Alpinia galanga induces caspase-dependent apoptotic cell death in human lung and cervical cancer cells

Introduction: Alpinia galanga (L.) Willd is a rhizomatous, recurrent herb used to treat numerous diseases, including cancer. This study examines the efficiency of the different parts of A. galanga for their phytochemical, antioxidant, and anti-cancer properties. Methods: The powdered leaf, stem, and rhizome of A. galanga were extracted using hexane, ethyl acetate and methanol; the phytochemical compositions of the extracts were characterized using high performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS). Their antioxidant potentials were evaluated using different assays, including 2,2-Diphenyl-1picrylhydrazil (DPPH), 2-Azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), Superoxide anion (O2-), Hydroxyl radical (OH), and Phosphomolybdenum assays. The in vitro anticancer activity was studied using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Comet assay was used to determine the level of DNA damage. Inductions of morphological alterations were studied using the AO/Et-Br dual staining method. The ELISA kits were used to measure caspase activities. Results: The cytotoxicity results showed that the various extracts had inhibitory and cytotoxic effects on cancer cell lines. The leaf hexane (LH) extract of A. galanga induced DNA damage with prominent increased tail length and tail moment followed by the induction of apoptotic cells and up-regulation of the caspase activities. HPLC and GC-MS analysis allowed the identification of bioactive compounds, recognized as apoptotic inducers in human cancer cells by activating caspase-dependent pathways. Conclusion: This work reports for the first time the effect of LH extract of A. galanga in triggering apoptosis in A-549 and HeLa cells through the upregulation of caspase-8 and caspase-3 activities.