Naringenin improves the sunscreen performance of vegetable nanocarriers†
Abstract
The aim of this study was to evaluate the potential role of naringenin (NAR) in developing polyphenol-rich sunscreens by encapsulation into nanostructured lipid carriers (NLCs) based on vegetable oils. The functionality of NLCs loaded with NAR (NAR–NLC), NAR together with an UVA filter (NAR–UVA–NLC), and with an UVA filter (UVA–NLC) was evaluated by studying their photostability, UV protection factors, antioxidant activity and cytotoxic effect on L929 mouse fibroblasts. The photostability study revealed that NLCs loaded with NAR and/or the UVA filter were photostable under UV exposure. NAR–UVA–NLCs formulated into hydrogels exhibited the best photoprotection with an SPF of 8.4 and a UVAPF of 13.8, as compared with the same formulation without NAR which showed an SPF of 6 and a UVAPF of 10.5. The photoprotective values obtained for NAR–UVA–NLCs underline an efficient sunscreen performance, 87.5% of UVB radiation and 81.1% of UVA radiation being filtered. The antioxidant activity against short- and long-life radicals was also improved by co-loading NAR and a UVA filter into lipid nanocarriers. At low concentrations (25 and 50 μg mL−1) the nanocarriers showed no cytotoxicity and the presence of NAR inside the nanocarriers increased the cell viability. The in vitro drug release studies showed that the NLC system provides an increased release and permeation of NAR. All results indicated that NAR has the potential to be used in developing safer and efficient polyphenol-rich sunscreens, by improving the anti-UV and antioxidant performance of the vegetable nanocarriers.