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New Developments in the Science Behind Anti-Aging Skin Care Products

M. Anne Curtis, MD, FRCPC

Division of Dermatology, University of Toronto. Toronto, Ontario

Introduction

Albert Kligman coined the term "cosmeceutical" and defined it in 1984 as a formulation that is used to improve the appearance of skin, but is not for therapeutic purposes.1

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Major Classes of Cosmeceuticals

Retinoids

Natural and synthetic derivatives of vitamin A
Drugs:

  • Retinoic acid (tretinoin), adapalene, and tazarotene
  • Substantial scientific data confirm their anti-aging and anti-acne benefits.2
  • Retinoic acid is considered by dermatologists to be the anti-aging gold standard.
  • It is available only through a doctor's prescription
  • Cosmeceuticals: retinol, retinaldehyde, retinyl propionate, retinyl palmitate
  • In many cases, bioavailability and activity are unproven when formulated.

Moisturizers

  • Include emollients, occlusives and humectants.
  • Considered to be the most useful product for the management of various skin conditions (e.g., atopic dermatitis, psoriasis, pruritus, aging skin).

Other Vitamins and Minerals

Antioxidants:

  • Include vitamins A, C, and E; alpha lipoic acid; ubiquinone (coenzyme Q-10); idebenone; polyphenols (e.g., catechins, flavenoids); kinetin; botanicals (e.g., teas, grapeseed, grape skins and stems, coffeeberry).
  • Enhance the skin's natural antioxidant protection system with topical application.
  • Reduce free-radical damage by blocking the oxidative processes in cells.
  • Inhibit inflammation that causes collagen depletion.
  • Protect against photodamage and skin cancer.
  • Do not reverse signs of photo-aging.

Hydroxy acids (alpha, beta, poly)

  • Include glycolic acid, lactic acid, citric acid, tartaric acid, pyruvic acid, and malic acid.
  • Can improve skin texture and dyspigmentation.
  • Can induce actual structural changes in skin, so the potential exists for regulatory scrutiny.

Botanicals/ Plant Extracts

  • Have experienced a rapid rise due to the popularity of "natural" compounds.
  • Represent the largest group of additives found in marketed products.
  • Limited scientific data to support efficacy and safety.

Epidermal Growth Factors

  • Naturally occurring chemicals in the body that influence cellular proliferation and differentiation.
  • Potential applications include regeneration of damaged or aged skin.

Proteins/Peptides

  • These can trigger skin repair as needed. There are some indications that they can reduce the signs of aging and accelerate the skin's healing processes.3,4

Plant Stem Cells

  • Stem cells are of significant interest in the anti-aging field because they are essential for cellular repair, and this repair capacity is known to diminish with age.
  • Epidermal turnover decreases with time and the skin gradually becomes thinner and more fragile, with impaired wound healing.5
  • 2-7% of the cells in the basal layer of the epidermis are adult stem cells, with the capacity to regenerate the rest of the skin. There are also reservoirs of stem cells in the hair bulge. Epidermal stem cells renew themselves slowly. Fewer divisions mean fewer opportunities to accumulate damaging DNA mutations and less telomere loss.
  • Cells have a finite capacity to divide, so the slower the process, the longer the capacity is preserved.
  • Epidermal stem cells are able to do their work because they generate transient amplifying cells, which divide more rapidly and produce the epidermal turnover.6
  • Epigenetic signals regulate the turning on and off of genes. These signals are tags on the DNA or the surrounding histone proteins. It is theorized that the beneficial effects observed in human stem cells in the presence of the stem cells of the Uttwiler Spatlauber apple are related to epigenetic factors from the apple stem cells.6

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PhytoCellTec Malus Domestica

  • PhytoCellTec Malus Domestica contains fruit stem cells derived from the Uttwiler Spatlauber apple. This is a rare heritage variety of Swiss apple which had been cultivated for superior storage over the winter as it did not tend to wizen when stored for long periods.
  • The apple stem cells are incorporated into lecithin liposomes which enhance the colony forming efficiency of human stem cells in vitro and the capacity to form 3D epidermis in older stem cells which would otherwise become senescent.7-10
  • The stem cells are obtained by first cutting the plant, and then culturing the cells of the callus which appears as the plant attempts to repair itself.
  • The cells can be propagated in the lab so that sterile preparations are available regardless of the season.
  • There have been several in vitro studies of the PhytoCellTec apple stem cell preparations. In one, fibroblasts were stressed for 2 hours by exposure to hydrogen peroxide, then incubated for 72 hours either with or without 2% Malus Domestica stem cell extract.7 The fibroblasts were then analyzed for genetic upregulation or downregulation. The control groups showed downregulation of 5 genes by 63- 89%. These same genes were upregulated by 117- 211% in the PhytoCellTec group.
  • The genes affected were cyclin B1, which induces proliferation, cyclin E1, a cell cycle regulator, p53, a tumour suppressor gene, insulin like growth factor II, a cell proliferation enhancer, and heme oxigenase I, an antioxidant enzyme.
  • Another in vitro study on umbilical cord derived stem cells showed that incubation with 0.01% and 0.1% PhytoCellTec gave a progressive concentration dependent increase in cell counts from 70,000 in the control group to over 120,000 at the higher concentration.8
  • There was also protection against ultraviolet damage. In the control group over 40% of the cells were lost after UV exposure whereas that number was less than 10% in the treated group.
  • Research on PhytoCellTec using a special cell culture medium designed to select for epidermal progenitor cells showed that keratinocytes cultured in this medium had a 10 fold increase in the CD34/alpha 6 integrin doubled labeled cells by the fourth passage.
  • When these cells are then cultured with 0.01% and 0.04% Malus Domestica there is a progressive and concentration dependent increase in colony forming efficiency, which is a proxy for concentration and activity of progenitor stem cells, to 92% above control for the higher concentration.9
  • Lengthening the hair growth cycle is an important mechanism for lash enhancement, and 0.2% PhytoCellTec kept hairs in culture growing well past the 14 days when they typically senesce.
  • A similar effect was noted in vitro on 3D epidermis produced by epidermal progenitor cells. Epidermis, produced by young progenitor cells after 5 passages, grows well in regular culture medium. Epidermis produced by old progenitor cells which have undergone 14 passages, grows to day 14, but is noticeably thinner and less developed. It will not grow to day 21, but if incubated with PhytoCellTec it is still growing at 28 days and producing thicker better differentiated epidermis.10
  • Data from a study of 2% PhytoCellTec cream using plant stem cells incorporated into lecithin liposomes have shown beneficial effect. In the study, 20 women applied the cream twice daily to the crow's feet for 28 days and wrinkle depth was compared before and after.15
  • Wrinkle depth was found to have decreased by 15%, however there was no control cream, making it difficult to ascertain how much benefit could be attributed to the vehicle.15
  • Another study involved 37 women, 21 of whom applied a placebo serum followed by a placebo cream twice daily. The other 16 used a treatment serum twice daily, with a treatment day cream and a treatment night gel. A qualitative survey revealed that patients in both groups were very positive about their creams and found them cosmetically appealing. Hydration was evaluated by corneometer and improved in both groups with no difference between them.10
  • Skin colour analysis showed some improvement in evenness of skin tone over the course of treatment but this did not differ between the groups. Profilometry to assess skin wrinkles at day 56 did show a 12.1% decrease in total wrinkles in the treatment group which was statistically significant compared to the placebo group.11

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Survixyl IS

  • Survixyl IS (Vincience Biofunctionals (Lucid Inc.)), is a peptide that provides a supportive environment for epidermal stem cells.
  • In vivo, on confocal reflectance microscopy, Survixyl IS was found to decrease sunburn cells by 33.8% after ultraviolet light exposure.12
  • It also provides a 30% increase in active dermal papillae as evidenced by confocal microscopy after 29 days of twice-daily use in vivo.12
  • The complex consists of survivin, which prevents apoptosis due to loss of cell adhesion, p63, which maintains the self-removal potential of epidermal stem cells, and 3 proteins which influence anchoring- beta 1 integrin, alpha 6 integrin and keratin 15, a cytoskeletal protein found in stem cells and progenitor cells.12
  • There are ex-vivo studies documenting the effect of Survixyl IS on all three of these proteins. For example, survivin shows a 20.5% increase in staining of the epidermis at the base of the rete ridges in skin biopsy specimens after incubation with 0.5% Survixyl IS and a 55% increase after incubation with 1% Survixyl IS.12
  • In vivo data come from a double blind, placebo controlled study of 10 patients who applied 1% Survixyl IS twice daily to the thigh for two weeks. On day seven there was UV exposure sufficient to elicit sunburn cells. The sunburn cells were counted using the confocal microscope in vivo on days 8, 9 and 13.12
  • Compared to control areas where Survixyl IS had not been used, the treated areas had 24 - 34% fewer sunburn cells at day 8, and 33.8% fewer sunburn cells at day 13.12
  • A similar double blind placebo controlled study, with twice-daily application of 1% Survixyl IS to the thigh for 29 days used the confocal reflectance microscope to assess dermal papillae in vivo. They found a 30% increase in the number of active dermal papillae with the product.12

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Quintescine IS

  • Quintescine IS is a peptide dimer which mimics glutathione and increases the enzymes which remove reactive oxygen species. It also decreases glycation so that collagen fibers do not stiffen as much.13
  • Culture with Quintescine IS increases levels of both manganese super oxide dismutane (MnSOD) and catalase, especially in the presence of a stressor like UVA.13
  • MnSOD is a free radical scavenger that catalyzes the breakdown of harmful reactive oxygen species like superoxide dismutase into hydrogen peroxide, which in turn is broken down to water and oxygen with catalase as the required enzyme.
  • Fibroblasts produce 33% more MnSOD and 23% more catalase when Quintescine IS is present.13
  • Protein carbonylation is also decreased when Quintescine IS is present- 36% if there is no UVA stress and 137% if there is UVA stress.13
  • Lipid peroxidation is decreased 44% with Quintescine IS under UVA stress.13
  • DNA damage induced by UVB is decreased by 73% in this fibroblast culture model when Quintescine IS is added to the culture medium.13
  • Glycation produces cross links which stiffen collagen fibers and decrease tissue elasticity. Quintescine IS decreases glycation by 33% in the in vivo fibroblast culture model. Benefit was also shown on 6 mm punch biopsies of skin ex vivo, using methylglyoxal as the stress: it increased protection by 30-33%.13

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Conclusion

Taken together, these data are encouraging and suggest a worthwhile adjunct to sunscreen. The benefits one might hope to obtain from preserving and enhancing stem cell function, decreasing damage due to reactive oxygen species and decreasing glycation would all accrue over far extended time periods. While these newest skin care products will not take the place of rejuvenating procedures like lasers, botulinum toxin and fillers, they do give patients the opportunity to get more than simple hydration from their skin care routines. Clinically, it is important that patients have realistic expectations when they are applying topical anti-aging creams.

References

  1. Kligman AM, et al. J Am Acad Dermatol. 1986;15:836-859.
  2. Sorg O, et al. Dermatol Ther. 2006;19:289-296.
  3. Gold MH, et al. J Drugs Dermatol. 2007;6:1018-1023.
  4. Lupo MP. Dermatol Surg. 2005;31:832-836.
  5. Schmid D, Zulli F. Stimulating epidermal regeneration with plant-derived stem cells. Cosmetics & Toiletries. 2010;125:61-69.
  6. Schmid D, Schurch C, Zulli F. Stimulation of stem cells for real rejuvenation. Mibelle Biochemistry. 2008.
  7. Juchaux F. Delaying effect of PhytoCellTec Malus Domestica on senescence of dermal fibroblasts. Mibelle Biochemistry.
  8. Sieber M. Effect of PhytoCellTec Malus Domestica on human stem cells. Mibelle Biochemistry.
  9. Cell Culture Research Institute. Effect of PhytoCellTec Malus Domestica on epidermal progenitor cells. Mibelle Biochemistry.
  10. PhytoCellTec Malus Domestica Plant stem cells for skin stem cell protection. Mibelle Biochemistry.
  11. Oula M-L. Comparative study of two anti-aging facial treatments. Final report of 12 E-0130. Sanofi Consumer Health. 2012.
  12. Vincience Survixyl IS Presentation
  13. Vincience Quintescine IS Presentation

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