Green Tea Polyphenol Sensitizes Breast Cancer Cells to Chemotherapy Agent
Posted Jan 15 2010 12:00am
While chemotherapy is an effective and important part of breast cancer treatment, breast cancer cells often become resistant to the chemotherapy drugs. Because of this, the discovery of agents that can re-sensitize breast cancer cells to chemotherapy is an active area of research.
Newly published breast cancer research examined the ability of epigallocatechin gallate (EGCG), a bioactive phytochemical found in green tea, to sensitize breast cancer cells to the chemotherapy drug paclitaxel in cell culture and in a mouse model of breast cancer.
In the cell culture test, the study investigators treated three different breast cancer cell types with either EGCG alone, paclitaxel alone, or a combination of EGCG + paclitaxel. Compared with paclitaxel alone, treatment of breast cancer cells with the combination of EGCG + paclitaxel resulted in a dramatic decrease in cell viability and increase in programmed cell death.
For their mouse study, the researchers injected breast cancer cells under the skin of mice and allowed tumors to develop. After the tumors were large enough to feel, the mice were treated with either EGCG alone, paclitaxel alone, or a combination of EGCG + paclitaxel. At the amounts used, neither paclitaxel nor EGCG had much effect on preventing tumor growth. However, co-treatment with EGCG + paclitaxel substantially reduced tumor growth. This reduction in tumor growth appeared to be related to programmed cell death since the index used to measure cell death was greater with co-treatment (12%) compared to either treatment alone (1.8% for EGCG alone and 4.2% for paclitaxel alone).
These study results indicate that the main bioactive phytochemical in green tea, EGCG, is capable of sensitizing breast cancer cells to a standard chemotherapy drug. These results suggest that EGCG has the potential to improve the effectiveness of standard breast cancer chemotherapy, which is great news. The dose of EGCG used in this study was 30 mg/kg of body weight. For a 150-lb person, this would translate into about 2 grams of EGCG per day. While this would probably be difficult to obtain from drinking green tea, it could be more easily obtained in capsule form. However, smaller doses were not tested in this study and future studies might show that lower amounts might also be effective. Overall, this is more good news for green tea. In addition to the benefits shown in this study, other studies have shown that drinking green tea can reduce breast cancer risk, something I discussed in an earlier blog.
To learn about other foods that can help reduce your breast cancer risk, read my book Fight Now: Eat & Live Proactively Against Breast Cancer at www.fightBCnow.com.