Natural Health Products from North American Hawthorns

Hawthorns (Crataegus L., Rosaceae) have well-established uses in natural health products (NHPs), and a handful of Eurasian species have demonstrated efficacy in treating symptoms of chronic heart failure. Until recently, however, almost nothing was known about the NHP potential of native North American hawthorns, of which approximately 50 occur in Canada. We seek to lay the foundation for the agroforestry exploitation of native hawthorn species by developing methods for the analysis, traceability, and authentication of NHPs derived from Canadian hawthorn species by using DNA barcodes and microsatellite fingerprints, by deploying new methods of chemical analysis, and by developing and optimizing methodologies to aid in their production. Because little is known about either hawthorn NHP functional components or their mode of action, this project will document these aspects by seeking to (1) confirm heart and cardiovascular protective properties in an established rodent model and (2) elucidate their mode of action. Field collections of Pacific Northwest hawthorns comprise most of the taxa known from the region and demonstrate (by means of flow cytometry) the predominance of polyploidy and gametophytic apomixis in all except a limited number of diploid C. suksdorfii. ITS2 is the only DNA barcode locus to yield species-level resolution, but its use as a barcode is complicated by paralogy and by the occurrence of hybridization and polyploidy in many Crataegus species. A UPLC (ultra-fast high performance liquid chromatography) method for the detection and quantification of hyperoside and the vitexins has been developed and used to quantify these metabolites in a total of 131 samples, of which approximately 60% were leaf and flower samples, and the remainder fruit samples. NMR methods have been developed that enable us to analyze trend data from flowers through fruits, in both native British Columbia species in different clades and in a naturalized Eurasian species. These methods are also being used to characterize commercial products made from and containing hawthorn leaf, flower, and/or fruit.  These are produced using the Eurasian species, and comparisons between them, the Eurasian species, and the North American species will provide information as to the differences and similarities between them. A farm trial employing North American and Eurasian species is underway and demonstrates the feasibility of cultivation as an alternative to wildcrafting. North American hawthorn species are comparable to Eurasian ones with respect to the kind and quantity of compounds associated with therapeutic activity. Morphological and molecular methods will permit us to characterize taxa; it remains to be seen to what extent individual genotypes, of interest because of their chemical content, can be distinguished by molecular fingerprints or other means.