Vaccinium myrtillus L. extract associated with octocrylene, bisoctrizole, and titanium dioxide: in vitro and in vivo tests to evaluate safety and efficacy.

OBJECTIVE: The harmful effects induced by ultraviolet exposition and the significant increment in skin cancer diagnosis confirm the necessity to develop effective and safe sunscreens. Limited efficacy and cutaneous adverse reactions of traditional formulations drove the incorporation of natural extracts into multifunctional sunscreens. Vaccinium myrtillus L. extract (VME), that contains anthocyanins and flavonoids, is a potential candidate for such systems. METHODS: Considering that, we performed in vitro and in vivo tests to evaluate the sun protection factor (SPF), photostability, and safety of sunscreen samples containing VME. RESULTS: As main results, the SPF was reduced in both in vitro and in vivo evaluation in the presence of VME; nonetheless, the samples were photostable and safe. CONCLUSION: Further investigation is required to better understand the unexpected effects of VME over photoprotection, decreasing the SPF value. As a conclusion, even with interesting findings, we highlight the importance of case-by-case investigations to develop multifunctional bioactive sunscreens.

Anthocyanin-rich açaí (Euterpe oleracea Mart.) extract attenuates manganese-induced oxidative stress in rat primary astrocyte cultures.

Manganese (Mn) is an essential element for human health. However, at high concentrations Mn may be neurotoxic. Mn accumulates in astrocytes, affecting their redox status. In view of the high antioxidant and anti-inflammatory properties of the exotic Brazilian fruit açaí (Euterpe oleracea Mart.), its methanolic extract was obtained by solid-phase extraction (SPE). This açaí extract showed considerable anthocyanins content and direct antioxidant capacity. The açaí extract scavenged 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) with an EC50 of 19.1 ppm, showing higher antioxidant activity compared to butylated hydroxytoluene (BHT), but lower than ascorbic acid and quercetin. This obtained açaí extract also attenuated Mn-induced oxidative stress in primary cultured astrocytes. Specifically, the açaí extract at an optimal and nutritionally relevant concentration of 0.1 µg/ml prevented Mn-induced oxidative stress by (1) restoring GSH/GSSG ratio and net glutamate uptake, (2) protecting astrocytic membranes from lipid peroxidation, and (3) decreasing Mn-induced expression of erythroid 2-related factor (Nrf2) protein. A larger quantity of açaí extract exacerbated the effects of Mn on these parameters except with respect to lipid peroxidation assessed by means of F2-isoprostanes. These studies indicate that at nutritionally relevant concentration, anthocyanins obtained from açaí protect astrocytes against Mn neurotoxicity, but at high concentrations, the "pro-oxidant" effects of its constituents likely prevail. Future studies may be profitably directed at potential protective effects of açaí anthocyanins in nutraceutical formulations.