UV Protection by Natural Products: C. myrrha Oil Versus Sunscreen
August 2018 | Volume 17 | Issue 8 | Original Article | 905 | Copyright © August 2018
Nikhil Chakravarty,a,b Caitlyn Kellogg,b Jason Alvarez,b,c Ozlem Equils MD FAAP,b,d,e Margie Morgan PhDe
aUniversity of California, Irvine, Irvine, CA bMiOra Foundation, Los Angeles, CA cCalifornia State University Northridge, Northridge, CA dUniversity of California, Los Angeles, School of Medicine, Los Angeles, CA eCedars-Sinai Medical Center, Los Angeles, CA
Exposure to various types of ultraviolet (UV) radiation from the sun has been linked to skin cancer. Use of sunscreen can reduce the damaging and carcinogenic effects of UV radiation. However, multiple chemicals in sunscreen can trigger allergic responses, making people less inclined to use sunscreen. Thus, finding natural, plant-based alternatives to sunscreen with similar efficacy has become an important area of research. Myrrh oil, extracted from the shrub Commiphora myrrha, has been used in the treatment of topical wounds and studies have shown that it may provide protection against solar radiation. This study sought to further investigate if C. myrrha oil can confer protection against UV radiation. A UV-sensitive strain of Saccharomyces cerevisiae was grown in petri dishes with one half covered by aluminum foil and the other half covered by clear polyethylene food wrap. The polyethylene half was treated with either SPF 15 or SPF 30 sunscreen, C. myrrha oil or a combination of C. myrrha oil and either sunscreen. The plates were exposed to sunlight. Colony death was quantified using visual estimation. While UV blocking by C. myrrha oil alone was not as effective as that by the synthetic sunscreen, the 1:1 combination of C. myrrha oil and SPF 15 sunblock was significantly more effective than SPF 15 sunblock alone to prevent S. cerevisiae death. These data suggest that naturally-based sunscreens supplemented with synthetic UV deterrents may provide a more holistic approach to prevent UV-induced skin damage.J Drugs Dermatol. 2018;17(8):905-907.
The link between exposure to solar ultraviolet (UV) radiation and cancer incidence is well-established.1,2 Interventions to promote the use of protection against UV radiation, such as the use of sunscreen, have proved successful across various age ranges.3 Though sunscreen is successful in protecting against UV radiation, some of the FDA-approved ingredients used in sunscreens, most commonly benzophenones and dibenzoylmethanes, can trigger allergic and photoallergic contact dermatitis (PACD) reactions.4 In addition, approximately 1-2% of the general population is allergic to fragrances present in sunscreens.5 Recent studies that replaced some synthetic ingredients in sunscreens with natural alternatives have yielded no change in sun protection factor (SPF).6Myrrh oil, which is extracted from Commiphora myrrha, a shrub indigenous to Ethiopia and Somalia, is used in the treatment of topical wounds and has been shown to have topical anti-microbial properties.7,8 In addition, it has been shown to provide protection against UV-induced squalene peroxidation.9,10Here we investigated the potential for C. myrrha oil to be a natural alternative to synthetic, traditional sunscreens. This study sought to determine if C. myrrha essential oil could confer SPF.
MATERIALS AND METHODS
Cell CultureA UV-sensitive strain of the yeast Saccharomyces cerevisiae (Carolina Biological Supply Company, US) was plated on Yeast Extract + Dextrose (YED) and incubated for 48 hours at 30oC.Treatment and UV ExposureHalf of the plates were covered with clear polyethylene food wrap and the other half was covered with aluminum foil (Figure 1). The polyethylene half was covered with two drops of either C. myrrha oil (Healing Solutions, US), sunscreen with either SPF 15 or 30 (Sun Pharmaceuticals Corporation, India), or a 1:1 combination of sunscreen (SPF 15 or 30) and C. myrrha oil. The plates were then exposed to sunlight for an amount of time dependent on time of day (as defined by a kit supplied with the S. cerevisiae by Carolina Biological Supply Company) and were incubated for another 48 hours.AnalysisS. cerevisiae growth was quantified by two blinded investigators; the investigators visually split the plates into grids and calculated the number of colonies that were alive on the test side divided by the number of colonies on the side covered with aluminum foil and protected from UV light. Table 1 rep-