An investigation on the effects of the Aloe Vera extract on the thickness of the retina in male diabetic rats

Retina is a part of the central nervous system derived from the neuroectoderm and made up of 5 layers. In this study، the changes in the thickness of the retinal layers as a consequence of diabetes and effect of Aloe Vera gel extract in male rats were assessed. Thirty Sprague Dawley adult male rats (175 ± 25 g) in two age groups (4 and 8 weeks) were divided into 6 groups of 5 as control، diabetic and diabetic receiving 400 mg/kg Aloe Vera extract. Diabetes was induced by IP injection of 50 mg/kg of STZ (streptozotocin). The animals were weighed and their blood sugar was measured by glucometer before STZ administration and 24 h thereafter. Animals were anesthetized with sodium thiopental (40 mg/kg) via IP injection. After removal of eyes on both sides، retina was dissected out precisely and fixed in 4% glutaraldehyde، post fixed in osmium tetroxid 1%، dehydrated and then embedded in TAAB resin. Thin sections (1 μm) were stained with toluidine blue stain and viewed under light microscope. Ten slides were prepared from each animal. The results revealed reduction of the blood glucose levels and body weight in treated rats in comparison to diabetic groups. The thickness of neural retina and its layers were different as well. In the group treated with Aloe Vera the thickness of retina and its layers retained their normal histologic structures.