Anti-tumor effect of water-soluble propolis on mouse sarcoma cell line in vitro and in vivo

The honeybee product propolis and its extracts have biological activities including antibiotic, antiviral, anti-inflammatory and antitumoral effects. The purpose of this study is to investigate whether the water-soluble propolis (WSP) inhibits tumor growth. The tumor cell line we used was mouse sarcoma 180 (S-180) and its growth was determined in vivo and in vitro under different concentrations of WSP. Oral administration of WSP was carried out 24 hours after transplantation of S-180 cells. The WSP was administered to the mouse 5 times, for 10 days on every other day. The doses were 10 mg/mouse (320 mg/kg body weight) and 30 mg/mouse (960 mg/kg b.w.). All mice were sacrificed 10 days after transplantation of tumor cells, and tumor growth was then evaluated. The effect of WSP on tumor cells in vitro was evaluated by measuring intracellular uptake of ³H-thymidine. The uptake of ³H-thymidine was decreased according to the concentration of WSP. The minimum concentration of WSP for ³H-thymidine uptake inhibition was 60 μ g/ml and it suppressed uptake at the level of 80% of the non-treated cells. In the experiment with tumor bearing mice, oral administration of WSP significantly (p<0.05) inhibited the growth of transplanted tumor. Furthermore, in the histological findings, a significant reduction of mitotic cells and tumor invasion of muscular tissue were observed at the two-dose level of WSP.