Agriculture Reference
In-Depth Information
Ethnomedicinal Uses —
The dried inner bark of
Quillaja saponaria
and other related species
is used in pharmacy as an emulsifying agent. The plant is employed in folk medicine for the treat-
ment of inflammation of the mucous membrane.
Constituents —
The plant contains a mixture of saponins known as quillaja-saponin (ca. 10%).
The saponins on hydrolysis yield quillaic acid (hydroxygypsogenin) and sugar derivatives.
904
It also
contains tannins and calcium oxalate.
123
Pharmacological Studies —
Quilla bark is employed in pharmacy as an emulsifying agent. It
is also used as an expectorant, as an anti-inflammatory, and as a detergent.
220
The anti-inflammatory
and antihypercholestrolemic properties of the saponins in animals have been reported.
904,905
The saponin mixture has been shown to possess immunostimulatory properties, and it is
employed in veterinary medicine as an adjuvant for vaccines, particularly against foot-and-mouth
disease.
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The saponin was found to be a powerful adjuvant for the antibody response to strong
antigens in the mouse, eliciting both IgG
1
and IgG
2
antibody and cell-mediated immunity, which
may account for its success in experimental vaccines against parasitic protozoal diseases such as
malaria, babesiosis, and trypanosomiasis.
The exact mechanism of the immunostimulatory activity of quilla saponins has not been
determined. It has been suggested that the surface activity and surface-binding property of the
saponins may be important factors in the observed immunostimulant activity.
907,908
The target
cell in the immune system to which the saponin activity is directed is believed to be the mac-
rophage or antigen-presenting cell (APC), which is stimulated to release IL-1. It has also been
argued that quilla saponin cannot substitute for T-cell helper since the adjuvant activity of sapo-
nin for sheep red blood cells (SRBC) in the mouse is abolished by depletion of T lymphocytes.
909
It is likely that the saponins act by promoting the interaction between APCs and T cells; they
are, however, considered adjuvant for T-independent antigen and therefore may be able to boost
B-cell function directly.
910
Saponins have been shown to form ordered particulate structures of around 35-nm diameter
(i.e., about the size of a virus particle) with the surface proteins from enveloped viruses.
911,912
These
particulate structures, or immunostimulating complexes (ISCOMs) as they are called, are highly
immunogenic and contain very little saponin, thus reducing the required dose for an adjuvant
effect. ISCOM vaccines against a number of viruses have been prepared, and it is very possible
that quilla saponin may be introduced soon into human medicine. The saponin exhibits immunos-
timulant activity even when given orally.
913
RAUWOLFIA CAFFRA
Botanical Name —
Rauvolfia caffra
Sond.
Synonyms —
Rauvolfia natalensisi
Sond.,
Rauvolfia inebrians
K. Schem
., Rauvolfia ochrosi-
oides
K. Schum
., Rauwolfia foetzi
Stapf
., Rauvolfia obliquinervis
Stapf
.
Family —
Apocynaceae
Common Name —
Quinine tree
African Names —
Kiswahili: mwembemwitu, mkufi; Kimeru (Kichaegga): msesewe, mseseve,
Kisambaa: mweti; Kihehe: muveliveli; Kividuanda: mlolo; Kimassai: oljabokalyan; Kingu: mlen-
gwelengwe; Kiarusha: njavolikalia oltawakalian; Kibende: mtawentwe; Kigogo: mkongo; Kirangi:
msumai; Kikuyi: mwerere taveta; Meru: nutu; Bemba (Kaonde, Tonga): mwinbi; Kaonde (Lunda):
mototo; Lunda: mutochi; Nyanja: muyesani, mpambamvula, msabua, mvumbamvula, mwimbe
Description —
Rauvolfia caffra
is a medium-size tree with straight bole; it is slightly but-
tressed, crown dense, and much branched. It has a light brown or gray bark with irregular fissures.
The slash is cream, turning light brown, and exudes a bitter white latex. The leaves are simple,
