Revealing the Reversal Effect of Galangal (Alpinia galanga L.) Extract Against Oxidative Stress in Metastatic Breast Cancer Cells and Normal Fibroblast Cells Intended as a Co- Chemotherapeutic and Anti-Ageing Agent

Abstract

Objective: This study intends to explore the potential of galangal extract as a co-chemotherapeutic agent through the analysis of its cytotoxic and migratory effects on metastatic breast cancer cells and as an anti-ageing agent through its senescence inhibitory effect on normal fibroblast cells. Methods: Galangal ethanolic extract (GE) was subjected to a cytotoxicity test with the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay alone or in combination with doxorubicin (Dox) against 4T1 cells but not in NIH-3T3 cells. Evidence of senescent cells was detected using a SA-β galactosidase based assay. In addition, the level of reactive oxygen species (ROS), apoptosis, and cell cycle were measured with a flow cytometry-based assay. Meanwhile, cell migration and matrix metalloproteinase (MMP)-9 expression after GE treatment on 4T1 cells were measured using the scratch wound healing assay and gelatin zymography assay, respectively. The metabolomic profiles of GE were traced using gas chromatography-mass spectrometry (GC-MS) analysis. Results: GE effectively inhibited the growth of 4T1 cells with an IC50 value of 135 µg/mL and increased the cytotoxic effect of Dox at concentrations of 50 and 100 µg/mL. GE increased the number of senescent cells arrested in the G2/M phase but did not cause apoptosis. This effect is compounded by increasing intracellular levels of ROS. However, GE reduced senescence to normal in fibroblast cells (NIH 3T3 cells) under oxidative stress by Dox without any changes in the ROS level. Moreover, GE also inhibited the migration of 4T1 cells and suppressed the expression of MMP-9 induced by Dox. Conclusion: Galangal has the potential for use as a co-chemotherapeutic agent by inducing senescence in correlation with increasing intracellular ROS toward metastatic breast cancer. However, the effect of GE in decreasing the senescence phenomena toward normal fibroblast cells illustrates its potential as a promising anti-ageing agent.<br />