Elucidation of the Mechanistic Basis of Chemopreventive Activity of Polyphenol-Rich Extracts of Garcinia kola in Experimentally Induced Hepatocellular Carcinoma: An Integrated Pharmacological Study

Hepatocellular carcinoma is among the most prevalent cancers in Nigeria, driven substantially by high hepatitis B infection rates and aflatoxin dietary exposure. Garcinia kola (bitter kola), widely consumed across South West and South South Nigeria, contains structurally distinctive biflavonoids including kolaviron with reported anticancer activity. The mechanistic pharmacological basis of kolaviron's chemopreventive activity in hepatocarcinogenesis has not been comprehensively characterised using contemporary cancer biology approaches. This study conducted an integrated mechanistic investigation of kolaviron-enriched G. kola seed extract in diethylnitrosamine-induced hepatocellular carcinoma in Wistar rats and in HepG2 cell lines. Hepatocarcinogenesis was initiated by DEN injection and promoted by phenobarbital, followed by chemopreventive intervention with kolaviron extract at 100 and 200 mg/kg. Tumour biochemistry was characterised by NF-kB signalling pathway analysis, reactive oxygen species profiling, apoptosis assessment by flow cytometry, and mTOR pathway activity. Transcriptomic analysis of treated versus control tumours was performed by RNA-seq. In HepG2 cells, kolaviron induced caspase-3-mediated apoptosis and cell cycle arrest at G0/G1 phase. In the animal model, significant reduction in tumour nodule number and size correlated with NF-kB p65 nuclear translocation inhibition. RNA-seq identified 312 differentially expressed genes, with KEGG pathway enrichment confirming suppression of PI3K/AKT/mTOR and JAK/STAT signalling. These mechanistic findings provide an original comprehensive basis for the chemopreventive activity of kolaviron in experimental hepatocarcinogenesis, supporting translation into clinical chemopreventive trial design. Keywords: Garcinia kola, kolaviron, hepatocellular carcinoma, chemoprevention, NF-kB signalling.