Histological changes in the filiform and fungiform lingual papillae of streptozotocin-induced diabetic albino rats and the possible protective role of curcumin

ABSTRACT

It has been a growing interest recently in dietary intervention, particularly the use of traditional food derived from natural sources in management of diabetic complications as oral lesions. The aim of the present study was to elucidate the histological changes in the lingual papillae in an experimental model of induced diabetes in rats by streptozotocin and evaluate the possible protective effect of curcumin using light and scanning electron microscopes. Thirty adult male albino rats were divided into 3 equal groups group 1; [control group], group II;[diabetic group] diabetes was induced by a single intraperitoneal injection of streptozotocin in a dose of 65 mg/kg and group [Unprotected group] rats were treated as in diabetic group with simultaneous administration of' curcumin in a daily dietary dose of 15 mg/kg for 4 weeks. By the end of the 4 weeks all animals were sacrificed and the tongues of all rats were dissected and processed for light and scanning electron microscopic examination. Examination of dorsal surface of tongues of diabetic rats revealed numerous filiform papillae with evidently disturbed shape and orientation. Some of them depicted notched or bifurcated ends; others were severely destroyed with desquamation of their epithelial covering. There were hyperkeratosis and markedly reduced connective tissue papillae. Disfigured fungiform papillae with vacuolated taste buds depicting peripheral arrangement of the cells and empty center were also seen. Dorsal surface rats' tongues of the protected group with curcumin revealed almost normal direction, distribution and structure of the papillae except for few filiform papillae with serrated tips. The present study illustrated that diabetes has a deleterious effect on tongue papillae and taste buds. On the other hand, curcumin provided considerable protection against these effects most probably via its antioxidant, anti-inflammatory and neuroprotective effects