Unilever (China)

Photoaging is common and represents one of the primary pathways for hair damage in daily life. Hydrolyzed keratin, which is usually derived from wool and consists of a series of polypeptide molecules, has been investigated as a UV damage prevention ingredient for hair care. Scanning Electron Microscopy (SEM) and fluorescent penetration experiments verified that hydrolyzed keratin can deposit on the hair cuticles to form a film and partly penetrate into the hair cortex. This film played as a UV reducer and helped hair resist surface damage and maintain a sleek and healthy morphology after UV radiation. Surprisingly, it was found that hydrolyzed keratin treatment combined with subsequent UV radiation could significantly improve the tensile properties of hair. For hydrolyzed-keratin-treated hair, tensile strength was maintained after UV radiation, while, as a comparison, it decreased by 14.32% for untreated hair. This phenomenon is explained by a UV-induced degradation-penetration mechanism. During UV radiation, an increase in free amino acid content and conductivity was observed for the hydrolyzed keratin solution, demonstrating photodegradation into smaller peptides and amino acids. The degradation of hydrolyzed keratin allowed it to more easily enter the interior of the hair cortex, thereby enhancing its tensile properties by enhancing the chemical bonds.

The heterogeneity of the viscoelasticity of a lamellar gel network based on cetyl-trimethylammonium chloride and cetostearyl alcohol was studied using particle-tracking microrheology. A recurrent neural network (RNN) architecture was used for estimating the Hurst exponent, H, on small sectionsof tracks of probe spheres moving with fractional Brownian motion. Thus, dynamic segmentation of tracks via neural networks was used in microrheology and it is significantly more accurate than using mean square displacements (MSDs). An ensemble of 414 particles produces a MSD that is subdiffusive in time, t, with a power law of the form t^{0.74±0.02}, indicating power law viscoelasticity. RNN analysis of the probability distributions of H, combined with detailed analysis of the time-averaged MSDs of individual tracks, revealed diverse diffusion processes belied by the simple scaling of the ensemble MSD, such as caging phenomena, which give rise to the complex viscoelasticity of lamellar gels.

UV radiation exposure causes skin irritation, erythema, darkening and barrier disruption by inducing oxidative stress and inflammation. Glutathione, a master antioxidant, plays an important role in the antioxidant defence network of the skin. This study aimed to assess the invitro protective effects of the glutathione amino acid precursors blend (GAP) on transcriptomic and phenotypic endpoints against UVB-induced challenges. Normal human epidermal melanocytes (NHEMs) were exposed to GAP, ascorbic acid (AA) and its derivatives. Viability was assessed using the CCK8 method. Melakutis®, a pigmented living skin equivalent (pLSE) model, underwent repeated 50 mJ/cm2 UVB irradiation with or without GAP treatment. Images of the model were captured with consistent camera parameters, and the model's light intensity was measured using a spectrophotometer. Melanin content was determined by measuring absorbance at 405 nm. Confirmation of melanin deposition and distribution was achieved through Fontana-Masson staining. Transcriptomic analysis was conducted using RNA sequencing (RNA-Seq), and a machine learning approach was employed for transcriptomic aging clock analysis. In NHEMs, all tested compounds exhibited over 85% viability compared to the vehicle control, indicating no heightened risk of cytotoxicity. Notably, GAP demonstrated greater efficacy in inhibiting melanin production than AA derivatives at equivalent concentrations. In pLSE models, GAP notably enhanced model lightness, and reduced melanin content and deposition following the UVB challenge, whereas AA showed minimal impact. GAP effectively counteracted UVB-induced alterations in gene expression linked to pigmentation, inflammation and aging. Moreover, recurrent UVB exposure substantially elevated the biological age of pLSE models, a phenomenon mitigated by GAP treatment. In NHEMs, GAP exhibited enhanced effectiveness in inhibiting melanin production at identical tested doses in comparison to AA derivatives. Noteworthy protective effects of GAP against UVB irradiation were observed in the pLSE models, as evidenced by skin pigmentation measurements and transcriptomic changes.

Objectives: Cohort and epidemiology studies have previously revealed potential associations between air pollution exposure and acne vulgaris. However, the molecular mechanisms that drive these associations are not currently well understood. In this study, we compared the molecular signatures of acne and PM2.5-exposed skin to infer whether common underlying biological mechanisms exist. Methods: Acne microarray data sets were downloaded from GEO. RMAExpress was used for microarray normalization, and TMeV was used to identify differential expressed genes (DEGs). A random-effects model in MetaVolcanoR was used to determine fold changes and P values. DEGs of PM2.5-exposed skin-cell models were obtained from the literature. DEGs were compared using GeneOverlap and a custom R script. Analyses of pathways, upstream regulators, and causal networks were conducted using ingenuity pathway analysis (IPA). Results: The molecular signatures of acne skin and the effect of PM2.5 on skin in vitro were compared at 3 levels: (1) gene expression, (2) pathway activity, and (3) upstream regulators. Significant concordant overlaps of both upregulated (P < 3e-23) and downregulated DEGs (P< .005) were observed in acne skin and PM2.5-exposed keratinocytes. However, for the PM2.5-exposed 3D skin model, significant overlap with acne skin was only observed for upregulated DEGs (P < 8e-14). Fold changes of DEGs in both acne and PM2.5-exposed data sets showed significant correlation (Pearson correlation coefficient > 0.6; P < .001). An IPA analysis identified 13 pathways commonly enriched in acne and PM2.5 data sets, including IL17, IL6, Toll receptor PPAR, LXR–RXR, and acute-phase response pathways. Common upstream regulators were further identified including TNFα, NFκB, CAMP, AhR, and IL17A. Finally, causal network analysis revealed several potential hub regulators shared in acne pathogenesis and PM2.5-exposed skin, including HIF1α, TNF, IL1α, and CCL5. Conclusions: Our analysis revealed significant concordant molecular signatures between acne and PM2.5-exposed skin. Biological insights from this study offer clues that build the causal links between air pollution and acne pathogenesis.

Extracts of mulberry have been shown to reduce post-prandial glucose (PPG) and insulin (PPI) responses, but reliability of these effects and required doses and specifications are unclear. We previously found that 1·5 g of a specified mulberry fruit extract (MFE) significantly reduced PPG and PPI responses to 50 g carbohydrate as rice porridge, with no indications of intolerance. The trials reported here aimed to replicate that work and assess the efficacy of lower MFE doses, using boiled rice as the carbohydrate source. Two separate randomised controlled intervention studies were carried out with healthy Indian males and females aged 20-50 years (n 84 per trial), with PPG area under the curve over 2 h as the primary outcome. Trial 1 used doses of 0, 0·37, 0·75, 1·12 and 1·5 g MFE in boiled rice and 0 or 1·5 g MFE in rice porridge. Trial 2 used doses of 0, 0·04, 0·12, 0·37 g MFE in boiled rice. In trial 1, relative to control, all MFE doses significantly decreased PPG (-27·2 to -22·9 %; all P ≤ 0·02) and PPI (-34·6 to -14·0 %, all P < 0·01). Breath hydrogen was significantly increased only at 1·5 g MFE (in rice porridge), and self-reported gastrointestinal symptoms were uniformly low. In trial 2, only 0·37 g MFE significantly affected PPG (-20·4 %, P = 0·002) and PPI (-17·0 %, P < 0·001). Together, these trials show that MFE in doses as low as 0·37 g can reliably reduce PPG and PPI responses to a carbohydrate-rich meal, with no apparent adverse effects.

ObjectivesTo demonstrate the synergistic effect of 4‐hexylresorcinol (4‐HR) with niacinamide in boosting anti‐melanogenic efficacy in vitro and establish the in vivo efficacy and safety of the combination in a human trial.MethodsPrimary human epidermal melanocytes and 3D pigmented skin equivalents were treated with 4‐HR, niacinamide, and their combinations for their effect on pigmentation. This was followed by a randomized, double‐blind, split‐face clinical study in Chinese subjects, and effects on skin tone, hyperpigmentation, fine lines and wrinkles, hydration, and skin firmness were measured for a 12‐week study period.ResultsIn vitro tyrosinase enzyme activity studies showed that 4‐HR is one of the most potent tyrosinase inhibitors. The combination of 4‐HR and niacinamide showed a synergistic reduction in melanin production in cultured melanocytes and lightened the 3D skin equivalent model. In vitro as well as in the human trial, the combination of 4‐HR and niacinamide showed significantly improved efficacy over niacinamide alone on hyperpigmentation spots as measured by L*, the visual appearance of fine lines and wrinkles in crow's feet and perioral area and skin firmness, with no product‐related adverse events.ConclusionsA formulation containing a combination of 4‐HR and niacinamide delivered superior skin tone and anti‐ageing benefits significantly better than niacinamide alone with no adverse events. This study demonstrates that a product designed to affect multiple pathways of melanogenesis, inflammation, and ageing may provide an additional treatment option, beyond hydroquinone and retinoids, for hyperpigmentation and ageing.

Abstract Three N‐alkyl bis‐quaternary ammonium salt surfactants were synthesized by using epichlorohydrin, trimethylamine hydrochloride, and N,N‐dimethylalkyl amine as raw materials in a two‐step manner. The products were characterized by 1H NMR and MS, confirming the successful synthesis of 2‐Hydroxy‐N1,N1,N3,N3‐tetramethyl‐N3‐dodecylpropane‐1,3‐diammonium chloride (HPDDC), 2‐Hydroxy‐N1,N1,N3,N3‐tetramethyl‐N3‐tetradecylpropane‐1,3‐diammonium chloride (HPTDC), and 2‐Hydroxy‐N1, N1, N3, N3‐tetramethyl‐N3‐hexadecylpropane‐1,3‐diammonium chloride (HPHDC). Moreover, the influence of carbon chain length on surface‐active properties, foaming properties, and paraffin liquid emulsion stability was investigated. Results indicated that critical micelle concentrations (cmc) decreased with increasing carbon chain length from 12 to 16, and the cmc and γcmc were lower than those of Dodecyl trimethyl ammonium chloride (DTAC). The products exhibited better foam properties and worse emulsifying performance than those of DTAC. The Krafft points of all products were determined to be below 0 °C. Moreover, the products also demonstrated outstanding antibacterial properties.