Effects of a phytotherapeutic agent, PC-SPES, on prostate cancer: a preliminary investigation on human cell lines and patients

Authors

  • De La Taille,

    1. The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York,
    Search for more papers by this author
  • Hayek,

    1. The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York,
    Search for more papers by this author
  • Buttyan,

    1. The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York,
    Search for more papers by this author
  • Bagiella,

    1. Department of Biostatistics, Columbia University School of Public Health, New York, USA
    Search for more papers by this author
  • Burchardt,

    1. The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York,
    Search for more papers by this author
  • Katz

    1. The Squier Urological Clinic, Columbia University College of Physicians and Surgeons, Department of Urology, Columbia-Presbyterian Medical Center, New York,
    Search for more papers by this author

Dr Katz Columbia-Presbyterian Medical Center, The Atchley Pavilion, 11th Floor, 161 Fort Washington Avenue, New York, NY 10032, USA.

Abstract

Objectives

 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.

Patients and 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 μL 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 μL/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.

Ancillary