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World J Hepatol. Sep 27, 2011; 3(9): 228-249
Published online Sep 27, 2011. doi: 10.4254/wjh.v3.i9.228
Terpenoids as potential chemopreventive and therapeutic agents in liver cancer
Roslin J Thoppil, Anupam Bishayee
Roslin J Thoppil, Anupam Bishayee, Cancer Therapeutics and Chemoprevention Group, Department of Pharmaceutical Sciences, Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Rootstown, OH 44272, United States
Anupam Bishayee, Department of Internal Medicine, Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Rootstown, OH 44272, United States
Author contributions: Thoppil RJ performed literature search and collection as well as drafted the manuscript; Bishayee A performed additional bibliographic work as well as revised and edited the manuscript.
Correspondence to: Anupam Bishayee, PhD, Department of Pharmaceutical and Administrative Sciences, School of Pharmacy, American University of Health Sciences, 1600 East Hill Street, Signal Hill, CA 90755, United States.
Telephone: +1-562-9882278 Fax: +1- 562-9881791
Received: December 13, 2010
Revised: August 15, 2011
Accepted: August 22, 2011
Published online: September 27, 2011

Despite significant advances in medicine, liver cancer, predominantly hepatocellular carcinoma remains a major cause of death in the United States as well as the rest of the world. As limited treatment options are currently available to patients with liver cancer, novel preventive control and effective therapeutic approaches are considered to be reasonable and decisive measures to combat this disease. Several naturally occurring dietary and non-dietary phytochemicals have shown enormous potential in the prevention and treatment of several cancers, especially those of the gastrointestinal tract. Terpenoids, the largest group of phytochemicals, traditionally used for medicinal purposes in India and China, are currently being explored as anticancer agents in clinical trials. Terpenoids (also called “isoprenoids”) are secondary metabolites occurring in most organisms, particularly plants. More than 40 000 individual terpenoids are known to exist in nature with new compounds being discovered every year. A large number of terpenoids exhibit cytotoxicity against a variety of tumor cells and cancer preventive as well as anticancer efficacy in preclinical animal models. This review critically examines the potential role of naturally occurring terpenoids, from diverse origins, in the chemoprevention and treatment of liver tumors. Both in vitro and in vivo effects of these agents and related cellular and molecular mechanisms are highlighted. Potential challenges and future directions involved in the advancement of these promising natural compounds in the chemoprevention and therapy of human liver cancer are also discussed.

Keywords: Terpenoids, Liver cancer cells, Hepatocellular carcinoma, Hepatocarcinogenesis, Chemoprevention, Treatment, Apoptosis, Cell cycle