Inhibitory Effect of Sarcophytol A on Development of Spontaneous Hepatomas in Mice

The inhibitory effect of sarcophytol A, a cembrane‐type diterpene isolated from a marine soft coral, Sarcophyton glaucum, on development of spontaneous hepatomas was investigated in C3H/HeNCrj mice. A total of 80 mice were divided equally into two groups. The experimental and control groups were given basal diets with and without 0.01% sarcophytol A, respectively. At week 65 of the experiment, mice were examined for hepatomas. The percentages of hepatoma‐bearing mice of the subgroup with three or more tumors and the tumor diameters of the group treated with sarcophytol A were smaller than those of the control group. Ridit analysis revealed that these differences were statistically significant. The body weight gain, and the food intake were not significantly different between these two groups. Analysis of blood serum revealed that feeding the diet containing 0.01% sarcophytol A for 65 weeks did not show any adverse effects. These results suggest that sarcophytol A inhibits the development of spontaneous hepatomas without toxicity, and should he considered as a possible cancer chemopreventive agent for hepatomas in humans.