Incorporation of Cró thermal water in a dermocosmetic formulation: cytotoxicity effects, characterization and stability studies and efficacy evaluation

Development and Characterization of Thermal Water Gel Comprising Helichrysum italicum Essential Oil-Loaded Chitosan Nanoparticles for Skin Care

Helichrysum italicum essential oil (H. italicum EO) is recognized for its anti-inflammatory, antimicrobial and wound-healing properties. The main goal of the present work was the development and characterization of a gel formulation comprising H. italicum EO loaded in chitosan nanoparticles (NPs) for dermatological applications. H. italicum EO-loaded chitosan NPs presented hydrodynamic diameter and PdI of about 300 nm and 0.28, respectively, and a surface charge of +19 mV. The H. italicum EO-loaded chitosan NPs were prepared by means of ionic gelation and then incorporated into a thermal water gel formulation. The organoleptic and physicochemical properties of the developed gel were studied. The gel remained stable under accelerated test conditions, maintaining pH, viscosity and organoleptic properties. In addition, the formulation presented pH, viscosity and spreadability properties suitable for topical application. Finally, the performance of the gel in topical application was evaluated on the skin of volunteers using non-invasive methods, particularly, by means of biometric evaluation. These assays showed that the properties of the developed thermal water-based gel formulation with H. italicum EO-loaded chitosan NPs can improve skin hydration and maintain healthy skin conditions, demonstrating its putative role for distinct dermatological applications.

Formulation and rheological evaluation of liposomes-loaded carbopol hydrogels based on thermal waters

The aims of this study were to develop topical liposomal hydrogels based on thermal waters (TWs) acquired in the region of Biskra (Northeast Algeria) and also to investigate their rheological properties. Liposomes containing two highly mineralized thermal waters, Baraka (BTW) and Salhine (STW), were prepared by probe sonication using phosphatidylcholine (PC) and cholesterol (Chol), plain or mixed with phosphatidylglycerol (PG). Based on their lipid composition, obtained liposomes presented vesicle sizes of 60 nm, a low polydispersity index, and various negative zeta potentials. It was noted that with increasing counterions charge in TWs the zeta potential of liposomes decreased toward neutral values.Carbopol (1%, w/w) hydrogels prepared with BTW, STW, and also demineralized water (placebo hydrogel) showed a non-Newtonian behavior, pseudoplastic fluid adjusted to Carreau model. The composition of thermal waters influenced highly the rheological properties of Carbopol hydrogels. Liposomal hydrogels were prepared by dispersing liposomes in hydrogels formulated with the same encapsulated thermal water. Regardless of composition or lipid concentration of added liposomes, the viscosity and viscoelastic parameters of Carbopol hydrogels changed negligibly. Indeed, liposome composition and lipid concentration seemed to have no effect on the rheological properties of Carbopol hydrogel in the presence of an important charge of cations. Hence, hydrogels and liposomal hydrogels based on thermal waters had suitable rheological properties for topical application and delivery of minerals in the skin.

Protective role of Portuguese natural mineral waters on skin aging: in vitro evaluation of anti-senescence and anti-oxidant properties

Natural mineral waters (NMWs) emerge from the earth as springs and their beneficial therapeutic effect has been empirically recognized in different countries. Portugal has diverse NMW resources that are sought for the relief of different afflictions including dermatological complications. However, there is a lack of scientific validation supporting this empiric knowledge. In this study, we aimed to screen the in vitro bioactivity of Portuguese NMWs with different chemical profiles, namely sulfurous/bicarbonate/sodic (SBS), bicarbonate/magnesium, sulfated/calcic, sulfurous/chlorinated/sodic, sulfurous/bicarbonate/fluoridated/sodic, and chlorinated/sodic, focusing on aging-related skin alterations. Mouse skin fibroblasts and macrophages were exposed to culture medium prepared in different NMWs. Cellular viability was evaluated by MTT assay and etoposide-induced senescence was analyzed through the beta-galactosidase staining kit. Wound healing was investigated by the scratch assay, and phototoxicity/photoprotection after UVA irradiation was evaluated using a neutral red solution. ROS production was quantified using the 2'7'-dichlorofluorescin diacetate dye, and the activity of superoxide dismutase (SOD) was analyzed by a commercial kit after lipopolysaccharide exposure. NMWs within the SBS profile demonstrated anti-senescence activity in skin fibroblasts, along with a variable effect on cellular viability. Among the tested NMWs, two decreased cellular senescence and preserved cell viability and were therefore selected for subsequent studies, together with a SBS NMW with therapeutic indications for dermatologic diseases. Overall, the selected NMW promoted wound healing in skin fibroblasts and activated SOD in macrophages, thus suggesting an anti-oxidant effect. None of the NMWs prevented phototoxicity after UV irradiation. Our results shed a light on the anti-aging potential of Portuguese NMW, supporting their putative application in cosmetic or medical products.

Anti-inflammatory effects of free and liposome-encapsulated Algerian thermal waters in RAW 264.7 macrophages

The main objectives of this work were to formulate liposomes encapsulating highly mineralized thermal waters (TWs) and to study anti-inflammatory effect of free and encapsulated thermal waters on RAW 264.7 macrophage cells stimulated with lipopolysaccharide (LPS). TWs-loaded conventional and deformable liposomes (TWs-Lip and TWs-DLip) were prepared by sonication and extrusion, respectively. They were considered for their vesicle size, zeta potential, entrapment efficiency, physical stability and in vitro anti-inflammatory effect. Formulated liposome suspensions have a low polydispersity and nanometric size range with zeta potential values close to zero. The vesicle size was stable for 30 days. Entrapment efficiency of TWs was above 90% in conventional liposomes and 70% in deformable liposomes. Pretreatment of LPS-stimulated murine macrophages, with free and liposome-encapsulated TWs, resulted in a significant reduction in nitric oxide (NO) production and modulated tumor necrosis factor-α (TNF-α) production suggesting an anti-inflammatory effect which was even more striking with TWs-Lip and TWs-DLip. Liposome formulations may offer a suitable approach for transdermal delivery of TWs, indicated in inflammatory skin diseases.

Are There Benefits from Thermal Bacteria for Health? The Hydrogenome Role

In recent years, natural thermal mineral waters have been gaining the special attention of the scientific community, namely in the prevention and treatment of some diseases, due to the microbial properties that exist in these habitats. The aim of this work was to characterize the physicochemical composition and the microbial taxonomic communities present in three thermal waters of the Galician region in Spain and two samples of the northern region in Portugal. These collected water samples were analyzed for physicochemical characterization and the respective hydrogenome of the waters using next generation sequencing together with 16S rRNA gene sequencing. The sequencing showed a high diversity of microorganisms in all analyzed waters; however, there is a clear bacterial predominance of Proteobacteria phylum, followed by Firmicutes, Deinococcus-Thermus, Aquificae and Nitrospira. The main physicochemical parameters responsible for the clustering within the Spanish waters were sulfur compounds (SO32− and S2−), CO32− and neutral pH, and in the Portuguese waters were Mg, Ca and Sr, nitrogen compounds (NO3− and NH4+), Na, Rb, conductivity and dry residue. This work will allow for a better understanding of the microbial community’s composition and how these microorganisms interfere in the physicochemical constitution of these waters often associated with medicinal properties. Furthermore, the hydrogenome may be used as an auxiliary tool in the practice of medical hydrology, increasing the likelihood of safe use of these unique water types.

In vitro and in vivo trans-epidermal water loss evaluation following topical drug delivery systems application for pharmaceutical analysis

The measurement of Trans-Epidermal Water Loss (TEWL) allows to evaluate the integrity of Stratum Corneum Epidermis (SCE) barrier after topical application of colloidal nanocarriers by using a non-invasive method. The temporarily modifications of SCE lipids are important for the passage of colloidal nanocarriers across the skin; this passage causes a modification of TEWL values. Niosomes, ethosomes®, and transfersomes® are used as topical drug delivery systems due to their biopharmaceutical properties, and capability to permeate intact through the SCE. In vitro and in vivo evaluation of TEWL values was studied for niosomes, ethosomes® and transfersomes® in occlusive and non-occlusive conditions. TEWL values in vivo, using healthy human volunteers, are ∼12 g/m²∙× h for all nanoformulations after 72 h, due to the rearrangement of lipids forming the SCE membranes. Conversely, TEWL values of healthy human volunteers, that are topically treated with niosomes, ethosomes® and transfersomes®, in non-occlusive conditions, are ∼20 g/m²∙× h. This data was lower than those obtained in occlusive conditions (∼35 g/m²∙× h). In vitro studies agreed results which are obtained in occlusive conditions using healthy human volunteers. SCE lipids of the skin restore their native structure after 72 h of nanocarrier application. In vitro and in vivo results showed that niosomes, ethosomes®, and transfersomes® interact with the skin in a temporary and reversible mode, and they can be used as suitable colloidal nanocarriers to increase the percutaneous permeation of drugs after topical application without damaging the native structure of the skin.