Symphytum asperum

Symphytum officinale (L.), S. tuberosum, Sympytum x uplandicum Nyman (Russian comfrey, a hybrid of S. officinale and S. asperum) (Anonymous, 1995), Symphytum asperum Lepech (prickly comfrey) (USP, 1998), boneset, knitback, knitbone (Awang, 1987), consound, common comfrey, blackwort, bruisewort, slippery root, yalluc, gum plant, consolida, ass ear (Grieve, 1971)... 

Commercial comfrey is usually derived from the leaves or roots of Symphytum officinale (common comfrey) (USP, 1998). However, some products are derived from Symphytum x uplandicum Nyman (Russian comfrey) or Symphytum asperum Lepech (prickly comfrey), which appear to be more toxic than common comfrey (Anonymous, 1998). Russian comfrey and prickly comfrey contain a very toxic pyrrolizidine alkaloid (PA) called echimidine that common comfrey does not contain (Tyler, 1994). Although common comfrey does not contain echimidine, it does contain other hepatotoxic PAs. These alkaloids include 7-acetylintermedine, 7-acetyllycopsamine, their unacetylated precursors, and symphytine (Tyler, 1993). 

Symphytum asperum Lepechin SCN prickly comfrey OCN rough comfrey... 

Eutrochium fistulosum herb, root, and rhizome Eutrochium maculatum herb, root, and rhizome Eutrochium purpureum herb, root, and rhizome Symphytum asperum leaf, root Symphytum officinale leaf, root Symphytum x uplandicum leaf, root Tussdago farfarc flower, leaf. 

Plants containing 1,2-dehydro-pyrrolizidine alkaloids may cause liver necrosis to domestic animals and humans. Therefore, care must be taken not to consume plants that are known to contain pyrrolizidine alkaloids, such as the flower stalks of Petasites japonicus (Asteraceae),comfrey Symphytum officinale (Boraginaceae), and Borago officinalis (Boraginaceae). Lycopsamine was isolated as a main alkaloid of Russian comffey (a hybrid of S. officinale and Symphytum asperum) [5]. 

Accumulation of Alkaloids in Symphytum asperum Dependent on the Phase of... 

Borago officinalis Pulmonaria spp. Symphytum officinale S. asperum S. X upland1cum... 

A number of recent studies of the pyrrolizidine alkaloids in various Symphytum species have succeeded in characterizing twelve mono- and di-ester alkaloids of retronecine and hellotridine (31, 95-104). We have examined twelve samples each of comfrey root and leaf sold as herbs in the U.S. As determined by nmr, the total alkaloid content of the leaf samples was < 0.005% the roots, on the other hand, contained from 0.14-0.42% (130). Examination of the root alkaloid mixture by capillary gc-ms after derivatization allowed identification of seven alkaloids (Figures 4 and 7) in all of the samples the first four peaks, lycopsamine, intermedlne, and their 7-acetyl derivatives, accounted for 75% or more of the total alkaloids. The same seven alkaloids have been found in Russian comfrey, a cross between Symphytum officinale and asperum, sometimes called Symphytum X uplandIcum (31,96,104). 

Huizing, H.J., T.W.J. Gadella, and E. BQiphuis. 1982. Chemotaxonomical investigations of the Symphytum officinale jxjlyploid complex and S. asperum (Boraginaceae) The pyrrolizidine alkaloids. Plant Sys. Evol. 140(4) 279-292. 

Symphytum uplandicum is a hybrid of S. asperum and S. officinale (Culvenor et al. 1980). 

Source Symphytum officinale L. Symphytum X uplandicum Nym. S. asperum Lepechin. (Family Boraginaceae). 

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