Nasrin Ranjbar - Student Scientific Research Center, Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.|Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences,
Ramin Saravani - Cellular and Molecular Research Center, Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.|Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences,
Zohreh Faezizadeh - Department of Laboratory Sciences, Borujerd Branch, Islamic Azad University, Borujerd, Iran

Objective: Silymarin is a herbal extract containing flavonolignans, and it has inhibitory effects against the growth of different cancer cell lines by inducing apoptosis. Toll-like receptors are suggested as a novel and attractive target to treat cancer. The current study aimed at examining the mechanism of silymarin-induced apoptosis in Ramos cells and investigating its effects on TLR8 expression. Materials and Methods: The half maximal inhibitory concentration (IC50) of silymarin in Ramos cells was determined via MTT viability test while the type of cell death was tested by annexin V/propidium iodide (PI) double staining method. The activity of caspase-3 and expression of TLR8 were measured in a time-dependent manner (in IC50) by colorimetric assay and real-time polymerase chain reaction (RT-PCR), respectively. Results: The results of MTT showed that IC50 of silymarin in Ramos cells was 100 μg/ml after 48 hr treatment (p<0.01). Flow cytometry by annexin V/PI, showed that silymarin induced early/late apoptosis in this cell line (p Conclusion: The results indicated a new mechanism in the anticancer activity ofToll-like receptor (TLR) signaling after silymarin treatment in Ramos cancer cell line. This plant could be used to develop anticancer agents inhibiting TLRs.

Toll-Like Receptor, TLR8, Gene expression, Silymarin, Apoptosis, Ramos cells