Ginseng Metabolism Study using Hybrid Quadrupole Linear Ion Trap (QqLIT)

Herbal medicines are gaining popularity all over the world. Ginseng is one of the most commonly used herbal remedies. Ginsenosides are the major active ingredients in ginseng and have shown pharmacological benefits to human health because they appear to affect multiple pathways. The work presented here demonstrates the ability of the hybrid Quadrupole linear ion trap (QqLIT) mass spectrometer; QTRAP 5500^® and LightSight^® software for the rapid identification of metabolites using positive and negative ion detection. Adult male Zucker rats were dosed daily with Ontario-grown North American ginseng by oral gavage for 42 days to evaluate the effect on vascular and reproductive health. For the present study, plasma was obtained at the time of sacrifice. Ginsenosides can be ionized both in positive and negative polarities; however, some ginsenosides are better detected as positive ions. Also, when using positive ionization, the ginsenosides and their metabolites are mainly detected as the sodium adduct, which makes structural elucidation difficult. Therefore, the samples should be analyzed using both polarities. A LC-MS method with polarity switching allows for all the information about metabolites to be collected from a single injection. A total of 6 ginsenosides (Rg1, Re, Rb1, Rc, Rb2 and Rd) account for over 90% of the ginsenosides content in ginseng root which reduces the complexity of the analysis. Some of the mechanisms identified and characterized include oxidation, glucuronidation and loss of glucose moieties. The software allows for detection and structural elucidation using both the positive ion and negative ion data.