Isoalantolactone inhibits the proliferation of human liver cancer cells by inducing intrinsic apoptosis

Abstract

Purpose: To investigate isoalantolactone's potential as an anticancer agent targeting liver cancer cells and to elucidate the underlying mechanism. 
 Methods: Cell counting kit-8 (CCK-8) and colony formation assays were employed to analyze the anti-growth effects of isoalantolactone against liver cancer cells. Cell apoptosis was studied using Acridine orange/ethidium bromide (AO/EB) and Annexin V-FITC/Propidium iodide (PI) staining methods. The intracellular levels of reactive oxygen species (ROS) were estimated using the 2’-7’-Dichlorodihydrofluorescein diacetate (DCF-DA) method. Liver cancer cell invasion was assessed through Transwell assays. 
 Results: Isoalantolactone inhibited the proliferation and colony formation of HuH7 cells by inducing apoptosis. Isoalantolactone showed IC50 of 9 μM against HuH7 liver cancer cells. The MRC-5 normal cells treated with isoalantolactone also showed loss of viability and the IC50 was estimated to be 40 μM. HuH7 cancer cells administered with isoalantolactone exhibited modulation of apoptotic marker protein expression levels. Apoptosis was shown to result from ROS elevation. Isoalantolactone also restricted liver cancer cell invasion. 
 Conclusion: Isoalantolactone shows anti-proliferative and anti-metastatic effects against liver cancer cells via ROS-mediated apoptosis induction thereby making it a potential source of potent therapeutic agents against human cancer.