[Cytotoxic and transforming activities of salted fish stocks on C3H 10T 1/2 CL8 cells].

ABSTRACT

Epidemiological case-control study had shown that consumption of salted fish might be a causative factor for human nasopharyngeal carcinoma. In order to test this hypothesis, salted fish extract was studied by C3H 10T 1/2 CL8 cell transformation system. Neither cytotoxicity nor transformation effect was found in the solvent control, but a definite dose-response relation was obtained using relative transformation index when the cells were treated with 0.025-2.000 micrograms/ml 3-methylcholanthrene in the positive control. Current study showed that in the salted fish extract, dose-response relation in cytotoxicity was present in twelve fractions and transformation index significantly increased in five fractions. The maximum relative transformation indices in dichloromethane-methanol, hexane and acetone extract fractions from Murihura croaker were 15.38, 7.69 and 4.29, respectively; and those of dichloromethane-methanol and hexane extract fractions from Sudyoke croaker were 21.69 and 7.69, respectively. In addition, one type-III-focus of cell transformation was found in dichloromethane-methanol fraction and another in acetone fraction of Murihura croaker. In conclusion, there must be more than one carcinogen in the salted fish.