Experts Q&A about UV-protecting properties of algae and plant derivatives
We discussed with Florent Allais, Professor of Green Chemistry and Director and at URD ABI - AgroParisTech (France) and Prof. Vasilios Stavros, Professor of Physical Chemistry, at the University of Birmingham (UK) to gain a deeper understanding on how new-generation UV filters are set to revolutionize the suncare industry.
As the demand for hybrid and versatile sun care products grows, new ingredients are being introduced into formulations, offering more options to the formulator palette. Research in algae, plant, and herb derivatives demonstrates natural UV-protecting capabilities. According to experts in dermatology, they can replace the chemical filters in “green” sunscreen formulations while being a rich source of antioxidants and polyphenols [1].
Algae are promising for such purpose, as they produce microspores rich in amino acids that naturally protect plants from UV damage: this inherent UV defense can be harnessed in biomimetic formulations, offering enhanced sun protection via compounds called “mycrosporine-like amino-acids” (MAAs).
What properties do new-generation sunscreens need to have to replace current filters?
Florent: The novel sunscreens must possess major properties:
- Being able to absorb UVs (UVA, UVB, both, and eventually blue light)
- Being photostable for a period of time long enough to protect customers and avoid too many applications on skin
- Be safe for both customers and the environment (e.g. corals)
Multifunctional additives/ingredients are highly sought by industry, therefore UV filters that also exhibit extra properties – such as antioxidant, antityrosinase, antimicrobial – are of great interest.
Vasilios: From a fundamental spectroscopic viewpoint, a UV filter must absorb radiation, and from an excited state, undergo molecular processes that ultimately leave the UV filter unchanged. In other words, the UV filter should absorb this energy and convert this to harmless heat, bypassing any photodegradation or light emission.
The former (photodegradation) could generate toxic reactive oxygen species (ROS) whilst the later (light emission) could lead to surrounding biological molecules absorbing this emitted radiation and undergo further reactions.
What promising innovations are underway or desirable in suncare science?
Florent: UV filters mimicking what is found in nature, e.g., mycosporine-like amino-acids, are probably the most promising alternatives to current decried petro-based sunscreens.
Vasilios: Learning from nature is leading the way. For example, mycosporine-like amino acids (MAAs), which are the UV filters of microbial species such as algae have impressive absorption strength as well as incredibly low photodegradation. There is therefore (clearly) enormous potential in developing next generation UV filters based on MAAs. The difficulty is in their synthesis which needs to be overcome.
How these new molecules are answering today's expectations regarding efficacy, regulation, safety and environment concerns?
Florent: As they mimic natural compounds that have been optimized by Mother nature for millions of years, these UV filters shall be able to not only effectively absorb UV radiation, but also not to exhibit any deleterious effects on the environment.
Vasilios: MAAs are produced by microbial species, many of which are exposed to intense radiation. These species (e.g. algae) have had many years to optimise the most effective UV filter. And MAAs are the end product! MAAs are natural, and (as far as I am aware) harmless to aquatic species and the environment. This inevitably is a major bonus in terms of safety and allays any environmental concerns.
What are the challenges of these new generation UV filters? (production, manufacturing cost, organoleptic impacts...)
Florent: Extracting natural UV filters (e.g., mycosporine-like aminoacids) directly from biomass is not only costly but does not provide them in quantities large enough to address the market. Mimicking nature is not easy when it comes to synthesizing these compounds. The chemical process is quite often complicated and costly. Although the alternative biotechnological approach may be easier to implement, they are generally even more costly!
Besides the synthetic/production aspects, registering new UV filters is also a major bottleneck as these compounds are usually not present in the China list, thus requiring lengthy and costly registration processes.
Sources:
[1] Sunscreens: What might the future hold? https://www.jintegrativederm.org/article/92544-sunscreens-what-might-thefuture-hold