Deoxyelephantopin induces cell death in oral cancer cells via the downregulation of AKT1-mTOR-mediated mechanisms.

Background: Oral cancer, particularly oral squamous cell carcinoma (OSCC), is a prevalent malignancy in Southeast Asia with low survival rates. Deoxyelephantopin (DET), a natural compound derived from Elephantopus scaber Linn. (E. scaber), has shown promising anti-cancer activity.

Aim: By focussing on the AKT1/mTOR signalling pathway, which controls tumour cell proliferation and survival, this study explores the molecular underpinnings behind DET's therapeutic potential in OSCC.

Materials and methods: In vitro cytotoxicity of DET on human oral cancer cells (KB) was evaluated using the 3 (4,5 dimethylthiazol 2 yl) 2,5 diphenyltetrazolium bromide (MTT) assay, reactive oxygen species (ROS) detection, and enzyme activity analysis. Apoptosis markers were assessed through cell morphology and quantitative reverse transcription polymerase chain reaction (q-RT-PCR) analysis of apoptotic gene expression. Bioinformatics and molecular docking studies identified potential targets of DET, evaluating its binding affinity to apoptotic and survival proteins.

Results: The MTT assay showed that DET inhibited KB oral cancer cell growth in a dose-dependent manner, increasing oxidative stress and reducing superoxide dismutase (SOD) and catalase (CAT) activities. RT-PCR revealed a shift in gene expression, with upregulation of pro-apoptotic genes (BAX, CASP-3, CASP-6, and CASP-9) and downregulation of anti-apoptotic genes, confirming mTOR pathway inhibition. Molecular docking indicated strong binding affinities between DET and key apoptotic and survival proteins. MD simulations showed strong stability for protein target against DET.

Conclusions: DET effectively disrupts AKT1/mTOR signalling, inducing apoptosis and oxidative stress in OSCC cells. Its high biocompatibility (SWISS-ADME) and strong molecular interactions support its potential as a novel therapeutic agent for OSCC. This integrative approach provides valuable insights into DET's mechanism of action, paving the way for pre-clinical and clinical applications.