Investigation of the Relationship Between Brown HT Dye Exposure and Mammary Tumor Development in Female Rats: An Assessment of the Potential Risk of Breast Cancer.

Background:  Azo dyes featuring one (monoazo) or several intramolecular NQN bonds are utilized in the food, pharmaceutical, and textile industries. The food azo dye chocolate brown HT (E155) adversely affects hepatic and renal function upon prolonged consumption. This study aimed to assess the carcinogenic potential of E155 in the development of mammary tumors and breast cancer.

Methods:  A total of 20 female Long-Evans rats (eight to nine weeks old) were randomly assigned to five groups, each consisting of four rats. The control (female control) group received a regular diet, whereas the positive control (female positive control) group received 7,12-dimethylbenz(a)anthracene. The remaining three groups received 200, 400, or 600 mg/kg body weight (BW)/day E155 for 40 weeks. Tumor development, BW, and biochemical, hematological, and histological data were monitored.

Results:  BW decreased significantly with increasing dosages in the female moderate dose (FMD) group. Blood counts indicated potential microcytic anemia and inflammation in the treatment groups, especially in the female high-dose (FHD) group. E155 dose-dependently impaired renal function and increased blood creatinine and uric acid levels. Elevated serum glutamic pyruvic transaminase (SGPT) and serum glutamic-oxaloacetic transaminase levels indicate abnormal liver function. FHD animals had more tumors and larger sizes. Higher alpha-fetoprotein (AFP) and cancer antigen levels were detected even at low doses. Histopathological analysis revealed that E155 causes mammary gland fibroadenomas, ductal carcinoma in situ, and hyperplasia. It also causes circular layer granulomas, fibrosis, and crypt abscesses in the intestines of FMD and FHD.

Conclusion:  The current study suggests that prolonged exposure to E155 may result in a higher incidence of mammary tumors, indicating an elevated risk for the onset of breast cancer.