RESUMO
BACKGROUND: Ovarian cancer is one of the most lethal gynecological cancers among women worldwide. Cisplatin (Cis) is an effective chemotherapeutic agent used to treat several types of cancer. Silymarin (SLM) is an extract of medicinal plant Silybum marianum (milk thistle) with anti-inflammatory, anti-angiogenesis, antioxidant, and anticancer properties used alone or in combination with other drugs. OBJECTIVE: This study aimed to explore the effects of co-treatment with SLM and Cis on A2780 human ovarian cancer cell lines. METHODS: In this study, A2780 cells were treated with various concentrations of SLM and Cis, separately and in combination. Cell cytotoxicity, scratch, clonogenic, and flow-cytometry assays were accomplished to estimate cell viability, migration, colony formation, and apoptosis, respectively. Real-time PCR was utilized to determine the expression levels of miR-155 and miR-27a. RESULTS: SLM significantly reduced the proliferation of A2780 cells in a concentration- and time-dependent manner. Combination treatment with SLM and Cis was more potent than either single treatment in reducing viability, suppressing migration, inhibiting colony formation, and promoting the induction of apoptosis. Additionally, gene expression analysis revealed a significant decline in the expression levels of miR-155 and miR-27a in response to all separate and combined treatments, and co-treatment was more effective than individual treatments in altering miRNAs expression. CONCLUSION: Based on our findings, SLM boosts the anticancer activity of Cis and mitigates its side effects. Thus, the co-treatment of SLM and Cis can be proposed as a promising therapeutic strategy for further investigation.