The Anti-Inflammatory Effect of Hydrogen Gas Inhalation and Its Influence on Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular Age-Related Macular Degeneration

Abstract

Background: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Choroidal neovascularization (CNV) is the major pathologic feature of neovascular AMD. Oxidative damages and the ensuing chronic inflammation are representative of trigger events. Hydrogen gas (H2) has been demonstrated as an antioxidant and plays a role in the regulation of oxidative stress and inflammation. This experiment aimed to investigate the influence of H2 inhalation on a mouse model of CNV. Methods: Laser was used to induce CNV formation. C57BL/6J mice were divided into five groups: the control group; the laser-only group; and the 2 h, 5 h, and 2.5 h/2.5 h groups that received laser and H2 inhalation (21% oxygen, 42% hydrogen, and 37% nitrogen mixture) for 2 h, 5 h, and 2.5 h twice every day, respectively. Results: The severity of CNV leakage on fluorescence angiography showed a significant decrease in the H2 inhalation groups. The mRNA expression of hypoxia-inducible factor 1 alpha and its immediate downstream target vascular endothelial growth factor (VEGF) showed significant elevation after laser, and this elevation was suppressed in the H2 inhalation groups in an inhalation period length-related manner. The mRNA expression of cytokines, including tumor necrosis factor alpha and interlukin-6, also represented similar results. Conclusion: H2 inhalation could alleviate CNV leakage in a laser-induced mouse CNV model, and the potential mechanism might be related to the suppression of the inflammatory process and VEGF-driven CNV formation.

Pharmacological Role of Functionalized Gold Nanoparticles in Disease Applications

“…However, the laser can damage the surrounding retinal tissue and cause persistent discomfort. Frequently required repeated intravitreal injections increase the risk of endophthalmitis and retinal detachment [ 9 ]. The eye consists of an anterior segment and a posterior segment.…”

Neovascular Progression and Retinal Dysfunction in the Laser-Induced Choroidal Neovascularization Mouse Model

“…Although angiogenesis and inflammation may appear to be two distinct processes, they are actually tightly related, particularly when angiogenesis occurs in adult organisms and is frequently accompanied by inflammation [ 71 ]. Recent studies suggest that several anti-inflammatory approaches such as Resveratrol/Metformi [ 72 ], Lycopene [ 73 ], cerium oxide nanoparticles [ 44 ], hydrogen gas [ 74 ], Shikonin [ 75 ], fursultiamine [ 76 ], Andrographolide [ 77 ], 5′-glucuronyl azidothymidine [ 78 ], and Pirfenidone [ 79 ], among others, can reduce laser-induced CNV formation in mice in a proof-of-principle method.…”

Hydrogen Gas Inhalation Regressed Coronary Artery Aneurysm in Kawasaki Disease-Case Report and Article Review

“…Their study demonstrated that H2 reduced oxidants of the detrimental ROS, thus protecting against oxidant-induced cell injury. Hydrogen gas inhalation has been reported to decrease the levels of inflammatory cytokines including TNF-α, IL-1β, IL-6, and hypoxia-inducible factor 1 alpha ( 17 ), which were found to be elevated in KD and even higher in KD with CAL formation. Long et al reported that hydrogen gas had protective effects in a rat model of branch retinal vein occlusion via decreasing Vascular endothelial growth factor (VEGF)-α expression ( 18 ).…”