title: Antibiofilm and quorum sensing inhibitory activity of Achyranthes aspera on cariogenic Streptococcus mutans: an in vitro and in silico study.
abstract: BACKGROUND
  Traditionally, many cultures use chewing sticks for oral hygiene maintenance. When properly used, these chewing sticks are found to be efficient due to the combined effect of mechanical cleaning, enhanced salivation and the antimicrobial action of leached out plant compounds.
  
  
  OBJECTIVE
  Achyranthes aspera L. (Amaranthaceae), an ethanomedicinal herb was evaluated for its potential to inhibit growth and biofilm formation by cariogenic isolate Streptococcus mutans as an alternative means of caries management by quorum quenching (QQ).
  
  
  METHODS
  Biofilm forming cariogenic isolates were isolated and their susceptibility to the petroleum ether, benzene, methanol, aqueous extracts of A. aspera was evaluated. Gas chromatography-mass spectrometry (GC-MS), phytochemical analyses and structure-based virtual screening for their quorum sensing (QS) inhibitory activities, drug-likeness and bioavailability were also carried out.
  
  
  RESULTS
  The biofilm inhibition percentage obtained for methanol, benzene, petroleum ether and aqueous extracts (125 µg/mL) were ≤94%, ≤74%, ≤62% ≤42%, respectively. GC-MS analyses indicated 61 compounds, of which betulin recorded efficient interaction exhibiting comparable binding energy of -8.72 with S. mutans glycosyltransferase (GTF-SI) whereas 3,12-oleandione exhibited binding energy -5.92 with OmpR subfamily QS regulatory DNA-binding response regulator. Computer-assisted molecular descriptor and Lipinski's rule violation calculation uncovered the presence of more drug-like compounds.
  
  
  CONCLUSIONS
  Anticaries bioactive compounds of A. aspera with higher QS response regulator binding energy, low toxicity and optimal pharmacokinetic properties were revealed. These compounds with possible QQ ability hold the potential for use as anticaries drug leads and antibiofilm preventative medicine.
authors.affiliation: Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. murutan@gmail.com
authors.forename: K
authors.initials: K
authors.lastname: Murugan
authors.forename: K
authors.initials: K
authors.lastname: Sekar
authors.forename: S
authors.initials: S
authors.lastname: Sangeetha
authors.forename: S
authors.initials: S
authors.lastname: Ranjitha
authors.forename: S A
authors.initials: SA
authors.lastname: Sohaibani
mesh_terms: D029044:Achyranthes / Q000737:chemistry*; D018441:Biofilms / Q000187:drug effects*; D003198:Computer Simulation; D003731:Dental Caries / Q000382:microbiology / Q000517:prevention & control; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008519:Medicine, Traditional; D010936:Plant Extracts / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D053038:Quorum Sensing / Q000187:drug effects; D012997:Solvents / Q000737:chemistry; D013295:Streptococcus mutans / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology
chemical_list: D010936:Plant Extracts; D012997:Solvents