Biological effect of alkaloid enriched fractions and reticuline from the Stephania dielsianaY. C. Wu on promyelocyte HL-60 cell line

Stephania dielsiana Y. C. Wu is a traditional medicinal plant that, like the other species of the genus Stephania , is used in some Asian countries for the treatment of various conditions and diseases. Phytochemical studies have revealed that the species’ therapeutic activity is mainly due to isoquinoline alkaloids. This study focused on the biological effects of S. dielsiana root tuber extract, alkaloid enriched fractions and the isolated alkaloid reticuline on promyelocytic cell line HL-60. Systematic chromatographic techniques were applied to obtain three alkaloid-enriched fractions and eleven pure alkaloids from the methanolic extract of S . dielsiana root tubers. The quantities of alkaloids in the plant extract and its fractions were determined using HPLC method. The biological effects of the extract, alkaloid fractions and the reticuline were evaluated using colorimetric and flow cytometric assays. The crude extract and alkaloid enriched fractions inhibited cell growth at concentrations higher than 50 µg/ml. One of the alkaloid enriched fractions (St-2) affected the synchronicity of proliferation till day 3. Based on the quantification analysis, reticuline was found as the predominant alkaloid in this fraction with the relative content of 64.9%. Reticuline (9.5 µg/ml) modestly affected mitochondrial functions, decreased the level of phosphorylated p38 kinase in non-stimulated cells, but increased stimulus-induced p38 phosphorylation and elevated the CD11b + cells, indicative for myeloid differentiation. In conclusion, we provide evidence that reticuline derived from S. dielsiana root tubers affected growth, proliferation, apoptosis and differentiation of HL-60 cell line.