EC-18 (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol) Exhibits the Immune Regulatory Role through HSC Differentiation of Bone Marrow Cells in Mice

EC-18 (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol) was originally isolated as a component of an extract from deer antler is traditionally used as an oriental medicine for hematopoiesis. A trace of MADG (monoacetyldiacylglyceride) could be detected in the deer antler, animal tissue, seed oils and bovine udder, which is identical to its natural source of MADG was chemically synthesized with glycerol, palmitic acid and linoleic acid. Previous study described that EC-18 has effect on the proliferation of hematopoietic stem cells (HSCs) (Biol. Pharm. Bull. 2004, 27(7): 1121-1125). Successively, we investigated the biological role of EC-18 in the differentiation of bone marrow cells into progenitor cell population in mice. EC-18 was administered daily for 1, 5 and 15 days to 6 week-aged C57BL/6 mice. Bone marrow cells of EC-18 administrated mice were collected from femurs and tibiae. Cell population was analyzed by FACs. As results, the total number of bone marrow cells was increased in EC-18 administered mice. To identify hematopoietic lineage cell population, we used lineage cocktail antibody kit including anti-mouse CD3, CD11b, CD45R, Gr-1 and TER-119. The lineages negative population contains HSCs which can self-renew and generate into all lineages of the hematopoietic system. The lineage negative cells significantly increased in time dependent manner in the EC-18-daily administrated mice. Cell population between myeloid progenitor (Lin- Sca1- Kit+) and common lymphoid progenitors (Lin- Sca1+ Kit+ IL-7R-α+) were analyzed using the antibody for Sca-1, c-Kit, IL-7R-α. The data showed that the population of myeloid progenitor cells was markedly increased rather than common lymphoid progenitor cells. In myeloid progenitor cell population, the cell population of megakaryocyte/erythrocyte progenitors (MEP) and granulocyte-monocyte progenitors (GMP) also elevated significantly. Taken together, EC-18 may have a potential role in the HSC differentiation and could be used as a therapeutic agent for anemia and neutropenia.