F. Goldenseal
Goldenseal (Hydrastis canadensis) is a member of the Ranunculus family that is native to the North
American continent [31,38]. This plant is a herbaceous perennial that grows primarily in damp areas
that are shaded, such as low areas in forested regions [31,40,41]. Goldenseal has a short horizontal rhi-
zome with multiple slender roots, and it is the rhizome that serves as the source for production of the
phytomedicinal [41]. The use of goldenseal as a medicinal plant originated with Native American
tribes, primarily the Cherokee peoples [12,31]. In addition to its use as a medicine for infection and res-
piratory problems, goldenseal rhizome was used for production of a bright gold dye used for clothing
[31,40,41].
Current interest in goldenseal is related to its use for infections such as upper respiratory infections
[40,42]. Often, goldenseal is used in conjunction with Echinaceafor treatment of symptoms related to
colds and flu [42]. Despite wide interest in its use as an antimicrobial agent, relatively little work has
been conducted on this plant. As yet, the pharmacological activity of this medicinal plant has not been
demonstrated in any well-constructed clinical trial [42]. Hence, most evidence for the beneficial effects
of this medicinal plant for infections such as respiratory illness is anecdotal. However, from the limited
in vitro studies that have been conducted, the isoquinoline alkaloids, berberine and hydrastine, would
appear to play a major role in the pharmacological activity of this medicinal plant (Figure 6). These
compounds have strong antibacterial action against many organisms including Staphylococcus, Strep-
tococcus, Salmonella, and Proteus[12]. Although it has also been claimed that goldenseal has im-
munostimulatory activity similar to that of Echinacea(Ref. 42 and references therein), this has never
been confirmed.
PHYTOMEDICINAL CHEMICAL PRODUCTION BY PLANTS 493
Figure 5 Examples of immunostimulating phytochemicals present in Echinaceaextracts. (Adapted from
Refs. 12 and 21.)