Suppression of photo-induced histological changes in the retina by bilberry extract.
(a) TUNEL assay performed 2 days after light exposure. TUNEL-positive cells (red) appeared only in the ONL following light exposure. The number of apoptotic cells was significantly reduced by bilberry extract. DAPI staining of the control is shown as a guide for retinal layers. (b) H&E staining of retinal sections 4 days after light exposure. ONL thickness was lower in vehicle-treated, light-exposed mice than in vehicle-treated, non-light-exposed mice. Photo-induced ONL thinning was significantly attenuated by bilberry extract treatment. (c and d) Rhodopsin (c) and blue opsin (d) immunostaining 4 days after light exposure. The OS lengths of both rod (c) and cone (d) photoreceptors were lower in vehicle-treated light-exposed mice than in vehicle-treated non-light exposed mice. Photo-induced OS shortening was significantly attenuated by bilberry extract treatment (n = 4/ group). Scale bar, 25 μm. ONL, outer nuclear layer; DAPI, 4',6-diamidino-2-phenylindole; H&E, hematoxylin and eosin; IS, inner segment; OS, outer segment. **P < 0.01.