The comparative effects between the water and the ethanol extracts from Strephania venosa tuber on white blood cells

Abstract

Strephania venosa (Bl.) Spreng (S.venosa), a Thai folk medicinal plant, has been used as a Thai traditional medicine in various diseases including cancer, by boiling in water or soaking in alcohol. This study aimed to compare cytotoxic, antiproliferarive and apoptotic effects of the water and the ethanol extracts of S.venosa tuber on peripheral blood mononuclear cells (PBMCs) and T-cell leukemia (Jurkat cells). Cytotoxicity test was determined using alamarBlue reduction and trypan blue dye exclusion methods. Both extracts significantly exhibited cytotoxic effects on PBMCs in a concentration-dependent manner. The concentration at 50% inhibition (IC50) of the water and the ethanol extracts were 200 and 40 µg/ml, respectively, as determined by alamarBlue reduction assay. This result was further confirmed by trypan blue dye exclusion assay. Further study, cytotoxicity effect of S.venosa tuber extracts on Jurkat cells was determined by trypan blue dye exclusion assay. The IC50of the water and ethanol extracts were 200 and 100 µg/ml, respectively. The antiproliferative effect on mitogen-stimulated PBMCs were also compared between both extracts using MTT assay. The ethanol extract was more potent than the water extract in inhibiting phytohemagglutinin (PHA), pokeweed mitogen (PWM), and Staphylococcus protein A (SPA) stimulated PBMCs proliferation. Then, the extract-induced apoptosis was investigated by fluorescence activated cell sorting (FACS) using annexin V and propidium iodide staining. Both extracts significantly induced apoptotic cell death in PBMCs. The ethanol extract had higher potency than the water extract. Apoptosis was the predominant pattern of cell death induced by the ethanol extract. This pattern was only observed at a high concentration of the water extract These results suggested that S.venosa tuber extracts may possess anticancer action through its cytotoxicity, antiproliferation, and apoptotic induction. The ethanol extract had higher potency than the water extract in all effects. Furthermore, the ethanolic soaking solution of S.venosa appears to be more potent than the boiling water preperation when it was used in antitumor remedy. So, the caution should be addressed when it prescribed in traditional medicine.