European Journal of Molecular & Clinical Medicine

Abstract

Background:One of the most frequent chronic disorders is hypothyroidism. It affects various
organs including the salivary glands. It causes pathophysiological changes including
xerostomia. Alpha lipoic acid (ALA) can provide health benefits through its role as a potent
antioxidant, metal chelator and reducing agent of the oxidized forms of other antioxidants
such as vitamins C and E. Aim: To estimate the influence of hypothyroidism on rat’s parotid
gland and to illuminate the possible curative role of alpha lipoic acid(ALA). Methodology:
Thirty-six adult male rats were haphazardlyarranged into four groups; nine animals in each
as follows: Group 1 (control group): 4 rats were givenpurified water (vehicle of carbimazole)
for threeweeks, the other 5 rats were given a daily oral dose of 2ml /kg corn oil only (vehicle of
ALA) for four weeks after initiation of hypothyroidism. Group 2 (ALA group): were given a
daily oral dose of 60 mg /kg ALA dissolved in its vehicle for 4 weeks. Group 3 (hypothyroidinduced
group): were givena daily oral dose of 1.35 mg/kg of carbimazole liquified in its
vehicle for 3 weeks to induce hypothyroidism. Group 4 (hypothyroid- ALA group): were givena
daily oral dose of 1.35 mg/kg of carbimazole for 3 weeks followed by a daily oral dose of 60 mg
/kg ALA treatment for the consecutive 4 weeks.The animals were anaesthetized and
slaughtered at the end of the experiment. Parotid glands were collected, and the specimens
were prepared for light microscopic examination using Hematoxylin and Eosin and Masson's
trichrome stains were used, Morphometric analysis using ANOVA and Tukey's post hoc
testswas performed.Results: Hypothyroidism caused histopathological changes in the form of
general cellular distortion, cytoplasmic vacuolations, cellular infiltration, blood vessels
congestion and fibrosis and morphometric changes in the form of a significant increase of
collagen fibres in hypothyroid group. Alpha lipoic acid succeeded to improve those changes.
Conclusion: Hypothyroidism has destructive effects on the Parotid gland structure.
Fortunately, it is recommended to take Alpha Lipoic Acid in hypothyroid cases to help in
decreasingsuch effects.