Effects of Curcumin on Proliferation and Apoptosis of Colorectal Carcinoma LoVo Cells

To study the biological function and regulation mechanism of curcumin on proliferation and apoptosis of colorectal carcinoma cells LoVo, the LoVo cells were cultured and treated by curcumin in different concentrations in vitro. Effect of Curcumin on cell proliferation level was examined by MTT colorimetry method. The morphological changes of curcumin-treated LoVo cells were observed under inverted microscope. The mRNA levels of Bax, Bcl-2 and Caspase-3 were tested by RT-PCR. The cell apoptosis rate was detected by Annexin V-FITC/PI double staining. Western blotting and immunofluorescence staining were used to detect the different expressions of c-myc protein of LoVo cells before and after curcumin treatment. MTT test indicated curcumin could inhibit the growth and proliferation of LoVo cells in a time-and concentration-dependent manner. The inhibitory concentration 50%(IC50) of curcumin were 26.45±0.41 μmol/L, 19.13±0.09 μmol/L and 10.12±0.04 μmol/L in LoVo cells at 24, 48 and 72 h, respectively. Flow cytometry instrument analysis showed that curcumin induced apoptosis of LoVo cells. Curcumin activated the expression of Bax and Caspase-3 genes, while inhibited the expression of Bcl-2 gene and c-myc protein. Curcumin significantly inhibited the proliferation and induced the apoptosis of human colorectal carcinoma cells LoVo. Such biological effect may be associated with activating Caspase-3 signal channel by activating Bax expression and inhibiting Bcl-2 and c-myc expression.