Hydrogen Injection Reduces Nerve Pain in Rats by Fighting Inflammation
- Authors
- Yanhu Ge, Feixiang Wu, Xuejun Sun, Zhenghua Xiang, Liqun Yang, Shengdong Huang, Zhijie Lu, Yuming Sun, Wei-Feng Yu
- Journal
- PLoS One
- Year
- 2014
- DOI
- 10.1371/journal.pone.0097436
- Study Type
- Rat
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- China
- Health Condition
- Neuropathic Pain
- Body System
- Nervous System
TL;DR
Injecting a solution high in hydrogen into the spine reduces nerve pain in rats without losing effectiveness over time by decreasing inflammation and nerve damage.
Key Finding
Hydrogen-rich saline injected into the spinal fluid reduced neuropathic pain in rats and prevented pain development when given before nerve injury, without causing tolerance with repeated use.
Summary
Researchers injected hydrogen-rich saline directly into the spinal fluid of rats with nerve pain caused by spinal nerve injury. The treatment reduced pain sensitivity and prevented pain from developing in the first place. The pain relief appeared to work by reducing harmful molecules called free radicals and decreasing inflammation in the spinal cord, without the rats developing tolerance (becoming less responsive to repeated doses).
Practical Takeaway
This rat study suggests hydrogen may help with nerve pain by reducing oxidative stress and inflammation in the spinal cord. However, this is early-stage animal research; human studies would be needed to determine if these findings apply to people, and the injection method used here is not comparable to drinking hydrogen water.
Abstract
Background Reactive oxygen and nitrogen species are key molecules that mediate neuropathic pain. Although hydrogen is an established antioxidant, its effect on chronic pain has not been characterized. This study was to investigate the efficacy and mechanisms of hydrogen-rich normal saline induced analgesia. Methodology/Principal findings In a rat model of neuropathic pain induced by L5 spinal nerve ligation (L5 SNL), intrathecal injection of hydrogen-rich normal saline relieved L5 SNL-induced mechanical allodynia and thermal hyperalgesia. Importantly, repeated administration of hydrogen-rich normal saline did not lead to tolerance. Preemptive treatment with hydrogen-rich normal saline prevented development of neuropathic pain behavior. Immunofluorochrome analysis revealed that hydrogen-rich normal saline treatment significantly attenuated L5 SNL-induced increase of 8-hydroxyguanosine immunoreactive cells in the ipsilateral spinal dorsal horn. Western blot analysis of SDS/PAGE-fractionated tyrosine-nitrated proteins showed that L5 SNL led to increased expression of tyrosine-nitrated Mn-containing superoxide dismutase (MnSOD) in the spinal cord, and hydrogen-rich normal saline administration reversed the tyrosine-nitrated MnSOD overexpression. We also showed that the analgesic effect of hydrogen-rich normal saline was associated with decreased activation of astrocytes and microglia, attenuated expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the spinal cord. Conclusion/Significance Intrathecal injection of hydrogen-rich normal saline produced analgesic effect in neuropathic rat. Hydrogen-rich normal saline-induced analgesia in neuropathic rats is mediated by reducing the activation of spinal astrocytes and microglia, which is induced by overproduction of hydroxyl and peroxynitrite.