Resveratrol is found in at least 72 plant species and exists in two structural isomeric forms, cis and trans, with the trans form being more common and possessing greater biological activity. Polygonum cuspidatum, which is a plant used in traditional Chinese and Japanese medicine, is one of the richest sources of resveratrol. The primary dietary sources for human consumption are peanuts, red grapes and red wine.
Resveratrol has a diverse range of biological properties including antioxidant, cardioprotection, anticancer activity, anti-inflammatory effects, estrogenic/anti-estrogenic properties, many of them mediated by modulation of cellular signal transduction pathways.
The polyphenolic structure of resveratrol confers its antioxidant activity. Polyphenols are known for protecting against oxidative stress, degenerative diseases, and aging process. The antioxidant and ‘anti-aging’ properties of resveratrol are believed to be through the activation of SIRT1 gene and by mimicking calorie-restriction conditions.1,2,3,4
Current literature search suggest that resveratrol supplementation could offer the potential for modulating the risks in development and progression of age-related macular degeneration (AMD).
In one recent study resveratrol has shown strong protective effects against oxysterol-induced cell death and VEGF secretion and prevented neovascularization (development of new blood vessels), which is a major complication of AMD. The authors suggest a new “therapeutic perspective” for treatment of AMD using resveratrol.5
Abnormal angiogenesis (new blood vessels growing) is central to the pathophysiology of visually debilitating eye diseases such as AMD, and can lead to blindness.
Resveratrol in in vitro and in vivo experiments (in mouse retinas) inhibited pathological angiogenesis, induced by laser injury, and resulted in inhibition of proliferation and migration of vascular endothelial cells.
According to Dr. Rajendrar S. Apte the senior investigator of one of these studies, “resveratrol could potentially be a preventive therapy in high-risk patients, and because it works on existing abnormal blood vessels, it may be a therapy that can be started after angiogenesis has already started to cause its damage.6
This suggested a broad beneficial effect by resveratrol against retinal diseases associated with damage and loss of retinal cells
More studies are being conducted on potential of resveratrol for ameliorating age-related retinal cell degeneration. In one particular study synergistic effects were seen by combining zeaxanthin with resveratrol for alleviating the oxidative damage in the acute acrolein toxicity models.7
Resveratrol also has shown protective effects against ultraviolet A-mediated damage to human retinal cells. We know that light damage to the retina accelerates its degeneration and can lead to macular degeneration and vision loss.8
In one study, although it included only one 80-year old man who had complaints of unremitting night driving difficulty and parafoveal deposition of retinal lipofuscin, resveratrol showed clinically measurable and subjective improvements in vision, including self-reported night vision, and dramatic improvement in contrast sensitivity function and mental function.9
The antioxidative, gene modifying and anti-angiogenic properties of resveratrol suggest a strong rationale for using this compound as a nutritional supplement ingredient in early AMD.