LOS ANGELES, CALIFORNIA. A team of University of California (San Diego) researchers recently reported that PC-SPES, a much touted herbal remedy for prostate cancer, had been found to be heavily contaminated and had been taken off the market. Nevertheless, researchers at the UCLA Center for Human Nutrition in Los Angeles now report that they have found PC-SPES to be highly effective in preventing the initiation and progression of colon cancer. They evaluated PC-SPES in vitro using three different colon cancer cell lines. They found that the herbal compound caused a 95 per cent inhibition of cell proliferation in all three lines. In contrast, estradiol did not stop cell proliferation at all. Thus it is unlikely that the observed effect of PC-SPES is due to possible contamination with diethylstilbestrol, another estrogenic compound. The researchers also evaluated PC-SPES (250 mg/kg/day) in laboratory mice genetically engineered to develop multiple tumours in the gastrointestinal tract within a few weeks after birth. They found that mice treated 5 times a week for 10 weeks with PC-SPES developed 58 per cent less tumours than did control mice. They conclude that the components of PC-SPES, either independently or in combination, act to produce a drastic reduction in tumour initiation and progression in the gastrointestinal tract.
Huerta, Sergio, et al. PC-SPES inhibits colon cancer growth in vitro and in vivo. Cancer Research, Vol. 62, September 15, 2002, pp. 5204-09