Introduction: Three plants, Equisetum diffusum D. Don. (KT03 – whole plant), Glochidion eriocarpum Champ. ex Benth. (KT05 – whole plant), Clerodendrum cyrtophyllum Turcz. (KT07 – branches and leaves), grown in Northern Vietnam, are used for the treatment of stomachache, diarrhea, dysentery, gastralgia, pharyngitis and healing of insect wounds in traditional Vietnamese medicine. The purpose of this study is to examine the cytotoxicity of extracts of these three medicinal plants via MTT assay. This study is part of a project aiming at (i) evaluating the safety of Vietnamese traditional medicines; and (ii) their eventual interest in drug discovery.
Methods: These medicinal plants were collected in autumn in the Northern provinces of Vietnam then air-dried and powdered. The samples were extracted at room temperature, sequentially with solvents of increasing polarities: n-hexane, ethyl acetate and finally methanol. The cytotoxicity of the 12 obtained extracts was tested using MTT assay on two cell lines: non-cancerous epithelial intestinal cells (FHs74 Int) and epithelioid cervix carcinoma cells (Hela).
Results: The ethyl acetate extract of branches of Clerodendrum cyrtophyllum Turcz. (KT07) showed the highest toxicity towards FHs74Int (IC50 = 0.39 mg/mL) and Hela (IC50 = 0.27 mg/mL) cell lines. The methanolic extract of Glochidion eriocarpum Champ. ex Benth. (KT05) showed cytotoxicity against non-cancerous epithelial intestinal cells (IC50 = 0.48 mg/mL) and Hela cells (IC50 = 0.56 mg/mL). We also found that the ethyl acetate extract of KT07 leaves is more cytotoxic towards intestinal cells FHs74 Int (IC50 = 0.60 mg/mL) than Hela cells (IC50 = 1.89 mg/mL).
Conclusions and perspectives: The ethyl acetate extract of KT07 branches has the potential to be considered for anti-cancer research. In the next steps, this extract will be studied for its cytotoxic activity on further cell lines and the active compounds will be identified.