Accurate in vivo real-time determination of the hydrogen concentration in different tissues of mice after hydrogen inhalation

As an antioxidant, anti-inflammatory and anti-apoptotic agent, hydrogen (H2) shows a promising potential in basic and clinical research against various diseases owing to its safety and efficacy. However, knowledge involving its underlying mechanisms of action, dosage effects, and dose duration remains limited. Previously, the dynamics of H2 concentrations in different tissues of rats after exogenous H2 inhalation had been detected by our team. Here, sequential changes of H2 concentrations in different tissues of another most commonly used experimental rodent mice were monitored in real time with an electrochemical H2 gas sensor during continuous different concentrations of H2 inhalation targeting on five tissues including brain, liver, spleen, kidney, and gastrocnemius. The results showed that the H2 saturation concentrations varied among tissues significantly regardless of the concentration of H2 inhaled, and they were detected the highest in the kidney but the lowest in the gastrocnemius. Meantime, it required a significant longer time to saturate in the thigh muscle. By comparing the H2 saturation concentrations of mice and rats, we found that there were no differences detected in most tissues except the kidney and spleen. Both gas diffusion and bloodstream transport could help the H2 reach to most organs. The results provide data reference for dosage selection, dose duration determination to ensure optimal therapeutic effects of H2 for mice experiments.

Hydrogen-rich saline inhibits tobacco smoke-induced chronic obstructive pulmonary disease by alleviating airway inflammation and mucus hypersecretion in rats

Chronic obstructive pulmonary disease induced by tobacco smoke has been regarded as a great health problem worldwide. The purpose of this study is to evaluate the protective effect of hydrogen-rich saline, a novel antioxidant, on chronic obstructive pulmonary disease and explore the underlying mechanism. Sprague-Dawley rats were made chronic obstructive pulmonary disease models via tobacco smoke exposure for 12 weeks and the rats were treated with 10 ml/kg hydrogen-rich saline intraperitoneally during the last 4 weeks. Lung function testing indicated hydrogen-rich saline decreased lung airway resistance and increased lung compliance and the ratio of forced expiratory volume in 0.1 s/forced vital capacity in chronic obstructive pulmonary disease rats. Histological analysis revealed that hydrogen-rich saline alleviated morphological impairments of lung in tobacco smoke-induced chronic obstructive pulmonary disease rats. ELISA assay showed hydrogen-rich saline lowered the levels of pro-inflammatory cytokines (IL-8 and IL-6) and anti-inflammatory cytokine IL-10 in bronchoalveolar lavage fluid and serum of chronic obstructive pulmonary disease rats. The content of malondialdehyde in lung tissue and serum was also determined and the data indicated hydrogen-rich saline suppressed oxidative stress reaction. The protein expressions of mucin MUC5C and aquaporin 5 involved in mucus hypersecretion were analyzed by Western blot and ELISA and the data revealed that hydrogen-rich saline down-regulated MUC5AC level in bronchoalveolar lavage fluid and lung tissue and up-regulated aquaporin 5 level in lung tissue of chronic obstructive pulmonary disease rats. In conclusion, these results suggest that administration of hydrogen-rich saline exhibits significant protective effect on chronic obstructive pulmonary disease through alleviating inflammation, reducing oxidative stress and lessening mucus hypersecretion in tobacco smoke-induced chronic obstructive pulmonary disease rats.

Effects of hydrogen as adjuvant treatment for unstable angina

Oxidative stress and inflammation are closely related to atherosclerotic cardiovascular disease. It is established that hydrogen has significant protective effects on many diseases as a potential antioxidative and anti-inflammatory agent. The purpose of this study is to evaluate the effect of hydrogen on unstable angina in vitro and in vivo. An atherosclerosis model in vitro was constructed by ox-LDL-induced injury of human umbilical vein endothelial cells and in vitro testing indicated hydrogen inhibited ox-LDL-induced oxidative stress and inflammatory response by down-regulating LOX-1/NF-kB signaling pathway. Subsequently, the attenuating effect of hydrogen-rich water intake on unstable angina was further confirmed in clinic. Forty hospitalized subjects with unstable angina were enrolled and consumed either 1000-1200 mL/d hydrogen-rich water or the same amount of placebo pure water in addition to conventional drugs for three months. Clinical analysis showed hydrogen-rich water intake relieved angina symptoms in unstable angina patients. Serum analysis showed that hydrogen-rich water addition resulted in more effective reductions of total-cholesterol, low-density lipoprotein-cholesterol, and apolipoprotein B levels compared with conventional treatment. These results support that hydrogen as adjuvant treatment has a beneficial effect on unstable angina.