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The effect of nanoencapsulation on the in vitro photoprotection and antioxidant properties of blueberry (Vaccinium myrtillus) extract, before and after their dispersion into an oil-in-water emulsion and its final stability under stress conditions. Besides its skin healing activity, chitosan was chosen as wall material due to its natural origin, and possibility of obtention from shrimp residues. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with blueberry extract were produced and characterized. Three different semi-solid oil-in-water emulsions, using Ecocert certified materials, were developed containing, respectively, (i) 5% (wt/wt) of extract-free nanoparticles, (ii) 5% (wt/wt) of extract-loaded nanoparticles, (iii) 2% (wt/wt) of free extract. Sun protection factor (SPF), antioxidant activity and stability under stress conditions were evaluated. The concentration of rutin was determined by High Performance Liquid Chromatography (HPLC). The loading of blueberry extract into nanoparticles kept their physicochemical properties, as well as SPF and antioxidant activity, over the course of the stability study. Extract-loaded nanoparticles were dispersed in a semi-solid oil-in-water emulsion and were shown to protect the extract from oxidation, suggesting that formulation containing 5% (wt/wt) of extract-free nanoparticles could presented lower difference between initial and final SPF and antioxidant activity values after 90 days of analysis. The developed formulation is proposed as a greener potential formulation to be used as photoprotector, especially if associated with physical sun filters. The role of blueberry flavonoids and the synergistic effect of nanoparticles against skin aging are here discussed., This research was funded by FAPESP (grant number 2015/25533–7, 2017/14757–7, 2017/05275–9) and in part by CAPES (Finance Code 001). This study was financed by CNPq (301436/2017–7) granted to PGM, and by the Portuguese Science and Technology Foundation (FCT / MCT) and from European Funds (PRODER/COMPETE) under the project reference UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020, granted to EBS., info:eu-repo/semantics/publishedVersion

Nature has been a source of medicinal treatments for thousands of years, with the use of plants as prototypes for drug development and for the extraction of active compounds. Skin injuries occur regularly in everyday life, and the human skin has the ability to promote repair spontaneously under healthy conditions. However, some intrinsic and external factors may interfere with skins' natural ability, leading to nonhealing lesions and chronic wounds, which directly affect health and quality of life. Thus, attention should be given to this health problem, using an appropriated management when necessary. In this scenario, phytotherapy may be an option for cutaneous wound treatment, although further high-quality studies are needed to firmly establish the clinical efficacy of plants. This article reviews traditionally used natural actives for wound healing, highlighting their characteristics and mode of action.

The aim of the present study was to carry out stability tests and in vitro sun protection factor (SPF) evaluations of formulations containing free or microencapsulated chemical sun filters to improve their use. To this end, three formulations were developed and subjected to stability studies. The most stable formulation was chosen as a vehicle for free and microencapsulated chemical sun filters, and subjected to further stability studies and in vitro SPF assays. The SPF values were approximately 12 and 11 for formulations containing free and encapsulated sun filters, respectively, and both types were stable under stress. Chemical sun filters can be microencapsulated, which may aid in generating innovative sunscreen formulations.

The aim of this study was to develop a phytocosmetic sunscreen emulsion with antioxidant effect, containing a blend of flavonoid-enriched plant extracts. In vitro sun protection factor, antioxidant activity, skin irritation, photostability, cutaneous permeation, and retention of flavonoids were evaluated. Thermodynamically stable emulsions were obtained and tested for sensorial analysis after loading the blend of extracts. The selected emulsion was stable when stored at low temperatures (5 C), for which after 120 days the concentration of quercetin and rutin were above their limit of quantification, i.e., 2.8 &plusmn, 0.39 &micro, g/mL and 30.39 &plusmn, g/mL, respectively. Spreadability, low rupture strength and adhesiveness were shown to be similar to a conventional topical product. Higher brittleness, pseudo-plastic, and viscoelastic behaviors were also recorded for the developed phytocosmetic sunscreen. The product presented a critical wavelength of 387.0 nm and ultraviolet rays A and B (UVA/UVB) rate of 0.78, confirming that the developed formulation shows capacity for UVA/UVB protection, protecting skin against damages caused by Ultraviolet (UV) radiation. Rutin was shown to permeate the skin barrier and was also quantified in the stratum corneum (3.27 &plusmn, 1.92 &micro, g/mL) by tape stripping and retention test (114.68 &plusmn, 8.70 &micro, g/mL). The developed flavonoid-enriched phytocosmetic was shown to be non-irritant to skin by an in vitro assay. Our results confirm the antioxidant activity, sun protection, and physical properties of the developed phytocosmetic for topical application.

The aim of study was to determine the in vitro sun protection factor (SPF) and the photostability profile of a topical formulation composed of nanoparticles loaded with vegetable extracts and to assess its physicochemical properties. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with flavonoids-enriched vegetable extracts (Ginkgo biloba L., Dimorphandra mollis Benth, Ruta graveolens, and Vitis vinifera L.) were produced and characterized for their morphology, mean particle size, zeta potential, and encapsulation efficiency. A final topical formulation was obtained by dispersing chitosan/TPP nanoparticles in an o/w emulsion. Results showed that nanoparticles dispersion exhibited yellowish color, spherical shape, and uniform appearance. Extract-loaded chitosan/TPP nanoparticles showed a mean particle size of 557.11±3.1 nm, polydispersity index of 0.39±0.27, zeta potential of +11.54±2.1 mV, and encapsulation efficiency of 75.89% of rutin. The recorded texture parameters confirm that the developed formulation is appropriate for skin application. The SPF obtained was 2.3±0.4, with a critical wavelength of 387.0 nm and 0.69 UVA/UVB ratio. The developed formulation exhibited photostability, allowing the release of flavonoids from nanoparticles while retaining rutin into the skin in a higher extension., The authors acknowledge FAPESP (grant number 2015/25533-7 and 2017/14757-7), CAPES, and CNPq agencies for the financial support of this study. The authors also acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from the European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020., info:eu-repo/semantics/publishedVersion

The aim of this study was to validate a HPLC method for the assay of flavonoids in extracts obtained from natural sources, i.e., from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L., and Vitis vin&iacute, fera L. The potential sun protecting effect, antioxidant activity, and cell viability of the extracts were also determined. Individual extracts (obtained from each individual species) and a mixed extract (containing the four extracts) were analyzed by the validated HPLC method for the identification of flavonoids and quantification of rutin and quercetin. An in vitro cell viability study was carried out using the neutral red method. The in vitro sun protection factor was determined by spectral transmittance and in vitro antioxidant efficacy was evaluated against DPPH, ABTS, and AAPH radicals. The HPLC method used for the identification and quantification of flavonoids in extracts exhibited linearity, precision, accuracy, and robustness. Detection and quantification limits were, respectively, 2.881 &plusmn, 0.9 &mu, g&middot, mL&minus, 1 and 0.864 &plusmn, 1 for quercetin, and 30.09 &plusmn, 1 &mu, 1 and 9.027 &plusmn, 1.1 &mu, 1 for rutin. All extracts did not affect cell viability at the evaluated concentration range and exhibited a sun protection effect and antioxidant activity. Among the evaluated extracts, Ginkgo biloba L. and the mixed extract depicted the most expressive antioxidant activity. The mixed extract exhibited sunscreen protection against ultraviolet A (UVA) and ultraviolet B (UVB) and a critical wavelength of 372.7 &plusmn, 0.1. Our results translate the enhanced flavonoids&rsquo, composition of the mixed extract, which may be a potential alternative over sunscreens and antioxidants in pharmaceutic/cosmetic formulations.

Bromelain has many therapeutic properties including wound healing and blood circulation improvement. However, bromelain is usually unstable and suffers autolysis, which results in a decrease of enzymatic activity and limited applications. Encapsulation of bromelain in nanoparticles can diminish degradation by protease immobilization, which may increase its stability and efficacy. The natural polymer chitosan can be nanostructured and trap the enzyme, maintaining the claims of biocompatibility, biodegradability and natural source of the formulation ingredients. Considering the above, chitosan-bromelain nanoparticles (C-B-NP) were produced by ionic crosslinking and presented spherical shape (electron microscopy) of 100.9 ± 0.5 nm and polydispersity index of 0.222 ± 0.012 (dynamic light scattering). Encapsulation efficiency was calculated as 85.1 ± 1% with regard to enzymatic activity, and C-B-NP presented 4.9 U/mL of enzymatic activity, which corresponds to 104.7% of free bromelain activity, confirming its integrity upon encapsulation. However, C-B-NP were unstable when stored in aqueous suspension, leading to freeze-drying studies of the formulation. Glycine and maltose were used as potential lyoprotectors and the formulation optimized by a factorial design; resultant products presented short resuspension time, slightly altered nanoparticles mean size and increased encapsulation rate compared to the previous liquid form. Maltose was able to better maintain formulation's enzymatic activity over time (90 days), especially when stored under refrigeration. Therefore, freeze-dried C-B-NP can effectively improve bromelain and nanoparticle stability, which allow further in vivo applications as a dried powder for topical administration or as a raw material for other dosage forms.

Sunscreens contain molecules with the ability to absorb and/or reflect UVA (ultraviolet A) and UVB (ultraviolet B) radiation, thereby preventing this radiation from reaching the epidermis or dermis. Their photo stabilities after exposure to UV radiation are well known and described, but there is little data on the stability of these filters after fluorescent indoors light radiation, such as from light emitted by commercial lamps present in homes and offices. Those lamps can expose people to varying levels of UVB, UVA, visible light, and IR (infrared). This study assesses the photostability of four different commercial products containing chemical sun filters after artificial UV and fluorescent irradiation, correlating the UVB and UVA absorption efficiencies of each product against the different types of radiation. The tested products were applied on a plate of polymethylmethacrylate (PMMA) and irradiated by a solar simulator with specific filters for UVA and UVB and a commercial fluorescent light source. According to the results, three formulations did not show photostability, suffering significant changes in their UV absorption spectra, and one of the selected formulations can be considered photostable. This reinforces the importance of conducting stability studies for sunscreen formulations in different conditions, including under artificial (indoor) light exposure.

Background Berries are known for their antioxidant activity due to the presence of flavonoids. Antioxidants' usage guarantees skin protection against free radicals and, flavonoids, especially, can act as sunscreen. The aim of this paper was to evaluate solar protection factor (SPF) and antioxidant activity in vitro of blackberry and raspberry extracts incorporated in topical formulation and study their stability. Results Raspberry presented 29.93 mg of anthocyanins/100 g of fruit and blackberry 65.58 mg of anthocyanins/100 g of fruit. In vitro solar protection factor was 54.57 to blackberry and 37.32 to raspberry. When incorporated in O/W emulsions, final formulations showed light pink color, creamy aspect, and typical fruity odor. Formulations submitted to indirect light and stove showed odor and color alterations. Conclusions Based on the results, formulations containing extracts should be kept under refrigeration in opaque package to ensure stability due to the presence of flavonoids. In addition, blackberry and raspberry extracts are potential natural alternatives to be used as sunscreen and to prevent skin aging.