Flavokawain B (FKB) is a naturally occurring
chalcone that can be isolated through the root extracts of the kava-kava plant (Piper methysticum). It can also be synthesized chemically to increase the yield. This compound is a promising candidate as a
biological agent, as it is reported to be involved in a wide range of
biological activities. Furthermore, FKB was reported to have antitumorigenic effects in several
cancer cell lines in vitro. However, the in vivo antitumor effects of FKB have not been reported on yet.
Breast cancer is one of the major causes of
cancer-related deaths in the world today. Any potential treatment should not only impede the growth of the
tumor, but also modulate the immune system efficiently and inhibit the formation of secondary
tumors. As presented in our study, FKB induced apoptosis in 4T1
tumors in vivo, as evidenced by the
terminal deoxynucleotidyl transferase dUTP nick end labeling and
hematoxylin and
eosin staining of the
tumor. FKB also regulated the immune system by increasing both helper and cytolytic T-cell and natural killer cell populations. In addition, FKB also enhanced the levels of
interleukin 2 and
interferon gamma but suppressed
interleukin 1B. Apart from that, FKB was also found to inhibit
metastasis, as evaluated by clonogenic assay, bone marrow smearing assay, real-time polymerase chain reaction, Western blot, and
proteome profiler analysis. All in all, FKB may serve as a promising
anticancer agent, especially in treating
breast cancer.