Flor-Essence® herbal tonic does not inhibit mammary tumor development in Sprague Dawley rats

Background: Women who are diagnosed with breast cancer often self-administer complementary and alternative medicines to augment their conventional treatments, improve health, or prevent recurrence. Flor-Essence ^® tonic is a complex mixture of herbal extracts used by cancer patients because of anecdotal evidence that it can treat or prevent disease. Methods: Female Sprague-Dawley rats were given water or exposed to 3 or 6% Flor-Essence ^® beginning at 1 day of age. Mammary tumors were induced with a single oral 40 mg/kg/bw dose of dimethyl-benz[a]anthracene at 50 days of age and sacrificed at 23 weeks. Rats were maintained on AIN-76A diet. Results: Control rats had palpable mammary tumor incidence of 51.0% at 19 weeks of age compared to 65.0 and 59.4% for the 3 and 6% Flor-Essence ^® groups respectively. Overall, no significant difference in time until first palpable tumor was detected among any of the groups. At necropsy, mammary tumor incidence was 82.5% for controls compared to 90.0 and 97.3% for rats consuming 3 and 6% Flor-Essence ^®, respectively. Mean mammary tumor multiplicity (±SES) for the controls was 2.8 (±0.5) and statistically different from the 3 or 6% Flor-Essence ^® groups with 5.2 (±0.7), and 4.8 (±0.6), respectively (p £ 0.01). As expected, the majority of isolated tumors were diagnosed as adenocarcinomas. Conclusions: Flor-Essence ^® can promote mammary tumor development in the Sprague-Dawley rat model. This observation is contrary to widely available anecdotal evidence as well as the desire of the consumer that this commercially available herbal tonic will suppress and/or inhibit tumor growth.