Creative Developments
(Cosmetics) Limited
Active
Ingredients from Natural Resources, John Woodruff 1999.
The
identification of active molecules in natural materials is one of the most
interesting areas of cosmetic ingredient development. To find proof of effect
for items that have long been used by indigenous populations for body
treatments is both satisfying and rewarding. In 1826 Culpeper described natural
medicines as either hot, cold, moist, dry or temperate. Culpeper was more
interested in their internal consumption than topical application but he does
describe making ointment using hog’s grease and also the making of plaisters
and poultices. A bruise or a scald could be treated with neatsfoot oil mixed
with beeswax and oil of elder plus red lead! For treating facial pimples
Culpeper recommended lemon juice and rose water in an ointment or
alternatively, camphor dissolved in vinegar and mixed with celandine-water as a
face wash; suggestions that can be found in use today.
Now
the properties commonly claimed for natural ingredients are moisturising,
stimulating, protecting, soothing, cooling and astringent. The active elements
derived from natural ingredients are shown to be hygroscopic and therefore
moisturising; rubefacient and therefore stimulating; antioxidant and therefore
protective; anti-inflammatory and therefore soothing and cooling or astringent
and therefore skin-tightening. They may have sun protection properties, be
antimicrobial or promote cell metabolism. They may be emollient and skin
softening like natural oils or promote exfoliation of the outer layers of the
stratum corneum like the naturally occurring fruit acids.
For
those interested in effect rather than label dressing the quality and strength
of herbal extracts has long been of concern. Also it is important to define the
parts of the plant used and the methods of extraction. Most responsible
suppliers now offer standardised extracts although not all are to the same
standard! 5kg of material may be used to prepare 1kg of extract or 1kg of
material may be used to yield 5kg of extract. The whole plant or selected parts
may be used and the plant material may be dry or fresh [REF 1]. Even adjusting
the strength to a marker constituent is not always a guarantee as natural
differences in the harvest may affect its level and also that of the desired
active constituents. However perusal of the suppliers literature should answer
most of these queries and all the materials mentioned in this review are fully
supported by documentary evidence.
The
deleterious effects of solar radiation on human skin are well known and many
materials have been developed to mitigate the damage. Professor Chawla [Ref 2]
has isolated 9,10,16-trihydroxypalmitic acid from Laccifera Lacca. This was
converted to 16-hydroxy-9-hexadecenoic acid and treated with zinc dust or zinc
oxide to yield Zinc-methyl-16-hydroxy-9-decenoate. When incorporated into a sun
filter composition it was shown that 5-12% of the material helped counter UVR
damage, increased the firmness of the stratum corneum and reduced visible
wrinkles. It was also found that the methyl ester played an important role in
the sun protection mechanism as well as in the rejuvenation of sun damaged
skin.
A
natural-based material from Seppic has been specifically developed to combat
the effects of UV and chemical stress on the skin [REF 3]. Comprising an
extract of water lilies combined with a lipoaminoacid, Sepicalm VGÔ is said to
have a cooling effect on the skin and to reduce stinging intensity. Clinical
trials demonstrate that the application of 1% Sepicalm VGÔ in a suitable
base lowers skin temperature by 0.80°C
24 hours after exposure, making it an interesting additive for aftersun
products. Its anti-stinging effectiveness was measured using the lactic
acid/nose test and 3% in a base was shown to reduce stinging intensity by 45%
compared to a reduction of 25% using the base alone.
Reducing
the appearance of wrinkles is high on the list of desirable skin care
attributes. An instant effect is much sought after and this may be achieved by
tightening the skin. At one time bovine serum albumin was used but with the
swing away from animal products in general and bovine ones in particular,
vegetable-derived materials have been tried. Cereal proteins with a
film-forming action have some effect but two new materials from Laboratoires
Serobiologiques SA are claimed to be more effective. Vegeseryl HGPÔ is a high
molecular weight protein while DansonylÔ
is mucilage of polysaccharides and it also has a significant content of uronic
acid. In-vitro and in-vivo tests measured the mechanical properties of the skin
before and after treatment and electron scanning micrographs on silicon
replicas visualised the effect. The results show that 5% of either material is
significantly more effective than cereal protein and that 10% of DansonylÔ is
particularly effective. This effect is dose-dependant and improves with
application over time.
Also
recommended for skin tightening is DermotenseurÔ
from LIBiol. This is an extract of Kigelia africana, known as the sausage tree,
blended with Quillaja. LIBiol supplies botanical and marine source extracts and
blends of these to provide specific properties. CytobiolÔ Iris is a
complex based on the astringent effects of Iris germanica combined with zinc
and water-soluble vitamin A. Literature form the suppliers show it to be
effective in controlling skin flora and it may be used to alleviate acne. From
the same source are two kaolin-type clays that are naturally coloured; one red
and one green. With the same properties as kaolin they are used for producing
facemasks and claims may be made for the trace elements responsible for the
natural coloration. Marine materials from LIBiol include DNA from fish milt;
elastin and collagen from the conjunctival tissue of tuna and
mucopolysaccharides from shark cartilage.
Another
material with skin-tightening properties is Pronalen Flash-tenseÔ from Provital.
It is an enzyme hydrolysate of amino acids and peptides obtained from
organically grown wheat (Triticum sp.) seeds that have been allowed to
germinate for seven days. This period is said to release them in their optimum
ratio and molecular weight distribution. The hydrolysed materials have a mean
molecular weight of 3000 Daltons and form ionic or hydrogen bonds upon skin
contact, which have a substantive film forming and skin tightening effect.
Calming,
soothing and anti-irritant properties are claimed for an extract of Olibanum (Boswellia
serrata) gum supplied by Quest International as SoothexÔ. The gum is
also known as frankincense and it is admixed with isostearyl alcohol to give a
clear brown liquid that is readily incorporated into cosmetic products. It is
said to inhibit the enzyme 5-lipoxygenase from breaking down arachidonic acid
in the cell membrane that causes inflammation and pain in the skin. Quest also
offers protein hydrolysates from various natural sources including soy, wheat,
whey, rice and cotton. These water-soluble materials are used for moisturising,
hair conditioning and skin-softening. To complete the natural look Quest has a
variety of vegetable colours.
Although
essential to life and good health enzymes are also responsible for many of the
untoward reactions in the human body. Phosphodiesterase inhibits the breakdown
of body fats leading to cellulite. Guarana (Paullinia cupana) extract from
Exsymol contains catechols that bind with caffeine and stimulate lipolysis.
Elastase causes the breakdown of connective tissue and its activity is
increased by solar radiation. A red vine (Vitus vinifera) extract, also from
Exsymol, inhibits the activity of elastase and it also has antioxidant
properties. Tyrosinase is the key enzyme in the synthesis of melanin. It is
activated when exposed to UV rays and intervenes inductively in several intermediate
stages of pigment formation. Various materials of natural origin are used to
inhibit its activity including arbutin, liquorice (Glycyrrhiza Glabra) extract
and ascorbic acid from citrus fruits. Rovisome Whitening from ROVI is a
combination of two tyrosinase inhibitors, each with different working
mechanisms for skin lightening and it is supplied in liposome form. Aloesin is
an active extracted from the Aloe plant and arbutin is extracted from the
leaves of the common bearberry, Arctostaphylos Uva Ursi.
In
cases of acne an inflammatory reaction is caused by free fatty acids resulting
from breakdown of triglycerides of sebum by Propionibacterium acnes enzymes on
the one hand, and by the immune response induced by propionibacteria, on the
other. C.L R. Dr. Kurt Richter has investigated the effect of Tea Tree (Melaleuca
alternifolia) oil on the bacteria responsible and found it to have an M.B.C. of
5% in-vitro but because of its volatility it is not effective on topical
application. It was found however that if the tea tree oil was encapsulated
within cyclodextrins its bioavailability was increased. The material is
trade-named Epicutin-TT and skin moisture and ambient humidity provide for
controlled release of tea tree oil from the complex, thereby allowing small
amounts of tea tree oil to reach the skin and to act there over a long time.
Meanwhile, emptied cyclodextrins can absorb excess sebum from the skin surface.
Dragoco
was one of the first companies to supply natural extracts to cosmetic manufacturers
and is still very active in developing new ideas and testing the efficacy of
existing materials. Willowherb (Epilobium angustifolium) extract is suggested
as an anti-irritant and to reduce solar-induced erythema while Green Tea
Concentrate is said to be a more effective antioxidant than vitamin E and
inhibits DNA damage caused by singlet oxygen and free OH radicals. The same
company also markets Drago-b-GlucanÔ
as a natural skin protective and immune-stimulating agent. b-Glucan is said to
reduce the extrinsic signs of ageing by improving skin elasticity, protecting
against UV damage and stimulating collagen synthesis of fibroblasts and the
release of Interleukin-1a, which improves the skin’s natural immunity.
AglycalÔ from
Laboratoires Serobiologiques is an extract of bearberries containing flavonoids
and tannins mixed with a non-reducing marine polysaccharide. It has
antiglycation properties, inhibiting the formation of glucose-protein bonds and
it also has anti free radical and anti-inflammatory properties. Pronalen
Bio-ProtectÔ
from Pronalen is described as a complex of natural plant extracts blended to
provide maximum protection against skin damage by atmospheric pollutants,
especially free radicals and heavy metals. The ability to increase cellular activity
is claimed for Pronalen Fibro Actif, a material obtained from wheat germ seeds
and for which in-vitro evidence demonstrates an ability to increase
mithocondrial activity in the mitochondra and fibroblasts.
CrodaromÔ extracts from Croda
International are manufactured in France using botanicals that have been grown
free of pesticides and synthetic fertilisers. Microwave technology is used to
disrupt the cell membranes and it is claimed that this facilitates faster
extraction by the aqua, glycerin and butylene glycol solvent mixtures. Although
not as extensive as some lists the main botanicals in current use are listed.
The principal active ingredients are identified, the marker used for
standardising the extract is disclosed with its target level and the properties
and cosmetic application of each is summarised.
Another
approach to extraction is practised by Arkopharma Laboratories which uses
supercritical CO2 extraction technology to produce a number of extracts
including those of pollen, shiitake mushrooms and seabuckthorn. Pollen extract
at a concentration of 0.0008 – 0.004% is said to significantly improve cell
proliferation. It maintains the tone of the collagen network and improves the
elasticity and suppleness of skin. These properties make the material of
interest for sun protection products as well as moisturising compositions.
Shiitake (Lentinus edodes) mushroom extract contains about 10% ergosterol and
is used in cell regenerating, wound healing and skin firming products. Seabuckthorn
(Hippophae rhamnoides) extract is a viscous oil consisting mainly of
palmitoleic (C16:1) 25%, oleic (C18:1) 25% and linoleic (C18:2) fatty acids
plus about 5% non-saponifiable matter containing carotinoids, tocopherols and
sterols. Palmitoleic acid is a principal constituent of skin fat and the
extract is recommended for skin softening and antiwrinkle products.
The
plants of the Amazon basin have created much interest for medical and cosmetic
applications. Ennagram supply hydro-alcoholic extracts of nine such plants plus
extracts of Chinese herbs and a number of marine extracts as well as an array
of the more traditional materials. Also of interest are the active principals
derived from the natural materials and the mixtures for specific applications that
it supplies. A&E Connock has further increased its range of natural oils
from round the world. Literature available from the company describes no less
than sixty-six different natural oils and their cosmetic applications. These
include a number from the African continent and also from the Amazon basin.
Further literature form A&E Connock describes the difficulties of
suspending natural exfoliants in various products. Yield value is more
important than viscosity in creating stable suspensions and the literature
describes practical methods of determining this and tabulates the values needed
for many different particulates.
REF 1: Standardised
botanical ingredients, D’Armelio F et al, Cosmetic & Toiletries Manufacture
Worldwide, 17-20,1999
REF 2. New naturally
occurring sun protection agents; H. Mohindra Chawla; 2nd European UV Conference,
Paris, November 1999
REF
3: Stolzt C, A Lipoaminated phytocomplex: A solution adapted to the needs of
sensitive and damaged skin, 2nd European UV Conference, Paris, November 1999