Mycosporine-Like Amino Acids: Making the Foundation for Organic Personalised Sunscreens

Abstract

The surface of the Earth is exposed to harmful ultraviolet radiation (UVR: 280–400 nm). Prolonged skin exposure to UVR results in DNA damage through oxidative stress due to the production of reactive oxygen species (ROS). Mycosporine-like amino acids (MAAs) are UV-absorbing compounds, found in many marine and freshwater organisms that have been of interest in use for skin protection. MAAs are involved in photoprotection from damaging UVR thanks to their ability to absorb light in both the UV-A (315–400 nm) and UV-B (280–315 nm) range without producing free radicals. In addition, by scavenging ROS, MAAs play an antioxidant role and suppress singlet oxygen-induced damage. Currently, there are over 30 different MAAs found in nature and they are characterised by different antioxidative and UV-absorbing capacities. Depending on the environmental conditions and UV level, up- or downregulation of genes from the MAA biosynthetic pathway results in seasonal fluctuation of the MAA content in aquatic species. This review will provide a summary of the MAA antioxidative and UV-absorbing features, including the genes involved in the MAA biosynthesis. Specifically, regulatory mechanisms involved in MAAs pathways will be evaluated for controlled MAA synthesis, advancing the potential use of MAAs in human skin protection.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020

“…Jurisdictions have banned some sunscreen compounds, including oxybenzone (also known as benzophenone-3), octinoxate, and octocrylene, based, in part, on measured environmental concentrations in coastal zones and on laboratory experiments, indicative of their potential toxicity and contributions to coral bleaching [ 273 ]. This has motivated research on the use of natural sunscreens called mycosporine-like amino acids [ 274 ], which are synthesised, for example, by many species of macroalgae and cyanobacteria [ 275 , 276 ].…”

Klebsormidin A and B, Two New UV-Sunscreen Compounds in Green Microalgal Interfilum and Klebsormidium Species (Streptophyta) From Terrestrial Habitats

“…Therefore, the ecological success of terrestrial algae was explained by their typically high UVR tolerance of basic physiological processes such as photosynthesis, respiration, and growth. As fundamental underlying mechanism for such broad tolerance against UVR the biochemical capability to produce and intracellularly enrich MAAs as natural sunscreen compounds was reported Rosic, 2019). There is strong experimental evidence that MAAs indeed act like an umbrella, i.e., as passive shielding molecules which dissipate the previously absorbed UVwaveband energy as rather harmless heat, thereby avoiding the generation of any uncontrolled photochemical reaction (Rosic, 2019).…”

“…Otherwise longterm survival would be at risk. The protective traits are represented by avoidance, such as growing deeper in the biocrust, thereby experiencing self-shading (Gray et al, 2007), DNA repair processes (Jones and Baxter, 2017), de novo biosynthesis of proteins (Karsten, 2008), as well as by the formation/accumulation of antioxidants and UV-screening compounds (Colabella et al, 2014;Rosic, 2019).…”

Unravelling the Photoprotective Mechanisms of Nature-Inspired Ultraviolet Filters Using Ultrafast Spectroscopy

“…The photoprotective properties of MAAs have been deduced from their efficient absorption in the UV region of the electromagnetic spectrum and because there is a correlation between MAA concentration and exposure to UVR [ 65 , 66 ]. There are more than 30 known MAAs to date [ 63 ], each with an absorption maximum in the UV-A or UV-B region (310–362 nm) and molar extinction coefficients in the range of 28,100 to 50,000 M −1 cm −1 [ 67 , 68 ], cf. 34 140 M −1 cm −1 for avobenzone [ 69 ].…”

“…In addition to their strong UV absorption, some MAAs, such as mycosporine-glycine, exhibit antioxidant properties that make them highly desirable to the commercial industry [ 61 , 62 , 70 , 71 ]. A recent publication by Rosic [ 68 ] reviewed some of the aforementioned roles of MAAs, and linked them to how MAAs could be used in the commercial industry to overcome some of the drawbacks with current UV filters covered in Section 1.1.2 . It is noted here that several publications have identified the instability of some MAAs, in particular those with a cyclohexenone core, as they undergo hydrolysis of the amine on carbon three [ 72 , 73 , 74 ].…”