title: Antiproliferation and induction of cell death of Phaffia rhodozyma (Xanthophyllomyces dendrorhous) extract fermented by brewer malt waste on breast cancer cells.
abstract: Astaxanthin has been shown to have antiproliferative activity on breast cancer and skin cancer cells. However, the high cost of production, isolation and purification of purified astaxanthin from natural sources or chemically synthetic methods limit its usage on cancer therapy. We show that astaxanthin could be produced by fermentating the Phaffia rhodozyma (Xanthophyllomyces dendrorhous) yeast cells with brewer malt waste using a 20 L B. Braun fermentor. The percentage composition of astaxanthin from the P. rhodozyma was >70% of total pigment as estimated by the high performance liquid chromatographic analysis. Furthermore, the antiproliferative activity of this P. rhodozyma cell extract (PRE) was demonstrated on breast cancer cell lines including the MCF-7 (estrogen receptor positive) and MDA-MB231 (estrogen receptor negative) by using the [3-(4,5-dimethylthiazol-2-yl)-5-(3-arboxymethoxyphenyl)-2- (4-sulfophenyl)-2H-tetrazolium] (MTS) assay. No apoptotic cell death, but growth inhibitory effect was induced after 48 h of PRE incubation as suggested by morphological investigation. Anchorage-dependent clonogenicity assay showed that PRE could reduce the colony formation potential of both breast cancer cell lines. Cell death was observed from both breast cancer cell lines after incubation with PRE for 6 days. Taken together, our results showed that by using an economic method of brewer malt waste fermentation, we obtained P. rhodozyma with a high yield of astaxanthin and the corresponding PRE could have short-term growth inhibition and long-term cell death activity on breast cancer cells.
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Shenzhen, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, PR China.
authors.forename: Ivy Tuang Ngo
authors.initials: IT
authors.lastname: Teo
authors.forename: Chung Hin
authors.initials: CH
authors.lastname: Chui
authors.forename: Johnny Cheuk On
authors.initials: JC
authors.lastname: Tang
authors.forename: Fung Yi
authors.initials: FY
authors.lastname: Lau
authors.forename: Gregory Yin Ming
authors.initials: GY
authors.lastname: Cheng
authors.forename: Raymond Siu Ming
authors.initials: RS
authors.lastname: Wong
authors.forename: Stanton Hon Lung
authors.initials: SH
authors.lastname: Kok
authors.forename: Chor Hing
authors.initials: CH
authors.lastname: Cheng
authors.forename: Albert Sun Chi
authors.initials: AS
authors.lastname: Chan
authors.forename: Kwok Ping
authors.initials: KP
authors.lastname: Ho
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000096:biosynthesis* / Q000627:therapeutic use*; D017209:Apoptosis; D001487:Basidiomycota / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D053938:DNA Fragmentation; D002523:Edible Grain / Q000378:metabolism; D005260:Female; D005285:Fermentation; D006801:Humans; D014866:Waste Products; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000627:therapeutic use
chemical_list: D000903:Antibiotics, Antineoplastic; D014866:Waste Products; D024341:Xanthophylls; D019207:beta Carotene; C005948:astaxanthine