Integrated Phytochemical Profiling, Biological Activities and in-silico Mechanistic Insights of Plumeria obtusa Pod Essential Oil

Abstract

Essential oils, extracted from various parts of the plant, have been studied for their potential health benefits, showcasing impressive biological properties. This study presents an integrated phytochemical, biological, and in-silico evaluation of the essential oil extracted from Plumeria obtusa pods. The essential oil was obtained by hydrodistillation and characterized using GC-MS analysis, which identified eight volatile constituents predominantly composed of oxygenated monoterpenoids, with menthol and linalool as major components. The essential oil exhibited significant antioxidant activity, as demonstrated by DPPH and hydrogen peroxide (H₂O₂) radical scavenging assays, indicating effective free radical neutralization mechanisms. The anti-inflammatory activity significantly highlighted the suppression of inflammatory responses, indicating the potential of the essential oil as a natural anti-inflammatory agent. In addition, the essential oil showed promising anticancer activity, which was mechanistically validated through molecular docking analysis by employing Parkin (PDB ID: 4I1H), and its interaction with key constituents such as (Z)-lanceol acetate (-6.1 kcal/mol) and α-copaene (-6.0 kcal/mol) that exhibited nearly same binding interactions comparable to the reference drug (-7.1 kcal/mol). PASS prediction analysis confirmed high probabilities for antioxidant, anti-inflammatory, and anticancer activities of the major compounds. Furthermore, in-silico ADMET, toxicity profiling, and BOILED-Egg analysis demonstrated favorable drug-likeness, high oral bioavailability, blood–brain barrier permeability, and low predicted toxicity for most constituents. Moreover, in-vitro study via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in colorectal cancer cell line (HCT-116, IC50 value= 278.501 µL/mL) also validates our results in correlation to antineoplastic activity present in essential oil of Plumeria obtusa pods. Thus, this study provides the first comprehensive insight into the therapeutic potential of P. obtusa pod essential oil, highlighting its promise as a multifunctional natural source for drug development against cancer.