Protective role of vitamin D against oxidative stress in diabetic retinopathy

Abstract

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus. There is much evidence showing that a high level of mitochondrial overproduction of reactive oxygen species in the diabetic retina contributes in modifying cellular signalling and leads to retinal cell damage and finally to the development of DR pathogenesis. In the last few decades, it has been reported that vitamin D is involved in DR pathogenesis. Vitamin D, traditionally known as an essential nutrient crucial in bone metabolism, has also been proven to be a very effective antioxidant. It has been demonstrated that it modulates the production of advanced glycosylated end products, as well as several pathways including protein kinase C, the polyol pathway leading to the reduction of free radical formation. It prevents the translocation of nuclear factor kappa B, preventing the inflammatory response, acting as an immunomodulator, and modulates autophagy and apoptosis. In this review, we explore the molecular mechanisms by which vitamin D protects the eye from oxidative stress, in order to evaluate whether vitamin D supplementation may be useful to mitigate the deleterious effects of free radicals in DR.

Do Nutrients and Nutraceuticals Play a Role in Diabetic Retinopathy? A Systematic Review

“…Nevertheless, some diabetes patients without these traditional risk factors can likewise develop a retinal damage, suggesting the involvement of other pathogenetic elements [ 70 ]. Preclinical and clinical studies investigated whether nutraceuticals could influence the course of DR [ 23 , 24 ]. Moreover, diabetes itself can alter the nutritional status, suggesting an attitude to deficiency of micronutrients in diabetes patients [ 61 ].…”

“…Among modifiable risk factors, unhealthy lifestyles, such as dietary intake, physical activity, tobacco consumption could influence the course of DR [ 21 , 22 ]. In particular, preclinical and clinical studies indicated a possible role of vitamins and micro- or macro-nutrients intake—through usual feeding or dietary supplementation—in the course of DR and its therapy [ 23 , 24 ]. However, current evidence is heterogeneous and controversial, raising the need for a deep evaluation of the role of nutrients and nutraceuticals in DR. For this reason, we carried out a systematic review of both observational and interventional studies, which evaluated the effect of nutrients and/or nutraceuticals on the risk of DR and their potential use for the treatment of patients with DR.…”

Immunoregulation of Ghrelin in neurocognitive sequelae associated with COVID-19: an in silico investigation

“…This receptor is expressed in many cells of the immune system including T and B cells, monocytes, neutrophils, macrophages, and dendritic cells ( Zeng et al, 2015 ). It has been demonstrated that GHSR-1A is expressed in alveolar macrophages (AMs) and that Ghre alleviates septic ARDS in rats ( Valle et al, 2021 ) exerting an antiapoptotic effect on AMs. This effect is mediated by GHSR-1A.…”

The role of vitamin D in the onset and progression of diabetic retinopathy

“…Thus, DR is a multifactorial condition that is etiopathogenically characterized by hyperglycemia, chronic inflammation, leukostasis, microvascular lesions associated with increased vascular permeability, local ischemia, angiogenesis and neurodegeneration [ 6 ].…”