Chelidonium majus L. alkaloid extract enhances TRAIL-induced apoptosis in HeLa cell line through death receptors 4 and 5 upregulation

Abstract Cervical carcinoma is the third leading cancer in women. There is a possibility of treatment failure of conventional chemotherapy due to the resistance of cancer cells to the apoptotic effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). The use of herbal drugs for the treatment of cancer has been considered an effective solution. Chelidonium majus L. (C. majus) alkaloid extract can induce apoptosis on cancer cells. This study examined how the crude alkaloid extract of C. majus on HeLa cells is mediated apoptosis by evaluating DR4, DR5, and FADD as death receptors. The cytotoxicity of Chelidonium majus L. alkaloid extract on HeLa and human fibroblast cells was assessed using an MTT assay. The percentage of apoptotic cells was evaluated by flow cytometry. The gene expression levels of DR4, DR5, FADD, caspase 8, and caspase 3 were evaluated by real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. The half-maximal inhibitory concentration (IC50) of Chelidonium majus L. alkaloid extract was determined 75 μg/ml and 860 μg/ml for HeLa and fibroblast cells, respectively, after 48 h. The subtoxic concentration of extract with 65% viability was determined 50 μg/ml for the HeLa cell line. Quantitative RT-PCR analysis demonstrated a significant increase in DR4, DR5, caspase 8, and caspase 3 mRNA expression at both 50 μg/ml and 75 μg/ml concentrations of extract compared to control. In contrast, FADD gene expression did not significantly differ at any of 50 μg/ml and 75 μg/ml concentrations. It was demonstrated in this study crude alkaloid extract of C. majus induces an extrinsic apoptotic pathway through DR4, DR5 in the HeLa cell line and can be a natural product candidate for exerting synergism for cervical carcinoma chemotherapy. Further investigations are needed to clarify the essential components of C. majus alkaloid extract that induces apoptosis.