MOLECULAR CARCINOGENESIS Black Currant Phytoconstituents Exert Chemoprevention of Diethylnitrosamine- Initiated Hepatocarcinogenesis by Suppression of the Inflammatory Response Anupam Bishayee, 1 * Roslin J. Thoppil, 2 Animesh Mandal, 2 Altaf S. Darvesh, 2 Vahagn Ohanyan, 3 J. Gary Meszaros, 3 Erzse ´ bet Ha ´ znagy-Radnai, 4 Judit Hohmann, 4 and Deepak Bhatia 2 1 Department of Pharmaceutical and Administrative Sciences, School of Pharmacy, American University of Health Sciences, Signal Hill, California 2 Cancer Therapeutics and Chemoprevention Group, Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio 3 Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio 4 Department of Pharmacognosy, University of Szeged, Szeged, Hungary Black currant fruits containing high amounts of anthocyanins are known to possess potent antioxidant and anti- inflammatory properties. We have previously reported that anthocyanin-rich black currant skin extract (BCSE) inhibits diethylnitrosamine (DENA)-initiated hepatocarcinogenesis in rats although the underlying mechanisms are not fully understood. Our present study investigates the anti-inflammatory mechanisms of BCSE during DENA rat liver carcino- genesis. Dietary BCSE (100 or 500 mg/kg) treatment for 22 wk afforded a striking inhibition of DENA-induced hepatic gamma-glutamyl transpeptidase-positive preneoplastic foci in a dose-responsive fashion. There was a significant increase in hepatic expression of heat shock proteins (HSP70 and HSP90), cyclooxygenase-2, and nuclear factor-kB (NF-kB) in DENA-exposed rat livers. Dietary BCSE dose-dependently abrogated all these elevated inflammatory markers. The possible cardiotoxicity of BCSE was assessed by monitoring cardiac functions using transthoracic echo- cardiography. BCSE-mediated anti-inflammatory effects during rat liver carcinogenesis have been achieved without any cardiotoxicity. Our results provide convincing evidence, for the very first time, that suppression of the inflammato- ry cascade through modulation of the NF-kB signaling pathway could be implicated, at least in part, in the chemo- preventive effects of black currant bioactive phytoconstituents against experimental hepatocarcinogenesis. These results coupled with an excellent safety profile of BCSE support the development of black currant phytochemicals for the chemoprevention of inflammation-driven hepatocellular cancer. ß 2011 Wiley Periodicals, Inc. Key words: hepatocarcinogenesis; inflammation; chemoprevention; nuclear factor-kB signaling; cyclooxygenase-2; heat shock proteins INTRODUCTION Cancer has progressed to surpass most chronic diseases to be the leading cause of mortality in both the developed and developing world [1]. Diagnosed as the 5th most common cancer world- wide, liver cancer represents the second most fre- quent cause of cancer death [2]. Hepatocellular carcinoma (HCC) qualifies as the major subtype affecting the population of liver cancer patients, mostly in east and south-east Asia as well as in middle and western Africa [2,3]. Increase in liver cancer incidence has been witnessed all over the world including central and western Europe as well as north America [4–6]. The United States too has reported more than 70% increase in the inci- dence of HCC in the last 25 yr [7]. HCC arises from underlying viral infections, such as hepatitis B and hepatitis C, and alcoholic cirrhosis; however, beyond these triggering factors, chronic oxidative stress and inflammation play a pivotal role in adding insult to injury, ultimately resulting in a full-blown condition of liver cancer. In addition to these insults, metabolic disorders (obesity), auto- immune hepatitis as well as environmental and dietary exposure to carcinogens, including aflatox- ins and nitrosamines, contribute to HCC occur- rence [8–11]. Liver transplantation and surgical resection serve as current curative treatments while Abbreviations: HCC, hepatocellular carcinoma; BCSE, black currant skin extract; DENA, diethylnitrosamine; PB, phenobarbital; GGT, gamma-glutamyl transpeptidase; HSP, heat shock protein; COX-2, cyclooxygenase-2; NF-kB, nuclear factor-kappaB; HRP, horse radish peroxidase; PCR, polymerase chain reaction. *Correspondence to: Department of Pharmaceutical and Admin- istrative Sciences, School of Pharmacy, American University of Health Sciences, 1600 East Hill Street, Signal Hill, CA 90755. Received 16 October 2011; Revised 22 November 2011; Accepted 30 November 2011 DOI 10.1002/mc.21860 Published online in Wiley Online Library (wileyonlinelibrary.com). ß 2011 WILEY PERIODICALS, INC.