Psidium guajava Leaves n-Hexane Fraction Antibacterial Activity and the Inhibition of Gene Expression of gtfB and gtfC in the Combination Streptococcus mutans ATCC 25175 and Veillonella parvula ATCC 10790T

Ame Suciati Setiawan,1,2 Anas Subarnas,3 Ariadna Adisatya Djais,4 Tiana Milanda,5 Solachudin Jauhari Arief Ichwan6 1Doctoral Program Pharmacy, Faculty of Pharmacy, Padjadjaran University, Bandung, West Java, Indonesisa; 2Department of Oral Biology, Faculty of Dentistry, Padjadjaran University, Bandung, West Java, Indonesia; 3Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, Padjadjaran University, Bandung, West Java, Indonesia; 4Department of Oral Biology Faculty of Dentistry, University of Indonesia, Jakarta, Indonesia; 5Department of Biological Pharmacy, Faculty of Pharmacy, Padjadjaran University, Bandung, West Java, Indonesia; 6PAPRSB Institute of Health Sciences, University of Brunei Darussalam, Brunei, DarussalamCorrespondence: Ame Suciati Setiawan, Email [email protected]: Oral biofilm is an extracellular polymeric matrix produced by Streptococcus mutans as the early colonizer in the formation of an oral biofilm. Glucosyltransferase (Gtfs) enzyme is a virulence factor for S. mutans in biofilm that is resistant to antibacterial agents. Veillonella parvula influences S. mutans to increased quantities of Gtfs, thereby accelerating the growth of oral biofilms. Decreasing the production of Gtfs by the use of additional materials is necessary to inhibit biofilm formation.Objective: The study was determined the inhibitory activity of the Psidium guajava leaves n-hexane fraction on the production of Gtfs by a single and combination of S. mutans and V. parvula.Methods: Antibacterial effect of the P. guajava leaves n-hexane fraction against S. mutans and V. parvula was examined by the inhibition zone and, and MBC. The antibiofilm was examined on the expression of gtfB and gtfC in S. mutans, V. parvula, and their combination using qRT-PCR. The results were analyzed with Kruskal–Wallis test and Mann–Whitney U-test.Results: P. guajava leaves inhibited the growth of S. mutans and V. parvula at the lowest concentration (3.125%), with the inhibition zones are larger than chlorhexidine (CHX). The effect on the Gtfs activity shown the gene expression of gtfB remained unchanged in both single S. mutans and combined species, while it was decreased in the single V. parvula at a concentration of 0.78%, but itdoes not exhibit a significant difference between single and double species. Conversely, gtfC gene expression in the dual-species was reduced 90.43% by the n-hexane fraction at a concentration of 0.78%.Conclusion: The P. guajava leaves n-hexane fraction exhibited antibacterial activity against S. mutans and V. parvula. It may exhibit antibiofilm formation, as it could reduce the expression of the gtfC in the double species bacteria.Keywords: V. parvula, S. mutans, glucosyltransferase, P. guajava, antibiofilm