Protective effects of Lycopene on hepatocarcinogenesis in Long-Evans Cinnamon rats

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10670480
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Gastroenterology
• Research Institution: Kagawa Medical University
• Principal Investigator: WATANABE Seishiro Kagawa Medical University, School Hospital, Lecturer, 医学部・附属病院, 講師 (00158635)
• Co-Investigator(Kenkyū-buntansha): ARIMA Keiji Kagawa Medical University, Undergraduate School of Medicine, Assistant, 医学部, 助手 (50212650) ; NISHIOKA Mikio Kagawa Medical University, Undergraduate School of Medicine, Professor, 医学部, 教授 (30034937)
• Project Period (FY): 1998 – 1999
• Keywords: Hepatocellular carcinoma / Experimental carcinogenesis / Lycopene / Syo-saiko-to / LEC rat / Differentiation of tumor

Research Abstract

A high incidence of hepatocellular carcinoma (HCC) in long surviving Long Evans Cinnamon (LEC) rats was reported. In order to investigate whether Lycopene and Sho-saiko-to (TJ-9) have anti-hepatocarcinogenesis, Lycopene and TJ-9 were administered orally for one and a half years in LEC rats and studied the effect to natural hepatocarcinogenesis of these rats. All rats were sacrificed in 76 week life for autopsy and histopathological examination was performed. Fifty five percent (1 1/20) of control rats had HCC, 55% (11/20) of Lycopene group had HCC, and, 75% (12/16) of TJ-9 group had HCC in 76 week life. Percentage of HCC bearing rats did not differ among the three groups. Number of preneoplastic lesions stained with GST-P per lcmィイD12ィエD1 of the liver specimen was smaller in Lycopene group compared with control group (p = 0.00124) . Concentration of iron ion in the liver of Lycopene group were lower compared with TJ-9 group (p=0.0207). Concerning the report that iron deprivation also inhibited the liver tumor development, the finding of lower concentration of iron ion in the liver of Lycopene group compared with TJ-9 group has a possibility to have some link to the result of lower number of preneoplastic lesions stained with GST-P. Serum α-fetoprotein levels were 331.0 ± 249.1 ng/ml in control groups (n=9), and 559.4 ± 1211.4 ng/ml in Lycopene group (n=11), and 5883 ± 653.4 ng/ml in TJ-9 group (n=11). There were no differences in serum α-fetoprotein levels among the three groups. In conclusion, anti-hepatocarcinogenesis were not foud in Lycopene and TJ-9. Further study will be needed to clarify the preventive effect of preneoplastic lesions by Lycopene.