Evaluation of the effects of the anticonvulsant carbamazepine on the stimulated salivary flow rate, biochemical composition, and redox state of young Wistar rats

Abstract

Clinical and experimental studies have demonstrated the relationship between epilepsy and the use of medications that disrupt oral health homeostasis. Carbamazepine (CBZ) is a widely used anticonvulsant for controlling epileptic seizures, and one of its common adverse effects is dry mouth. Therefore, the aim of this study is to evaluate the possible effects of CBZ on the stimulated salivary flow rate, biochemical composition, and salivary redox state of young adult rats.For this purpose, young male Wistar rats (6 weeks old) will be randomly divided into 3 groups (n=10 per group): Control (C), CBZ25 (25 mg/kg), and CBZ50 (50 mg/kg). CBZ (Tegretol® 10 mg, Novartis, Taboão da Serra, Brazil) diluted in saline will be administered for 28 days via intragastric gavage. The Control group will receive a volume of saline solution proportional to that of the CBZ50 group. After the experimental period, the animals will be anesthetized for the collection of pilocarpine-induced saliva and then euthanized by exsanguination to obtain plasma.Immediately after collection, salivary flow rate, pH, and buffering capacity will be determined. Total protein content, salivary amylase activity, calcium, phosphate, oxidative damage to lipids (assessed by the thiobarbituric acid reactive substances (TBARs) assay), oxidative damage to proteins (measured by carbonylation reaction with 2,4-dinitrophenylhydrazine (DNPH)), total antioxidant capacity, and total oxidative capacity will be measured using spectrophotometric methods. The normality and homoscedasticity of the data will be analyzed to select the most appropriate parametric or non-parametric tests. For all tests, the significance level will be set at 5% (p < 0.05).