Gintonin is a novel ginseng-derived
G protein-coupled
lysophosphatidic acid (
LPA) receptor ligand.
Gintonin elicits an [Ca(2+)]i transient in animal cells via activation of
LPA receptors. In vitro studies have shown that
gintonin regulates various
calcium-dependent
ion channels and receptors. In in vivo studies,
gintonin elicits anti-
Alzheimer's disease activity through the activation of the non-amyloidogenic pathway and anti-metastatic effects through the inhibition of autotaxin. However, a method for
gintonin quantitation in ginseng has not been developed. In the present study, we developed an
enzyme immunoassay (EIA) to measure
gintonin. A
monoclonal antibody was raised in a mouse using
gintonin as the immunogen, and an indirect competitive EIA was used to measure
gintonin. The working range was 0.01-10 µg per assay. The anti-
gintonin monoclonal antibody did not cross-react with the
ginsenosides Ra, Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, and Rg3 or with LPAs such as LPA C16:0, LPA C18:0, LPA C18:1, and LPA C18:2. Using a standard curve, we measured the amount of
gintonin in various ginseng extract fractions. Interestingly, we only detected a little amount of
gintonin in conventional hot water extracts of Korean red ginseng. However, we can measure
gintonin after
ethanol extraction of Korean red ginseng marc. Thus,
gintonin can be extracted from ginseng with
ethanol but not water, and the remaining Korean red ginseng marc can be used to obtain
gintonin. These results indicate that the EIA with the anti-
gintonin monoclonal antibody can be used to quantify
gintonin in various ginseng preparations, including commercial ginseng products.