Honokiol and Magnolol Induce Apoptosis and Cell Cycle Arrest in Human Ovarian Cancer Cells

Introduction: Ovarian cancer is a major cause of cancer-related death among women. The growth, persistence, and cancer metastasis are causes of poor prognosis and high mortality rate. Honokiol and magnolol are derivative compounds extracted from the root and stem bark of Magnolia officinalis. Many studies have reported that honokiol and magnolol have anti-tumour effects on various types of cancer. The present study investigates the anti-tumour effect of these compounds on human ovarian cancer. Methods: Ovarian cancer cell lines, SKOV3 and ES-2 cells were tested with honokiol and magnolol to determine their responses including the cytotoxicity, cell proliferation, induction of cell apoptosis and metastasis ability. Result: The results indicate that low concentrations of honokiol and magnolol suppressed the proliferation of ovarian cancer cells through induction of cell cycle arrest at G0/G1 and down-regulation of the cyclin D1 protein. These compounds also exhibited an anti-metastatic ability mediated by inhibiting migration, adhesion, and MMP activities. Additionally, high concentrations of honokiol and magnolol could activate cell death associated with the apoptosis signalling pathway, either along an intrinsic or extrinsic pathway. Conclusion: The data provides evidence that honokiol and magnolol have potential anti-tumour properties and minimal toxicity on normal cells, and could therefore be applied in the treatment of ovarian cancer.