Hydrogen nanobubbles enhance intracellular hydrogen delivery and significantly improve mitochondrial function by strengthening mitochondrial complexes I and V activity, increasing membrane potential, and accelerating electron transfer rates under oxidative stress conditions. This mechanism demonstrates that hydrogen nanobubbles effectively scavenge reactive oxygen species and provide protection against heavy metal-induced cellular toxicity, suggesting potential therapeutic applications for mitigating oxidative stress-related cellular damage and restoring mitochondrial bioenergetics in biological systems exposed to environmental toxins.
Plain-Language Summary
Researchers created water containing tiny hydrogen bubbles (nanobubbles) and tested whether they could protect algae cells from damage caused by toxic heavy metals like copper and cadmium. They found that the hydrogen nanobubbles were better at delivering hydrogen into the cells and protecting them by reducing harmful molecules called reactive oxygen species. The nanobubbles also improved how well the cells' energy-producing structures (mitochondria) worked by boosting their activity and helping them transfer electrons more efficiently.
Abstract
In biological systems, nanobubbles (NBs) effectively enhance hydrogen molecule retention and scavenging reactive oxygen species (ROS), but the underlying mechanisms remain elusive. To investigate this, we prepared hydrogen NB water samples with consistent dissolved hydrogen levels but varying NB densities to explore their physicochemical properties and effects on green algae (Chlorella vulgaris) under oxidative stress induced by copper ions (Cu2+) and cadmium ions (Cd2+). The results indicated a strong correlation between the hydrogen NB number density and the 25 % inhibitory concentration of Cu2+ over 24 h, with ROS removal efficiency increased with the NB number density. Gas chromatography showed that the hydrogen NBs in the solution had a high gas density that enhanced hydrogen transport into C. vulgaris. With regard to mitochondrial activity, hydrogen NBs were observed to enhance the function of mitochondrial complexes I and V and increase the mitochondrial membrane potential. Experiments with C. vulgaris mitochondrial electrodes showed that the electron transfer rates increased significantly in the presence of hydrogen NBs. We concluded that the high gas density of hydrogen NBs augments intracellular hydrogen delivery and strengthens mitochondrial functions.
