Although solar exposure is necessary for human health, phototoxicology induced by excessive UVB and UVA radiation, which involves sunburns, skin aging and even tumorigenesis, has been widely researched. Sunscreen is one of the most important ways to protect skin from UV phototoxic damage. However, the efficacy and safety of most artificial sunscreen constituents are hindered by their photostability, toxicity and damage to marine ecosystems.
Natural selection and evolution have ensured that plants and animals have developed effective protective mechanisms against the deleterious side effects of oxidative stress and ultraviolet radiation (UV). Indeed, some natural products or plant extracts with aromatic rings in their structures, such as flavonoids or polyphenols, can absorb UV to reduce sunburn, acting as a natural UV filter, showing also antioxidant or/and anti-inflammatory activity. This could explain why, although there are no officially approval natural commercial sun-filters, more and more commercial sunscreen products containing plant extracts are available on the market.
The review published in Biomedicine & Pharmacotherapy, by the chinese Group of Ding, presents an overall profile of the botanical extracts or components with anti-UV radiation identified in the last 6 years, including classification of the components, their main biological effects, and the mechanisms of anti-UV activity involved.
In particular, the review identified the plant extracts that have photo protective properties and the species with major constituent and main biological effects. Total flavonoids and total polyphenolicsT are the most studied components with photoprotective properties, while only few polysaccharides have been reported to possess anti-UV ability. Other compounds, like lignin and phenylpropionic acids have also shown significant UV-protectant abilities.
Researcher provided a list of most used anti-UV evaluation model in vitro and in vivo and reported the potential mechanisms underlynig plants sunscreen filters ability. UVA and UVB absorption, anti-oxidant activity, decrease of reactive oxygen species, matrix metalloproteinases and MAPK signaling pathways expression are the main mechanism by which botanical extracts exert photo-protective activity.
Research suggests that natural products are reasonably likely to be the future of cosmetics, and this trend necessarily involves UV filters. This review will provide a strong foundation for evaluating the status and potential use of natural UV filters.
DOI: 10.1002/ame2.12295
