Agriculture Reference
In-Depth Information
Ethnomedicinal Uses —
Aspalathus linearis
is a major South African medicinal plant and has
been used in the Cape region of that country for centuries. Its main uses in South African traditional
medicine include alleviating infantile colic, allergies, asthma, and dermatological problems. It has
also been used for its anti-inflammatory and antiallergic properties.
Constituents —
Rooibos is the only known source of the chalcone aspalathin. Other phyto-
chemicals found include nothofagin, caffeic acid, chrysoeriol, isoquercitrin, orientin, isoorientin,
luteolin, vitexin, isovitexin, luteolin, rutin, flavonoids, quercetin, and polyphenols.
Pharmacological Studies —
Although reports of double-blind clinical studies with rooibos
are scarce in the scientific literature, animal studies suggested it has potent antioxidant, immune-
modulating, and chemopreventive effects. Clinical outcome observations have shown that consump-
tion of rooibos tea may relieve fever, asthma, insomnia, colic in infants, and skin disorders. Rooibos
extracts are used in ointments against eczema. In South Africa, it is common to give rooibos tea to
babies who suffer from stomach cramps (colic).
The presence of quercetin and lutein has been linked to prevention of cardiovascular diseases,
some cancers, and stroke and has been supported by
in vitro
and animal studies. A trial to test
the effects of rooibos on various biological markers considered to be indicative of risk for car-
diovascular disease and other degenerative diseases has shown that a high intake of rooibos tea
resulted in significant reductions in lipid peroxidation, low-density lipoprotein (LDL) cholesterol,
and triglycerides and an increase in high-density lipoprotein (HDL) cholesterol levels compared
with the control group. The investigators concluded that rooibos lowered risk factors associated
with degenerative heart diseases.
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Rutin has been associated with the maintenance of blood ves-
sel walls. The low level of tannins in rooibos is believed to prevent problems with iron absorption
associated with some tannin-rich herbal teas. Some trade journal publications have suggested that
rooibos extracts from fermented rooibos leaves could reduce cancerous transformation of mouse
cells irradiated with X-rays, but extracts from unfermented green rooibos tea did not show this
protective effect.
According to entries in the Internet free encyclopedia, Wikipedia, rooibos is purported to assist
with nervous tension, allergies, and digestive problems. Rooibos tea has been shown to inhibit
in
vitro
activity of xanthine oxidase (XO), yet an
in vivo
study has not been conducted. XO plays a role
in conversion of purine to uric acid in humans, and reducing the activity of XO could limit uric acid
production, which would aid in treatment of gout.
Toxicity —
Rooibos is generally considered as nontoxic, but a recent report identified a pos-
sible case of hepatotoxicity due to rooibos consumption.
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However, it has been suggested that it
was possible that the tea may have been contaminated by another hepatotoxic compound or that the
person may have had a genetic predisposition to react negatively to any one of the other bioactive
properties found in the tea.
Commerce —
Rooibos is a major herbal tea from South Africa. A trade controversy surround-
ing the name
Rooibos
became a case study on the possible abuse of intellectual property rights to
gain an illegal monopoly. In 1994, Burke International obtained a patent from the U.S. Patent and
Trademark Office for the use of the name
Rooibos
, which gave the company a monopoly on the
use of the name in America at a time when it was virtually unknown in America. When the plant
later entered more widespread use, Burke demanded that companies either pay fees for use of the
name or cease its use. In 2005, the American Herbal Products Association and a number of import
companies succeeded in challenging the trademark through petitions and lawsuits, and after losing
one of the cases, Burke surrendered the name to the public domain.
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However, it is interesting that
South Africa has a legal framework for the protection and restriction of commercial use of the name
Rooibos
in that country. It has drawn parallel inferences to similar legislation that already exists in
Europe (for the protection of the names
Champagne
and
Port,
for example). This is despite Rooibos
South Africa's decision to contest the Burke trademark on the grounds that rooibos is a generic
term, rather than claiming it as a geographic indication.
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