Chronic stress and depression impact on tongue and major sublingual gland histology and the potential protective role of Thymus vulgaris: An animal study

Abstract

Objectives

Reporting the histological effects of chronic stress on certain oral tissues, as well as the capacity of Thymus vulgaris (thyme) to protect tissues from stress and link both serum cortisol and serotonin levels.

Methods

30 rats were randomly divided into a trio of groups: normal control (no treatment), stress group (chronic stress without treatment), and treatment group (chronic stress treated with thyme at a dose of 200 mg/kg BW orally via needle gavage daily for 21 days). At the end of the experiment, tongues and major sublingual glands (SLGs) were surgically removed and processed for histological and histochemical studies. Blood samples were taken shortly before scarification for the biochemical study of cortisol and serotonin serum levels.

Results

Examination of tongue and SLG sections of the stress group indicated significant alterations in histology and changes in SLG secretion. An examination of tongue and SLG histological sections of the thyme-treated group are showed an improvement. Chronic stress raises cortisol serum levels and lowers serotonin serum levels.

Conclusions

Chronic stress causes alteration of the tongue and major SLG histology, as well as changes in SLG secretion. Thyme may protect tissues from stress, and there is a relation between cortisol and serotonin levels.