Betulinic acid selectively inhibits the growth of ovarian
carcinoma cell lines without affecting the normal cells. In the present study, the effect of
5-fluorouracil (5-FU) and
betulinic acid (BA) combination on ovarian
carcinoma cells was studied. The results demonstrated that ovarian
carcinoma cells on concurrent or
5-FU followed by BA treatment show increased Sub-G1 cell population, increased rate of cell apoptosis and morphological changes in mitochondrial membrane. In OVCAR 432 cells treatment with sequential combination of
5-FU and BA increased the Sub-G1 cell population to 51.3% and growth inhibition rate of > 72%. However, exposure to BA before
5-FU treatment caused a decrease in rate of inhibition to < 35%. Treatment with combination of 5 μM of
5-FU and 1 μM of BA for 48 h, led to an induction of apoptosis in 79.7% and induced morphological changes in OVCAR 432 cells. The Western blot results showed high concentration of
cytochrome c in the cell cytosol after 24 h of
5-FU and BA combination treatment. Treatment of BA-responsive RMS-13 cells with
5-FU and BA combination resulted in inhibition of GLI1, GLI2, PTCH1, and IGF2 genes. In addition, we found a significant reduction in hedgehog activity of RMS-13 cells after
5-FU and BA combination treatment by means of a hedgehog-responsive reporter assay. Therefore,
5-FU and BA combination can be a promising regimen for the treatment of ovarian
carcinoma.