Lack of a Significant Effect of Arctiin on Development of 7,12-dimethylbenz(a)anthracene-induced Mammary Tumors in Ovariectomized Sprague-Dawley Rats

Abstract:

Arctiin, a plant lignan, is metabolized to hormone-like compounds with weak estrogenic and antioxidative activity in experimental animals and man. To clarify its influence on mammary carcinogenesis, female rats were administrated 7,12-dimethylbenz(a)anthracene (DMBA) once, and when the incidence of palpable mammary tumors reached 50%, subjected to ovariectomy (OVX) and divided into tumor-bearing [DMBA-Tumor (+)] and no-tumor-bearing [DMBA-Tumor (−)] groups, subgroups of each then being fed soybean-free diet containing 0, 40, 200, and 1000 ppm of arctiin for 31 wk. The incidence and multiplicity of palpable tumors in the 200 ppm DMBA-Tumor (+) subgroup from week 12 of arctiin treatment tended to be decreased as compared to the 0 ppm subgroup and at terminal sacrifice, the volume of histopathologically defined mammary tumors was decreased in the 40 ppm DMBA-Tumor (−) subgroup, but again without statistical significance. In conclusion, weak inhibitory effects of arctiin on DMBA-induced mammary tumor development were suggested in OVX rats, but any further assessment is needed to obtain conclusive results.

Acknowledgments and Notes

This study was supported by a Health Sciences Research Grant (Research on Environmental Health) from the Ministry of Health, Labour, and Welfare of Japan.

Notes

∗: Significantly different from the Tumor(−)-0 ppm group at p < 0.05 (Fisher's exact test).