Background:
Clinical symptoms of prostatitis, prostatodynia, and benign prostatic hyperplasia are relieved by the pollen extract cernilton, and the water-soluble fraction of this extract selectively inhibits growth of some prostate cancer cells. a cyclic hydroxamic acid, diboa, has been isolated from this extract and mimics its cell growth-inhibitory properties, but the specificity of diboa for inhibition of prostate cell growth has not been reported.
Methods:
The in vitro growth inhibitory effects of diboa and nine structurally related compounds on du-145 prostate cancer cells, mcf-7 breast cancer cells, and cos-7 monkey kidney cells were determined by treatment of the cells with various concentrations of the compounds for 2-6 days.
Results:
The compounds exhibited a wide range of potencies, but none of them exhibited selective inhibition of du-145 cell growth. mcf-7 cells were more sensitive to diboa than either du-145 cells or cos-7 cells. 3,4-dihydroquinoline-2(1h)-one, compound (4), and 1-hydroxy-6-chloro-3,4-dihydroquinolin-2(1h)-one, compound (7), selectively inhibited mcf-7 cell growth at a concentration of 10 micrograms/ml. 1-hydroxy-3,4-dihydroquinolin-2(1h)-one, compound (3), and compound 7 were the most potent inhibitors of du-145 cell growth. treatment of du-145 cells with 3 (100 micrograms/ml) substantially decreased the number of viable cells within 2 days, and no viable cells remained in the culture by day 4.
Conclusions:
It is unlikely that diboa, compound (1), is responsible for the selective growth inhibition of prostate cancer cells by the water-soluble fraction of the pollen extract cernilton. cell morphology results indicate that the growth-inhibitory effects of diboa and structurally related agents on du-145 cells are due to their ability to cause cell death.