Alpha Lipoic Acid Exerts a Therapeutic Effect on Parotid Tissue in a Hypothyroidism Rat Model by LC-3 Suppressing Autophagic Cell Death (Immunohistochemical, Morphometric, Ultra-structural and Biochemical Study).

Introduction: Hypothyroidism is a common thyroid problem that can be experimentally induced by the anti-thyroid drugs as Carbimazole. Hypothyroidism is recorded to affect the salivary glands. Aim of the Work: To assess the therapeutic ability of Alpha Lipoic Acid (ALA) on the parotid tissue in a hypothyroidism experimentally induced rat model. Material and Methods: The animals were distributed into: (1) Control group was subdivided into: group 1: got an oral dose of distilled water daily for 3-weeks, group 2: received 2 ml/kg/day corn oil dosage for 4-weeks, (2) Hypothyroidism-Induced Group received an oral dose of 1.35 mg/kg/day Carbimazole for 3-weeks, (3) Hypothyroidism-ALA group: received an oral dose of 1.35mg/kg/day Carbimazole for 3 weeks then a 60 mg/kg/day ALA oral dosage for another 4-weeks, (4) ALA Group: received a dose of 60mg/kg/day ALA orally for 4-weeks. Estimation of the body, gland weights, T3, T4 and TSH hormones levels were performed. A histopathological and statistical study of the parotid tissue was performed. Results: In hypothyroid rats, the acinar cells showed irregular heterochromatic nucleus, cytoplasmic vacuolations and cellular infiltration. The striated and interlobar ducts showed dilatation and hyperplasia. In comparison with the control group, the hypothyroid rats exhibited a significant rise in area percentage of LC3 immune-expression, diameters of acini and ducts and TSH level with a significant decrease in T3 level, the numbers of the ducts and acini. On ALA use, all those findings were improved. Conclusion: ALA serves as a good therapeutic agent leading to an obvious improvement in the parotid gland histopathological features. [ABSTRACT FROM AUTHOR]