Effect of crude ethanolic extract of Ratchadat (Brucea amarissima) fruit on cell cytotoxicity and Wilms’ tumor 1 protein expression in K562 leukemic cell line

Abstract

Introduction: Leukemia is a hematologic cancer. It is characterized by the uncontrolled production of blood cells. It has been shown that leukemic cells overexpressed WT1 gene level compared to normal blood cells. Ratchadat (Brucea amarissima) is a herb that its fruits have been used in traditional Chinese medicine to treat malaria, amoebiasis as well as cancers.

Objective: The purpose of this study is to investigate the cytotoxicity effect of crude ethanolic Ratchadat fruit extract on K562 cells and the effect of non-cytotoxic dose on Wilms’tumor 1 (WT1) protein expression.

Materials and methods: The cytotoxicity of crude ethanolic Ratchadat fruit extract on K562 cells was determined by MTT assay. The WT1 protein levels were examined by Western blot analysis.

Results: The crude ethanolic Ratchadat fruit extract showed cytotoxic effect on K562 cells with the inhibitory concentration at 50% growth (IC50) value of 1.6±0.18 μg/mL but did not affect PBMCs. Non-cytotoxic dose (IC20) value (0.6±0.03 μg/mL) of crude extract decreased WT1 protein levels at the various time periods of 24, 48, and 72 hours by 16, 38, and 43%, respectively. In addition, at 48 hours of incubation with various doses (0.4, 0.6, and 0.8 μg/mL) could reduce WT1 protein levels by 12, 37, and 45%, respectively.

Conclusions: The crude ethanolic extract of Ratchadat fruit could induce cell cytotoxicity and reduce WT1 protein expression in a dose- and time-dependent manner. However, it did not affect PBMCs. It also exhibited strong anti-cancer properties higher than vincristine (chemotherapeutic drug) for 16.5 fold.

Bull Chiang Mai Assoc Med Sci 2014; 47(1): 45-52