A Comparative Study between Onion Peel Extracts, Free and Complexed with β-Cyclodextrin, as a Natural UV Filter to Cosmetic Formulations

Int J Mol Sci. 2023 Nov 1;24(21):15854. doi: 10.3390/ijms242115854.

Abstract

The growing concern regarding the adverse effects of synthetic UV filters found in sunscreens has spurred significant attention due to their potential harm to aquatic ecosystems and human health. To address this, the present study aimed to extract and microencapsulate sensitive bioactive compounds derived from by-product onion peel (OP) by molecular inclusion using β-cyclodextrin as the wall material. Identification and quantification of bioactive compounds within the extract were conducted through high-performance liquid chromatography (HPLC-DAD) analysis, revealing quercetin and resveratrol as the primary constituents. The photoprotection capacity, evaluated by the sun protection factor (SPF), revealed a protection factor comparable to the value for a synthetic UV filter. The produced microparticles presented high antioxidant capacity, significant photoprotection capacity, encapsulation efficiency of 91.8%, mean diameter of 31 μm, and polydispersity of 2.09. Furthermore, to comprehensively evaluate the performance of OP extract and its potential as a natural UV filter, five O/W emulsions were produced. Results demonstrated that microparticles displayed superior ability in maintaining SPF values over a five-week period. Photoprotection evaluation-skin reactivity tests revealed that both extract and microparticles absorb UV radiation in other regions of UV radiation, revealing their potential to be used as a natural UV filter to produce a sustainable and eco-friendly value-added sunscreen.

Keywords: UV filters; microencapsulation; onion peel; phenolic compounds; sunscreen.

MeSH terms

  • Ecosystem
  • Humans
  • Onions
  • Skin
  • Sunscreening Agents / pharmacology
  • Ultraviolet Rays* / adverse effects
  • beta-Cyclodextrins* / pharmacology

Substances

  • Sunscreening Agents
  • beta-Cyclodextrins

Grants and funding

This work was supported by LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE), funded by national funds through FCT/MCTES (PIDDAC); Project S4Hort_Soil&Food—Sustainable practices for soil health & horticultural products quality improvement in the Entre Douro e Minho Region, with reference NORTE-01-0145-FEDER-000074 and cofinanced by the European Regional Development Fund (ERDF) through the North Portugal Regional Operational Programme (NORTE2020) under the Portugal 2020 Partnership Agreement.