Psychological stress has no association with salivary levels of beta-defensin 2 and beta-defensin 3

Abstract

Background: Recent studies suggest that stress can predispose an individual to the development of periodontal disease, but the exact biological mechanism is unknown. Considering that psychological stress can down-regulate the production of beta-defensins (antimicrobial peptides produced in the oral cavity), the aim of the present study was to evaluate the association between stress and salivary levels of beta-defensin 2 (HBD-2) and beta-defensin 3 (HBD-3). Methods: For this purpose, seventy five volunteers, classified as periodontally healthy, were submitted to a psychological evaluation using a validated questionnaire (Questionnaire of Lipp-ISS). Following analysis of the questionnaires, the subjects were divided in two groups (Group A: Absence of stress and Group B: Presence of stress). Unstimulated saliva samples were collected and the concentration of total protein was determined using the BCA method, and the concentrations of HBD-2 and HBD-3 were determined by ELISA. Results: The levels of total protein did not show a statistically significant difference between the groups. Analyses of HBD-2 and HBD-3 concentrations indicate that the stress condition was not associated with the levels of either peptide in saliva (P = 0.3664 for HBD-2 and P = 0.3608 for HBD-3). Conclusion: In periodontally healthy subjects, HBD-2 and HBD-3 levels are not influenced by stress.