Levels of manganese superoxide dismutase activity are increased in tears from patients with thyroid-associated ophthalmopathy

The human eye is subjected constantly to oxidative stress due to daily exposure to sunlight, high metabolic activities, and oxygen tension. Reactive oxygen species generated from environmental insults and pathological conditions render the human eye particularly vulnerable to oxidative damage. The ocular surface composed of the tear film, the cornea, and the aqueous humor forms the first physical and biochemical barrier of the eye and plays a pivotal role in combating free radicals. These ocular compartments are enriched in certain antioxidants in the form of metabolic enzymes or small molecules. Such an antioxidant defense system in the ocular surface is essential for the maintenance of redox homeostasis in the eye and protection against oxidative damage. Herein, we review the properties and functions of key constituent antioxidants of the ocular surface.

show abstract

“…99 The only reported antioxidant enzyme in the tear film is SOD, which displays a activity at 1~32 U/mg protein. 31,100 …”

Section: Antioxidants In the Tear Film And Aqueous Humormentioning

confidence: 99%

Antioxidant Defenses in the ocular surface

2009

View full text Add to dashboard Cite

show abstract

“…Zinc and selenium were also identified in the tear film [ 8 ]. However, the only reported antioxidant enzyme in the tear film is SOD [ 9 ]. On the contrary, many enzymatic antioxidants have been documented in the cornea.…”

Section: The Structure Of the Eye And Ocular Antioxidant Defense Systemmentioning

confidence: 99%

Section: The Structure Of the Eye And Ocular Antioxidant Defense Systemmentioning

confidence: 99%

“…CAT: catalase; CoQ10: coenzyme Q10; GPXs: glutathione peroxidases; GR: Glutathione Reductase; GSH: Glutathione; SOD: superoxide dismutase. Reference for figure content: [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ] created with BioRender.com.…”

Section: Figurementioning

confidence: 99%

“…In addition, vitamin C was shown to be an effective scavenger of oxygen and nitrogen oxide species, such as superoxide radical ion, hydrogen peroxide, hydroxyl radical, and singlet oxygen. Its oxidation gives rise to dehydroascorbate, which is then reconverted to ascorbate, using GSH or NADPH as electron donors [9] (Figure 2). The ascorbate accumulation in the eye is achieved primarily by active transport through the iris-ciliary body into aqueous humour and subsequent transport into the cornea and lens.…”

Section: Antioxidants Arsenal In the Anterior Segmentmentioning

confidence: 99%

See 2 more Smart Citations

Antioxidant Nutraceutical Strategies in the Prevention of Oxidative Stress Related Eye Diseases

Rodella

Honisch

Gatto³

et al. 2023

Nutrients

View full text Add to dashboard Cite

This review aims to discuss the delicate balance between the physiological production of reactive oxygen species and the role of antioxidant nutraceutical molecules in managing radicals in the complex anatomical structure of the eye. Many molecules and enzymes with reducing and antioxidant potential are present in different parts of the eye. Some of these, such as glutathione, N-acetylcysteine, α-lipoic acid, coenzyme Q10, and enzymatic antioxidants, are endogenously produced by the body. Others, such as plant-derived polyphenols and carotenoids, vitamins B2, C, and E, zinc and selenium, and omega-3 polyunsaturated fatty acids, must be obtained through the diet and are considered essential nutrients. When the equilibrium between the production of reactive oxygen species and their scavenging is disrupted, radical generation overwhelms the endogenous antioxidant arsenal, leading to oxidative stress-related eye disorders and aging. Therefore, the roles of antioxidants contained in dietary supplements in preventing oxidative stress-based ocular dysfunctions are also discussed. However, the results of studies investigating the efficacy of antioxidant supplementation have been mixed or inconclusive, indicating a need for future research to highlight the potential of antioxidant molecules and to develop new preventive nutritional strategies.

show abstract

Levels of manganese superoxide dismutase activity are increased in tears from patients with thyroid-associated ophthalmopathy

Cited by 2 publications

References 17 publications

Antioxidant Defenses in the ocular surface

Antioxidant Defenses in the ocular surface

Antioxidant Nutraceutical Strategies in the Prevention of Oxidative Stress Related Eye Diseases

Contact Info

Product

Resources

About