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α-Mangostin, a xanthone from mangosteen fruit, promotes cell cycle arrest in prostate cancer and decreases xenograft tumor growth.

Department of Pharmacy Practice, University of Illinois at Chicago College of Pharmacy, 833 South Wood Street, Chicago, IL 60612-7230, USA.
Carcinogenesis (Impact Factor: 5.27). 12/2011; 33(2):413-9. DOI: 10.1093/carcin/bgr291
Source: PubMed

ABSTRACT There is a need to characterize promising dietary agents for chemoprevention and therapy of prostate cancer (PCa). We examined the anticancer effect of α-mangostin, derived from the mangosteen fruit, in human PCa cells and its role in targeting cell cycle-related proteins involved in prostate carcinogenesis. Using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, we found that α-mangostin significantly decreases PCa cell viability in a dose-dependent manner. Further analysis using flow cytometry identified cell cycle arrest along with apoptosis. To establish a more precise mechanism of action, we performed a cell free biochemical kinase assay against multiple cyclins/cyclin-dependent kinases (CDKs) involved in cell cycle progression; the most significant inhibition in the cell free-based assays was CDK4, a critical component of the G1 phase. Through molecular modeling, we evaluated α-mangostin against the adenosine triphosphate-binding pocket of CDK4 and propose three possible orientations that may result in CDK4 inhibition. We then performed an in vivo animal study to evaluate the ability of α-mangostin to suppress tumor growth. Athymic nude mice were implanted with 22Rv1 cells and treated with vehicle or α-mangostin (100 mg/kg) by oral gavage. At the conclusion of the study, mice in the control cohort had a tumor volume of 1190 mm(3), while the treatment group had a tumor volume of 410 mm(3) (P < 0.01). The ability of α-mangostin to inhibit PCa in vitro and in vivo suggests α-mangostin may be a novel agent for the management of PCa.

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