Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices.

Farrukh Aqil,Srivani Ravoori,David Schultz,Manicka Vadhanam,Radha Munagala,Jeyaprakash Jeyabalan,Ramesh Gupta

doi:10.3390/ijms18020425

Abstract

Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (w/w) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control group. At the end of the study (25 weeks), the tumor incidence was 96% in the control group compared with only 70% in the caraway group. A significant reduction in tumor volume (661 ± 123 vs. 313 ± 81 mm3) and tumor multiplicity (4.2 ± 0.4 vs. 2.5 ± 0.5 tumors/animal) was also observed in the caraway group compared with the control group. Together, our data show dietary caraway can significantly delay and prevent the hormonal mammary tumorigenesis by modulating different cellular and molecular targets.

Highlights

An estimated 252,710 new cases of invasive breast cancer will be diagnosed in 2017 [1]
The favorable modulation of all of the three biomarkers related to proliferation we studied, proliferative cell nuclear antigen (PCNA), cyclin D1, and estrogen receptor α (ERα) suggests that dietary caraway can be an effective chemopreventive approach in high risk groups and cancer survivors
Sections of the mammary tissues were stained with hematoxylin and eosin (H&E) or proliferating cell nuclear antigen (PCNA) using Zymed PCNA kit (Invitrogen Co., Carlsbad, CA, USA) following manufacturer’s guidelines as described previously [55]

Summary

Introduction

An estimated 252,710 new cases of invasive breast cancer will be diagnosed in 2017 [1]. New molecular breast imaging (MBI) technology [7] can readily detect small tumors or suspected tumors in dense breast tissue and add more women to the “watch and wait” list, while increased genetic testing can identify women with BRCA1 and BRCA2 mutations that elevate risk for developing BC [8]. Prophylactic mastectomy can reduce the risk of developing BC by nearly 90% for women with these genetic mutations [9,10,11] It is not known whether this risk reduction translates into longer survival for the patient [11]. Because breast cancer is a major health problem for all women, effective prophylactic prevention strategies are an attractive addition to the established roles of early screening, detection, and treatment

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Discussion

Conclusion