Abstract
BACKGROUND: Breast cancer is the most common cancer in women which can be cured in most individuals with early-stage non-metastatic disease. Imbalance in estrogen signaling pathways and propagating levels of estrogens has important roles in breast cancer development. Targeting the estrogen receptor signaling pathway is linked to breast cancer treatment. Royal jelly is one of the bee products containing 10-hydroxy-2-decenoic acid, a structure similar to mammalian estrogen, allowing it to attach to estrogen receptors. It is considered as a general tonic and immunomodulator which may be helpful in reducing the side effects of cancer treatments. Currently, there are controversial data regarding the pros and cons of royal jelly in cancer. Here we provide an overview of the effects of royal jelly on sex hormones and its possible role in breast cancer. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched with the search terms royal jelly, cancer, and sexual hormones. All preclinical and clinical studies regarding the hormonal effects of royal jelly were included. RESULTS: According to the collected preclinical data, consumption of royal jelly at daily doses below 200 mg/kg can be useful to decrease the risk of breast cancer since it reduces the serum level of estrogen; whereas increases progesterone, which subsequently decreases the expression of ERs on the ER-positive cells. CONCLUSION: Future clinical studies are essential to confirm the safe dose of royal jelly as an adjuvant therapy in breast cancer.