Mycosporine-like Amino Acids: Sunscreen for Coral… and People too

Written By Sofia Perez

As the summer drifts away and the socially distant chill of a winter under COVID-19 dawns, there are few things more pleasant than the thought of a lazy day at the beach. Imagine feeling the sand between your toes as you wade in the water, squinting as you stare into the shimmering blue horizon. On days like this, everything feels perfect, like the world can truly be reduced to a Jimmy Buffet song.

But days like this end in tragedy the moment you look into a mirror and see what can only be described as a human tomato. You turn to your memory for solace only to realize you never reapplied… As it turns out, a high SPF sunscreen can’t protect you forever. What was once a Jimmy Buffet song has now turned into you scavenging the nearest pharmacy for aloe vera.

In defense of the sunscreen in this situation (which was not reapplied), it did its best to filter or absorb ultraviolet radiation (UVR). This is extremely important in order to prevent any skin damage, especially when spending too much time in the sun. There are three types of UVR: UVA, UVB, and UVC. For us here on the ground, only UVA and UVB are concerning because UVC is absorbed by the atmosphere. However UVA radiation (315-400nm) is known to damage the epidermis, cause wrinkles, skin aging, and skin cancer. Additionally, with a higher energy than UVA, albeit less common, UVB (280-315nm) is a major carcinogen and tissue hazard which is responsible for sunburn, skin cancer, and eye damage. To avoid these horrific predicaments, make a note to always buy broad spectrum sunscreen which protects from both UVA and UVB.

So far, the message seems clear, but perhaps you already wear plenty of sunscreen and boast pristinely perfect skin. If so, splendid! But you must also watch out for the culprits within sunscreen. Some of the most common ingredients used are octinoxate, homosalate, octocrylene, octisalate, avobenzone, oxybenzone, and titanium/zinc oxide. While these might not ring any bells, some of these ingredients are known to have adverse effects not only when washed into the sea  but also when used by people. One particularly contentious example is oxybenzone, which can cause allergic skin reactions and through enough exposure is even thought to disrupt hormones.

While this is alarming, oxybenzone has been FDA-approved for forty years and is still found in approximately two thirds of all products analyzed for the EWG’s 2019 sunscreen guide. Not only this, but oxybenzone has also been known to harm or even kill coral. However, there is still hope. In a poetic way that seems to transcend the world of skin care, there is an answer to the plea for improvement from the very environment from which our sunscreen harms.

Mycosporine-like amino acids (MAAs) are microbial sunscreens which can be found in marine environments. They are colorless, water-soluble, UV-absorbing compounds which are characterised by a small molecular mass and high molar extinction coefficients(how strongly a substance absorbs light at a particular wavelength).

There are over thirty types found in nature eg. mycosporine-glycine, mycosporine-2-glycine, shinorine, palythine, porphyra, etc. which are characterised by their UV-absorbing & antioxidative capacities. Mostly found in marine species such as phytoplankton, cyanobacteria, fungi, algae, and coral, these amino acids represent a natural defense against UVR. In corals, MAAs are transferred through symbiosis with algae and help to prevent damage to photosynthetic mechanisms. So perhaps there is an opportunity for MAAs to protect humans as well.

Firstly, it is important to understand the reasons why MAAs aren’t already in widespread use in the skin-care industry. This is in large part due to a poor understanding of various biosynthesis pathways involved in making specific MAAs in an industrially economic manner. Additionally, the chiral centres of these amino acids make them highly difficult to synthesise chemically. In order to solve the unfortunate and ever-present issue of financial cost in this case, scientists have proposed alternative MAA-like compounds which are structurally similar to MAAs and are cheaper to synthesize.

Moreover, even if MMAs were widely used, they are water-soluble, making them a poor candidate for application before water sports or a beach vacation. This essentially means that no, sunscreen with MAAs will not prevent your sunburns during your beach visits. But don’t despair! MAAs still offer a valuable opportunity for normal day-to-day use, and after all, most days are not spent at the beach or in the water.

In fact, there are products already available, such as Helioguard 365, which uses the MAAs porphyra-334 and shinorine from the red algae Porphyra. It should be noted that the concentration of MAAs in Helioguard 365 is miniscule compared to the concentration of UVR filters in most sunscreens. Nevertheless, it still serves as a beginning of a wider development of eco-friendly sunscreens.

So while it may be not the time of year to race down to the beach and spend a day in the sand, it is definitely time to prepare for a sunscreen revolution! It is not only vital that we use it, but that we produce it responsibly and safely using ingredients that are safe for human health as well as the environment.

References

Alain Ko, Stephen. 2016. “‘Physical’ vs. ‘Chemical’ Sunscreens and Other Sunscreen Myths.” KindofStephen. September 1, 2016. https://kindofstephen.com/physical-vs-chemical-sunscreens-myths/.

Barr, Sabrina. 2019. “Sunscreen That Lasts 10 Times Longer Could Be Possibility in near Future.” The Independent. October 18, 2019. https://www.independent.co.uk/life-style/sunscreen-suncream-eco-friendly-longer-lasting-protein-plants-discovery-a9161921.html.

Chrapusta, Ewelina, Ariel Kaminski, Kornelia Duchnik, Beata Bober, Michal Adamski, and Jan Bialczyk. 2017. “Mycosporine-Like Amino Acids: Potential Health and Beauty Ingredients.” Marine Drugs 15 (10). https://doi.org/10.3390/md15100326.

Korin Miller. 2019. “Is Oxybenzone In Sunscreen Dangerous? Here’s How It May Impact Your Health.” Prevention. Prevention. May 22, 2019 https://www.prevention.com/health/a27556739/oxybenzone-sunscreen-safety/.

Lawrence, Karl P., Paul F. Long, and Antony R. Young. 2019. “Mycosporine-Like Amino Acids for Skin Photoprotection.” Current Medicinal Chemistry 25 (40): 5512–27. https://doi.org/10.2174/0929867324666170529124237.

Ohara, Penny. 2017. “Shedding Light on Sunscreens.” Curious. Nova. November 23, 2017. https://www.science.org.au/curious/sunscreen.

Rosic, Nedeljka. 2019. “Mycosporine-Like Amino Acids: Making the Foundation for Organic Personalised Sunscreens.” Marine Drugs 17 (11): 638. https://doi.org/10.3390/md17110638.

Sunscreens, EWG’s 2020 Guide to. n.d. “EWG’s 2020 Guide to Safer Sunscreens.” https://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/#:~:text=The%20most%20common%20sunscreens%20contain.