title: beta-carboline alkaloid-enriched extract from the amazonian rain forest tree pao pereira suppresses prostate cancer cells.
abstract: Bark extracts from the Amazonian rain forest tree Geissospermum vellosii (pao pereira), enriched in alpha-carboline alkaloids have significant anticancer activities in certain preclinical models. Because of the predominance of prostate cancer as a cause of cancer-related morbidity and mortality for men of Western countries, we preclinically tested the in vitro and in vivo effects of a pao pereira extract against a prototypical human prostate cancer cell line, LNCaP. When added to cultured LNCaP cells, pao pereira extract significantly suppressed cell growth in a dose-dependent fashion and induced apoptosis. Immunodeficient mice heterotopically xenografted with LNCaP cells were gavaged daily with pao pereira extract or vehicle control over 6 weeks. Tumor growth was suppressed by up to 80% in some groups compared with tumors in vehicle-treated mice. However, we observed a striking U-shaped dose-response curve in which the highest dose tested (50 mg/kg/d) was much less effective in inducing tumor cell apoptosis and in reducing tumor cell proliferation and xenograft growth compared with lower doses (10 or 20 mg/kg/d). Although this study supports the idea that a pao pereira bark extract has activity against human prostate cancer, our in vivo results suggest that its potential effectiveness in prostate cancer treatment may be limited to a narrow dose range.
authors.affiliation: Department of Urology, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA. dbemis@licr.org
authors.forename: Debra L
authors.initials: DL
authors.lastname: Bemis
authors.forename: Jillian L
authors.initials: JL
authors.lastname: Capodice
authors.forename: Manisha
authors.initials: M
authors.lastname: Desai
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Katz
authors.forename: Ralph
authors.initials: R
authors.lastname: Buttyan
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002243:Carbolines / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000517:prevention & control*; D014197:Trees / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002243:Carbolines; D010936:Plant Extracts