Cytotoxic Effect of Halimeda macroloba Crude Extract on Cervical Cancer Spheroid Cells via p-mTOR/mTOR, Apoptosis, and Ferroptosis Pathways.

Abstract

Background: Because of the limited efficacy of existing therapeutic strategies and the emergence of treatment resistance, cervical cancer remains a major global health burden. Recently, marine-derived natural compounds have attracted attention as potential sources of novel anticancer agents. We aimed to investigate the cytotoxic effects of crude Halimeda macroloba extract on cervical cancer spheroid cells and to explore its underlying molecular mechanisms.

Methods: Three-dimensional spheroid cultures of SiHa cervical cancer cells were treated with varying concentrations of H. macroloba extract, followed by assessment of migration, cell viability, caspase activity, and protein expression profiles using liquid chromatography-tandem mass spectrometry, with selected findings validated by Western blotting.

Results: Treatment with H. macroloba extract significantly reduced spheroid migration and decreased cell viability in a dose-dependent manner, accompanied by increased caspase activity. Proteomic analysis demonstrated altered expression of proteins associated with mitochondrial function, apoptosis-related pathways, and oxidative stress-related processes. Mechanistic studies further revealed downregulation of phosphorylated mTOR (p-mTOR) and total mTOR, together with increased expression of pro-apoptotic markers.

Conclusion: The H. macroloba crude extract exerts anticancer effects in cervical cancer spheroids, primarily through apoptosis-associated mechanisms and modulation of the mTOR signaling pathway, supporting its potential for further investigation as a marine-derived bioactive compound.