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

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.

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).

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 (ED50) 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.

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.