Crocetin treatment inhibits proliferation of colon cancer cells through down-regulation of genes involved in the inflammation.

The current study was designed to investigate the effect of crocetin on the proliferation inhibition of colon cancer cells and the underlying mechanism.MTT assay showed inhibition of proliferation of colon cancer cells in a dose based manner by crocetin treatment. At 30 µM concentration of crocetin proliferation rate of colon cancer cells was reduced to 14% after 24 h. Flow cytometry and fluorescence microscopy revealed induction of apoptosis in colon cancer cells on treatment with crocetin. The tube formation was suppressed significantly in the cultures of HUVEC treated with 30 µM concentration of crocetin compared to the control cultures.The results from transwell assay revealed a significant reduction in the population of DU-145 cells passing through filters of transwell on treatment with crocetin compared to the control cells. Treatment of the DU-145 cells with crocetin caused a significant reduction in the expression levels of NF-κB, VEGF and MMP-9. The results from RT-PCR analysis revealed a significant reduction in the expression of genes involved in inflammation including, HMGB1, IL-6 and IL-8 on treatment of DU-145 cells with crocetin. However, the expression of NAG-1 gene was increased by crocetin treatment in DU-145 cells significantly compared to the control cells.Crocetin inhibits growth of colon cancer cells and prevents tube formation through induction of apoptosis. Therefore, crocetin can be used efficiently for the treatment of colon cancer.