Skip Navigation

This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (21)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Shiota, G.
Right arrow Articles by Kawasaki, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shiota, G.
Right arrow Articles by Kawasaki, H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1999 Oxford University Press

Article

Inhibition of hepatocellular carcinoma by glycyrrhizin in diethylnitrosamine-treated mice

Goshi Shiota2, Ken-ichi Harada, Masato Ishida, Yasushi Tomie, Michiko Okubo, Shunsuke Katayama, Hisao Ito1 and Hironaka Kawasaki

Second Department of Internal Medicine, Tottori University School of Medicine, Yonago 683-8504 and
1 First Department of Pathology, Tottori University School of Medicine, Yonago 683-8504, Japan


   Abstract
Top
 Abstract
Introduction
 Materials and methods
 Results
 Discussion
 References
 
Glycyrrhizin (GL) is widely used in Japan as a therapeutic agent for chronic active liver diseases. However, its action on hepatocarcinogenesis remains to be elucidated. To clarify its effect, mice treated with diethylnitrosamine (NDEA) with or without GL were analyzed. Five-week-old male BALB/c mice were divided into two groups, GL (n = 50) and C (n = 47). Mice in the GL group intramuscularly received 2 mg of GL 3 days a week, and mice in the C group received the same volume of saline in the same way. After 2 weeks, the mice were treated with an i.p. injection of 75 mg/kg body wt of NDEA weekly for 3 weeks and 100 mg/kg body wt of NDEA weekly for the following 3 weeks. Thirty additional mice that did not receive NDEA treatment were divided into two groups, GC (n = 15) and SC (n = 15). They received GL or saline, respectively. Mice in the 4 groups were killed every 5 weeks after the last injection of NDEA from 7 weeks to 32 weeks. Liver function tests such as AST and albumin were significantly improved in the GL group compared with the C group (P < 0.05, each). Although liver nodules appeared in the C group at 22 weeks, they were not observed until 32 weeks in the GL group. At 32 weeks, the mean number of liver tumors, composed of adenoma and hepatocellular carcinoma (HCC), in the GL group was 0.71, which was significantly decreased compared with 1.64 of the C group (P < 0.05). The mean number of HCC in the GL group was 0.29/liver, which was lower than 0.82/liver in the C group (P < 0.05). The incidence rate of HCC at 32 weeks was 64% in the C group and 21% in the GL group (P < 0.05, C versus GL group). Our results suggest that GL treatment inhibits the occurrence of HCC.

Abbreviations: AFP, {alpha}-fetoprotein; ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; GA, glycyrrhetic acid; GL, glycyrrhizin; GOT, glutamic oxaloacetic transaminase; GPT, glutamic pyruvic transaminase; HBC, hepatitis C virus; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; IFN, interferon; LW/BW, liver weight/body weight; NDEA, diethylnitrosamine.


   Introduction
Top
 Abstract
 Introduction
Materials and methods
 Results
 Discussion
 References
 
Hepatocellular carcinoma (HCC) is one of the most common cancers with a poor prognosis (1). There are ~500 000–1 000 000 new HCC cases per year (2). Major risk factors for HCC include cirrhosis, aflatoxin exposure, hepatitis B virus (HBV) and hepatitis C virus (HCV) infection (3). Studies on the prevalence of anti-HCV antibody in patients with HCC indicate that the highest prevalence of anti-HCV positivity is found in Japan (66–94%), that a relatively high prevalence (57–79%) is found in Africa, Italy and France, and that a lower prevalence (<40%) is typical in the USA, Switzerland, Austria, China and Hong Kong (2). HCC can develop late in the course of viral infection, especially of chronic HCV infection, after the development of cirrhosis (4). HCV carriers demonstrate higher rates of developing HCC than HBV carriers (5); the incidence of HCC in HCV carriers is 4.2-fold higher than in HBV carriers, and it is 572-fold higher than in normal individuals (6). Therefore, prophylaxis of HCC occurrence from chronic viral hepatitis is likely as important as the progress of HCC therapy.

Glycyrrhizin (GL), a molecule of glycyrrhetic acid (GA) and two molecules of glucuronic acid, is an aqueous extract from licorice root (7). This compound is well known for its anti-inflammatory properties in Chinese medicine (8). GL and the GA derivatives exhibit anti-ulcerous (9), anti-viral (10–12) and interferon (IFN)-inducing activity (13). GL was proven to be useful for therapy of chronic hepatitis (14). Indeed, double blind controlled trials showed that GL improved hepatic function tests such as GOT, GPT and {gamma}-GTP in patients with chronic active hepatitis (15,16). Thereafter, GL has often been used in treatment for chronic active liver diseases in Japan. We examined the effect of GL on hepatocarcinogenesis in mice treated with diethlynitrosamine (NDEA). An NDEA model was used because nitrate and nitrosamine synthesis is increased in viral hepatitis (17,18). Therefore, a NDEA model may be useful as a model of hepatocarcinogenesis due to viral hepatitis.


   Materials and methods
Top
 Abstract
 Introduction
 Materials and methods
Results
 Discussion
 References
 
Chemicals
NDEA was purchased from Wako Pure Chemical Industries (Osaka, Japan). GL was kindly provided from Minophagen Pharmaceutical (Tokyo, Japan).

Animals
Five-week-old male BALB/c mice, weighing 22–23g, were purchased from Charles River Japan (Yokohama, Japan). The mice were fed a CE-2 diet (CLEA Japan, Tokyo, Japan) and were given water ad libitum. Light and dark alternated at 12 h intervals. All animals received humane care in compliance with the guidelines of our university.

Experimental procedure
Ninety-seven BALB/c mice were divided into two groups, GL (n = 50) and C (n = 47). The experimental schedule is shown in Figure 1Go. In brief, mice in the GL group intramuscularly received 2 mg/mouse of GL 3 days a week, and mice in the C group received the same volume (0.1 ml) of saline in the same way (Figure 1AGo). Two weeks after the start of administration of GL or saline, an i.p. of 75 mg/kg body wt of NDEA was given weekly for 3 weeks (19). Then, 100 mg/kg body wt of NDEA was weeky given for the following 3 weeks. Thirty additional mice without NDEA treatment were divided into two groups, GC (n = 15) and SC (n = 15). Mice in the GC group intramuscularly reveived 2 mg/mouse of GL 3 days a week, and mice in the SC group received 0.1 ml of saline in the same way (Figure 1BGo). Mice in the four groups were killed every 5 weeks from 7 to 25 weeks. The numbers of mice killed in the GL group at 12, 17, 22, 27 and 32 weeks were 9, 9, 9, 9 and 14, respectively, and those in the C group at 12, 17, 22, 27 and 32 weeks were 9, 9, 9, 9 and 11, respectively. The number of mice in the GC and SC groups at each time point was three. Animals were killed under ether anesthesia, weighed, necropsied and examined for the presence of grossly visible lesions. The livers were removed in total, weighed and sectioned into 1–2 mm strips to examine the presence of tumors. Strips of liver were fixed in 4% paraformaldehyde for 24 h, and then embedded in paraffin. Sectioned paraffin blocks were stained with hematoxylin & eosin.



View larger version (24K):
[in this window]
[in a new window]
  		Fig. 1. Experimental schedule of the NDEA model. (A) Experimental schedules of the GL and C groups are shown. (B) Experimental schedules of the GC and SC groups are shown.

 
Histology
The morphology of hepatocellular neoplasms was classified by cell size, tinctorial properties of the cytoplasm, pattern of growth and other morphological features as previously described (20). Two independent investigators performed the histological assessment in a blind manner. The liver sections from the four groups were randomly shown to the investigators.

Liver function tests
Liver function was examined since HCC develops from chronic liver diseases (21,22). Blood parameters were used since they were useful to assess liver function of chronic liver diseases (23). Serum bilirubin was measured by the azobilirubin method, using Kurimate BIL-2 (Daiichi Kagaku Pharmaceutical, Tokyo, Japan). Serum albumin was measured by the bromcrezol green method, using Alb Jisseiken (Jisseiken, Japan). Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured by the ultraviolet spectrometry method, using Quickauto II, glutamic oxaloacetic transaminase [GOT(S)] Shinotest (Shinotest, Japan) and Quickauto II glutamic pyruvic transaminase [GPT(S)] Shinotest (Shinotest, Japan), respectively. Serum alkaline phosphatase (ALP) was measured by the SSCC method, using ALP Jisseiken (Jisseiken, Japan). These were analyzed using a Biochemical Autoanalyzer (AU5232; Olympus, Tokyo, Japan). Measurement of {alpha}-fetoprotein (AFP) was performed by a radioimmunoassay, using AFP Eiken (Eiken Kagaku, Tokyo, Japan), and followed by counting by {gamma}-counter (ARC-950; Aroka, Tokyo, Japan).

Statistics
All data were expressed as means ± SEM. The difference between the two groups was determined by the Mann–Whitney U-test and the {chi}2 test. Significance was set at P < 0.05.


   Results
Top
 Abstract
 Introduction
 Materials and methods
 Results
Discussion
 References
 
Body weight and liver weight
The changes in body weight are shown in Figure 2Go. Body weights increased with time except that the body weight in the C group decreased after 22 weeks. Body weights of the GC group were greater than those of the GL group throughout the experiment (P < 0.05, each). Body weights of the C group were lower than the SC group at 12, 17, 27 and 32 weeks (P < 0.05, each). Mice in the GL group had similar body weights to the C group throughout the experiment. Liver weights of the GL group at 12 and 32 weeks were higher than those of the C group at the corresponding weeks (data not shown). Although liver weight/body weight (LW/BW) gradually decreased with time in the SC and GC groups, it gradually increased in the GL and C groups (data not shown). At 32 weeks, LW/BW in the GL group was significantly higher than in the GC group (P < 0.05, data not shown) and the C group was also higher than the SC group (P < 0.05; data not shown).



View larger version (13K):
[in this window]
[in a new window]
  		Fig. 2. Changes in body weights in the four groups. *P < 0.05, compared with the GL group; **P < 0.05, compared with the SC group.

 
Liver function tests
Serum bilirubin levels in the GL and C groups at 32 weeks were higher than those at 12 weeks (P < 0.05, respectively; Table IGo). However, no difference was observed between the GL and C groups. Serum albumin levels gradually decreased in the GL and C groups. However, the albumin decrease in the GL group was smaller than that in the C group. Serum albumin in the GL group was higher than in the C group throughout the experiment. At 22 weeks, serum albumin in the GL group was significantly higher than that in the C group (P < 0.05). Serum AST in the GL group was lower than in the C group throughout the experiment. Levels of serum AST at 12, 27 and 32 weeks in the GL group were significantly lower than those in the C group (P < 0.05, respectively). Changes in serum ALT were similar to those of AST. Serum ALT was slightly lower in the GL group, compared with the C group at 32 weeks. Levels of AFP were <1 ng/ml in all samples (data not shown). There were no changes in serum bilirubin, albumin, AST, ALT, ALP or AFP levels between the GC and SC groups throughout the experiment (Table IGo).


View this table:
[in this window]
[in a new window]
  		Table I. Effect of glycyrrhizin on liver function tests in mice
 
Tumor incidence
No tumors were observed until 17 weeks in the GL and C groups. At 22 weeks in the C group, a tumor which was a histologically hyperplastic nodule developed. After 27 weeks, adenoma developed in the C group. The numbers of tumors in the C group at 22, 27 and 32 weeks were 0.11 ± 0.11, 0.44 ± 0.34 and 1.64 ± 0.36/liver, respectively. However, the number of tumors in the GL group at 32 weeks was 0.71 ± 0.22/liver, which was significantly lower than in the C group (P < 0.05; Figure 3AGo). HCC first developed in the C group at 20 weeks. The numbers of HCC in the GL and C groups at 32 weeks were 0.29 ± 0.13 and 0.82 ± 0.18 /liver, respectively. There was a significant difference between the two groups (P < 0.05; Figure 3BGo). Histological examination at 32 weeks showed that 18 tumors in the C group were composed of nine HCCs and nine adenomas, and that 10 tumors in the GL group were composed of four HCCs and six adenomas (data not shown). Macroscopic examination of HCCs in the C group at 32 weeks is shown in Figure 4AGo. The color of HCCs was whitish and the tumor edges were sharp. The tumors were clearly discriminated from the surrounding tissues (Figure 4BGo). Cystic dilatation of bile ducts and mild fatty changes were features observed in non-cancerous tissues in this experimental model. Microscopic examination revealed that HCC had a trabecular structure, which is a typical feature of hepatocellular carcinoma (Figure 4CGo) (20). Although three mice in the C group at 32 weeks exhibited lung metastasis (Figure 4DGo), no mice in the GL group had lung metastasis. Therefore, the results suggest that this experimental model is useful to assess anti-cancerous drugs. Table IIGo shows the incidence of HCC in the four groups at 32 weeks. The incidence rate of HCC in the GL group was 3/14 (21%), which was significantly <7/11 (64%) of the C group (P < 0.05). No tumors were observed in the GC and SC groups throughout the experiment. These data suggest that GL decreased the occurrence of HCC in mice treated with NDEA.



View larger version (12K):
[in this window]
[in a new window]
  		Fig. 3. Tumor incidence in mice. Numbers of tumors (A) and HCC (B) are shown.

 


View larger version (133K):
[in this window]
[in a new window]
  		Fig. 4. Gross and microscopic appearances of HCC. (A) HCCs (arrows) are whitish and their margins are clear. (B) HCC (T) and surrounding tissue (N) are shown. Cystic dilatation of bile ducts and mild fatty change are characteristic features of non-cancerous tissues (magnification x40). (C) Trabecular appearance of HCC tissue (magnification x200). (D) Lung metastasis in mice from the C group at 32 weeks (magnification x40).

 

View this table:
[in this window]
[in a new window]
  		Table II. Incidence of hepatocellular carcinoma in mice at 32 weeks
 

   Discussion
Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
References
 
HCC is one of the most common cancers worldwide (1). Although many risk factors have been reported (3), viral infection is an important factor for HCC (2,5,6). In the general population of Japan, the carrier rates of HBV and HCV are 1.3 and 1.5%, respectively. However, HBV and HCV carriers account for 20 and 70% of HCC in Japan (6), and the incidence of HCC is ~3-fold higher in chronic hepatitis C than in chronic hepatitis B (5). These data suggest that HCC develops at a fairly high rate in chronic viral liver diseases, especially in HCV carriers. Therefore, chemoprevention of HCC may be as important as therapies for HCC.

IFN has been reported to be effective for reducing and eliminating HCV RNA (24). IFN has been therapeutically useful for patients with chronic hepatitis C with viral clearance rates of <40–50% (25,26). Furthermore, IFN-{alpha} (6 mU 3 days a week for 12–24 weeks) significantly decreased the incidence of HCC in cirrhotic patients (27), and responders to IFN therapy exhibited a lower cumulative incidence of HCC (28). Thus, IFN therapy decreases viral replication, resulting in a lower incidence of HCC. In addition, IFN may activate the immune system, or directly reduce cell proliferation which leads to the development of HCC or precancerous cells.

This is the first experimental animal study in which GL was used as a chemopreventive agent of HCC. However, the inhibitory mechanism of HCC by GL remains unclear. It has been recently reported that long-term treatment with GL for chronic hepatitis C was effective in lowering the incidence of HCC (29). The 10 year rates of cumulative HCC incidence in patients treated with and without GL were 7 and 12%, and 15 year rates were 12 and 25%, respectively. The relative risk of HCC in patients treated without GL was 2.49-fold higher than patients treated with GL (P < 0.05, GL-treated versus control group). The authors concluded that the anti-cancerous effect of GL may be associated with its anti-inflammatory effect. Nitrosoamine elevation has been reported in viral hepatitis (17,18). Therefore, GL may decrease nitrosoamine levels in liver tissues. Furthermore, in our preliminary study, the expression rate of proliferating cell nuclear antigen (PCNA) in hepatocytes of the GL group at 7 weeks was 3-fold higher than that in the C group (data not shown). In addition, the apoptotic rate of hepatocytes in the GL group at 12 weeks was similar to that in the C group. However, it increased to 0.41 ± 0.09% in the GL group at 32 weeks, which was 2-fold higher than that in the C group at the corresponding week (data not shown). Therefore, modulation of cell proliferation and apoptosis by GL may be associated with inhibition of HCC in NDEA-treated mice. The inhibitory effect of GL on hepatocarcinogenesis requires further investigation to clarify the mechanism of these findings.


   Notes
 
2 To whom correspondence should be addressed Back


   References
Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 

  1. Parkin,D.M., Stjernsward,J. and Muir,C.S. (1984) Estimates of the worldwide frequency of twelve major cancers. Bull. WHO, 62, 163–182.[ISI][Medline]
  2. Hubert,B. (1994) Does hepatitis C virus cause hepatocellular carcinoma? Hepatology, 19, 251–255.[ISI]
  3. Tsukuma,H., Tomohiko,H., Tanaka,S. et al. (1994) Risk factors for heatocellular carcinoma among patients with chronic liver diseases. N. Engl. J. Med., 328, 1797–1801.
  4. Kiyosawa,K., Sodeyama,T., Tanaka,E. et al. (1991) Interrelationship of blood transfusion, non-A, non-B hepatitis and hepatocellular carcinoma: Analysis by detection of antibody to hepatitis C virus. Hepatology, 12, 671–675.[ISI]
  5. Takano,S., Yokosuka,O., Imazeki,F., Tagawa,M. and Omata,M. (1995) Incidence of hepatocellular carcinoma in chronic hepatitis B and C: a prospective study of 251 patients. Hepatology, 21, 650–655.[ISI][Medline]
  6. Omata,M. and Takano,S. (1994) Occurrence of hepatocellular carcinoma in chronic viral hepatitis. Cancer Chemother. Pharmacol., 33, S153–S154.[Medline]
  7. Ohtsuki,K., Oh-ishi,M. and Nagata,N. (1992) The stimulatory and inhibitory effects of glycyrrhizin and a glycyrrhetinic acid derivative on phosphorylation of lipocortin 1 by A-kinase in vitro. Biochem. Int., 28, 1045–1053.[ISI][Medline]
  8. Finney,R.S.H. and Somers,G.F. (1959) The anti-inflammatory activity of glycyrrhetic acid and derivatives. J. Pharmacol., 10, 613–620.[Medline]
  9. Doll,R., Hill,I.D., Hutton,C. and Underwood,D.L. (1962) Triterpenoid liquorice compound in gastric and duodenal ulcer. Lancet, 2, 793–796.
  10. Pompei,R., Flore,O., Marccialis,M.A., Pani,A. and Loddo,B. (1979) Glycyrrhizic acid inhibits virus growth and inactivates virus particles. Nature, 281, 689–690.[Medline]
  11. Dargan,D.J. and Subaka-Sharpe,J.H. (1986) The antiviral activity against herpes simplex virus of the triterpenoid compounds carenoxolone sodium and cycloxolone sodium. J. Antimicrob. Chem., 18, 185–200.[Abstract/Free Full Text]
  12. Hirabayashi,K., Iwata,S., Matsumoto,H. et al. (1991) Antiviral activity of glycyrrhizin and its modified compounds against human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus type 1 (HSV-1) in vitro. Chem. Pharm. Bull., 39, 112–115.[Medline]
  13. Abe,N., Ebina,T. and Ishida,N. (1982) Interferon induction by glycyrrhizin and glycyrrhetinic acid in mice. Microbiol. Immunol., 26, 535–539.[ISI][Medline]
  14. Fujisawa,K., Watanabe,Y. and Kimura,K. (1990) Therapeutic approach to chronic active hepatitis with glycyrrhizin. Asian Med. J., 23, 745–756.
  15. Suzuki,H., Ohta,Y., Takino,T., Fujisawa,K. and Hirayama,C. (1983) Effects of glycyrrhizin on biochemical tests in patients with chronic hepatitis–double blind trail. Asian Med. J., 26, 423–438.
  16. Takino,T. (1984) The effects of hepatotherapeutic drugs on chronic liver diseases evaluated by double blind trials in Japan. J. Kyoto Pref. Univ. Med., 93, 689–703.
  17. Liu,R.H., Baldwin,B., Tennant,B.C. and Hotchkiss,J.H. (1991) Elevated formation of nitrate and N-nitrosodimethylamine in woodchucks (Marmota monax) associated with chronic woodchuck hepatitis virus infection. Cancer Res., 51, 3925–3929.[Abstract/Free Full Text]
  18. Liu,R.H., Jacob,J.R., Tennant,B.C. and Hotchkiss,J.H. (1992) Nitrate and nitrosamine synthesis by hepatocytes isolated from normal woodchucks (Marmota monax) and woodchucks chronically infected with woodchuck hepatitis virus. Cancer Res., 52, 4139–4143.[Abstract/Free Full Text]
  19. Matsuzaki,T., Murase,N., Yamaguchi,A., Shinozuka,H., Furuya,T., Burrell,N., Iwatsuki,S. and Starzl,T.E. (1992) Liver transplantation for diethylnitrosamine-induced hepatocellular carcinoma in rats. Transplant. Proc., 24, 748–751.[ISI][Medline]
  20. Ward,J.M. (1980) Morphology of hepatocellular neoplasmas in B6C3F1 mice. Cancer Lett., 9, 319–325.[ISI][Medline]
  21. Di Bisceglie,A.M., Goodman,Z.D., Ishak,K.G., Hoffnagle,J.H., Melpolder, J.J. and Alter,H.J. (1991) Long-term clinical and histological follow-up of chronic posttransfusion hepatitis. Hepatology, 14, 969–974.[ISI][Medline]
  22. Kiyosawa,K., Sodeyama,T., Tanaka,E. et al. (1990) Interrelationship of blood transfusion, non-A, non-B, hepatitis and hepatocellular carcinoma. Analysis by detection of antibody to hepatitis C virus. Hepatology, 12, 671–675.[ISI][Medline]
  23. Shiota,G., Okano,J., Kawasaki,H., Kawamoto,T. and Nakamura,T. (1995) Serum hepatocyte growth factor levels in liver diseases: clinical implications. Hepatology, 21, 106–112.[ISI]
  24. Hagiwara,H., Hayashi,N., Mita,E., Ueda,K., Takehara,T., Kasahara,A., Fusamoto,H. and Kamada,T. (1993) Quantitative analysis of hepatitis C virus RNA in serum during interferon alfa therapy. Gastroenterology, 104, 877–883.[ISI][Medline]
  25. Hoofnagle,J.M., Mullen,K.D., Jones,D.B. et al. (1986) Treatment of chronic non-A, non-B hepatitis with recombinant human alpha interferon. N. Engl. J. Med., 315, 1575–1578.[Abstract]
  26. Bisceglie,A.D., Martin,P., Kassianidies,C. et al. (1989) Recombinant interferon alfa therapy for chronic hepatitis C: a randomized, double-blind, placebo-controlled trial. N. Engl. J. Med., 321, 1506–1510.[Abstract]
  27. Kasahara,A., Hayashi,N., Mochizuki,K. et al. (1998) Risk factors for hepatocellular carcinoma and its incidence after interferon treatment in patients with chronic hepatitis C. Hepatology, 27, 1394–1402.[ISI]
  28. Nishiguchi,S., Kuroki,T., Nakatani,S. et al. (1995) Randomized trial of effects of interferon-{alpha} on incidence of hepatocellular carcinoma in chronic active hepatitis C with cirrhosis. Lancet, 346, 1051–1055.[ISI][Medline]
  29. Arase,Y., Ikeda,K., Murashima,N. et al. (1997) The long term efficacy of glycyrrhizin in chronic hepatitis C patients. Cancer, 79, 1494–1500.[ISI][Medline]
Received May 5, 1998; revised August 18, 1998; accepted September 23, 1998.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Evid Based Complement Alternat MedHome page
J. R. Lee, S. J. Park, Y. K. Kwon, S. Y. Jee, J. Seo, H.-S. Lee, T. K. Kwon, and S. C. Kim
Hepatoprotective Activity of Licorice Water Extract against Cadmium-induced Toxicity in Rats
Evid. Based Complement. Altern. Med., August 9, 2007; (2007) nem078v1.
[Abstract] [Full Text] [PDF]

Home page
 Jpn J Clin OncolHome page
H. Tsuda, A. Naito, C. K. Kim, K. Fukamachi, H. Nomoto, and M. A. Moore
Carcinogenesis and Its Modification by Environmental Endocrine Disruptors: In Vivo Experimental and Epidemiological Findings
Jpn. J. Clin. Oncol., June 1, 2003; 33(6): 259 - 270.
[Abstract] [Full Text] [PDF]

Home page
 CarcinogenesisHome page
K. Oyama, G. Shiota, H. Ito, Y. Murawaki, and H. Kawasaki
Reduction of hepatocarcinogenesis by ursodeoxycholic acid in rats
Carcinogenesis, May 1, 2002; 23(5): 885 - 892.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Cancer Res.Home page
S. Maruyama, N. Nagasue, D. K. Dhar, A. Yamanoi, O. N. El-Assal, K. Satoh, and K. Okita
Preventive Effect of FK143, a 5{{alpha}}-Reductase Inhibitor, on Chemical Hepatocarcinogenesis in Rats
Clin. Cancer Res., July 1, 2001; 7(7): 2096 - 2104.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (21)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Shiota, G.
Right arrow Articles by Kawasaki, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shiota, G.
Right arrow Articles by Kawasaki, H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?