Bioevaluation, pharmacokinetics and molecular docking study of terpenoid-rich rhizome essential oil of Zingiber officinale

Abstract

The study focuses on the phytochemical composition, in vitro and in silico antioxidant and NO reduction potential of Zingiber Officinale rhizome essential oil (ZOREO). The GC–MS analysis has revealed the presence of 47 volatile constituents representing 94.35 % of the total area of EO. The major compounds identified were α-zingiberene (20.58 %), geranial (10 %), β-sesquiphellandrene (7.39 %), and neral (7.23 %). The EO was rich in sesquiterpene hydrocarbons (45.93 %) followed by monoterpene hydrocarbons (29.29 %). The EO showed moderate antioxidant activity compared to the standard (IC₅₀ = 5.16 ± 0.4 mg/mL for DPPH assay and EC₅₀ = 0.52 ± 0.6 mg/mL for FRAP assay). The cytotoxic analysis showed significant viability towards RAW 264.7 cell lines. Treatment with ginger EO at a concentration of 100 μg/mL showed significant anti-inflammatory activity by the significant reduction of LPS-induced nitric oxide (NO) production to 31.35 %, in comparison with the LPS-treated group. Further, the EO components were screened in order to provide mechanistic insights into Xanthine oxidase (XO) and iNOS inhibition. The docking results showed that the volatile constituents of ginger EO have substantial binding affinity with the active site residues of the receptor. The simulation conducted for the top compounds- geranyl acetate and β-eudesmol having the highest binding affinity towards both the proteins XO and iNOS respectively. Both the results showed the compounds steadily interacted with both of the proteins active site residues throughout the simulation. The current analysis showed the phytoconstituents showed better antioxidant activity than the EO. Hence these compounds could be further considered for in vitro and in vivo evaluation for the development of efficient phytopharmaceuticals.