Two ellagic acids isolated from roots of Sanguisorba officinalis L. promote hematopoietic progenitor cell proliferation and megakaryocyte differentiation

Abstract

Using a bioassay-directed chromatographic separation, two ellagic acids were obtained from the ethyl acetate extract of the roots of Sanguisorba officinalis L. On the basis of chemical and spectroscopic methods, the two ellagic acids were identified as 3,3',4-tri-O-methylellagic acid-4'-O-β-d-xyloside and 3,3',4-tri-O-methylellagic acid. Stimulation of cell proliferation was assayed in hematopoietic progenitor cells using the Cell Counting kit-8 method. The megakaryocyte differentiation was determined in human erythroleukemia (HEL) cells using Giemsa staining and flow cytometry analysis. The ellagic acids significantly stimulated the proliferation of Baf3/Mpl cells. Morphology analysis and megakaryocyte specific-marker CD41 staining confirmed that the ellagic acids induced megakaryocyte differentiation in HEL cells. This is the first time that 3,3',4-tri-O-methylellagic acid or 3,3',4-tri-O-methylellagic acid-4'-O-β-d-xyloside are reported to induce megakaryopoiesis, suggesting a class of small molecules which differ from others non-peptidyl, and appears to have potential for clinical development as a therapeutic agent for patients with blood platelet disorders.

Figure 1

Structure of compound 1.

Figure 2

Structure of compound 2.

Figure 3

Compounds promote the proliferation of Baf3/Mpl cells. (A) Compounds 1 and 2 stimulate cell proliferation in a dose-dependent manner. (B) Compounds 1 and 2 stimulate cell proliferation in a time-dependent manner. Results are representative of at least three independent experiments run in triplicate and expressed as the mean ± SD.

Figure 4

Compounds induced megakaryopoiesis in HEL cells. (A) Light microscopy shows that the image of megakarycytes (control and compound 1, left and right respectively) stained by Giemsa; (B) The percentage of megakaryocytes was determined on the basis of the number of endomitosis. Results are representative of at least three independent experiments run in triplicate and expressed as the mean ± SD.

Figure 5

Flow cytometric analysis of HEL cells stained with anti-CD41-PE. Histogram plot (left panel) and dot plot (right panel) show the percentage of CD41⁺ cells. Data represent one experiment of two independent experiments. (A) Control (DMSO); (B) Compound 1 (20 μg/mL); (C) Compound 2 (20 μg/mL).