Abstract
Zerumbone, a sesquiterpene extracted from rhizomes of ginger (zingiber zerumbet Smith) is reported to have anti-proliferative activities and can induce toxicity in human cancer cells. However, its molecular mechanisms' are still poorly understood. In this study, in vitro antioxidant (DPPH, H2O2, Fe2+ chelating and reducing power), apoptotic and anti-proliferative activities of zerumbone were investigated in human cancer cells. The specific objective was to identify whether zerumbone-induced cell death occurs through apoptosis, autophagy, necrosis or another fmID of cell death by undeliaking morphological and biochemical characterisation. Human cancer cell line (Caco-2, Huh-7 and EA.hy926) viability and activity with time and in the presence of different concentrations of zerumbone were investigated using LDH. In addition, characterisation of cell death induced by different concentrations of zerumbone including changes in cell sizerphosphatidylserine externalization, caspase activation and P ARP-l involvement were studied. The results showed that cancer cell death occulTed in the absence of DNA fragmentation and caspase activation at (5 g/μml). Additionally, cancer cell death was characterised by cell shrinkage and an absence of necrotic cell death pathway. Anti-proliferative activity of zerumbone (5 and 10 Ilg/ml) on human cancer cells was also investigated by changes in the DNA content using flow cytometry.