Glutathione amino acid precursors protect skin from UVB-induced damage and improve skin tone.

BACKGROUND: 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. OBJECTIVE: This study aimed to assess the in vitro protective effects of the glutathione amino acid precursors blend (GAP) on transcriptomic and phenotypic endpoints against UVB-induced challenges. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Topical glutathione amino acid precursors protect skin against environmental and oxidative stress.

BACKGROUND: Although glutathione (GSH) has long been considered a master antioxidant, poor stability and bioavailability limit its application in skin protection. To overcome the challenges, Unilever R&D formulated a Glutathione Amino acid Precursors blend (named GAP) to boost GSH de novo synthesis. OBJECTIVE: Determine whether GAP can boost GSH levels and provide skin protection against stressors. METHODS: Normal human epidermal keratinocytes were treated with GAP, with or without stressors, namely, menadione, blue light or pollutants. Ascorbic acid was used as a benchmark. The levels of GSH, glutathione disulfide (GSSG), adenosine triphosphate (ATP) and reactive oxygen species (ROS) were quantified. A placebo-controlled clinical study was conducted on 21 female subjects who received product applications and subsequent UV radiation. Tape strip samples were collected from the subjects for GSH and GSSG quantification using ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). The UV-protective effect of GAP was investigated using ex vivo skin. Biomarkers related to DNA damage and the skin barrier were analysed using immunohistochemistry. RESULTS: Glutathione amino acid precursors significantly increased the GSH levels and GSH/GSSG ratio in normal human epidermal keratinocytes. Menadione treatment resulted in excessive ROS production and a decline in ATP levels, which were effectively abrogated by GAP. The protective effects of GAP against menadione-induced oxidative stress were superior to those of ascorbic acid. In addition, GAP effectively protected the cells against blue light-induced ROS production and pollutant-induced ATP depletion. Topical application of the GAP formulation significantly elevated the skin GSH/GSSG ratio in a clinical study. Ex vivo skin treated with the GAP formulation displayed a reduction in DNA damage and high levels of barrier proteins after UV exposure. CONCLUSIONS: Glutathione amino acid precursors effectively increases cellular GSH levels to protect the skin from oxidative and environmental stresses.

Scalp hair loss is not random across follicular units: A new insight into human hair ageing.

OBJECTIVES: Scalp hair has the greatest number of hairs (typically 1-5) per follicular unit but is also the most susceptible body site to hair loss with age. Hence, we set-out to determine the degree to which scalp hair parameters change with age in women and men, any sex differences thereof and whether hair loss is random across follicular units. METHODS: A retrospective cross-sectional study of 200 Chinese men and 200 Chinese women (30-69 years). Image analysis and manual counting methods were used to measure occipital located hair parameters from 6 × 8 mm shaved scalp photographs and plucked hair microscopy images. RESULTS: Of the five hair parameters, the number of hairs per follicular unit had the greatest (negative) correlation with age in both men and women. Men had a greater number of hairs and follicular units than women on average but had a greater decrease in the number of hairs per follicular unit with age, particularly for the loss of multi-hair (3+) follicular units. The loss of hairs with age was significantly different to that expected by a random loss of hairs across follicular units and better described by a model of increased hair loss risk the greater number of hairs per follicular unit. CONCLUSIONS: We have found evidence of hair loss preferentially occurring in multi-hair follicular units, which was more pronounced in men. These data suggest that part of the reason scalp hair is more susceptible to hair loss than on other body sites is due to the greater presence of multi-hair follicular units on the scalp.

OBJECTIFS: Le cuir chevelu possède le plus grand nombre de cheveux (généralement de 1 à 5) par unité folliculaire, mais c'est aussi le site le plus sensible à la perte de cheveux avec l'âge. Nous avons donc entrepris de déterminer dans quelle mesure les paramètres des cheveux du cuir chevelu changent avec l'âge chez les femmes et les hommes, quelles sont les différences entre les sexes et si la perte de cheveux est aléatoire entre les unités folliculaires. MÉTHODES: Étude transversale rétrospective portant sur 200 hommes et 200 femmes chinois (30-69 ans). Des méthodes d'analyse d'image et de comptage manuel ont été utilisées pour mesurer les paramètres des cheveux situés dans la région occipitale à partir de photographies du cuir chevelu rasé de 6x8 mm et d'images microscopiques de cheveux arrachés. RÉSULTATS: Parmi les 5 paramètres capillaires, le nombre de cheveux par unité folliculaire présentait la corrélation la plus forte (négative) avec l'âge, tant chez les hommes que chez les femmes. Les hommes avaient en moyenne un plus grand nombre de cheveux et d'unités folliculaires que les femmes, mais le nombre de cheveux par unité folliculaire diminuait davantage avec l'âge, en particulier pour la perte d'unités folliculaires à plusieurs cheveux (3+). La perte de cheveux avec l'âge était significativement différente de celle attendue par une perte aléatoire de cheveux dans les unités folliculaires, et mieux décrite par un modèle d'augmentation du risque de perte de cheveux plus le nombre de cheveux par unité folliculaire est élevé. CONCLUSIONS: Nous avons trouvé des preuves que la perte de cheveux se produit préférentiellement dans les unités folliculaires à plusieurs cheveux, ce qui était plus prononcé chez les hommes. Ces données suggèrent qu'une partie de la raison pour laquelle les cheveux du cuir chevelu sont plus sensibles à la perte de cheveux que sur d'autres sites du corps est due à la plus grande présence d'unités folliculaires à cheveux multiples sur le cuir chevelu.

Characterization of two homogalacturonan pectins with immunomodulatory activity from green tea.

Two natural homogalacturonan (HG) pectins (MW ca. 20 kDa) were isolated from green tea based on their immunomodulatory activity. The crude tea polysaccharides (TPS1 and TPS2) were obtained from green tea leaves by hot water extraction and followed by 40% and 70% ethanol precipitation, respectively. Two homogenous water soluble polysaccharides (TPS1-2a and TPS1-2b) were obtained from TPS1 after purification with gel permeation, which gave a higher phagocytic effect than TPS2. A combination of composition, methylation and configuration analyses, as well as NMR (nuclear magnetic resonance) spectroscopy revealed that TPS1-2a and TPS1-2b were homogalacturonan (HG) pectins consisting of a backbone of 1,4-linked α-D-galacturonic acid (GalA) residues with 28.4% and 26.1% of carboxyl groups as methyl ester, respectively. The immunological assay results demonstrated that TPS1-2, which consisted mainly of HG pectins, showed phagocytosis-enhancing activity in HL-60 cells.

Using transcriptomics, proteomics and phosphoproteomics as new approach methodology (NAM) to define biological responses for chemical safety assessment.

Omic-based technologies are of particular interest and importance for hazard identification and health risk characterization of chemicals. Their application in the new approach methodologies (NAMs) anchored on cellular toxicity pathways is based on the premise that any apical health endpoint change must be underpinned by some alterations at the omic levels. In the present study we examined the cellular responses to two chemicals, caffeine and coumarin, by generating and integrating multi-omic data from multi-dose and multi-time point transcriptomic, proteomic and phosphoproteomic experiments. We showed that the methodology presented here was able to capture the complete chain of events from the first chemical-induced changes at the phosphoproteome level, to changes in gene expression, and lastly to changes in protein abundance, each with vastly different points of departure (PODs). In HepG2 cells we found that the metabolism of lipids and general cellular stress response to be the dominant biological processes in response to caffeine and coumarin exposure, respectively. The phosphoproteomic changes were detected early in time, at very low doses and provided a fast, adaptive cellular response to chemical exposure with 7-37-fold lower points of departure comparing to the transcriptomics. Changes in protein abundance were found much less frequently than transcriptomic changes. While challenges remain, our study provides strong and novel evidence supporting the notion that these three omic technologies can be used in an integrated manner to facilitate a more complete understanding of pathway perturbations and POD determinations for risk assessment of chemical exposures.

Landscape dynamic network biomarker analysis reveals the tipping point of transcriptome reprogramming to prevent skin photodamage.

Skin, as the outmost layer of human body, is frequently exposed to environmental stressors including pollutants and ultraviolet (UV), which could lead to skin disorders. Generally, skin response process to ultraviolet B (UVB) irradiation is a nonlinear dynamic process, with unknown underlying molecular mechanism of critical transition. Here, the landscape dynamic network biomarker (l-DNB) analysis of time series transcriptome data on 3D skin model was conducted to reveal the complicated process of skin response to UV irradiation at both molecular and network levels. The advanced l-DNB analysis approach showed that: (i) there was a tipping point before critical transition state during pigmentation process, validated by 3D skin model; (ii) 13 core DNB genes were identified to detect the tipping point as a network biomarker, supported by computational assessment; (iii) core DNB genes such as COL7A1 and CTNNB1 can effectively predict skin lightening, validated by independent human skin data. Overall, this study provides new insights for skin response to repetitive UVB irradiation, including dynamic pathway pattern, biphasic response, and DNBs for skin lightening change, and enables us to further understand the skin resilience process after external stress.

Inhibition of the intestinal postprandial glucose transport by gallic acid and gallic acid derivatives.

Inhibition of glucose uptake in the intestine through sodium-dependent glucose transporter 1 (SGLT1) or glucose transporter 2 (GLUT2) may be beneficial in controlling postprandial blood glucose levels. Gallic acid and ten of its derivatives were identified in the active fractions of Terminalia chebula Retz. fructus immaturus, a popular edible plant fruit which has previously been associated with the inhibition of glucose uptake. Gallic acid derivatives (methyl gallate, ethyl gallate, pentyl gallate, 3,4,6-tri-O-galloyl-ß-d-glucose, and corilagin) showed good glucose transport inhibition with inhibitory rates of 72.1 ± 1.6%, 71.5 ± 1.4%, 79.9 ± 1.2%, 44.7 ± 1.2%, and 75.0 ± 0.7% at 5 mM d-glucose and/or 56.3 ± 2.3, 52.1 ± 3.2%, 70.2 ± 1.7%, 15.6 ± 1.6%, and 37.1 ± 0.8% at 25 mM d-glucose. However, only 3,4,6-tri-O-galloyl-ß-d-glucose and corilagin were confirmed GLUT2-specific inhibitors. Whilst some tea flavonoids demonstrated minimal glucose transport inhibition, their gallic acid derivatives strongly inhibited transport effect with GLUT2 specificity. This suggests that gallic acid structures are crucial for glucose transport inhibition. Plants, such as T. chebula, which contain high levels of gallic acid and its derivatives, show promise as natural functional ingredients for inclusion in foods and drinks designed to control postprandial glucose levels.

Homoisoflavonoids Are Potent Glucose Transporter 2 (GLUT2) Inhibitors: A Potential Mechanism for the Glucose-Lowering Properties of Polygonatum odoratum.

Foods of high carbohydrate content such as sucrose or starch increase postprandial blood glucose concentrations. The glucose absorption system in the intestine comprises two components: sodium-dependent glucose transporter-1 (SGLT1) and glucose transporter 2 (GLUT2). Here five sappanin-type (SAP) homoisoflavonoids were identified as novel potent GLUT2 inhibitors, with three of them isolated from the fibrous roots of Polygonatum odoratum (Mill.) Druce. SAP homoisolflavonoids had a stronger inhibitory effect on 25 mM glucose transport (41.6 ± 2.5, 50.5 ± 7.6, 47.5 ± 1.9, 42.6 ± 2.4, and 45.7 ± 4.1% for EA-1, EA-2, EA-3, MOA, and MOB) than flavonoids (19.3 ± 2.2, 11.5 ± 3.7, 16.4 ± 2.4, 5.3 ± 1.0, 3.7 ± 2.2, and 18.1 ± 2.4% for apigenin, luteolin, quercetin, naringenin, hesperetin, and genistein) and phloretin (28.1 ± 1.6%) at 15 µM. SAP homoisoflavonoids and SGLT1 inhibitors were found to synergistically inhibit the uptake of glucose using an in vitro model comprising Caco-2 cells. This observed new mechanism of the glucose-lowering action of P. odoratum suggests that SAP homoisoflavonoids and their combination with flavonoid monoglucosides show promise as naturally functional ingredients for inclusion in foods and drinks designed to control postprandial glucose levels.

Employing observational method for prospective data collection: A case study for analyzing diagnostic process and evaluating efficacy of TCM treatments for diabetes mellitus.

ETHNOPHARMACOLOGICAL RELEVANCE: With the mounting pandemic of glucose metabolism dysregulation and type 2 Diabetes Mellitus (T2DM), traditional medicine such as traditional Chinese medicine (TCM) recipes has been widely adopted as a part of therapeutic approach, especially in Asian countries. AIM OF THE STUDY: A novel approach, which is adopted from cohort studies from epidemiology has been applied to explore the clinical efficacy, as well as the herbal component selection of a variety of TCM formulations against T2DM. MATERIALS AND METHODS: In the current study, 98 newly diagnosed T2DM patients were recruited in two hospitals. Over a span of 4 weeks, the patients were treated by prescriptions of their individual TCM physicians. General TCM symptoms, blood glucose parameters, as well as general metabolic health biomarkers were evaluated over the therapy period. The pattern of which herbs were used, together with association between blood glucose level change and the use of herbs, were analyzed. RESULTS: TCM diabetic syndrome diagnosis was made by physicians based on symptoms, who prescribed herbal TCM medication afterwards for individual subjects. The results showed significant reduction in fasting and postmeal glucose levels, as well as insulin after the TCM treatment regimen as compared to baseline. As secondary endpoint, total triglyceride level decreased over the period of study as well. Kudzuvine root, Rhemannia root, Figwoot root, and Mulberry leaf were the top herbs associated with pronounced glucose reduction. CONCLUSIONS: In conclusion, an observational study on a cohort of patients receiving TCM therapy has shown good clinical outcome for T2DM patients receiving TCM treatments. Association analysis on herbal usage and clinical outcome suggested opportunity in constructing optimized formulation for superior efficacy with future studies at a larger scale.

Homogalacturonans from preinfused green tea: structural characterization and anticomplementary activity of their sulfated derivatives.

Two homogeneous water-soluble polysaccharides (TPSR4-2B and TPSR4-2C) were obtained from preinfused green tea. Their average molecular weights were estimated to be 41 kDa and 28 kDa, respectively. A combination of composition, methylation, and configuration analysis, as well as NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1-4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and 28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester. Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid-pyridine ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C demonstrated a stronger inhibitory effect on the complement activation through the classic pathway, compared to that of heparin. Preliminary mechanism studies by using complement component depleted-sera indicated that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r, C1s, C2, C5, and C9 but not with C3 and C4. The relationship between DS and the anticomplementary activity of sulfated derivatives of homogalacturonans showed that low sulfated derivatives of homogalacturonans also exhibited potent anticomplementary effect, which might greatly reduce the side effects related to heparin and oversulfated chondroitin sulfate, such as anticoagulant activity and allergic-type reaction. These results suggested that sulfated derivatives of homogalacturonans might be promising drug candidates for therapeutic complement inhibition.