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Issue
40 — April 2006 |
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Article |
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Resurrection
plants: From a natural system to survive in the desert to skin protection
from environmental variations
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Magali
Ebersveiller, Olga Freis, Louis Danoux, Véronique Gillon, Philippe
Moser, Isabelle Benoit, Gilles Pauly |
A feeling of dryness, tightness and
discomfort: every day we are made acutely aware that «extreme» environmental
conditions have a disastrous effect on our skin. No need to travel to the desert
for this, there’s plenty of daily stress for our skin right where we are:
the dryness of the air-conditioning in summer, the chlorinated water of a swimming
pool, the thermal shock of entering an overheated shop in winter and going out
into the cold again, to name but a few. Dehydration of the skin is the first consequence
"visible to the naked eye": the microrelief of the skin changes rapidly
and skin scales start appearing.
Logically, a feeling of moisturization and comfort are primary demands of modern
women who do not want to make concessions to their beauty because of the active
life that they lead. To answer to this demand, we have drawn inspiration from
the miracles of adaptation found in nature: certain plants are able to thrive
under the most drastic conditions. Amongst these, are plants called resurrection
plants: growing in dry regions, in which periods of drought are followed by sudden
and intense rain, these plants have developed specific mechanisms of protection.
In fact, they can go into a state of anabiosis (a state of reduced metabolism)
when the climatic conditions are unfavorable, to be «reborn» during
the rainy season. The ability to do so is based on the content of components called
«survival fraction». Certain sugars such as for instance trehalose
are synthesized and play a role as osmoprotectant. Specific pigments, anthocyanes,
serve as a shield to protect chlorophyll. Gallic acid reduces the rate of peroxidation
of unsaturated fatty acids, thus protecting the cell membranes of the plant.
| Fig.1:
Dehydrated plant - Rehydrated plant |
 |
 |
When the conditions are favorable again (during the first rains) a real resurrection
takes place: during the first hours of rain the plant that looked dry and dead
is quickly rehydrated and normal cellular functions are restored. Within the class
of resurrection plants, Laboratoires Sérobiologiques has especially investigated
Myrothamnus Flabellifolia, the extract of which is used in PA Reviviscence®
LS 9562. Myrothamnus is a small shrub that grows on granitic soil in South Africa
and is exposed to the dryness of that region.
| Fig.2:
Myrothamnus flabellifolia |
 |
Thanks to the survival fraction of Myrothamnus in PA Reviviscence® LS 9562
the skin is strengthened and a dehydration due to environmental aggressions is
prevented.
PA Reviviscence® LS 9562 is an extract from the plant Myrothamnus flabellifolia,
rich in anti-oxidants, associated with oligosaccharides derived from the xyloglycans
from Tamarindus indica, immunostimulating and moisturizing, and trehalose, osmoregulating
and also moisturizing. This association recreates the survival fraction responsible
of the marvelous resistance of the resurrection plants. It has been tested in
a battery of in vitro and clinical tests. We have identified each stress skin
can be exposed to: UV, heat shock, cold shock and also osmotic shock. For each
condition we have demonstrated the capacity of PA Reviviscence® LS 9562 to
prevent the stress and dehydration linked to an exposure to extreme conditions.
This protective efficacy is visually and sensorially perceptible by the enduser.
Protection against UVA
Evaluation of the potential of the active matter of PA Reviviscence® LS 9562
to protect human fibroblasts against UVA.
Released malondialdehyde (MDA) is a marker for lipid peroxidation and thus for
oxidative stress. Fibroblasts were incubated with PA Reviviscence® LS 9562
and skin were irradiated by UVA at 20J/cm². The quantity of MDA synthesized
by fibroblasts after incubation and the protein level were measured. The active
matter of PA Reviviscence® LS 9562 has significantly protected human fibroblasts
against UVA.
| Fig.3:
UV-A cytophotoprotection on human fibroblasts by PA Reviviscence® LS
9562 |
Enlarged
version |
Protection against UVB
Evaluation of the potential of the active matter of PA Reviviscence® LS 9562
to protect human keratinocytes against UVB.
The marker of toxic effect on cell membranes is a release of cytoplasmic enzyme,
lactate dehydrogenase (LDH). Keratinocytes were incubated with PA Reviviscence®
LS 9562 and then irradiated by UVB at 50mJ/cm². The quantity of LDH released
by keratinocytes and the number of viable cells (DNA) after incubation were measured.
The active matter of PA Reviviscence® LS 9562 has significantly protected
human keratinocytes against UVB.
| Fig.4:
UV-B cytophotoprotection on human fibroblasts by PA Reviviscence® LS
9562 |
Enlarged
version |
Protection of human fibroblasts from heat shock
Evaluation of the potential of PA Reviviscence® LS 9562 to protect human cultured
fibroblasts from heat shock.
Fibroblasts were incubated with PA Reviviscence® LS 9562 and exposed to a
heat shock. The levels of adenosine triphosphate (ATP) and released LDH were measured.
PA Reviviscence® LS 9562 has displayed a good protection of human fibroblasts
against heat shock. This effect is dose dependant.
Protection of human cells from cold shock
Evaluation of the potential of PA Reviviscence® LS 9562 to protect human cultured
cells after a cold shock.
Propidium Iodide (PI) is a DNA intercalating dye which becomes fluorescent when
penetrating in the nucleus. At a certain level of fluorescence, the cell is called
PI (+). PI(+) marking is an indication of damage to the cellular membrane. Lymphoid
cells were incubated with PA Reviviscence® LS 9562, exposed to a cold shock.
The cell viability was measured by a test of propidium iodide exclusion 15 minutes
and 4 hours post shock. PA Reviviscence® LS 9562 has provided protection of
the human lymphoid cells against cold shock (decrease of PI(+) cells after cold
shock).
| Fig. 6:
Measurement of IP(+) cells rate 15 minutes and 4 hours after cold shock |
Enlarged
version |
Protection against osmotic stress on red blood cells (RBC)
Resistance against osmotic shock and the membrane stabilizing potential of PA
Reviviscence® LS 9562 to protect human skin from environmental stress, on
red blood cells (RBCs).
During an exposure to a hypo-tonic medium, RBCs absorb more water, swell and finally
explode, causing them to rupture and release the hemoglobin they contain. Red
blood cells were incubated with PA Reviviscence® LS 9562 in hypo-osmotic saline
solution for 60 minutes, then centrifugated for 10 min. The released hemoglobin
was measured. PA Reviviscence® LS 9562 has significantly protected red blood
cells from osmotic shock. This property can be extended to all types of skin cells.
Moisturizing activity (in vitro)
Evaluation of the long lasting moisturizing activity of PA Reviviscence® LS
9562 on stratum corneum by measurement of the dielectric conductivity.
PA Reviviscence® LS 9562 has shown a significant moisturizing activity in
vitro. In addition, this is a long lasting effect (up to 24 hours).
| Fig. 8:
Moisturizing activity of PA Reviviscence® LS 9562 compared to placebo |
Enlarged
version |
Moisturizing, softening and anti-drying effect (clinical test)
Demonstration of the immediate and long lasting properties of PA Reviviscence®
LS 9562 under extreme conditions : low / high relative humidity and low temperature.
For immediate properties, after one standardized application, skin moisturizing
and skin softening activities were measured by conductimetry and corneospinometry.
For long lasting properties, skin moisturizing effects were measured by conductimetry
on the back of the hands after one week of treatment.
| Fig. 9:
Moisturizing efficacy by conductimetry. Cinetic after standardized application
(2 mg/cm²) |
Enlarged
version |
| Fig. 10:
Softening and anti drying efficacy by corneospinometry |
Enlarged
version |
| Fig. 11: Measure
of the moisturizing effect after 1 week of treatment |
Enlarged
version |
A cream containing 5% PA Reviviscence® LS 9562 has shown a significant immediate
moisturizing effect. Additionally, this cream allows rehydration of dry skin under
very drastic winter conditions and prevents dehydration of the skin under environmental
stress. Thanks to PA Reviviscence® LS 9562 , the skin’s softness and
comfort are preserved under all conditions, but especially under conditions of
low relative humidity.
* PA Reviviscence® LS 9562 — INCI Name: Water (and)
Glycerin (and) Trehalose (and) Tamarindus Indica Seed Polysaccharide (and) extract
is a registered trademark of Laboratoires Sérobiologiques — Division
de Cognis France.
This topic, entitled “Reviviscence LS, a new active ingredient from resurrection
plants for skin cells protection” was presented by Freis, O. ; Moser, P.
; Henry, F. ; Danoux, L. ; Pauly Florentiny, M. ; Guezennec, J. ; Guesnet, J.
; Pauly, G., at the IFSCC International Conference 2001: Creation and Hope. September
17-19, 2001, Taipei, Taiwan.
A publication entitled " ‘Resurrection’ plants and skin protection”,
authored by Freis, O. ; Moser, P. ; Henry, F. ; Danoux, L. ; Pauly Florentiny,
M. ; Pauly, G., appeared in PARFUMS COSMETIQUES ACTUALITÉS 2002, pp. 49-60.
Author
Magali Ebersveiller
Magali Ebersveiller has a Master's degree in Biology. She is Product Manager at
Cognis France, Division Laboratoires Sérobiologiques (Marketing Department)
where she is in charge of active ingredients for use in cosmetic products.
Laboratoires Sérobiologiques, Division de Cognis France - 3, rue de Seichamps
- 54425 PULNOY - France Tel: + 33 3.83.29.97.92 - Fax: + 33 3.83.29.98.65 customer-service.LS@cognis.com
- www.laboratoires-serobiologiques.com m
