In vitro α-amylase and α-glucosidase inhibitors study of Cymbopogon martinii essential oil and molecular docking study of predominant components, PASS prediction and ADME/Tox studies

A-Amylase and alpha-glucosidase inhibition is a hopeful curative target against type II diabetes as it can downgrade fierce digestion and absorption of carbohydrates into absorbable monosaccharides. Medicinal plants have been used as blood sugar reducers; on the other hand, the inhibitory action of phytocompounds found in these plants on alpha-amylase is yet limited. Palmarosa essential oil (PRO) from Cymbopogon martinii is complementary and conventional medicine worldwide. The aim of the study presented is compositional profiling of PRO and in silico docking of main bioactive compounds: geraniol, geranial, linalool, fenchyl alcohol, 6-methyl-hept-5-en-2-one, borneol, elemol, delta-cadinol against alpha-amylase and alpha-glucosidase. GC-FID was used to find out bioactive components in PRO. For docking, Cb-dock2 tool was utilized. Ligand-protein 2-D interactions were also studied. In silico ADMET pharmacoinformatics viewpoint along with PASS prediction of all the ligands has prospected from the point of view of human health. Wet laboratory validation was performed by using Aspergillus oryzae-derived alpha-amylase and Saccharomyces cerevisiae-derived alpha-glucosidase. GC-FID exposed presence of 13 bioactive components. Docking investigation demonstrated the effective binding of all the ligands with the enzymes. The interaction results imply that the enzyme-ligand complexes form hydrogen, hydrophobic, and other interactions. Furthermore, molecular dynamics (MD) simulations were also carried out for the best-docked complexes from docking studies (alpha-amylase-elemol, alpha-glucosidase-elemol, and alpha-glucosidase-delta-cadinol) to clarify some information on their thermodynamic and dynamic properties and confirm the docking results as well. In silico ADMET examination disclosed that all the ligand molecules have no toxic effect and acceptable absorption as well. PRO retains inhibition in dose-dependent manner against alpha-amylase (IC50 = 194.78 mu g/ml) and alpha-glucosidase (IC50 = 162.36 mu g/ml). A kinetic study showed that PRO inhibited the alpha-amylase and alpha-glucosidase competitively. It could be inferred that the phytochemicals present in PRO might be responsible in alpha-amylase and alpha-glucosidase inhibition and thus have potential to be produced as an antidiabetic drug.