Development and in vitro photoprotective evaluation of curcuminoid mixture and structurally related chalcones

Abstract

The cosmetic market is experiencing a tendency to use sunscreens of natural origin in photoprotective formulations, either independently or as adjuvants to synthetic filters. Curcuma (Curcuma longa) had its medicinal value recognized by SUS in 2009, being included by RENISUS. Thus, the curcuminoid mixture (MC) was extracted and modified to generate MCA. The chalcones (CH and CHA) were planned considering the molecular structure of octyl methoxycinnamate, commercial sunscreen, and MC. Mansur and Diffey's in vitro methods were used to determine the sun protection factor (SPF-UVB) and the critical wavelength (λc) of the formulations containing the compounds under study. MC, MCA, CH and CHA showed the following SPF-UVB and λc (nm) values: MC (0.9 and 394), MCA (5.2 and 391), CH (5.4 and 388) and CHA (11.6 and 358). These results indicate that the compounds can provide protection against UVB and/or UVA radiation. Among the chemical filters evaluated, CHA demonstrated the potential to act as a broad-spectrum UV filter, exhibiting a photoprotective effect comparable to that of oxybenzone (SPF 11.3 and λc 348 nm), a commercial chemical filter.