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

Nedeljka Rosic

doi:10.3390/md17110638

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.

Highlights

Due to a reduction in aerosols and cloud cover, the levels of ultraviolet radiation (UVR) reaching the Earth’s surface are predicted to increase during the 21st century [1]
mycosporine-like amino acids (MAAs) are found in a large number of aquatic species, including marine and freshwater organisms that have been exposed to high levels of damaging UVR [6]
Over a long period of history, cyanobacteria were exposed to extremely high UVR and these organisms developed additional protection of their DNA by applying two powerful UV-absorbing compounds, scytonemin and MAAs [10,59]

Summary

Introduction

Due to a reduction in aerosols and cloud cover, the levels of ultraviolet radiation (UVR) reaching the Earth’s surface are predicted to increase during the 21st century [1]. Organisms have developed several photoprotective mechanisms to survive high levels of UVR. Different mitigation strategies are utilised by different species and often in combination including DNA repair systems, antioxidant activities, and the application of UV-absorbing compounds. MAAs are found in a large number of aquatic species, including marine and freshwater organisms that have been exposed to high levels of damaging UVR [6]. The vast variety of species containing MAAs includes phytoplankton, cyanobacteria, fungi, macroalgae, microalgae, as well as animals coming from both aquatic and terrestrial ecosystems [7]. This review assesses current knowledge about the biosynthesis of MAAs and suggests possible directions for the evolving biotechnological potential of MAAs in human skin protection

MAA Diversity

MAA Antioxidative Properties

MAA Anti-Inflammatory and Antiaging Properties

Fluctuation of the MAA Content in Aquatic Species

Genes from the MAA Biosynthetic Pathway and Their Regulation

Potential Use of MAAs in Human Skin Protection

Findings

Conclusions