Tokuro Kuniyasu

Inhibitory effect of chlorogenic acid on methylazoxymethanol acetate-induced carcinogenesis in large intestine and liver of hamsters

The effect of dietary chlorogenic acid on methylazoxymethanol (MAM) acetate-induced carcinogenesis was examined in Syrian golden hamsters. The combined incidence of total large intestinal tumors from male and female hamsters, and the combined incidence of large intestinal adenocarcinomas or the incidence of the carcinomas of male or female animals of the group given a single intravenous injection of MAM acetate (20 mg/kg body wt) and then fed the diet containing 0.025% chlorogenic acid for 24 weeks were significantly lower than those of hamsters given MAM acetate alone. The numbers of hyperplastic liver cell foci in male and female hamsters given MAM acetate and chlorogenic acid were also significantly smaller than those of hamsters given MAM acetate alone. These results indicate an inhibitory effect of chlorogenic acid on MAM acetate-induced carcinogenesis in hamsters.

Enhancing effect of cholecystectomy on colon carcinogenesis induced by methylazoxymethanol acetate in hamsters

The effect of cholecystectomy on colon carcinogenesis induced by methylazoxymethanol (MAM) acetate was examined in four groups of Syrian golden hamsters. For the sexes combined, the incidences of total large intestinal neoplasms and adenomas in Group 1, which received cholecystectomy and a single intravenous injection of MAM acetate (20 mg/kg body weight), were significantly higher than those of hamsters in Group 2, which were given MAM acetate alone. The combined multiplicities of total large intestinal neoplasms from male and female hamsters, and the multiplicities of those in females of Group 1 were also significantly higher than those in animals in Group 2, respectively. No intestinal tumors were observed in hamsters in Group 3 (cholecystectomy alone) or Group 4 (untreated control). These results indicate an enhancing effect of cholecystectomy on MAM acetate-induced large intestinal carcinogenesis in hamsters