Protective Effect of Highly Polymeric A-Type Proanthocyanidins from Seed Shells of Japanese Horse Chestnut (Aesculus turbinata BLUME) against Light-Induced Oxidative Damage in Rat Retina

Abstract

Retinal tissue is exposed to oxidative stress caused by visible light. Light-damaged rat used in age-related macular degeneration (AMD) studies clarified that antioxidants decrease retinal light damage. Albino rats were exposed to 5000 Lux light for 12 h with oral administration of the polyphenolic compounds fraction (PF) from the seed shells of Japanese horse chestnut (30 mg/kg, 100 mg/kg, and 300 mg/kg body weight: BW). To evaluate the protective effects against light damage, electroretinograms (ERGs), the outer nuclear layer (ONL) thickness, the antioxidant activity of plasma, oxidized retinal lipids, and the detection of apoptosis were examined. To reveal their active compounds, PF were separated into an A-type proanthocyanidin (PAF) and a flavonol O-glycosides fraction. The protective effects of these fractions against light damage were compared by measuring the thickness of the ERGs and ONL. Compared with the negative control, the PF group (100 mg/kg and 300 mg/kg BW) significantly suppressed the decrease of the ERG amplitudes and ONL thickness. PF (300 mg/kg BW) induced the elevation of in vivo antioxidant activity, and the suppression of retinal lipid oxidation. PF administration also suppressed apoptotic cell death. The protective effects against light damage were attributable to the antioxidant activity of PAF. The light-induced damage of retinas was protected by oral administration of PF and PAF. Taken together, these compounds are potentially useful for the prevention of the disease caused by light exposure. Highlights: The protective effects of retinal damage by light exposure were evaluated using polyphenolic compounds from the seed shells of Japanese horse chestnut (Aesculus turbinata BLUME) as an antioxidant. Decreases in the electroretinographic amplitude and outer nuclear layer thickness were suppressed by the polyphenolic compounds of the seed shells. Polyphenolic compounds from the seed shells of Japanese horse chestnut inhibited the oxidation of retinal lipids. Highly polymeric A-type proanthocyanidin from the seed shells protected the rat retina from light exposure damage by inhibiting oxidative stress and apoptotic mechanisms.

Lisosan G Protects the Retina from Neurovascular Damage in Experimental Diabetic Retinopathy

“…Similar observations have been reported for other substances of natural origin. Indeed, in the last few years a variety of nutraceuticals have been found to exert important antioxidant effects resulting in amelioration of ERG responses in different retinal disease or retinal injury models [32,33,34,35,36,37,38].…”

Structural and Functional Change in Albino Rat Retina Induced by Various Visible Light Wavelengths

“…Seven days after the light exposure, flash ERGs were recorded (LS-W, Mayo Corporation, Aichi, Japan) according to previous reports [ 8 , 9 ]. Twenty minutes before the recording, the animals were anesthetized and the pupils dilated using the same methods as used for the light exposure.…”

“…Recently, with the widespread use of tablets and smartphones, it has been suggested that the blue light from these electronic devices using light-emitting diodes (LEDs) may cause blue-light hazard [ 7 ]. In addition, as it has become clear that oxidative stress is involved in the pathogenesis of age-related macular degeneration (AMD), antioxidants, such as polyphenols, that are effective in inhibiting the onset or progression of AMD have been actively pursued [ 8 , 9 ]. In these studies, animal models of light-induced retinal damage are often used, especially rats and mice, which are widely used because they are easy to maintain and treat.…”

Neuroprotective Potential of Ginkgo biloba in Retinal Diseases

“…The main herbal medicines recommended to treat ARMD include xanthophylls lutein, zeaxanthin, and ginkgo [42,48,51,52]. The literature also describes the photo-protective effect of berries [bilberry (Vaccinium myrtillus L.), cranberry (Vaccinium oxycoccos L.), blackcurrant (Ribes nigrum L.), wolfberry (Lycium barbarum L.), grapes (Vitis vinifera L.)], stigmas [such as saffron (Crocus sativus L.)], and roots and rhizomes [such as turmeric (Curcuma longa L.) and Dan Shen (Salvia miltiorrhiza Bunge) [36,48,50,[53][54][55][56][57][58][59] on age-related ocular diseases. Ginkgo has become an increasingly well-known medicinal plant worldwide, and is used to treat peripheral vascular disease and cerebral insufficiency [16,[22][23][24].…”