Salivary Metabolites in Patients with Mucopolysaccharidosis

ABSTRACT Objective: To identify the salivary metabolites profile of Mucopolysaccharidosis (MPS) types I, II, IV, and VI patients. Material and Methods: The participants were asked to refrain from eating and drinking for one hour before sampling, performed between 7:30 and 9:00 a.m. Samples were centrifuged at 10.000 × g for 60 min at 4°C, and the supernatants (500µl) were stored at −80°C until NMR analysis. The salivary proton nuclear magnetic resonance (1H-NMR) spectra were acquired in a 500 MHz spectrometer, and TOCSY experiments were used to confirm and assign metabolites. Data were analyzed descriptively. Results: Differences in salivary metabolites were found among MPS types and the control, such as lactate, propionate, alanine, and N-acetyl sugar. Understanding these metabolite changes may contribute to precision medicine and early detection of mucopolysaccharidosis and its monitoring. Conclusion: The composition of low molecular weight salivary metabolites of mucopolysaccharidosis subjects may present specific features compared to healthy controls.

Salivary metabolomic profile in adolescents with juvenile systemic lupus erythematosus

Abstract The aim of this study was to characterize the salivary metabolomic profile in adolescents with juvenile systemic lupus erythematosus (jSLE). A total of 24 adolescents with jSLE (15.92 ± 2.06 years) and 12 systemically healthy controls (15.25 ± 2.7 years) were included in the study. Participants underwent rheumatologic testing and periodontal examination, with the recording of plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing index (BPI). Unstimulated whole saliva was collected from both groups and stored at -80 ºC. The salivary proton nuclear magnetic resonance (1H-NMR) spectra were acquired in a spectrometer operating at 500 MHz. Partial least squared discriminant analysis (PLS-DA) and orthogonal PLS-DA (O-PLS-DA) were used for statistical analysis. Mean CAL and PI were significantly increased in the group with jSLE (p < 0.01). Patients with jSLE presented a significantly different salivary metabolic profile (accuracy = 0.54; R2 = 0.86; Q2 = -0.293), significantly higher salivary levels of N-acetyl sugars, and significantly reduced levels of phenylalanine, glycine, taurine, hydroxybutyrate, and valerate compared with healthy controls (p < 0.05). It is suggested that the salivary metabolomic profile analyzed by 1H NMR in patients with jSLE presents a different fingerprint that the systemically healthy subjects. Integrating the variation of metabolites with the identification of the metabolic pathways involved seems to provide a better understanding of the influence of systemic disease on salivary metabolites.

Effect of antihistamine-containing syrup on salivary metabolites: an in vitro and in vivo study

Abstract This study tested the null hypothesis that antihistamine-containing syrup does not change salivary metabolites in vitro and in vivo. For the in vitro experiments, saliva from 10 volunteers was mixed with a syrup or pill suspension of loratadine (1 mg/ml Claritin®, Schering-Plough, Rio de Janeiro, Brazil). For the in vivo experiment, 10 volunteers performed a mouth rinse with 10 mL of antihistamine syrup (Claritin®; Schering-Plough, Rio de Janeiro, Brazil) for 20 seconds and then discarded the rinse water. After 20 seconds, 5 mL of unstimulated whole saliva was spit into a plastic tube kept on ice. The protein profile of in vitro and in vivo experiments was analyzed using 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The samples were also analyzed by nuclear magnetic resonance (NMR) spectroscopy, followed by Principal Component Analysis and Wilcoxon test (p < 0.05). There were differences in salivary metabolites after syrup interaction. The salivary concentrations of acetate, n-caproate, arginine, glutamate, and lysine among other metabolites were reduced with the syrup in both in vivo and in vitro experiments (p < 0.05), but no differences were observed when the pill suspension was used (p > 0.05). Similar changes in metabolite profiles were observed in both in vitro and in vivo experiments. Electrophoresis revealed no difference in the salivary protein pattern. The null hypothesis was rejected because the intake of syrup medicine changes the salivary composition and influences oral homeostasis and susceptibility to oral diseases.