In vitro mechanism of PC SPES.
PC SPES (BotanicLab, Brea, California) an herbal supplement for patients with prostate cancer, is composed of 7 highly concentrated Chinese herbs and 1 US herb. It was developed in seeking positive attributes of Chinese and Western medicine for cancer treatment. Chemical standardization of this composition showed that baicalin is the most abundant active compound. Several reports on phase 2 clinical studies of PC SPES suggest that it is a well-tolerated active treatment for androgen-independent prostate cancer. In this report, data obtained from various laboratory experiments will be presented to elucidate the in vitro mechanism. Profound biologic effects of PC SPES on prostate cancer cells were observed on both androgen-dependent (LNCap) and androgen-independent (DU-145) cell lines. These effects include the following: (1) induction of cell apoptosis and cell cycle modulation; (2) inhibition of cell proliferation; (3) downregulation of bcl-2, bcl-6, proliferating cell nuclear antigen, and prostate-specific antigen proteins; (4) downregulation of androgen receptor (AR); and (5) upregulation of p53, bax, and p21 proteins. Concurrent animal studies using 2 different models, Copenhagen rats and nude mice, confirmed a dose-dependent suppressive effect of PC SPES on tumor volumes and tumor progression. Our results show that the cytotoxic and cytostatic properties of PC SPES are not entirely dependent on the presence of AR. The antitumor mechanism of PC SPES is complex. It involves multiple metabolic pathways, such that the whole extract acts on redundant mechanisms, which otherwise will permit cell survival if a single-target agent is used.
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Brander Cancer Research Institute, New York Medical College, Hawthorne, New York, USA. Sophie_chen@nync.edu
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D004195:Disease Models, Animal; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D011944:Receptors, Androgen / Q000187:drug effects / Q000502:physiology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D011944:Receptors, Androgen; C114209:herbal preparation PC-SPES