Life Extension Magazine®

Woman with clear skin using seaweed extract for outer care

Protect the Skin's Outer Barrier

Two plant-stem cell extracts protect skin barrier function and generate epidermal renewal to keep skin fresh and smooth.

Scientifically reviewed by:  Dr. Gary Gonzalez, MD, in May 2022. Written by: Robert Goldfaden and Gary Goldfaden, MD.

For skin to maintain youthful hydration, a strong supporting barrier is required to lock in moisture and keep out irritants that accelerate the appearance of wrinkles.

Loss of barrier function occurs in response to normal aging, ultraviolet radiation, and other external factors.1,2

Scientists have identified 2 plant-stem cell extracts that have been shown to rebuild and protect the skin’s surface.

This topical formula can induce meaningful rehydrating effects on aging skin.

What you need to know

Two novel plant extracts have been identified for their ability to stimulate epidermal renewal of barrier function, combat sun-induced inflammation and enhance the water-holding capacity of skin surface cells. Find out more inside this insightful article.

Importance of the Skin Barrier Function

Test Tubes and Beekers

The skin’s outermost layer (stratum corneum) acts as a barrier to the external environment.3-5 Preserving skin barrier integrity as we age is crucial for keeping skin hydrated, soft, and youthful.

Repeated sun exposure,6 extreme temperatures,7,8 and over-cleansing9 take their toll on barrier function, creating cracks that allow moisture to escape. What ensue are dryness, flakiness, and wrinkles characteristic of dehydrated skin.

Euterpe oleracea Fruit Extract

Plants survive harsh environmental conditions due to their reservoirs of stem cells, which generate protective compounds when under extrinsic stress.10,11

For example, Euterpe oleracea (açaí or cabbage palm fruit) is a fruit tree that withstands high levels of ultraviolet radiation in Central and South America, thanks to its ability to synthesize a secondary metabolite called ferulic acid.12,13

When topically applied to human skin, Euterpe oleracea fruit extract prevents sun-induced oxidative stress and inflammation by neutralizing toxic free radicals.14-17 This finding is noteworthy since chronic sun exposure is one of the primary causes of decreased skin barrier function and increased moisture loss.

Additional research shows that Euterpe oleracea fruit extract rejuvenates aging skin by replenishing its energy supply in the form of adenosine triphosphate (ATP), which naturally decreases with age.17,18 This increased fuel availability promotes continuous cell renewal of the skin’s surface to leave it looking younger, healthier, and refreshed.

By strengthening and defending the skin’s barrier function, Euterpe oleracea fruit extract produces immediate and long-term rehydrating effects. In a human study, topical application of Euterpe oleracea fruit extract improved skin moisture by 51% within 24 hours and by 102% after 4 weeks.17

Centella asiatica Extract

Centella asiatica (also known as gotu kola) is another plant that depends upon secondary metabolites called triterpenoids to thrive in the different climate zones of subtropical and tropical regions.19-21

As the skin ages, it has a diminished capacity to bounce back from the damaging effects of environmental stressors. Researchers are finding that Centella asiatica extract has potent free-radical scavenging and anti-inflammatory actions that accelerate wound healing. This in turn repairs cracks to improve the protective barrier function.22-25

This effect was demonstrated in a clinical study in which healthy volunteers topically applied Centella asiatica extract or a placebo to their forearms twice daily for 4 weeks.25 At the end of the study, participants underwent exposure to a common skin irritant called methyl nicotinate and 2 hours later were evaulated for erythema, skin pH, and transepidermal water loss.

The results showed significant reductions in all of these skin parameters on the side treated with Centella asiatica extract compared with the placebo side, indicating better preservation of barrier function integrity.25 Researchers believe that Centella asiatica extract rapidly increased epidermal renewal through antioxidant and anti-inflammatory activity to reduce skin irritation.

The same study also observed a significant 12% increase in stratum corneum hydration on the side treated with Centella asiatica extract compared with the placebo side.25 This might be due to triterpenoids in Centella asiatica extract that act as powerful sponges to attract and capture water molecules within the epidermis.25 Another possible mechanism relates to its strong inhibition of the enzyme hyaluronidase.26 This translates to higher levels of hyaluronic acid in the stratum corneum, which is shown to boost hydration and support barrier function.27,28

Seaweed Extracts

Woman Smiling

Few plants stack up to the wealth of skin nourishing nutrients found in Chondrus crispus (Irish moss), a red seaweed that lives off the rocky shores of the North Atlantic Ocean. With its high content of essential vitamins, minerals, and phytonutrients, Chondrus crispus naturally drives cellular repair and regeneration in response to external enemies.29,30 When you add in its well-known moisturizing compound, carrageenan,31 Chondrus crispus is a potent and often overlooked weapon to hydrate skin optimally.

Laminaria digitata (brown seaweed) is rich in compounds called fucoidans. These polysaccharides quell inflammation and inhibit protein-degrading enzymes that destroy skin from the inside out.32,33 Remarkably, Laminaria digitata facilitates cell-to-cell signaling to maintain the function and structure of youthful skin.34

Unique Plant Extracts Enhance Skin Hydration
  • The skin’s outer surface (stratum corneum) acts as a barrier to retain moisture and nutrients, while defending against the entry of harmful bacteria and irritants, to keep skin healthy, smooth, and supple.
  • Barrier function naturally declines with age and is exacerbated by chronic sun exposure and other external factors.
  • Scientists have identified 2 plants—Euterpe oleracea and Centella asiatica—that produce secondary metabolites to help them survive some of the harshest environmental conditions.
  • Extracts of both plants have been shown to repair and protect skin barrier function from ultraviolet radiation and other environmental stressors.
  • Seaweed extracts provide an impressive repertoire of skin-supporting nutrients that further support barrier function and skin vitality.
  • These compounds have now been incorporated into one topical formula that restores optimal hydration in aging and dehydrated skin to leave it visibly smoother, softer, and younger looking.


Loss of moisture as we mature causes smooth, vibrant, and healthy skin to take on a rough, uneven, and dull appearance that makes wrinkles and fine lines more apparent.

Two plant-stem cell extracts—Euterpe oleracea and Centella asiatica—synthesize secondary metabolites shown to stimulate epidermal renewal of barrier function, combat sun-induced inflammation, and enhance the water-holding capacity of skin surface cells.

These natural extracts, along with skin-supporting seaweed extracts, have been combined into one topical formula to optimize skin hydration and promote a more youthful appearance.

Gary Goldfaden, MD, is a clinical dermatologist and lifetime member of the American Academy of Dermatology. He is the founder of Academy Dermatology in Hollywood, FL, and Cosmesis Skin Care. Dr. Goldfaden is a member of the Life Extension® Medical Advisory Board. All Cosmesis products are available online.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


  1. Boireau-Adamezyk E, Baillet-Guffroy A, Stamatas GN. Age-dependent changes in stratum corneum barrier function. Skin Res Technol. 2014 Nov;20(4):409-15.
  2. Biniek K, Levi K, Dauskardt RH. Solar UV radiation reduces the barrier function of human skin. Proc Natl Acad Sci U S A. 2012 Oct 16;109(42):17111-6.
  3. Menon GK, Cleary GW, Lane ME. The structure and function of the stratum corneum. Int J Pharm. 2012 Oct 1;435(1):3-9.
  4. Jensen JM, Proksch E. The skin’s barrier. G Ital Dermatol Venereol. 2009 Dec;144(6):689-700.
  5. Proksch E, Brandner JM, Jensen JM. The skin: an indispensable barrier. Exp Dermatol. 2008 Dec;17(12):1063-72.
  6. Alhasaniah A, Sherratt MJ, O’Neill C. The impact of ultraviolet radiation on barrier function in human skin: Molecular mechanisms and topical therapeutics. Curr Med Chem. 2017 Nov 6.
  7. Engebretsen KA, Johansen JD, Kezic S, et al. The effect of environmental humidity and temperature on skin barrier function and dermatitis. J Eur Acad Dermatol Venereol. 2016 Feb;30(2):223-49.
  8. Goad N, Gawkrodger DJ. Ambient humidity and the skin: the impact of air humidity in healthy and diseased states. J Eur Acad Dermatol Venereol. 2016 Aug;30(8):1285-94.
  9. Mukhopadhyay P. Cleansers and their role in various dermatological disorders. Indian J Dermatol. 2011 Jan;56(1):2-6.
  10. Nascimento NC, Fett-Neto AG. Plant secondary metabolism and challenges in modifying its operation: an overview. Methods Mol Biol. 2010;643:1-13.
  11. Hussain MS, Fareed S, Ansari S, et al. Current approaches toward production of secondary plant metabolites. J Pharm Bioallied Sci. 2012 Jan;4(1):10-20.
  12. Del Pozo-Insfran D, Brenes CH, Talcott ST. Phytochemical composition and pigment stability of Acai (Euterpe oleracea Mart.). J Agric Food Chem. 2004 Mar 24;52(6):1539-45.
  13. Pacheco-Palencia LA, Mertens-Talcott S, Talcott ST. Chemical composition, antioxidant properties, and thermal stability of a phytochemical enriched oil from Acai (Euterpe oleracea Mart.). J Agric Food Chem. 2008 Jun 25;56(12):4631-6.
  14. Lin FH, Lin JY, Gupta RD, et al. Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. J Invest Dermatol. 2005 Oct;125(4):826-32.
  15. Saija A, Tomaino A, Trombetta D, et al. In vitro and in vivo evaluation of caffeic and ferulic acids as topical photoprotective agents. Int J Pharm. 2000 Apr 10;199(1):39-47.
  16. Murray JC, Burch JA, Streilein RD, et al. A topical antioxidant solution containing vitamins C and E stabilized by ferulic acid provides protection for human skin against damage caused by ultraviolet irradiation. J Am Acad Dermatol. 2008 Sep;59(3):418-25.
  17. Available at: Accessed January 14, 2019.
  18. Phillip JM, Aifuwa I, Walston J, et al. The Mechanobiology of Aging. Annu Rev Biomed Eng. 2015;17:113-41.
  19. Bylka W, Znajdek-Awizen P, Studzinska-Sroka E, et al. Centella asiatica in cosmetology. Postepy Dermatol Alergol. 2013 Feb;30(1):46-9.
  20. James J, Dubery I. Identification and quantification of triterpenoid centelloids in Centella asiatica (L.) Urban by densitometric TLC. JPC - Journal of Planar Chromatography - Modern TLC. 2011;24(1):82-7.
  21. Gohil KJ, Patel JA, Gajjar AK. Pharmacological Review on Centella asiatica: A Potential Herbal Cure-all. Indian J Pharm Sci. 2010 Sep;72(5):546-56.
  22. Shukla A, Rasik AM, Jain GK, et al. In vitro and in vivo wound healing activity of asiaticoside isolated from Centella asiatica. J Ethnopharmacol. 1999 Apr;65(1):1-11.
  23. Somboonwong J, Kankaisre M, Tantisira B, et al. Wound healing activities of different extracts of Centella asiatica in incision and burn wound models: an experimental animal study. BMC Complement Altern Med. 2012 Jul 20;12:103.
  24. Shukla A, Rasik AM, Dhawan BN. Asiaticoside-induced elevation of antioxidant levels in healing wounds. Phytother Res. 1999 Feb;13(1):50-4.
  25. Ratz-Lyko A, Arct J, Pytkowska K. Moisturizing and Antiinflammatory Properties of Cosmetic Formulations Containing Centella asiatica Extract. Indian J Pharm Sci. 2016 Jan-Feb;78(1):27-33.
  26. Nema NK, Maity N, Sarkar BK, et al. Matrix metalloproteinase, hyaluronidase and elastase inhibitory potential of standardized extract of Centella asiatica. Pharm Biol. 2013 Sep;51(9):1182-7.
  27. Bourguignon LY, Ramez M, Gilad E, et al. Hyaluronan-CD44 interaction stimulates keratinocyte differentiation, lamellar body formation/secretion, and permeability barrier homeostasis. J Invest Dermatol. 2006 Jun;126(6):1356-65.
  28. Kage M, Tokudome Y, Matsunaga Y, et al. Effect of hyaluronan tetrasaccharides on epidermal differentiation in normal human epidermal keratinocytes. Int J Cosmet Sci. 2014 Feb;36(1):109-15.
  29. Park K. Role of micronutrients in skin health and function. Biomol Ther (Seoul). 2015 May;23(3):207-17.
  30. Pimentel FB, Alves RC, Rodrigues F, et al. Macroalgae-Derived Ingredients for Cosmetic Industry—An Update. Cosmetics. 2018;5(1):2.
  31. Chopin T, Gallant T, Davison I. Phosphorus and Nitrogen Nutrition in Chondrus Crispus (Rhodophyta): Effects on Total Phosphorus and Nitrogen Content, Carrageenan Production, and Photosynthetic Pigments and Metabolism1. Journal of Phycology. 1995;31(2):283-93.
  32. Lee SH, Ko CI, Jee Y, et al. Anti-inflammatory effect of fucoidan extracted from Ecklonia cava in zebrafish model. Carbohydr Polym. 2013 Jan 30;92(1):84-9.
  33. Moon HJ, Lee SH, Ku MJ, et al. Fucoidan inhibits UVB-induced MMP-1 promoter expression and down regulation of type I procollagen synthesis in human skin fibroblasts. Eur J Dermatol. 2009 Mar-Apr;19(2):129-34.
  34. Song YS, Li H, Balcos MC, et al. Fucoidan promotes the reconstruction of skin equivalents. Korean J Physiol Pharmacol. 2014 Aug;18(4):327-31.