Exploring Mycosporine-like Amino Acid UV-Absorbing Natural Products for a New Generation of Environmentally Friendly Sunscreens

Abstract

Human skin needs additional protection from damaging ultraviolet radiation (UVR: 280–400 nm). Harmful UVR exposure leads to DNA damage and the development of skin cancer. Available sunscreens offer chemical protection from detrimental sun radiation to a certain extent. However, many synthetic sunscreens do not provide sufficient UVR protection due to the lack of photostability of their UV-absorbing active ingredients and/or the lack of ability to prevent the formation of free radicals, inevitably leading to skin damage. In addition, synthetic sunscreens may negatively affect human skin, causing irritation, accelerating skin aging and even resulting in allergic reactions. Beyond the potential negative effect on human health, some synthetic sunscreens have been shown to have a harmful impact on the environment. Consequently, identifying photostable, biodegradable, non-toxic, and renewable natural UV filters is imperative to address human health needs and provide a sustainable environmental solution. In nature, marine, freshwater, and terrestrial organisms are protected from harmful UVR through several important photoprotective mechanisms, including the synthesis of UV-absorbing compounds such as mycosporine-like amino acids (MAAs). Beyond MAAs, several other promising, natural UV-absorbing products could be considered for the future development of natural sunscreens. This review investigates the damaging impact of UVR on human health and the necessity of using sunscreens for UV protection, specifically UV-absorbing natural products that are more environmentally friendly than synthetic UV filters. Critical challenges and limitations related to using MAAs in sunscreen formulations are also evaluated. Furthermore, we explain how the genetic diversity of MAA biosynthetic pathways may be linked to their bioactivities and assess MAAs’ potential for applications in human health.

Biotechnological Potential of Macroalgae during Seasonal Blooms for Sustainable Production of UV-Absorbing Compounds

“…To be able to improve the biotechnological application and use of MAAs in cosmetics and for medical purposes, a number of challenges need to be overcome, including the lack of sufficient research regarding the steps necessary for obtaining purified MAA standards, as well as overcoming strong water solubility issues and the low yields of MAAs coming from natural resources. These challenges are in some parts overpowered by an application of various methods for MAA isolation and characterizations [139] and via a use of heterologous expression systems [127,[140][141][142] and/or by stimulation of MAA synthesis via specific nutrient and UVR stimulative conditions [90,128,[143][144][145][146]. Recovered MAA quantities isolated from different red algae including bloom-forming Gracilaria sp.…”

Optimizing the Extraction of Bioactive Compounds from Porphyra linearis (Rhodophyta): Evaluating Alkaline and Enzymatic Hydrolysis for Nutraceutical Applications

“…In addition, MAAs’ molecules act as antioxidants [ 46 , 47 , 48 , 49 , 50 ] and demonstrate anticancer [ 51 , 52 ], anti-photoaging [ 50 , 53 , 54 , 55 ], wound-healing [ 56 ], and anti-inflammatory [ 48 , 51 ] effects. MAAs are being explored as a new generation of environmentally friendly sunscreens [ 57 , 58 , 59 ].…”

The Role of Nitrate Supply in Bioactive Compound Synthesis and Antioxidant Activity in the Cultivation of Porphyra linearis (Rhodophyta, Bangiales) for Future Cosmeceutical and Bioremediation Applications

“…The main function of MAAs is their photoprotective ability, described as "microbial sunscreens" [11][12][13]. Additionally, MAAs have antioxidant properties, and they have been studied for their anti-cancer, anti-photoaging, wound healing, and anti-inflammatory effects [14][15][16]; currently, MAAs are also being investigated as a new generation of eco-friendly sunscreens [17][18][19].…”