As a metalloenzyme that can catalyze hydrogen oxidation and proton reduction， hydrogenase plays a key role in the hydrogen metabolism of organisms. Previous studies have shown that hydrogen intervention has a positive impact on plant growth and stress resistance. At the same time， the phenomenon of endogenous hydrogen production in some higher plants has also been confirmed. However， little is known about the hydrogenase that catalyzes endogenous hydrogen production. Although many studies have shown that chloroplasts may be the key part of hydrogen production in higher plants， in view of the fact that many plants can still produce hydrogen during seed germination when chloroplasts have not been formed， combining that hydrogenase has evolutionary homology with mitochondrial complex Ⅰ， the hypothesis that higher plant mitochondria have hydrogenase activity was put forward and the preliminary experimental evidence of hydrogenase activity in mitochondria was summarized on the basis of summarizing the research status of hydrogenase， hoping to provide a reference for the follow-up study on the relationship between mitochondria and hydrogenase.

The selective antioxidant mechanism of hydrogen molecular （H₂）， as a scavenger of cytotoxic free radicals， has provided a new direction for research and application of free radical biomedical theory. Since the biological effect of H₂ was first reported in 2007， its beneficial biological effects have been demonstrated in animal models and human diseases， including ischemia/reperfusion injury， metabolic syndrome， inflammation and cancer. Although the medical target of H₂ is still controversial， many researches have demonstrated the medical and health promotion effect of H₂ biomedicine. This paper systematically introduced the research progress of H₂ regulating organisms and cellular biology deciphering its anti-oxidative， anti-inflammatory and antiapoptotic effect， and the protection of mitochondria and endoplasmic reticulum， as well as the regulation effect of intracellular signaling pathways and immune system， which amied to provide systemic knowledge for further research on the H₂ bio-mechanism and standard application.

To evaluate the regulatory effect of hydrogen-rich saline （HRS） on mitochondrial autophagy in myocardial cells of septic mice and its therapeutic effect on cardiac dysfunction， the seventy two male C57BL/6J mice were selected as the research objects and randomly divided into sham operation group （Sham group）， sham operation+hydrogen-rich saline group （Sham+HRS group）， sepsis （CLP group） and CLP+hydrogen-rich saline group （CLP+HRS group）， with 18 mice in each group. CLP model in mice was established by cecal ligation and puncture. Sham+HRS group and CLP+HRS group were intraperitoneally injected with 10 mL·kg^-1 hydrogen rich solution at 1 and 6 hours after modeling， respectively. Six mice in each group were randomly selected， and the mouse carotid blood sample was collected 24 hours after modeling， and the levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， cardiac troponin I （cTnI） and creatine kinase MB （CK-MB） in blood were determined by ELISA. Myocardial tissue was taken at 24 hours after modeling， ATP was detected by fluorescein fluorescent enzyme luminescence method， and mitochondrial membrane potential （MMP） was detected by fluorescence spectrophotometry. The expression of microtubule-associated protein 1 light/protein 3 light （LC3Ⅱ/LC3Ⅰ） and protein 62 （P62） in myocardial tissue was measured by Western blot at 24 hours after modeling. Results showed that， compared with Sham group， the levels of serum TNF-α， IL-1β， cTnI and CK-MB in CLP group were increased， the levels of myocardial ATP and MMP were decreased， the expression of myocardial LC3 Ⅱ/LC3 Ⅰ was increased， and the expression of P62 was decreased， the difference was statistically significant （P<0.05）. Compared with CLP group， the levels of serum TNF-α， IL-1β， cTnI and CK-MB in CLP+HRS group decreased， the levels of ATP and MMP in myocardial tissue increased， the expression of LC3Ⅱ/ LC3Ⅰ increased， and the expression of P62 decreased （P<0.05）. The results showed that the therapeutic effect of hydrogen-rich saline on cardiac dysfunction in sepsis mice may be achieved by regulating mitochondrial autophagy of cardiomyocytes. The study amied to explore the therapeutic effect and mechanism of hydrogen-rich saline on cardiac dysfunction in septic mice， and provide a theoretical basis for the clinical transformation of hydrogen-rich saline.

To evaluate whether hydrogen-rich saline could relieve psoriasis in imiquimod-induced mouse， the male BALB/C mice which were aged eight to twelve weeks， were intraperitoneal injected by hydrogen-rich saline and normal saline for 7 days， then 5% imiquimod cream（IMQ） was given on the back， and the intraperitoneal injection of hydrogen-rich saline or normal saline was continued for 7 days. The disease clinical parameters were rated independently for the animals using the modified target lesion psoriasis severity score. The skin sections， stained with hematoxylin-eosin， were scored on Baker score. Inflammatory cytokine levels were measured through quantitative RT-PCR and ELISA kits. Malondialdehyde （MDA） kit and paraoxonase-1（PON-1） activity was used to determin plasma oxidant. The results showed that the psoriasis mouse model was successfully induced，and the hydrogen-rich saline group had lower clinical and histological scores than the normal saline mice. In the hydrogen-rich saline group， these clinical and pathology were significantly less than the normal saline group. Moreover， in comparison with normal saline mice， the level of plasma interleukin-1 （IL-1）， IL-6 and IL-17A was lower within hydrogen-rich mice. The levels of IL-1， IL-6 and IL-17A and tumor necrosis factor -α （TNF-α） in skin of hydrogen-rich saline group was less than those in normal saline group. IL-1， IL-6 and IL-17A mRNA levels were less in hydrogen-rich mice compared with normal saline group. The level of MDA in hydrogen group were lower than those in normal saline group. Moreover， the activity of PON-1 in hydrogen group were higher than those in normal saline group. This results showed that hydrogen-rich saline could alleviate the pathological features of psoriasis in imiquimod-induced mouse model， it may be associated with reducing the level of the oxidative stress and inflammation.

To investigate the effect of hydrogen inhalation on postoperative delirium in patients undergoing thoracoscopic radical surgery for lung cancer， 124 patients with thoracoscopic radical surgery for lung cancer were selected as the research subjects， and the selection period was from June 2020 to May 2021. According to the random number method， they were divided into observation group （with hydrogen inhalation of 66.7%） and control group （with oxygen inhalation of 33.3%）， with 62 cases in each group. The oxygen saturation， oxygenation index， lung dynamic compliance， interleukin （IL-6） and superoxide dismutase （SOD） were compared between the two groups at 5 min before single lung ventilation （T0） and at the end of single lung ventilation （T1）， the incidence of delirium on the 1st， 3rd， and 7th days after the operation between two groups were observed. At T0， there was no significant difference in oxygen saturation， oxygenation index， pulmonary dynamic compliance， IL-6 and SOD between the two groups （P<0.05）. At T1 time， oxygen saturation， oxygenation index， the dynamic lung compliance and SOD in the observation group was higher than the control group， while IL-6 was lower than the control group （P<0.05）. The score of numerical rating scale （NRS） was lower in the observation group than that in the control group （P<0.05）. The incidence and time of delirium on the 1st， 3rd， and 7th postoperative days in the observation group was lower than that in the control group （P<0.05）. Hydrogen inhalation is beneficial to improve the oxygenation index of patients with thoracoscopic radical surgery of lung cancer， and reduce the concentration of inflammation and the incidence of postoperative delirium.