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| Issue 40 |  |
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| Category | Title | Author | ||
| Guest Article | Resurrection plants: From a natural system to survive in the desert to skin protection from environmental variations | 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 | |
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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 |
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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.
| Fig. 5: Measurement of cell ATP level and rate of released LDH |
 Enlarged version |
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.
| Fig. 7: Cytoprotection of red blood cells from osmotic shock |
 Enlarged version |
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
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