title: Evaluation of the antiproliferative effects of Essiac on in vitro and in vivo models of prostate cancer compared to paclitaxel.
abstract: Essiac, a widely consumed, sparsely tested herbal tea, was evaluated for preparation consistency and antiproliferative effects on prostate cancer cells and xenografts. High performance liquid chromatography (HPLC) was used to compare different lots of Essiac and evaluate extraction consistency by comparing peak areas in concentrated preparations. Repeated analysis of one lot showed < 2% RSD between corresponding peaks. Absolute peak areas varied widely between lots, but similarity in relative size of corresponding peaks was observed. Cytotoxic effects of Essiac were tested in vitro by crystal violet assay and analysis of cell cycle distribution by flow cytometry, but no differences between control and treatment groups was observed. Paclitaxel was used as a positive control in cell cycle analysis and was the only treatment which showed significant effects on cell cycle distribution. Toxicity in nude mice was tested, and efficacy in inhibiting PC-3 xenograft growth. No toxicity or tumour size difference was observed dosing up to 240 mg/kg QD, over 28 days, excepting the positive control group treated with paclitaxel. Ki-67 and PCNA expression was analyzed in treated tumors, but no difference in expression of either marker was observed. These evaluations suggest Essiac has no marked antiproliferative effect on the models tested.
authors.affiliation: Prostate Centre at Vancouver General Hospital, Vancouver, British Columbia, V6H 3Z6, Canada.
authors.forename: Andy
authors.initials: A
authors.lastname: Eberding
authors.forename: Candice
authors.initials: C
authors.lastname: Madera
authors.forename: Sherwin
authors.initials: S
authors.lastname: Xie
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Wood
authors.forename: Paula N
authors.initials: PN
authors.lastname: Brown
authors.forename: Emma S
authors.initials: ES
authors.lastname: Guns
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D019540:Area Under Curve; D002453:Cell Cycle / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D017239:Paclitaxel / Q000494:pharmacology; D010936:Plant Extracts / Q000032:analysis* / Q000494:pharmacology* / Q000633:toxicity; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D011897:Random Allocation; D014183:Transplantation, Heterologous
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C111756:Essiac; D019394:Ki-67 Antigen; D010936:Plant Extracts; D018809:Proliferating Cell Nuclear Antigen; D017239:Paclitaxel