Application of hydrogen in the treatment of human diseases
A number of clinical studies have shown that H2 has anti-inflammatory and antioxidant properties, and it has been recommended as the recommended drug in the latest treatment guidelines of novel coronavirus (NCP) in China.
Clinical experiments have surprisingly found that hydrogen has a protective effect on the lungs and extrapulmonary organs of NCP patients.
Hydrogen can regulate anti-inflammatory and antioxidant activities, mitochondrial energy metabolism, endoplasmic reticulum stress, immune system and cell death (including apoptosis, autophagy, cell scorch, iron death and biological clock), and has the potential to treat a variety of systemic diseases.
Hydrogen has great potential in regulating oxidative stress, inflammation, organelle energy metabolism and programmed cell death. A large number of animal experiments and clinical studies have proved the protective effect of hydrogen on many organs and systems.
In the past 15 years, research in this field has increased. However, the specific molecular mechanism behind the therapeutic effect of hydrogen is still unclear.
For example, it is unclear whether hydrogen can actually be used to regulate iron death, cell scorch or biological clock. Since H2 does not have a unidirectional (opposite) effect on autophagy like rapamycin or leucine, is it possible to regulate autophagy or apoptosis in a specific direction?
Previous studies have clearly explained the antioxidant stress effect of hydrogen. However, some recent clinical studies have shown that H2 can also induce oxidative stress under certain conditions.
H2 ventilation can slightly increase ROS, activate Nrf2 and NF-κB signaling pathways, and cause heat shock response. H2-induced ROS production was also observed in tumor cells.
The specific mechanism of inducing the increase of hydrogen oxidative stress needs further experimental clarification. These problems related to the mechanism of hydrogen action deserve further study.
Many factors limit the clinical application of hydrogen.
First of all, the concentration of hydrogen over 4% is considered unsafe, because such a high concentration is explosive and may have cytotoxic effects.
Previous studies have shown that the hydrogen concentration should be stable above 2% to prevent acute oxidative stress. But even 2% hydrogen is not completely safe.
Most clinical ventilators are equipped with platinum thermometers, because H2 and O2 at room temperature will overheat the platinum surface.
Secondly, there is a lack of special equipment to manage the effective concentration of hydrogen, while ensuring the safety of hydrogen.
Third, there are few large-scale human controlled studies on the effects of hydrogen.
Fourthly, Liu and his colleagues showed that compared with intraperitoneal, intravenous or oral administration, inhalation of H2 resulted in a slower increase in H2 concentration. However, the increase of H2 concentration lasts at least 60 minutes after inhalation.
Therefore, the administration mode of H2 should be carefully selected. Therefore, the dose-specific effect or side effect of hydrogen in human body is still unclear.
The known mechanism of hydrogen action suggests that hydrogen can alleviate multiple organ damage in NCP patients. The comparison of different forms of hydrogen shows the value of HW in the effective treatment of such patients.
Hydrogen is cheap and safe, and can be used in many ways. We expect that the full clinical potential of hydrogen will be realized when large-scale clinical trials confirm the therapeutic effect and safety of hydrogen.