PC-SPES: phytotherapy for prostate cancer

• Published in: The Lancet (British edition) Vol. 359; no. 9325; pp. 2213 - 2215
• Main Authors: Pandha, HS, Kirby, RS
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 29.06.2002; Elsevier Limited
• Subjects: Animals; Antineoplastic Agents, Phytogenic - economics; Antineoplastic Agents, Phytogenic - therapeutic use; Clinical trials; Drug therapy; Drugs, Chinese Herbal; Female; Humans; Ingestion; Male; Mice; Plant Extracts - economics; Plant Extracts - therapeutic use; Prostate cancer; Prostatic Neoplasms - drug therapy; Rats; Therapy; Tumor Cells, Cultured - drug effects; Yeasts
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(02)09313-3

Anecdotally, the side-effect profile of PC-SPES suggests some oestrogen-like activity. Although many prostate cancers express oestrogen receptors, oestrogen therapy suppresses the androgen receptor and is an effective treatment for prostate cancer. However, analysis fails to reveal large amounts of common oestrogens in PC-SPES,2 although diethylstilboestrol at significant concentrations (107-159 mg/g PC-SPES) has been recently reported.3 Nevertheless, some of its constituents have some oestrogenic activity.4,5 Liquorice competes with oestradiol in binding assays, and ginseng induces oestrogen-regulated expression of pS2, a small protein found in cultured breast-cancer cells.6 PC-SPES activated the human oestrogen-response element in two yeast systems.7 In ovariectomised CD-1 mice, PC-SPES ingestion resulted in the development of significantly heavier uteri than in control mice,2,7 although the actively treated mice received up to 80 times the dose of PC-SPES that is used clinically.