Abstract
<jats:p>The minor salivary glands are highly sensitive to systemic changes in the body; however, their response to neuroendocrine disorders remains poorly understood. One of the key mechanisms of damage is apoptosis, in which caspases play a leading role. The study aims to determine the effect of triptorelin on caspase-3 activity in the secretory cells of the palatal salivary glands of rats, followed by an evaluation of quercetin's protective effect. The experiment was conducted on male white rats, which were divided into three groups: a control group (n=10); a group that received prolonged administration of triptorelin (0.3 mg/kg; n=25); and a group that received a combination of triptorelin and quercetin (n=25). Samples of hard palate mucosa were collected at 1, 3, 6, 9 and 12 months. The control group received 0.9 % NaCl, while the experimental group received oral quercetin three times a week. Morphological examinations were performed on paraffin sections stained with haematoxylin and eosin. Immunohistochemical studies were conducted on deparaffinised, rehydrated paraffin sections following antigen retrieval in citrate buffer (pH 6.0) using specific antibodies. The immune response was visualised using a polymerase-based HRP detection system and diaminobenzidine as a chromogen. Prior to this, endogenous peroxidase and non-specific binding were inhibited, and the sections were counterstained with haematoxylin. Statistical analysis was performed using variational statistical methods and the Mann-Whitney U test. The dynamics of the apoptotic process in the tissues of the minor salivary glands of the hard palate in rats were investigated under conditions of prolonged triptorelin administration, as well as the potential for pharmacological correction with quercetin. It has been established that a hormone-induced imbalance is accompanied by apoptosis activation. A key marker of these changes is the expression of caspase-3, which was detected in all cellular components of the glands and exhibited temporal and cellular specificity. In the early stages (1-3 months), it predominated in interstitial cells, subsequently involving the acinar and ductal apparatus. Morphological signs of apoptosis were most pronounced in the later stages of the observation period. Administering quercetin provided a moderate protective effect by suppressing oxidative stress and inhibiting the mitochondrial pathway of apoptosis. Prolonged exposure to triptorelin, meanwhile, was associated with a progressive increase in caspase-3 expression (14.2 fold compared with the control group) and the depletion of compensatory mechanisms, a phenomenon that was partially counteracted by quercetin. Thus, the results obtained demonstrate the important role of hormonal homeostasis in maintaining the structural and functional integrity of the salivary glands, and indicate that quercetin could be used as a potential cytoprotective agent.</jats:p>