Curcumin Shows Promise as New Sunscreen Filter

It has been 20 years since the FDA approved a new sunscreen filter. However, positive outcomes in a recent murine study evaluating curcumin’s anti-inflammatory, antioxidant, and wound-healing properties could change that.¹ 

Delivered in encapsulated nanoparticles in a vehicle developed by the authors, this component of turmeric demonstrated efficacy in decreasing UV-induced cellular damage, oxidative stress, and inflammation, according to Adam Friedman, MD, FAAD, professor and chair of dermatology at George Washington University School of Medicine and Health Sciences in Washington, DC, and one of the study’s authors.

Adam Friedman, MD, FAAD

Friedman detailed the importance of the findings and what they could mean in the fight against skin cancer in an exclusive interview with Dermatology Times®.

Q: What first sparked your interest in exploring curcumin in relation to skin cancer? 

Adam Friedman, MD, FAAD: My first foray into the amazing world of curcumin was with wound healing and skin and soft tissue infections. I found that there was already an incredible body of knowledge. Curcumin, or diferuloylmethane, is a crystalline compound which gives the East Asian spice turmeric its bright orange-yellow color. The medicinal qualities of curcumin have been established for thousands of years and references to this spice have been seen in numerous countries and cultures throughout the world. 

Today there is growing scientific evidence suggesting curcumin’s utility in the treatment of chronic pain, osteoarthritis, and inflammatory dermatoses such as psoriasis; acceleration of wound closure; and bacterial, fungal, and viral skin infections, as well as cosmetic ailments such as dyspigmentation.

Although turmeric is commonly used in alternative medicine, curcumin has yet to emerge as a component of our mainstream dermatologic therapeutic armamentarium. Curcumin exerts its impact through a number of different pathways in the body. It is currently being investigated for therapeutic uses in various disease states ranging from cancer to autoimmune or inflammatory disorders. In addition, results from numerous studies have elucidated the protective effects of curcumin against various pollutants and cytotoxic agents, which also indicates that curcumin may be beneficial in a mitigatory or prophylactic role. That’s where this paper comes in. As curcumin is a potent anti-inflammatory and antioxidant, it would only make sense that it could protect [against] and mitigate injury from ultraviolet radiation. 

Q: Given its long history, why wasn’t curcumin at the forefront of adjuvant photoprotective treatment?

Friedman: Prior studies showed that curcumin decreased UV-induced inflammation, apoptotic changes in human keratinocytes and dermal fibroblasts, and the expression of matrix metalloproteinases. The problem was that its utility was hindered by poor aqueous solubility and rapid degradation in vivo. And, too, there was staining from the bright yellow-orange color. To overcome these limitations, we synthesized curcumin nanoparticles. That approach offered sustained topical delivery and enhanced bioavailability.

Q: You and your fellow authors developed and investigated nanoformulation curcumin (curc-np) in previous preclinical studies2-4 that focused on wound healing, infection, and oxidative stress. What brought about the decision to evaluate this compound’s potential in photoprotection?

Friedman: The data demonstrating its efficacy in wound healing, infection, and oxidative stress were factored into our decision to undertake this evaluation. So did the state of the industry. We’re seeing demands for an overhaul of the sunscreen industry, spiraling skin cancer rates, and increasing consumer interest in and understanding of the benefits of photoaging prevention. As we pointed out in the study background, the FDA recognizes only zinc oxide and titanium dioxide OTC sunscreens as safe, effective, and properly labeled.⁵ For some products, formulation instability is a problem. There are also safety concerns centering on organic filters.⁶ Clearly there is a need to explore new ingredients for skin protection and new vehicles to deliver them effectively.

Q: Did you find implications for curcumin beyond combating cancer?

Friedman: Actually, we focused more on preventive strategies. There was an incredible dearth of data examining whether curcumin could be used as an antineoplastic therapy. We have done studies looking at glioblastoma multiplex with our nanoparticles, for example, so there could be an opportunity there as well. 

Q: Do you see this as part of a growing trend to incorporate more natural therapies?

Friedman: Although the advantageous properties of curcumin in medicine are well established, its therapeutic potential thus far has been limited because of its poor bioavailability [soluble in water-based vehicles only up to 1 mg/mL] and its incredible ability to stain everything bright yellow-orange. This is why we turned to nanoparticle encapsulation to improve the cosmesis, enhance skin penetration, and allow for the sustained release of curcumin over time. I think there are many “natural” ingredients that have therapeutic potential but they may have limitations such as photolability, poor solubility, susceptibility to oxidation, or poor skin penetration or cell uptake, just to name a few.

It’s all about purposeful design and delivery. Without that, you hit a brick wall. Nanotechnology is one of several opportunities to capitalize on these high-drama ingredients. To deliver the undeliverable is the name of the game. 

Q: What would dermatologists need to consider when weighing curcumin as part of a treatment or prevention regimen? 

Friedman: Ideally this would be incorporated into a sunscreen or a moisturizer that would be used in conjunction with a sunscreen. 

The other unique opportunity we found in our animal experiments is that application of the curcumin nanoparticles post UVB exposure had a similar protective impact based on skin histology and cytokine profiling. This formulation could be used as a do-over, because let’s face it, we all forget to wear sunscreen here and there. I also see a curcumin formulation in the same vein as some of the products which function as photoprotection adjuvants to be used with sunscreen, like polypodium leucotomos or SunSpheres in L’Oréal sunscreens.

Q: What surprised you most about the results? What still needs to be studied to maximize outcomes? 

Friedman: What I was most surprised by was how little the curcumin in coconut oil, not in nanoparticles, did for these animals. Once again, that highlights the importance of vehicles. I also was impressed by how the nanoparticles minimized the yellow-orange discoloration. 

Q: What are the next steps? 

Friedman: Mouse studies are but a small step forward. The good news is both curcumin and the nanoparticle platform I codesigned have an exceedingly high amount of safety data—even some human phase 1-like toxicity studies. To take this to the next level always requires one thing…funding.

Disclosure:

Friedman is an inventor of the described technology, which has been licensed to Zylo Therapeutics for commercial development.

References:

1. Adusumilli NC, Mordorski B, Nosanchuk J, Friedman JM, Friedman AJ. Curcumin nanoparticles as a photoprotective adjuvant. Exp Dermatol. 2021;30(5):705-709. doi:10.1111/exd.14282

2. Liang H, Friedman JM, Nacharaju P. Fabrication of biodegradable PEG-PLA nanospheres for solubility, stabilization, and delivery of curcumin. Artif Cells Nanomed Biotechnol. 2017;45(2):297-304. doi:10.3109/21691401.2016.1146736 

3. Krausz AE, Adler BL, Cabral V, et al. Curcumin-encapsulated nanoparticles as innovative antimicrobial and wound healing agent. Nanomedicine. 2015;11(1):195-206. doi:10.1016/j.nano.2014.09.004

4. Baltazar LM, Krausz AE, Souza ACO, et al. Trichophyton rubrum is inhibited by free and nanoparticle encapsulated curcumin by induction of nitrosative stress after photodynamic activation. PLoS One. 2015;10(3):e0120179. doi:10.1371/journal.pone.0120179

5. Sunscreen drug products for over-the-counter human use. Federal Register. February 26, 2019. Accessed June 18, 2021. https://www.feder alreg ister.gov/d/201903019

6. Mancebo SE, Hu JY, Wang SQ. Sunscreens: a review of health benefits, regulations, and controversies. Dermatol Clin. 2014;32(3):427-438, x. doi:10.1016/j.det.2014.03.011