HerbalEGram: Volume 9, Number 9, September 2012

In the summer of 2012, the nonprofit Environmental Working Group (EWG) updated its “9 Surprising Truths about Sunscreens” webpage, stating that the US Food and Drug Administration has announced that there is no evidence that sunscreens prevent skin cancer, sunscreen users can have higher rates of melanoma, products marketing higher SPFs do not conclusively protect better, and that many sunscreens contain ingredients that are potentially carcinogenic when degraded by sunlight.¹ While EWG is encouraging companies to produce safer and more effective sunscreen products, recent studies and research reviews suggest that several herbs might help to provide sun-protection benefits.^2-4


Orally Ingested Herbs

In a research review in the August 2012 issue of the Journal of Alternative and Complementary Therapies (JACT), co-authors Eric Yarnell, ND, and Kathy Abascal, RH (AHG), JD, write: “Unlike anything in conventional medicine, there are several herbal products that appear to be active, when taken orally, to prevent sunburn or other local negative effects of excessive UV exposure.”²

Drs. Yarnell and Abascal focused on reviewing the current research on 2 main herbs: golden polypody (also called golden serpent fern; Phlebodium aureum) and green tea (Camellia sinensis).² While most sunscreens attempt to provide topical protection by absorbing or blocking ultraviolet (UV) rays, golden polypody’s antioxidant compounds work inside the body to stop UV’s effects. A small human study on 9 participants in 2004 found that a golden polypody extract taken orally resulted in a “significant decrease” in skin redness, as well as fewer sunburned skin cells, less DNA damage, less UV-induced skin cell division, and a decrease in introduction of mast cells, which play an important role in cancer.^2,5 A slightly larger study in 1997 on 21 participants found similar results.^2,6 Golden polypody also has been studied as a treatment for several sunlight-related diseases in humans, including vitiligo and solar urticaria, with results showing improvements in re-pigmentation and reduction of photodermatitis, respectively.²

“The data on golden serpent fern extracts look very promising for counteracting negative effects of UV exposure in healthy people wishing to avoid sunburn and in patients with conditions aggravated by the sun,” wrote Drs. Yarnell and Abascal.² “Further research is warranted, but it appears that this herb is safe and effective for clinical use as one of the first oral herbal photoprotectives.”

The JACT article also discusses green tea as being potentially helpful to “abate negative effects of excessive UV exposure” when ingested internally.² A 2009 study on 56 women taking 250 mg of a green tea extract twice daily found no statistical improvements over placebo, but a 2010 study on 60 women ingesting a larger dose of 1,402 mg green tea polyphenols in a beverage did show a decrease in skin aging and photodamage by up to 25% after 12 weeks.^2,6 “These results suggest that either the whole herb and/or larger doses should be used to have any chance of efficacy,” wrote Drs. Yarnell and Abascal.²

Additional research has shown several other ingested botanicals to be helpful at protecting against sun damage. Tomato (Lycopersicon esculentum) paste was shown in a 2010 study of 20 women to increase protection against photodamage by about 33%.⁷ An epidemiological study on adults in the state of Arizona during the late 1990s found that participants who did not have skin cancer consumed more citrus peel (but not citrus fruit and juice), which the researchers suggested could be due to the chemo-preventative effects of the peel’s component d-limonene.⁸


Topical Herbs for Sun Protection

In addition to orally ingested botanicals, several herbs might provide sun protection when applied to the skin. While a combination of 10% green tea cream on the skin and 300 mg of a green tea extract taken orally did not statistically improve photoaging (although it did improve participants’ skin elasticity), another study found that 2% and 3% green tea extract provided “significant protection” against photoaging.² Drs. Yarnell and Abascal point out in the JCAT article that the sun’s rays quickly degrade green tea extracts after about an hour of exposure on the skin but that combining it with other substances could lengthen its protective life.

According to Sonia Badreshi-Bansal, MD, a dermatologist with a private practice in California, many conventional dermatologists believe in the benefits imparted by some topical botanicals, especially when used with conventional sunscreens. “We carry a private label brand that has high concentration of green tea, along with other antioxidants such as [vitamins] C and E that potentiate the sunscreen effects," said Dr. Badreshi-Bansal (email, August 27, 2012). “In combination they work wonderfully for the synergistic effect.” 

Early lab and mice research has shown propolis, bee-collected plant resins and compounds, to provide significant topical sun protection factor (SPF) as well as protection against UV-A rays (SPF indicates only UV-B blockage).² In vitro and animal research suggests topical sun protection potential for Pycnogenol^® (an extract of the bark of the French maritime pine, Pinus pinaster), and a red grape (Vitis vinifera) seed extract.² Exciting research from the King’s College London (KCL) is investigating the sun protection potential of algae growing on the Great Barrier Reef in Australia. Researchers found that the algae contain compounds that protect the shallow-water reef from sun damage and also that the fish eating the algae experience protection from the sun.⁹ For the past year, the researchers have been working on reproducing the compound in the laboratory with the hopes of developing a sunscreen for human use.

Although promising, the current body of research on botanicals for sun protection is not yet conclusive, and according to the International Agency for Research on Cancer, clothing, hats, and shade are the best “primary barriers to UV radiation.”¹

“More thorough and complete research including work on optimal dosing and preparations — with direct comparisons to existing synthetic agents in every case to prove equivalence or superiority in terms of efficacy and safety — are urgently needed,” wrote Drs. Yarnell and Abascal.²


—Lindsay Stafford Mader


References

1. Sunscreens exposed: nine surprising truths. Environmental Working Group’s Skin Deep Sunscreens 2012 website. Available at: http://breakingnews.ewg.org/2012sunscreen/sunscreens-exposed/sunscreens-exposed-9-surprising-truths. Accessed August 7, 2012.

2. Yarnell E, Abascal K. Herbal sunscreens and ultraviolet protectants. Journal of Alternative and Complementary Therapies. 2012;18(4):192-198.

3. Keville K. Natural sun protection. The Herb Companion. July/August 2002. Available at: http://www.herbcompanion.com/body-care/Save-Your-Skin.aspx. Accessed August 30, 2012.

4. Rubino J. 9 emerging natural sunscreen ingredients. New Hope 360. August 7, 2012. Available at: http://newhope360.com/beauty-cosmetics-amp-skincare/9-emerging-natural-sunscreen-ingredients?cid=nl_360_daily#slide-6-field_images-262931. Accessed August 14, 2012.

5. Middelkamp-Hup MA, Pathak MA, Parrado C, et al. Oral polypodium leucotomos extract decreases ultraviolet-induced damage of human skin. J Am Acad Dermatol 2004;51:910–918.

6. González S, Pathak MA, Cuevas J, et al. Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-in- duced phototoxic reactions as well as depletion of Langerhans cells in human skin. Photodermatol Photoimmunol Photomed. 1997;13:50–60.

7. Heinrich U, Moore CE, De Spirt S, et al. Green tea polyphenols provide photoprotection, increase microcirculation, and modulate skin properties of women. J Nutr 2011;141:1202–1208.

8. Rizwan M, Rodriguez-Blanco I, Harbottle A, et al. Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo: a randomized controlled trial. Br J Dermatol. 2011;164(1):154–162.

9. Hakim IA, Harris RB, Ritenbaugh C. Citrus peel use is associated with reduced risk of squamous cell carcinoma of the skin. Nutrition and Cancer. 2000;37(2):161–168.

10. Coral could be used to create sunscreens [press release]. London, England: King’s College London. August 31, 2011. Available at: www.kcl.ac.uk/newsevents/news/newsrecords/2011/08August/Tropical-coral-create-novel-sun-screens-human-use-scientists.aspx. Accessed August 30, 2012.