In vitro study of antimicrobial action, antitoxin action, cytotoxicity, genotoxicity and anti-inflammatory activity of N-acetylcysteine, calcium hydroxide and chlorhexidine and their associations

• Grant number: 23/10158-2
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Amjad Abu Hasna
• Grantee: Amjad Abu Hasna
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

The complexity of the endodontic infection makes the search continuous for a chemical substance that has broad antimicrobial action and at the same time being biocompatible. This project have the objective of evaluating N-acetylcysteine, calcium hydroxide, chlorhexidine and their combinations regarding: I) antimicrobial action against anaerobic bacteria of endodontic interest: Porphyromonas gingivalis, Porphyromonas endodontalis, Parvimonas micra, Fusobacterium nucleatum and Prevotella intermedia in planktonic and biofilm forms; II) anti-endotoxin action (LPS); III) cytotoxicity and genotoxicity using mouse macrophages (RAW 264.7) and human osteoblasts (MG-63) cultures; and IV) anti-inflammatory action in culture of the same cells activated by LPS. The antimicrobial evaluation of intracanal medications will be performed by determining the minimum inhibitory concentration and minimum microbicidal concentration of the groups, evaluation of the anti-biofilm activity of the groups by the MTT test, evaluation of the biomass by the crystal violet test, and evaluation of anti-biofilm activity in teeth by confocal laser scanning microscopy. Evaluation of anti-endotoxin activity will be performed using the LAL (Lonza) chromogenic kinetic assay used to quantify endotoxins. Thus, cytotoxicity and genotoxicity will also be evaluated using MTT and micronucleus tests, respectively. And finally, the anti-inflammatory activity of intracanal medications will be evaluated by means of quantification of pro and anti-inflammatory cytokines by flow cytometry (CBA - cytometric beads array). All data will be submitted to normality test, and then analyzed with Kruskal Wallis test complemented with Dunn test for non-parametric data, or with one-way Anova and Tukey for parametric data (± d 0.05). (AU)