While we all know the importance of protecting our skin from the Sun’s damaging, cancer-causing UVA and UVB rays, traditional sunscreen application seems to range from mildly annoying to human sandpaper impersonation. And it’s terrible for waterways and marine environments such as coastal reefs.
Scientists from the São Paulo Research Foundation (FAPESP) set out to hit the proverbial two birds with one stone, creating an environmentally friendly product using a natural molecule found in herbs such as sage and peppermint and one that could see it offer more for less. When the smallest amount was added to a solution, the sunscreen's Sun protection factor (SPF) was boosted by 41%.
What’s more, that molecule – rosmarinic acid – is a polyphenol antioxidant and has antiviral, anti-inflammatory, immunomodulatory, antibiotic and anticancer properties. This could potentially make a multi-function product, such as a combined sunscreen and anti-aging cosmetic.
“Our research on photoprotective systems aims primarily to evaluate potential sunscreen enhancement strategies,” said co-author André Rolim Baby, professor at the University of São Paulo’s School of Pharmaceutical Sciences (FCF-USP). “We’re interested above all in discovering ways to increase sunburn protection while also improving the stability of the product so that it remains safe and effective for longer.”
In clinical and in vitro trials, just 0.1% of rosmarinic acid added to a solution greatly increased the sunscreen photoprotective efficacy, which is just a tiny amount compared to conventional products. This essentially means that much less sunscreen would be needed for skin protection, and fewer synthetic chemicals washing off into waterways.
“In another investigation, we found potential benefits of rosmarinic acid for skin surface hydration, reinforcing the need for more research on the substance in the field of cosmetology,” Baby said.
It’s a promising result for a molecule found abundantly in nature and paves the way for much greener multipurpose sunscreens.
“We’re also looking for products or systems with less environmental impact and ways of reducing the concentration of conventional filters by including natural ingredients that enhance the formulation,” Baby added. “And we’re very interested in mapping other cosmetic properties of photoprotective molecules, such as anti-free radical action and protection of biomarkers in the outermost skin layers.”
The study was published in the journal Cosmetics.
Source: São Paulo Research Foundation
