Introduction: Long-term hyperglycemia has toxic effects on all cells in the body, and its most profound effects on eye tissues are on the cornea and retina. Seventy percent of diabetic patients are complicated by keratopathy, including recurrent corneal epithelial erosions, delayed wound healing, ulcers and edema. Glycyrrhiza glabra; also called Liquorice; is a well-known medicinal plant used in traditional medicine for its pharmacological value. However, excess consumption of Liquorice can lead to hypertension. Therefore, Deglycyrrhizinated Liquorice extract (DGL) is mostly used to avoid the hypertensive side effects of the glycyrrhizin in whole liquorice. Moreover, fermentation of Liquorice can produce excess amounts of amylase and lipase beside a spectrum of flavonoids naturally occurring in liquorice, hence the newly innovated Fermented Deglycyrrhizinized Liquorice (FDGL) was used in this study.
Aim: In the present study we aimed to investigate the potential therapeutic effects of FDGL, as a natural product, on experimentally induced diabetic keratopathy in rats.
Materials and Methods: Forty adult male albino rats were divided into three groups. Group I: Control animals, which were divided into citrate buffer treated and FDGL treated subgroups (10 rats each). Group II (diabetic) and Group III (diabetic and FDGL treated), 10 rats each. At the end of experiment, the rats were sacrificed and the corneas of different groups were processed for light and electron microscopic examination. The thickness of corneal layers was measured by image analyser and statistical analysis was done.
Results: Light microscopic examination of the cornea of diabetic group showed numerous cells with darkly stained nuclei together with focal sloughing of the surface epithelial layers. Also there was a significant decrease of mean corneal thickness, comparable to the control group. Transmission electron microscopic examination of the cornea of the diabetic group revealed ill-defined hemidesmosomal junctions with interruption of the desmosomal junctions. The stroma showed focal loss of collagen fibrils. Diabetic and FDGL treated group (Group III) showed amelioration of the effects of diabetes on the structure of the cornea.
Conclusion: The data obtained from the present study revealed that FDGL has a potential ameliorating effect on diabetes mellitus induced structural changes in the cornea.
Keywords: Cornea; Diabetes Mellitus; Histology; Streptozotocin