Effects of a phytotherapeutic agent, PC-SPES, on prostate cancer: a preliminary investigation on human cell lines and patients.
OBJECTIVE
To evaluate the in vitro activity of PC-SPES, a complex phytotherapeutic agent, against prostate cancer cell lines, and to assess its activity in suppressing serum prostate specific antigen (PSA) level in patients with prostate cancer.


METHODS
Four variant prostate cancer cell lines (LNCaP and an apoptosis-resistant derivative, LNCaP-bcl-2, PC3 and DU145) were exposed to three different concentrations of PC-SPES extract. Cell viability was measured at 3, 4 and 5 days of exposure using a colorimetric assay and was compared with control cultures receiving aliquots of the ethanolic extraction medium alone. Clinically, a prospective study was initiated in patients with prostate cancer who refused conventional therapy or who had failed previous cryosurgery, radiation therapy and/or hormonal therapy. The patients were treated with PC-SPES (three capsules of 320 mg/day). The serum PSA responses and side-effects were evaluated.


RESULTS
All cultured prostate cancer cell lines showed a significant dose-dependent reduction in cellular viability (compared with control cultures) by exposure to 4 and 6 microL of PC-SPES extract/mL of culture medium (P<0.001). In contrast to the hormone-insensitive cell lines tested (LNCaP-bcl-2, PC-3 and DU-145), only the hormone-sensitive cell line LNCaP was affected by the lowest dose of PC-SPES extract tested (2 microL/mL medium). In the prospective clinical trial of 33 patients, with a mean (range) follow-up of 6.8 (2-24) months after initiating PC-SPES therapy, serum PSA levels were lower in 87% at 2 months and in 78% at 6 months (n=18, P=0.026). The side-effects in these patients were nipple tenderness in two (6%) and leg clots requiring heparinization in two (6%). No gynaecomastia or hot flashes were observed in this group and the treatment was well tolerated.


CONCLUSIONS
In this preliminary study, an extract of the phytotherapeutic agent PC-SPES was active in suppressing the growth of cultured hormone-sensitive and -insensitive prostate cancer cell lines. In the small clinical study, PC-SPES therapy decreased serum PSA levels in most patients. However, a longer follow-up and more patients will be required to evaluate the long-term efficacy of this new phytotherapy.
de la Taille
A
A
The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York, NY 10032, USA.
Hayek
O R
OR
Buttyan
R
R
Bagiella
E
E
Burchardt
M
M
Katz
A E
AE
D000368:Aged; D000369:Aged, 80 and over; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000627:therapeutic use*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy*; D014407:Tumor Cells, Cultured
D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; C114209:herbal preparation PC-SPES; D017430:Prostate-Specific Antigen