Department of Cell and Molecular Biology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street BSB 222, Honolulu, HI 96813, USA.
The incidence of breast cancer among women is high and increasing. This study investigated the inhibitory effect of an extract from bamboo Phyllostachys edulis on the development of 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer in female Sprague-Dawley rats. The rats were fed with bamboo extract (BEX) supplemented diet or control diet, and treated with DMBA after 3 weeks of the dietary regime. The incidence of mammary tumors was monitored by palpation for the next 11 weeks. At the end of the experiment, blood samples were collected for total antioxidant capacities (TAC) assay and liver samples for phase II enzyme activity assays. The TAC values, total contents of phenolics and flavonoids of BEX were also measured. The results showed that BEX delayed the onset of mammary tumor by 1 week, decreased the tumor incidence by 44% and tumor multiplicity by 67%, and increased the total sulfotransferases (SULT) activity by 63%. BEX showed high levels of TAC, total phenolic and total flavonoids. However, the serum TAC values were not affected by BEX supplementation. In summary, the results indicate that BEX possesses a potent anti-breast cancer effect, and the upregulation of SULT activity, therefore estrogen metabolism may be the underlying mechanism.