Hydrogen Injections Protect Eye Cells from Degeneration in Blindness Study

Authors
Journal
Frontiers in Pharmacology
Year
DOI
10.3389/fphar.2017.00587
Study Type
Rat
Outcome
Positive
Peer Reviewed
Yes
Country
China
Health Condition
Retinitis Pigmentosa
Body System
Visual

TL;DR

Injecting a solution rich in hydrogen into the eyes of rats was found to protect against a type of inherited blindness, with direct injection into the eye being more effective than into the body.

Key Finding

Direct injection of hydrogen-rich saline into the eye was more effective than abdominal injection at protecting photoreceptors from damage in a rat model of retinitis pigmentosa.

Summary

Researchers tested hydrogen-rich saline (a solution containing dissolved hydrogen gas) as a potential treatment for retinitis pigmentosa, a genetic eye disease that causes blindness. Using rats with chemically induced retinal damage similar to this disease, they compared two injection methods: one directly into the eye and one into the abdominal cavity. Both methods protected photoreceptors (light-sensing cells in the eye), but injecting directly into the eye was more effective, particularly for protecting cells in the back of the retina.

Practical Takeaway

This is an early-stage animal study suggesting hydrogen-rich saline may have protective effects against retinal cell damage. However, these results are from rats only, and it is unknown whether similar benefits would occur in humans or what the optimal delivery method would be for human patients. Much more research would be needed before this could be considered a viable treatment option.

Abstract

Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited retinal diseases leading to blindness. The present study explored the protective effects of hydrogen rich saline (HRS) against the photoreceptor degeneration in the N-Methyl-N-nitrosourea (MNU) administrated rat, a pharmacologically induced RP model. The therapeutic effects of intraperitoneal (IP) and intravitreous (IV) injections of HRS on regional retina was quantified via topographic measurements. The MNU administrated rats received IV or IP injections of HRS, and then they were subjected to electroretinography, multi electrode array, histological and immunohistochemistry examinations. The concentrations of the retinal malondialdehyde (MDA), superoxide dismutase (SOD), as well as the mRNA levels of apoptotic-associated genes were quantified. The IP and IV delivery pathways of HRS were both effective to ameliorate MNU induced photoreceptor degeneration. Moreover, the IV acted as a more efficient delivery method than the IP in terms of therapeutic effects. Particularly, the topographic measurements suggested that the IV delivery of HRS could alleviate MNU induced photoreceptor degeneration in the posterior retina. The immunostaining experiments also verified the comparative efficiency between IV and IP delivery of HRS on regional cone photoreceptors. Focal cone photoreceptors showed different susceptibilities to HRS and exhibited as a distinct spatial disequilibrium: cone photoreceptors in the ST quadrant were preferentially rescued; meanwhile, HRS induced protection was feeblest in the IN quadrant. Furthermore, the HRS treatment increased the level of retinal SOD, while reduce the level of retinal MDA in MNU administered rats. The expression levels of sever apoptotic -associated genes were significantly altered by HRS treatment. Collectively, these findings suggest that the IV space is an excellent target for HRS delivery. The IV delivery of HRS can efficiently alleviate the photoreceptors (especially these locate at the posterior retina) from MNU toxicity and act as a candidate treatment for RP.