A Nanophytomedicine Approach Including Tea Tree Essential Oil for Possible Dental Applications: In vitro and In silico Evaluations.

Introduction: Tea tree essential oil (TTO) incorporated polylactic-co-glycolic acid (PLGA) nanoparticulate powder form was aimed to desined that can be applied with water and is effective against oral pathogens to prevent caries, and that is able to provide a long-lasting oral antiseptic effect.

Methods: TTO-PLGA nanoparticles (TTO-NPs) was synthesized by single emulsion technique; average particle size, PdI value and zeta potential was measured by Zetasizer; TTO-PLGA interactions were investigated by FTIR, and morphological analysis was performed by TEM analysis. Phytoactive release and performans tests were carried out with in vitro dissolution and DNA binding-cleavage tests while antimicrobial performance was investigated by Ames-Salmonella assay, susceptibility test, in silico Molecular Docking and Molecular Dynamics studies.

Results: TTO-NPs had an average particle size of 221.6 nm, a PdI of 0.103, and a zeta potential of -5.22 mV, 59.25% encapsulation efficiency and 25.65%. loading capacity. At the end of 5 h and 72 h the TTO release was 33.34±2.17% and 97.61±3.91% respectively. TTO-NPs were not mutagenic and were effective on investigated four cariogenic bacteria. The binding interactions of terpinen-4-ol, the main component of TTO, with Streptococcus mutans and Lactobacillus casei were revealed with enzyme-active-site-key residues.

Discussion: In vitro and in silico studies confirmed that TTO-NPs were non-mutagenic and exhibited strong antimicrobial activity against dental caries-causing bacteria like Streptococcus mutans and Lactobacillus casei.

Conclusion: In conclusion, TTO-NPs, which can be used as a mouthwash or powder, represent a promising solution for reducing oral pathogens, meriting further in vivo and clinical evaluations.