Larix decidua bark is a waste of the timber industry and is widely diffused in Northern Italy. This material can be considered a good source of antioxidants and phytoconstituents with possible use in cosmetic or nutraceutical products. In this study, simple extraction of larch bark was performed using mixtures of ethanol/water. Furthermore, the phytochemical composition of larch bark extract was studied using LC-MSn methods and the main constituents were identified as flavonoids, spiro-polyphenols, and procyanidins. To confirm the identification by LC-MS semi-preparative HPLC was performed in order to isolate the main constituents and verify the structures by 1H-NMR. Antioxidant properties were studied using an in vitro approach combining DPPH assay and LC-MS in order to establish different roles of the various classes of phytochemicasl of the extract. DPPH activity of some of the isolated compounds was also assessed. The overall results indicate this waste material as a good source of antioxidant compounds, mainly procyanidins, whichresulted the most active constituents in the DPPH assay.

Despite the traditional trial and error formulation approach, industries require more rational, time, and money-saving procedures to achieve functional and sensorial objectives. We developed a methodology based on rheology and texture analysis to outline the physical–mechanical properties of aqueous dispersions of acrylic polymers belonging to three different classes: carbomers, acryloyldimethyltaurate derivatives, and predispersed acrylic polymers. Statistical analyses evidenced a significant correlation between rheological and textural parameters: viscosity (η) correlates with firmness, while storage (G′) and loss (G″) moduli with adhesiveness, and stringiness. The results demonstrated that the combined approach of these two instrumental techniques is useful to discriminate each cosmetic raw material on the basis of their applicative specificities and to rationalize their use in personal care products obtaining a wide range of textural characteristics.

Quality, safety, and efficacy concerns added to instability, poor absorption, and the dispersion of actives are common problems while formulating plant-based cosmetics. Furthermore, a correct balance between the stability of the emulsion, the sensory profile, and the high efficacy has to be considered to formulate an effective product. In this paper, we demonstrate that rheology is a methodological tool that can be used while designing a new product. In particular, we developed an O/W emulsion which is easy to spread on irritated skin, and that can soothe the redness and discomfort caused by the exposure to both physical and chemical irritating agents. The green active mixture consists of three natural raw materials: Bosexil®, Zanthalene®, and Xilogel®. Each ingredient has a well-demonstrated efficacy in terms of soothing, anti-itching, and moisturizing properties respectively. Starting from the selection of a new green emulsifying system, through the analysis of the rheological properties, we obtained a stable and easy-to-apply o/w emulsion. The efficacy of the optimized product was assessed in vitro on intact and injured skin using the SkinEthic™ Reconstituted Human Epidermis (RHE) as a biological model.

The natural cosmetics market is growing, in line with the interest of public opinion on environmental safety. The availability of polysaccharides for cosmetic use is very wide; each raw material has its own sensorial specificities and hardly matches the performance of synthetic polymers. We developed an instrumental protocol based on rheology and texture analysis to evaluate alternatives to acrylic polymers. The study has been carried out on a set of water dispersions prepared with different synthetic, semisynthetic, and natural polymers at different concentrations. Using statistical principal component analysis, three different clusters have been identified: group A includes polymers with a stringy viscoelastic behavior, group B includes polymers with low firmness and a weak-gel rheological pattern, and group C includes polymers which formed soft and elastic gels. This work showed that this instrumental approach is a powerful tool to comprehensively characterize new rheological modifiers and to forecast their contribution to the formulation based on their applicative features. Moreover, rheology and texture analysis turned out to be complementary tools useful to compare polymeric raw materials and to identify appropriate alternatives to synthetic ones in order to formulate green cosmetic products.

Larch (Larix decidua) bark is a sawmill waste, traditionally used for antiseptic, expectorant and dermatological (wound healing, eczema, psoriasis) purposes. In this work, we developed a food-grade dry larch bark extract (LBE) from sawmill by-products using hydro-alcoholic extraction. The antibacterial activity of LBE was evaluated against respiratory-tract pathogens, i.e. Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa and Haemophilus influenza, and it was compared to that of grapefruit seed extract (GSE), a commercially available raw material commonly proposed as antibacterial ingredient for over-the-counter products. Procyanidins (PACs) and other polyphenols contents in LBE were determined by HPLC-FLD-MS and HPLC-DAD-MSn, respectively. The antimicrobial activity of LBE and GSE was assessed using the micro-plate dilution technique in concentration range of 2–200 µg/mL, and the safety of these dosages was assessed in cellular and animal models. LBE showed considerable contents of PACs (15% w/w; especially B-type) and other polyphenols (3.8% w/w), among which the characteristic spiropolyphenols larixinol and epilarixinol were identified, together with the flavonoids isoquercitrin and rutin, already reported as growth inhibitors of different respiratory-tract pathogens. LBE showed higher antimicrobial activity compared to GSE, demonstrated by a growth inhibition range of 10–40% towards five of six strains tested, compared to 10–15% of GSE. These results suggest that LBE may represent a natural and sustainable source of active compounds with antibacterial activity for pharmaceutical and nutraceutical applications.