**Author details**

530 The Complex World of Polysaccharides

In addition to the well-recognized immuno-stimulatory activity of ginseng, an antiinflammatory effect was shown in the present study as reflected in the reduced responsiveness of alveolar macrophages collected from ginseng-treated animals to LPS challenges *ex vivo* (Figure 10). This apparent anti-inflammatory effect of ginseng PS is different from what we have previously reported for a specific component(s) of the alcoholic extract of American ginseng as well as the anti-inflammatory effects that have been ascribed to some ginsenosides and their metabolites [6, 21-22]. This potential anti-inflammatory mechanism is being validated by evaluating changes in LPS–induced inflammatory response following polysaccharide pretreatment *in vivo* in our on-going research. The intent is to determine whether ginseng PS causes desensitization of immune cells as reported for LPS [23]. This action of ginseng, when proven, may be particularly relevant to bacterial infection and related toxicemia. An anti-inflammatory effect of ginseng polysaccharide has been reported by Zhao et al. using a model of auto-immune disease, as evidenced by the reduction in the expression of TNF-α and IFN-γ in lymphocytes in the enteric mucosal immune system of rats with collagen induced arthritis [24]. In view of the diverse immunomodulatory effects of ginseng polysaccharide, the identification of specific

polysaccharides with unique property and biological action will be of great interest.

by suppressing LPS activation of macrophages.

characterize their structures.

It appears that AQ and PS ginseng extracts have a paradoxical effect on macrophage function: stimulation under normal condition, but reduction when the biological system is under a pro-inflammatory state. In the context of sepsis, AQ and PS immuno-stimulatory effect will be beneficial as a first line of defense during the initial infection stage of bacterial infection by rendering macrophages to be cytotoxic [25] whereas the immune-suppressive activity may be effective in antagonizing the cytokine storm at the later stages of infection

Carbohydrates analysis represents a major challenge in analytical chemistry since neutral or acidic saccharides (mono, oligo and poly) have little UV activity. The refractive index (RI) detector, which is commonly used in HPLC analysis, has issues with baseline stability and sensitivity. The ELSD used in the present study has the advantage of its independence of any optical properties in the solutes of interest. Our HPLC-based analysis allowed the measurement of 7 mono-saccharides within a 30 minute total run time. The monosaccharide composition of *P. quinquefolius* reported in this study was similar to that described previously [3] with the addition of galacturonic acid. The monosaccharide composition provides insight into the types of polysaccharides which may be found in *P. quinquefolius*. Polysaccharides structures in *P. quinquefolius* have not previously been thoroughly studied, though several polysaccharides have been isolated from *P. ginseng* and *P. notoginseng*. Glucose and galacturonic acid were the most prominent monosaccharides detected. Previously, polysaccharide fractions from *P. ginseng* with high levels of glucose have been determined to contain starch-like glucans and arabinogalactans and fractions with high levels of galacturonic acid have been shown to contain pectins with several linked galacturonic acid domains [26]. It is possible that polysaccharides similar to these may be present in Ontario-grown American ginseng though further work will have to be done to

Edmund M. K. Lui\* , Chike G. Azike and Hua Pei *Ontario Ginseng Innovation and Research Consortium Department of Physiology & Pharmacology, Schulich School of Medicine and Dentistry, Canada* 

José A. Guerrero-Analco and John T. Arnason *Ontario Ginseng Innovation and Research Consortium Department of Biology, University of Ottawa, Ottawa Ontario, Canada* 

<sup>\*</sup> Corresponding Author

Ahmad A. Romeh *Department of Chemical and Biochemical Engineering, Faculty of Engineering, University of Western Ontario, London Ontario, Canada* 

Sherif J. Kaldas *Department of Biology, University of Ottawa, Ottawa Ontario, Canada* 

Paul A. Charpentier *Ontario Ginseng Innovation and Research Consortium, Department of Chemical and Biochemical Engineering, Faculty of Engineering, University of Western Ontario, London Ontario, Canada* 
