性和多样性。最后，针对氢气生物学的若干重要的科学和实践问题进行了展望，并提出氢医学的进一步发展还依赖于大量且可信度高的临床试验，氢农业还需要完成多年多点的大规模大田实践。

Hydrogen Biology: It is just Beginning

Hydrogen gas (H₂) is a novel gaseous signaling molecule. Since 2007, more attention has been paid to the physiological functions and signal transduction pathways of H2. Thus, a new discipline, called hydrogen biology, has been gradually developed to elucidate the biological functions and corresponding molecular mechanisms of H2. Hydrogen biology can be divided into hydrogen medicine and hydrogen agronomy, according to its actual scope of application. In medicine, the anti-oxidative, anti-inflammatory, and anti-apoptotic effects of H₂ have been discovered based on studies in multiple animal models and thereafter some clinical trials. In fact, H₂ has ideal positive effects on ischemia/reperfusion, inflammatory-based acute tissue ischemic diseases and chronic degenerative diseases, such as Parkinson’s disease, Alzheimer’s disease, and atherosclerosis. In plants and agronomy, it was found that H₂ could enhance plant tolerance against abiotic stress in alfalfa, rice and Arabidopsis, regulate growth, development, and nutritional values of cucumber, tomato, kiwifruit, sprouting vegetable, black barley and edible fungi. It is also demonstrated that H₂ could extend the vase life of lisianthus, rose and lily cut flowers, and improve the resistance of livestock against pathogens. In this paper, the history of hydrogen biology is described firstly, and it is proposed that electrolyzed water might be the first source of hydrogen medicine. The determination approaches of H₂, the synthetic pathway(s) of endogenous H₂, and the progresses of molecular mechanism and corresponding signal transduction of hydrogen biology were reviewed. Subsequently, the application status of hydrogen medicine and hydrogen agronomy was introduced from the perspectives of delivery, biological effects and safety of H₂. It is very interesting that the selective antioxidant mechanism of molecular hydrogen can not fully explain the existing biological effects of H₂, reflecting the complexity and diversity of this discipline. Finally, some important scientific and practical issues of hydrogen biology are proposed. Importantly, we pointed out that further development in hydrogen medicine depends on a large number of clinical trials with high reliability. Meanwhile, hydrogen agriculture also relies on large-scale field trials with multi-year and multi-site experiments in the future.