| The rooibos tea plant (Aspalathus
linearis) grows only in the Cederberg mountains North
of CapeTown in South Africa. In recent times, the plant
has been recognized for its exceptional antioxidant properties.
Rooibos (pronounced "roy boss") contains 37
antioxidant Substances, and is also rich in minerals Such
as calcium and potassium.
Due to its potential health benefits,
rooibos (or "red bush") tea has become popular
throughout the world.
Not so well known is this plant's promising
effects when applied topically to the skin and hair.
In a study commissioned by a processor
of rooibos for use in cosmetic applications, and carried
out by an independent laboratory in France, rooibos
was perceived to positively affect the hair and hair
growth. In a 90 day trial, the action of a lotion containing
a broad spectrum rooibos extract was compared with a
placebo lotion without rooibos. The trial participants
were healthy men and women experiencing hair loss.
At trial end, using a videotrichogramme
that measures hair density and hair growth speed, the
laboratory noted that a significant increase in the
speed of hair growth had occurred in the participants
using the rooibos lotion. The participants were next
asked to fill in a questionnaire. When the results were
tallied, 67 percent rated their hair loss as zero or
low, 78 percent saw a low to medium improvement, 45
percent saw a low to medium regrowth of hair, and 63
percent considered their hair had become smoother and
more shiny.
While this study is not a clinical
trial, it nevertheless adds weight to anecdotal evidence
that rooibos may help reduce hair loss, increase growth
and improve the general texture and appearance of the
hair.
 |
Main growing
area of Rooibos: Cederberg Mountains around
Clanwilliam in South Africa
Botanical Family: Leguminosae
Common names:
Latin: Aspalathus linearis
English: Rooibos
French: Rooibos
German: Rotbusch |
Rooibos tea, also known as bush tea,
or Masai tea, is a totally unique South African product
of the redbush plant (Aspalathus linearis). The redbush
plant is a hardy shrub indigenous to the North Western
Cape of South Africa in the Cederberg Mountains around
Clanwilliam. The area has an average annual rainfall
of around 30cms; the soil is a pale golden sand, almost
devoid of nutrients with virtually no potassium or nitrogen.
The soil is also very acidic with a pH of about 3.8
- 4.2; a typical English loam for example is about pH
6 - 7, almost neutral. So how has the red bush survived
for so many centuries-
The secret may
lie in its extraordinarily long taproot, which
ensures that the plant is extremely drought resistant.
Even as a tiny seedling the roots can reach 30cms
into the ground (see picture), and up to 2m as
a fully-grown bush. Rooibos is also a legume and
as such it binds its own nitrogen from the sandy
soil, although it still has a very low yield and
slow growth. No fertilisation is given to the
plants, they grow in the soil as it naturally
exists, and periodically the plantations are left
fallow, allowing the soil to rest before replanting
in later years.
Rooibos or red bush tea is rapidly
growing in popularity as a result of the growing
evidence that it has no known side effects. |
 |
We now know that this remarkable plant
produces a unique beverage that is completely and naturally
caffeine free, and therefore undergoes no chemical process
to extract caffeine. It also contains on average less
than half the tannin of regular tea (Camellia sinensis).
Scientific research has also proven that rooibos is
rich in antioxidants, including the flavonoids quercetin
and luteolin, which have been shown to be both anti-spasmodic
and anti-inflammatory. Nobel Prize winning laureate
Albert Szent Gyorgy discovered bioflavonoids in the
1930's; quercetin is one of the most pharmacologically
active flavonoids. It also has a synergistic relationship
with Vitamin C, basically when combined the two together
they can enhance the efficacy of each other.
Rooibos started its life as a wild plant
and it is quite amazing that it was ever discovered.
It is one of the few plants that has made the transition
from the wild to a commercially cultivated crop; you
can still see wild Rooibos bushes growing at the side
of the road. Our Rooibos tea plants remain as they have
always been, never modified or subjected to hybridization,
indeed many of the farms continue to allow indigenous
wild plants and flowers to grow amongst the rows of
Rooibos, so maintaining a more natural and ecologically
sound environment.
Little is known about the early history
of Rooibos only that it has been used for many centuries
by the indigenous Khoisan tribes, primarily, it is believed
as a herbal medicine and as a part of their rituals.
They used a process thought to have been copied from
Malay slaves, but they were the first to harvest the
wild plants, chopping them with axes, bruising them
with hammers and leaving them to ferment in heaps before
drying them in the sun.
The following substances are listed
in the literature as actives of the plant:
- Phenolic carboxylic acids:
4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic
acid, 4-hydroxy-3, 5-dimethoxybenzoic acid, 4-
coumaric acid, caffeic acid, ferulic acid
- Tannins : approx.
3%; (+) – catechin, procyanidin B-3, bis-fisetinidol-catechin
- Flavone glycosides:
orientin, iso-orientin, vitexin, iso-vitexin (antioxidant
properties)
- Dihydrochalcone glycosides:
aspalathin* nothofagin (strong antioxidants)
- Flavones, Flavonols &
C-O Glycosides: luteolin, luteolin-7-0-glucoside,
quercetin, isoquercetin & rutin
- Flavonone glycosides:
dihydro-orientin, dihydro-iso-orientin
- Alpha hydroxy acids:
phenylpyruvic acid glucoside
- Minerals: iron, potassium,
calcium, copper, zinc, manganese, and sodium
- Miscellaneous: Vitamin
C, pinitol (non-phenolic)
| Antioxidant
and free radical scavenging properties | |
Aspalathin, unique to rooibos, contributes
to its high antioxidant properties. The antioxidant
and free radical scavenging activity of rooibos has
been compared with green, black and oolong teas. With
a DPPH (α,α-diphenyl-β-picrylhydrazyl) radical scavenging
method, both fermented and unfermented rooibos extracts
were found to be stronger free radical inhibitors then
either black or oolong tea but slightly less then green
tea on a mass equivalent basis. Other research, however,
suggests that rooibos has much high antioxidant activity
than green tea.
Although the water soluble solids of
green, Rooibos, oolong and black teas contain roughly
the same amount of flavonoids and polyphenols, the water
soluble matter of rooibos tea leaves is approximately
half of that of black tea, making the amount of antioxidant
activity of rooibos in the same volume of extract much
less. The processing conditions of the rooibos tea have
shown to have a significant effect on the level of antioxidants
present.
The polyphenol antioxidants identified
in rooibos tea include the monomeric flavonoids aspalathin,
nothofagin, quercetin, rutin, isoquercitrin, orientin,
isoorientin, luteolin, vitexin, isovitexin, and chrysoeriol.
Currently, rooibos is the only known natural source
of aspalathin. Nothofagin is similar in structure to
aspalathin and has only been identified in one other
natural source besides rooibos: the heartwood of the
red beech tree (Nothofagus fusca (Hook F.) Oerst, Nothofagaceae),
which is native to New Zealand.
A recent analysis of fermented rooibos
measured the levels of all the flavonoids listed above
except nothofagin (see Table 1). Of the 10 flavonoids
measured, the three that occurred in largest amounts
were aspalathin, rutin, and orientin, followed by isoorientin
and isoquercitrin. Nothofagin was identified by mass
spectrometry but was not quantified because a standard
was not available. The amount of nothofagin in fermented
and unfermented rooibos was estimated to be about three
times less than aspalathin in one study. Aspalathin
and nothofagin represent in relatively large amounts
in unfermented rooibos tea, but some of the aspalathin
and nothofagin oxidizes to other substances during fermentation;
thus, fermented rooibos contains less aspalathin and
nothofagin than unfermented rooibos. The change in polyphenol
composition is the reason the tea changes colour with
fermentation.
 |
In addition to flavonoid antioxidants,
rooibos also contains phenolic acids that have
been shown to have antioxidant activity. Like
flavonoids, phenolic acids are polyphenol substances
that are found in fruits, vegetables, and whole
grains. The phenolic acids identified in rooibos,
in decreasing order of antioxidant activity as
measured in one study with the commonly used 1,1-diphenyl-2-picrylhydrazyl
(DPPH) radical scavenging assay, include caffeic
acid, protocatechuic acid, syringic acid, ferulic
acid, vanillic acid, p-hydroxybenzoic acid, and
p-coumaric acid. Using the DPPH assay, caffeic
acid was just as active an antioxidant as the
most potent flavonoids tested (quercetin, isoquercitrin,
and aspalathin).
|
Elizabeth Joubert, Ph.D., specialist
researcher at South Africa's ARC Infruitec-Nietvoorbij
and a rooibos expert, says that the total polyphenol
content of an average 150 to 200 ml can be as much as
60 to 80 mg, depending on factors such as the brewing
time and amount of leaves used. For comparison, one
study found that brewing black tea leaves for 1 to 3
minutes at a concentration of 1 g leaves per 100 ml
water resulted in black tea that contains 128 to 199
mg of polyphenols per 200 ml serving of tea. The types
of polyphenols in rooibos are different than those in
green and black teas, so the potential health benefits
of the teas cannot be compared solely on their total
polyphenol content. Rooibos does not contain epigallocatechin
gallate (EGCG), which is a polyphenol in green tea that
has shown anticarcinogenic and antioxidant capabilities,
but many of the polyphenols in rooibos are also strong
antioxidants.
Two of the flavonoids in rooibos, quercetin
and luteolin, are potent antioxidants found in many
fruits and vegetables. Studies in vitro (in the test
tube) have shown that these antioxidants can cause cancer
cells to "commit suicide," referred to as
apoptosis. Quercetin decreased primary tumor growth
and prevented metastasis in a model of pancreatic cancer.
Luteolin and quercetin inhibited proliferation of thyroid
and colon cancer cells, respectively, in vitro. Quercetin
inhibited cyclooxygenase-2 (COX-2) expression in colon
cancer cells, which may help prevent colon cancer. Both
luteolin and quercetin can block the formation of lipid
peroxides.
Although studies like these show quercetin and luteolin
are strong antioxidants, researchers haven't yet determined
whether enough of either of these two flavonoids are
present in rooibos and absorbed by the body to have
beneficial effects. As shown in Table 1, recent analysis
of fermented rooibos found considerably more quercetin
than luteolin, but even quercetin was present in much
lower amounts than aspalathin, orientin, and rutin.
Based on the data in Table 1, a 150
ml serving of fermented rooibos tea made with 2.5 g
of tea leaves has about 0.27 mg of quercetin; for comparison,
one study found that C. sinensis contains 1.5 to 3.75
mg of quercetin per 150 ml serving of tea. A previous
study found 1.5 mg of quercetin per 150 ml serving of
fermented rooibos, but that may be an upper limit. Joubert
says that the 1.5 mg estimate is probably high, but
emphasizes that these estimates will vary with parameters
such as the brewing time and the amount of water and
tea leaves used. At any rate, the amount of quercetin
per serving of rooibos is a small percentage of the
total polyphenol content per serving of rooibos.
| Aspalathin
and Nothofagin | |
A unique polyphenol that is one of the
most abundant monomeric flavonoids in rooibos tea, aspalathin
seems to contribute to the antioxidant capabilities
of rooibos, but aspalathin is not as well studied as
quercetin and luteolin. Nothofagin is similar in structure
to aspalathin and may have similar antioxidant capabilities.
Joubert says that chief research technologist
Petra Snijman of the Program on Mycotoxins and Experimental
Carcinogenesis (PROMEC) at the Medical Research Council
of South Africa recently developed a way to isolate
pure aspalathin and nothofagin from rooibos. Joubert
says, "According to unpublished in vitro studies
done at ARC Infruitec-Nietvoorbij, aspalathin compared
well with quercetin in terms of antioxidant activity,
except in a fat medium where quercetin demonstrated
much higher potency than aspalathin. What is important
in these comparative studies is the test environment.
Relative efficacy will depend on the test system used
(the polarity of the medium, the type of free radical
that needs to be scavenged, etc.)."
Joubert co-authored a study that found
aspalathin compared well to other antioxidants with
the DPPH radical scavenging assay. The study measured
the antioxidant capability of many of the flavonoids
and phenolic acids found in rooibos tea and compared
them to several reference standards such as alpha-tocopherol
(vitamin E). The percent inhibition of the DPPH radical
by quercetin, isoquercitrin, aspalathin, rutin, luteolin,
and alpha-tocopherol was 98.27, 91.99, 91.74, 91.18,
90.85, and 75.10, respectively (using a 0.25 mole ratio
of antioxidant to DPPH). All of the flavonoids tested
showed potent hydrogen donating abilities with DPPH
except for vitexin, which only had a 7.26 percent inhibition
even at a 0.5 mole ratio to DPPH.
According to the data in Table 1, a
150 ml serving of fermented rooibos made with 2.5 g
of tea leaves has about 3 mg of aspalathin; since the
amount of nothofagin was measured to be three times
less than aspalathin in one study, a 150 ml serving
of fermented rooibos has on the order of 1 mg of nothofagin.
A serving of unfermented rooibos has considerably more
aspalathin and nothofagin than an equal serving of fermented
rooibos because a portion of these flavonoids oxidizes
to other substances during fermentation.
Orientin and rutin are two of the other
most abundant monomeric flavonoids in rooibos, and both
have been associated with health benefits. Orientin
is a potent free radical scavenger. It reduced by half
the number of cancer-associated changes in cells of
human blood exposed to radiation. When mice were exposed
to radiation, orientin protected against lipid peroxidation
in the liver and also reduced damage to the bone marrow
and gastrointestinal tract. Rutin, a flavonoid found
in buckwheat (Fagopyrum esculentum Moench, Polygonaceae)
and some fruits and vegetables, seems to help maintain
the strength of capillary walls; oral rutin as well
as oral and topical o-(beta-Hydroxylethyl)-rutoside
(HR) have been used to treat hemorrhoids, varicose veins,
and the lower leg edema associated with venous insufficiency
and venous hypertension. According to the data in Table
1, a 150 ml serving of fermented rooibos tea made with
2.5 g of tea leaves has about 2.5 mg of orientin and
3.2 mg of rutin.
| Total
Antioxidant Capability | |
Although the 10 flavonoids in Table
1 are important because they are known to have antioxidant
properties, they only represent a small percentage of
the total polyphenol content of a serving of fermented
rooibos. A 150 to 200 ml serving of rooibos can have
up to 60 to 80 mg of total polyphenols, and Table 1
shows that a 150 ml serving of fermented rooibos made
with 2.5 g of leaves has about 14 mg of the 10 flavonoids
in the table. Many other polyphenols are present, but
they have not all been identified or quantified.
To assess the antioxidant capability
of rooibos as a whole, researchers compared the antioxidant
activity of rooibos tea extracts to that of green and
black tea extracts with the DPPH radical scavenging
assay as well as the beta-carotene bleaching method.
All the teas showed strong antioxidant activity with
both methods. Using the DPPH method, the ranking from
highest to lowest antioxidant activity was green tea
(90.8 percent inhibition), unfermented rooibos (86.6
percent), fermented rooibos (83.4 percent), and black
tea (81.7 percent). Green tea was significantly higher
than the others (P < 0.05), but the other three teas
did not differ from each other significantly with respect
to DPPH inhibition. Using the beta-carotene bleaching
method, the ranking was green tea, black tea, fermented
rooibos, and unfermented rooibos. The relative ranking
varies with the type of test because the substance to
be tested will have different reactivity to the different
oxidizing agents used. These tests only measure the
antioxidant capability of substances outside of the
body and don't provide data on whether the antioxidants
are absorbed by the body and effective after the food
is consumed.
In this study, all the extracts were
diluted to the same amount of soluble solids rather
than to the amounts of solids found in the teas. This
method allows a comparison of antioxidant capability
on a mass equivalent basis, but does not reflect a comparison
of the antioxidant strength of equal volume servings.
Although the soluble solid content varies with the method
of tea preparation, it usually decreases in the order
green tea, black tea, unfermented rooibos, fermented
rooibos. The percent of soluble solids represented by
polyphenols is similar for the four teas and the DPPH
antioxidant activity is similar on a mass equivalent
basis, so the DPPH antioxidant capability of equal-sized
servings will decrease in the order of the soluble solid
content. Black and green teas have over twice as much
soluble solids as rooibos tea when prepared conventionally,
so over two 200 ml servings of rooibos tea would need
to be consumed to receive the same antioxidant benefit
(as measured by DPPH) as one 200 ml serving of black
or green tea (or the rooibos would need to be brewed
to twice the standard concentration). This result agrees
with the data given previously for 60 to 80 mg polyphenols
for a 150 to 200 ml serving of rooibos tea as compared
to 128 to 199 mg polyphenols for a 200 ml serving of
black tea.
The studies referenced above show that
rooibos contains antioxidants that have positive effects
when tested as isolated substances and that Rooibos
as a whole has good antioxidant activity in vitro.
| Anti-inflammatory
properties | |
In addition to the initial research
of Annique Theron other research has shown that rooibos
exhibits both anti-viral and anti-inflammatory properties
in vitro and is effective against various dermatological
diseases in vivo (when taken as a beverage), including
acne, atopic dermatitis and in one case protection against
photosensitisation17. Rooibos is often used to bathe
children with allergic skin conditions at the Allergy
and Asthma Clinic at the Red Cross Memorial Hospital
in Cape Town.
| Antimutagenic
and Antimicrobial properties | |
There are also various research studies,
which have shown that rooibos tea possesses both anti-mutagenic
and antimicrobial activities. There is currently work
in progress on the evaluation of compounds from rooibos,
as microbial inhibitors.
Polysaccharides isolated from rooibos
tealeaves have demonstrated antiviral properties in
vitro experiments.
| Summary
of test results to show improved hair growth | |
Studies were initiated by an independent
laboratory to study the effect of the use of Rooibos
Extract in a hair lotion on a group of healthy persons
who were suffering from the problem of hair loss.
A 90 day trial was conducted comparing
a hair lotion containing Rooibos with a placebo lotion.
5 ml of the aqueous alcoholic solutions were applied
daily. Rooibos is produced by a novel dual phase extraction
process, which ensures the production of an extract
with the widest spectrum of plant actives i.e. polar,
semi-polar and non-polar.
The efficacy of the products was evaluated
using a videotrichogramme, which determines:
- hair density ( total number of hairs)
- number and proportion of telogen hairs (hairs where
growth has ceased)
- number and proportion of anagen hairs (hairs which
are still growing)
- hair growth speed of anagen hairs
After 90 days results showed:
-Hair growth speed
| - a significant
increase of the hair growth speed in the lotion
containing Rooibos compared with the placebo
|
-an increase in the
hair growth speed was observed with 89% of the volunteers
|
- Global appreciation
- 78% of volunteers were rather satisfied with the
product
- 100% of volunteers found the treatment easy to
follow
 |
- Product
efficacy - results from a subjective evaluation
questionnaire by the volunteers showed:
- 67% rated hair loss as zero or low
- 78% saw an improvement (low to medium)
- 45% saw low to medium re-growth of hair
- 63% of volunteers found a positive effect on the
fragrance and smoothness of hair
- 67% liked to general aspect of their hair
|
- No undesirable reactions (irritation or
allergy) were recorded
- After 90 days of treatment with the "Rooibos
Scalp Formula", the hair growth speed increased significantly
- The subjective evaluation questionnaire
showed that 78%of volunteers were rather satisfied with the
product and saw an improvement.
Conclusion:
These results show that most of the volunteers had a remarkable
improvement in both the increase of the speed of hair growth,
the decrease in hair loss and an overall improvement in hair
condition.
| Rooibos
as a cosmetic ingredient | |
Although rooibos is sold internationally as
a health drink up until now it has rarely been used outside
South Africa as a cosmetic raw material. International Cosmeticare
Inc. is the first manufacturer to introduce this ingredient
into cosmetics produced outside South Africa. From the point
of view of the cosmetic formulator the most important characteristics
of rooibos are related to its antioxidant, anti-inflammatory
and antimicrobial properties and also to recent independent
research showing that it improves hair growth and condition.
The following cosmetic related activities of the plant are
extracted from the literature:
| Properties
|
Suggested cosmetic
applications |
- Increased hair growth, prevents hair
loss
- Improved overall hair condition |
- Hair care products |
- Good for acneic skin
- Antimicrobial
- Anti-inflammatory, anti-allergic
- Soothing
- Promotes healthy skin (AHAs) |
- Promotes healthy skin (AHAs)
- Products for anti-acne problem or blemished skin, including
skin creams, tonics, cleansers, facial washes, bar soaps
- Products for sensitive skins
- Baby products
- Aftersun products |
- Antioxidant
- Free radical scavenger
- Promotes healthy skin (AHAs) |
- Skin care products especially anti-ageing
products those for mature skins |
Study Conditions
Subject Selection
The measurements were taken on 10 women,
aged between 21 and 44 (average age: 34). All volunteers
had chronic hair loss (number of hairs > ten in the
combing test).
Subjects have to be compliant and do
not associate treatment during the study as precisely
mentioned in the information sheet.
Method and Instrumentation
- Growth speed
|
The video microscope is a mobile optic fiber microscope with
a variable-magnification lens connected to an
image acquisition and data processing system.
The lens (x25) faces the zone
to be studied but does not touch it. The 16 million
color image is displayed on the system monitor.
|
 |
This image is then analyzed with the Dermascan
software package "Count Hair" which counts the number
of hairs and measures their length.
Hair growth is calculated by hair length
measurements on Day 0 and Day 2 (on anagen hairs only).
The length difference between D0 and D2 is calculated
and related in mm per day.
- Subjective evaluation
A subjective evaluation questionnaire regarding the
organoleptic characteristics, tolerance and efficacy
of the product is given to the volunteers.
Experimental Schedule (in days)
Summary
of Study
The study was done from April 6 to July
8, 1998
The aim of the study was to evidence
and quantify the efficacy of the placebo product and
"Rooibos Scalp Formula", designed to prevent hair loss.
The efficacy of the products was studied
by videotrichogramme, which determines:
 hair density (total number of hair),
 number and proportion of telogen hairs,
 number and proportion of anagen hairs,
 hair growth speed of anagen hairs.
Measurements were carried out on 19
healthy volunteers (Volunteer 3 was untraceable on D90),
18 women and 1man, aged between 21 and 55 (average age:
34+/- 2). These volunteers suffered from hair loss.
The efficacy of the placebo product
and "Rooibos Scalp Formula" was evaluated after 90 days
of treatment (5ml per day).
No undesirable reaction (irritation
or allergy) was observed during test.
Results with Placebo Product
- After 90 days of treatment with the Placebo product,
the number of telogen hairs tended to decrease
(variation of –17% not statistically significant, with
p=0.408).
- The hair growth speed did not significantly increase
(variation of +38 +/- 16%, with p=0.089).
Results with Product containing
Rooibos
- After 90 days of treatment with the "Rooibos Scalp
Formula", the number of telogen hairs did not vary
(-2% with p=0.929).
- The hair growth speed increased significantly
(variation of +41+/- 14%, with p=0.013).
Conclusion
The incorporation of Rooibos in a hair lotion prevented
the loss of hair and increased the speed of hair growth
significantly compared to the placebo.
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