A brief method for preparation of gintonin-enriched fraction from ginseng

BACKGROUND: Ginseng has been used as a tonic for invigoration of the human body. In a previous report, we identified a novel candidate responsible for the tonic role of ginseng, designated gintonin. Gintonin induces [Ca(2+)](i) transient in animal cells via lysophosphatidic acid receptor activation. Gintonin-mediated [Ca(2+)](i) transient is linked to anti-Alzheimer's activity in transgenic Alzheimer's disease animal model. The previous method for gintonin preparation included multiple steps. The aim of this study is to develop a simple method of gintonin fraction with a high yield. METHODS: We developed a brief method to obtain gintonin using ethanol and water. We extracted ginseng with fermentation ethanol and fractionated the extract with water to obtain water-soluble and water-insoluble fractions. The water-insoluble precipitate, rather than the water-soluble supernatant, induced a large [Ca(2+)](i) transient in primary astrocytes. We designated this fraction as gintonin-enriched fraction (GEF). RESULTS: The yield of GEF was approximately 6-fold higher than that obtained in the previous gintonin preparation method. The apparent molecular weight of GEF, determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was equivalent to that obtained in the previous gintonin preparation method. GEF induced [Ca(2+)](i) transient in cortical astrocytes. The effective dose (ED(50)) was 0.3 ± 0.09 μg/mL. GEF used the same signal transduction pathway as gintonin during [Ca(2+)](i) transient induction in mouse cortical astrocytes. CONCLUSION: Because GEF can be prepared through water precipitation of ginseng ethanol extract and is easily reproducible with high yield, it could be commercially utilized for the development of gintonin-derived functional health food and natural medicine.