Apigenin is a flavone found in foods such as parsley, celery and Chinese cabbage. Diets with a high proportion of food sources of apigenin have been linked to reduced risk of breast cancer. Cell studies have demonstrated that apigenin has anti-cancer activities, especially against estrogen receptor negative (ER-) and HER2/neu overexpressing (HER2+) breast cancer. However, apigenin can act both as an estrogen and as an anti-estrogen depending on the dosage, and can actually stimulate the growth of estrogen receptor positive (ER+) breast cancer cells under some circumstances. Now a new study has demonstrated how apigenin induces programmed cell death in HER2+ breast cancer cells.
Apigenin and chemotherapy
Apigenin has been found to enhance the effectiveness of Taxol and 5-FU chemotherapy regimens, as well as to increase the sensitivity of breast cancer cells to radiation treatment. However, apigenin was found to reduce the cytotoxicity of Adriamycin in a study using leukemia cells. This finding indicates that apigenin has varying interactions with different types of chemotherapy and cannot be assumed to be universally beneficial.
Foods containing apigenin
The following foods are excellent or very good sources of apigenin and have also been associated with reduced risk of breast cancer:
- Parsley, both dried and fresh
- Celery, especially green celery hearts
- Bell peppers
- Chinese cabbage or bok choy
Obtain apigenin through food not supplements
Apigenin is a phytoestrogen whose interactions with breast cancer are still not well understood. There is some evidence that the influence of apigenin on breast cancer cells depends on the dosage, with low doses potentially stimulating breast cancer cell growth. When apigenin is consumed as part of food, it is combined with other micronutrients that have been shown to act synergistically against breast cancer. Consuming apigenin-rich foods is safe and can potentially reduce the risk of breast cancer and recurrence. On the other hand, safe and effective dosages of apigenin supplements have not been established. One study found that high doses of apigenin can cause liver damage in mice. Based on the available evidence, compared to consuming it as part of foods in the diet, supplementation with apigenin appears to be unwise.
Latest research shows how apigenin affects HER2+ breast cancer cells
The study referenced at the beginning of this news article was designed to investigate the effects of apigenin on the proliferation and apoptosis (programmed cell death) of MDA-MB-453 breast cancer cells. MDA-MB-453 cells are ER-/PR-/HER2+, like most HER2+ tumors. The authors used proliferation, MTT and ELISA assays, Western blotting, RT-PCR, and immunocytochemistry to conduct their analyses.
Apigenin was found to inhibit the proliferation of MDA-MB-453 cells. Apigenin also induced apoptosis and blocked the activation (phosphorylation) of JAK2 and STAT3. In addition, apigenin inhibited VEGF secretion and decreased the nuclear staining of STAT3. The authors conclude that apigenin induces antiproliferative activity by inhibiting STAT3 signaling. Apigenin could serve as a useful compound to prevent or treat HER2+ breast cancer, according to the authors.
Please see our articles on breast cancer diet for HER2+ patients and survivors and the prognosis of HER2+ breast cancer for more information.