Active component composition and efficacy variability in North American ginseng

North American Ginseng has a history of use by indigenous peoples of North America and has been harvested for export from the wild in Canada since the 1700's as well as grown commercially under artificial shade since the 1930 s. As it is a protected species in Canada, there is not a wild source of the plant available for commercial use and the commercial crop consists largely of collections of producer-maintained land races. It is grown mostly on the sandy loam soils of southern Canada and surveys of the root product from that area since 2007 have shown wide variation in root composition and the efficacy of immune-stimulatory and anti-oxidant activities in in vitro assays. As this crop is valued for its neutracetical properties, the high degree of variability is of concern for producers, natural health practitioners and consumers. The long reproductive cycle of ginseng has been prohibitive to the development of genetically superior and predictable-performance cultivars and the genetic basis of this unimproved crop is believed to be the primary reason for the variability in the root product. A clonal propagation protocol was developed and used to produce lines from “heritage” seed collections and clonal lines have been grown in the field since 2009. These clonal lines show potential for superior cultivar development. Ginsenosides are the widely recognised active component in ginseng and six forms make up the majority of the ginsenoside content; this content has been observed to vary from 1% to 11% in mature commercial root. Evaluation of the anti-oxidant activity using an ORAC assay adjusted to Gallic Acid Equivalents revealed a 4-fold range difference in individual lines grown under commercial field conditions and assessment of the immune-stimulatory response in clonal lines also showed a 9-fold range difference of activity. Assessment of 1- to 6-year old clonal lines confirmed that there is a strong genetic component responsible for the observed variability.