Bio-active components of Cymbopogon martinii essential oil as therapeutics targeting bacterial Penicillin-Binding-Proteins (PBPs): Aroma profile, in silico-docking, pharmacokinetics and wet-lab validation

Abstract

Cymbopogan martinii, also known as Palmarosa, is an underutilized plant of tropical region. Due to outstanding antioxidant potential it has been used as a part of conventional medicine and beauty product. The objective if present study was aromatic profiling of Palmarosa essential oil and molecular docking of Palmarosa essential oil bioactive components (Geraniol, Geranial, Linalool, Fenchyl alcohol, 6-methylhept-5-en-2-one, Borneol, Elemol, δ-cadinol) against six bacterial Penicillin-binding Proteins (PBP1a, PBP2a, PBP3, PBP4, PBP5, and PBP 6) and in-vitro support. GC-FID was used to find out aromatic profiling. For docking Cb-dock2 tool was used. Ligand-Protein 3D interactions were also studied. In-silico ADMET pharmacoinformatics aspects  with PASS prediction of all the ligands has been bioprospected. Wet lab validation was performed by Gram-positive and Gram-negative bacterial strains. GC-FID profiling revealed the presence of various major and minor components. Docking analysis indicated effective binding of all the ligands with all the six PBP’s (PBP1a, PBP2a, PBP3, PBP4, PBP5, and PBP 6). The interaction results indicate that the PBP-Ligand complexes form hydrogen and hydrophobic interactions. in-silico ADMET study revealed that all the ligand molecules have no toxic effect and good absorption as well. Wet lab validation was performed by Gram-positive and Gram-negative bacterial strains. In-vitro results revealed that the Palmarosa oil was able to inhibit the growth of the bacterial strains thus signifying its role as potent anti-bacterial drug.  The Palmarosa essential oil could be a promising antibacterial agent against various strains.