In Vitro Bioassays For Standardization Of Immune Enhancing Dietary Supplements

Immune enhancing botanicals and their derived extracts can exhibit substantial variation in the level of their chemical constituents and this has contributed to a lack of consistent product quality. Attempts to solve this product quality control problem using chemical standardization methods has had limited success because physiochemical properties cannot fully predict the biological potency of the high molecular weight substances that are typically responsible for the immune enhancing effects of these supplements. We have set-up three in vitro bioassay systems capable of quantitating the activity/potency exhibited by different high molecular weight components that activate macrophages (substances from endophytic bacteria, polysaccharides and inflammasome activators). The appropriate bioassay standardization methods have been defined for the following 8 dietary supplements: alfalfa herb (Medicago sativa), American ginseng root (Panax quinquefolius), Asian ginseng root (Panax ginseng), Echinacea purpurea root, ginger root (Zingiber officinale), green tea leaves (Camellia sinensis), Spirulina (Arthrospira platensis) and beta glucan from S. cerevisiae. Commercialization of these bioassay services will provide a technology to quantitate the potency of immune enhancing dietary supplements so that these products can be manufactured to exhibit consistent therapeutic properties for consumers and for use in clinical trials.

Acknowledgements: This research was partly funded by NIH NCCIH 1R41AT008772 – 01 (STTR Phase I) and by the USDA, ARS Specific Cooperative Agreement No. 58 – 6408 – 1-603.