Protective effect of saturated hydrogen saline against blue light-induced retinal damage in rats

Exploring the impact of nano platinum-hydrogen saline on oxygen-induced retinopathy in neonatal rats

OBJECTIVE

The objective of this study is to assess the impact of nano platinum-hydrogen saline (Pt NPs + H2) on oxygen-induced retinopathy (OIR) in neonatal rats, with the goal to contribute new insights into the therapeutic strategies for retinopathy of prematurity.

METHODS

Pt NPs + H2 formulation was synthesized to address OIR in a rat model. Subsequent examination included the assessment of retinal blood vessel distribution and morphology through hematoxylin and eosin (HE) and isolectin B4 (IB4) staining techniques. The levels of reactive oxygen species (ROS), malondialdehyde(MDA), and superoxide dismutase (SOD) were measured to reflect the oxidative stress in rats. Additionally, the protein expression of vascular endothelial growth factor (VEGF) in each experimental group was assessed using western blot analysis, while the gene expression of VEGF in retinal neovascularization tissues was assessed using reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, the extent of retinal cell apoptosis was measured using a TdT-mediated dUTP Nick-End Labeling (TUNEL) apoptosis kit.

RESULTS

HE staining and IB4 staining revealed positive retinal neovascularization in the OIR group, whereas neovascularization in the Pt NPs + H2 group exhibited reduced severity. Significantly fewer capillary globules and capillary tubules were observed in the Pt NPs + H2 group compared to the OIR group (p < 0.05). Also, the Pt NPs + H2 group demonstrated significant reductions in ROS and MDA levels within retinal tissues (p < 0.05, p < 0.001), along with a significant increase in SOD level (p < 0.05). Notably, the MDA level in the Pt NPs + H2 group was notably lower than that in the OIR group (p < 0.01, p < 0.05), and even lower than that in the H2 group. Pt NPs + H2 intervention was associated with decreased protein and mRNA expression of VEGF, with statistical significance (p < 0.05). While the H2 group exhibited a decreasing trend in apoptotic cell count in the retinal ganglion cell layer (p < 0.05), the Pt NPs + H2 group demonstrated a more pronounced reduction, with a significant difference (p < 0.01). No significant discrepancy in apoptosis within the inner nuclear layer was observed (p > 0.05).

CONCLUSIONS

The synergistic effect of hydrogen saline and nano platinum manifests as enhanced antioxidant, anti-apoptotic, and anti-neovascular properties. Nano platinum-hydrogen saline demonstrates inhibitory effects on OIR in rats.

A review on eye diseases induced by blue light: pathology, model, active ingredients and mechanisms

Blue light induced eye damage (BLED) belongs to modern diseases. It is an ophthalmic disease caused by prolonged exposure to electronic devices or screens containing a large amount of high-energy short waves (blue light). Specific symptoms include dryness and discomfort in the eyes, blurred vision, headache, insomnia, and in severe cases, it may also cause various eye diseases such as cataracts and glaucoma. At present, the development of health products and drugs for eye blue light injury faces many difficulties. Therefore, further exploration and research are needed on the pathogenesis, pathophysiology, and pharmacological mechanisms of blue light injury. Natural medicine ingredients and preparations have unique advantages in targeting eye blue light injury fatigue products due to their multi-component synergistic effects, overall regulation, and mild and safe characteristics. Starting from the disease-related mechanisms and pathophysiological characteristics of eye blue light injury, this article elucidates the pharmacological mechanisms of various drugs for treating eye blue light injury. At the same time, it reviews the research on in vitro cultured cell and animal model conditions for blue light injury eyes, in order to provide reference for subsequent blue light injury modeling experiments. And explore future research directions to provide new ideas and methods for the prevention and treatment of BLED.

Hydrogen promotes the activation of Cu, Zn superoxide dismutase in a rat corneal alkali-burn model

AIM

To investigate the effects of hydrogen (H₂) on Cu, Zn superoxide dismutase (SOD1) activation in a rat model of corneal alkali burn.

METHODS

In each rat, one cornea was subjected to alkali exposure. Physiological saline (saline group) or H₂-dissolved saline (H₂ group) was instilled continuously on the cornea for 5min before and after alkali exposure. Inflammatory cells, neovascularization, and cytoplasmic SOD1 levels were evaluated immunohistochemically in enucleated eyes from both groups. Three-dimensional ultrastructural tissue changes in the eyes were analyzed using low-vacuum scanning electron microscopy.

RESULTS

The numbers of both inflammatory and vascular endothelial cells were significantly reduced in the corneas of the H₂ group (P<0.01). Furthermore, H₂ treatment increased both cytoplasmic SOD1 levels (P<0.01) and activity in corneal epithelial cells (P<0.01). Notably, the SOD1 activity level in the H₂ group was approximately 2.5-fold greater than that in the saline group.

CONCLUSION

H₂ treatment suppresses inflammation and neovascularization in the injured cornea and indirectly suppresses oxidative insult to the cornea by upregulating the SOD1 enzyme protein level and activity.

An Immunohistochemical Study of the Increase in Antioxidant Capacity of Corneal Epithelial Cells by Molecular Hydrogen, Leading to the Suppression of Alkali-Induced Oxidative Stress

Corneal alkali burns are potentially blinding injuries. Alkali induces oxidative stress in corneas followed by excessive corneal inflammation, neovascularization, and untransparent scar formation. Molecular hydrogen (H₂), a potent reactive oxygen species (ROS) scavenger, suppresses oxidative stress and enables corneal healing when applied on the corneal surface. The purpose of this study was to examine whether the H₂ pretreatment of healthy corneas evokes a protective effect against corneal alkali-induced oxidative stress. Rabbit eyes were pretreated with a H₂ solution or buffer solution, by drops onto the ocular surface, and the corneas were then burned with 0.25 M NaOH. The results obtained with immunohistochemistry and pachymetry showed that in the corneas of H₂-pretreated eyes, slight oxidative stress appeared followed by an increased expression of antioxidant enzymes. When these corneas were postburned with alkali, the alkali-induced oxidative stress was suppressed. This was in contrast to postburned buffer-pretreated corneas, where the oxidative stress was strong. These corneas healed with scar formation and neovascularization, whereas corneas of H₂-pretreated eyes healed with restoration of transparency in the majority of cases. Corneal neovascularization was strongly suppressed. Our results suggest that the corneal alkali-induced oxidative stress was reduced via the increased antioxidant capacity of corneal cells against reactive oxygen species (ROS). It is further suggested that the ability of H₂ to induce the increase in antioxidant cell capacity is important for eye protection against various diseases or external influences associated with ROS production.

The potential utilizations of hydrogen as a promising therapeutic strategy against ocular diseases

Hydrogen, one of the most well-known natural molecules, has been used in numerous medical applications owing to its ability to selectively neutralize cytotoxic reactive oxygen species and ameliorate hazardous inflammations. Hydrogen can exert protective effects on various reactive oxygen species-related diseases, including the transplantation-induced intestinal graft injury, chronic inflammation, ischemia–reperfusion injuries, and so on. Especially in the eye, hydrogen has been used to counteract multiple ocular pathologies in the ophthalmological models. Herein, the ophthalmological utilizations of hydrogen are systematically reviewed and the underlying mechanisms of hydrogen-induced beneficial effects are discussed. It is our hope that the protective effects of hydrogen, as evidenced by these pioneering studies, would enrich our pharmacological knowledge about this natural element and cast light into the discovery of a novel therapeutic strategy against ocular diseases.

Use of Hydrogen as a Novel Therapeutic Strategy Against Photoreceptor Degeneration in Retinitis Pigmentosa Patients

Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterized by progressive photoreceptor apoptosis. Reactive oxygen species (ROS) have been recognized as critical initiators of the photoreceptor apoptosis in RP. Photoreceptor survival in RP mutants will not only require the inhibition of effectors of apoptotic machinery, but also the elimination of the initiating upstream signals, such as ROS. These cytotoxic ROS should be neutralized by the antioxidant defense system, otherwise they would interact with the macromolecules essential for photoreceptor survival. Hydrogen is a promising gaseous agent that has come to the forefront of therapeutic research over the last few years. It has been verified that hydrogen is capable of neutralizing the cytotoxic ROS selectively, rectifying abnormities in the apoptotic cascades, and attenuating the related inflammatory response. Hydrogen is so mild that it does not disturb the metabolic oxidation-reduction reactions or disrupt the physiologic ROS involved in cell signaling. Based on these findings, we hypothesize that hydrogen might be an effective therapeutic agent to slow or prevent photoreceptor degeneration in RP retinas. It is a logical step to test hydrogen for therapeutic use in multiple RP animal models, and ultimately in human RP patients.

Beneficial biological effects and the underlying mechanisms of molecular hydrogen - comprehensive review of 321 original articles

Therapeutic effects of molecular hydrogen for a wide range of disease models and human diseases have been investigated since 2007. A total of 321 original articles have been published from 2007 to June 2015. Most studies have been conducted in Japan, China, and the USA. About three-quarters of the articles show the effects in mice and rats. The number of clinical trials is increasing every year. In most diseases, the effect of hydrogen has been reported with hydrogen water or hydrogen gas, which was followed by confirmation of the effect with hydrogen-rich saline. Hydrogen water is mostly given ad libitum. Hydrogen gas of less than 4 % is given by inhalation. The effects have been reported in essentially all organs covering 31 disease categories that can be subdivided into 166 disease models, human diseases, treatment-associated pathologies, and pathophysiological conditions of plants with a predominance of oxidative stress-mediated diseases and inflammatory diseases. Specific extinctions of hydroxyl radical and peroxynitrite were initially presented, but the radical-scavenging effect of hydrogen cannot be held solely accountable for its drastic effects. We and others have shown that the effects can be mediated by modulating activities and expressions of various molecules such as Lyn, ERK, p38, JNK, ASK1, Akt, GTP-Rac1, iNOS, Nox1, NF-κB p65, IκBα, STAT3, NFATc1, c-Fos, and ghrelin. Master regulator(s) that drive these modifications, however, remain to be elucidated and are currently being extensively investigated.