Ageing, science and the cosmetics industry. The micro-inflammatory model serves as a basis for developing effective anti-ageing products for the skin

Dental Students' Positive and Negative Views on Aging at an Undergraduate Course at the University of British Columbia, Canada

Background

Different views of aging exist, including ageism as the stereotyped idea about older adults in general. The objective of this study was to perform an initial exploration on how third-year undergraduate dental students at the University of British Columbia (UBC), Vancouver, Canada self-perceived themselves at ages 65, 75, or 85 years old.

Methods

For a period of 10 years, and using a cross-sectional design, third-year undergraduate dental students were asked to envision themselves at 65, 75, or 85 years old in a brief 150-word written essay. We employed a thematic analysis of the textual data via a coding process as suggested. The main themes were identified and displayed in a table with their respective categories of information. NVivo® 12 (QSR International) software was used for data analysis.

Results

Between 2010 and 2020, a total of 519 students enrolled in the UBC undergraduate dental program; 425 essays were collected. Initial coding and thematic analysis led to the identification of four main themes and eight categories; themes included "Ups and Downs," "Financial Sustainability," while categories focused on "Trade-offs," and "Camaraderie," for example. Different levels of ageism were also apparent when students saw themselves experiencing isolation and forgetfulness regardless of the selected age and the academic year. For other students, they anticipate aging would be healthy, joyful, and productive.

Conclusion

Ageism was present when students imagined themselves at three different older ages, but so were more realistic views of an aging. Further studies are warranted to unravel the impact of geriatric education in tackling stereotypes and ageism.

Anti-Aging Potential of a Rosa centifolia Stem Extract with Focus on Phytochemical Composition by Bioguided Fractionation

Agricultural practices generate huge amounts of by-products, often simply discarded as waste that must be processed at some cost. The natural by-products revalorisation as raw material to produce high-added value ingredients for various industrial sectors may pave the way towards more sustainable industrial practices, via an optimised utilisation of natural resources. Integrating the circular economy precepts to production systems is considered to be a more and more promising management solution to significantly reduce the environmental impact of economic activities. This article discusses the valorisation of Rosa centifolia stem to produce a natural extract with cosmetic anti-aging potential. To do so, the cosmetic potential of 30 extracts obtained by maceration of agricultural by-products in a hydroalcoholic solvent was evaluated: their activities, as well as their inhibitory activities of specific enzymes were assessed in vitro to identify those that could be used effectively as anti-ageing actives while meeting the consumer's expectations in terms of sustainability, naturality, transparency and traceability.^[1] A hydroalcoholic extract of R. centifolia stem revealed itself particularly promising due to its valuable anti-hyaluronidase and antioxidant activities, and its interesting anti-elastase and anti-inflammatory potential. The bio-guided fractionation of this extract allows the characterisation of three major compounds, e. g., isoquercitrin, quercitrin and euscaphic acid, never identified in R. centifolia previously.

Safety and efficacy of a novel home-use device for light-potentiated (LED) skin treatment

Skin structure and function results from a dynamic interplay between dermal and epidermal cell types. Optimizing skin health through an effective and long-lasting skin care regime therefore requires a global approach, encompassing various mechanisms to stimulate this interplay beyond the action scope of a classical topical solution. This study evaluates the impact of a novel home-use device combining a topical serum, light-emitting diodes and massage on the clinical signs of extrinsic skin aging. The innovative principle relies on potentiating the effect of active ingredients contained in the topical serum with visible and near infra-red photons to prevent extracellular matrix degradation and promote its reconstruction. After in vitro and ex vivo investigations, a clinical study assessed the safety and efficacy of a daily treatment with the home-use device for 28 days. A significant increases in skin density and radiance while reducing the wrinkles was obtained with no side effects.

Development of Polymeric Micelles of Oleanolic Acid and Evaluation of Their Clinical Efficacy

Oleanolic acid has been used only as a subsidiary agent in cosmetic products. The aim of the study is to show the effect of oleanolic acid as an active ingredient for the alleviation of wrinkles in humans and to develop a polymeric micelle formulation that enables poorly soluble oleanolic acid to be used as a main ingredient in cosmetic products for reducing wrinkles. The solubility of oleanolic acid was evaluated in solubilizers, surfactants, and polymers. The particle sizes and shapes of polymeric micelles containing oleanolic acid were evaluated by electrophoretic light scattering spectrophotometer and scanning electron cryomicroscopy. Encapsulation efficiency and skin permeation were measured by HPLC. Stability of the polymeric micelles stored at 40 °C for 3 months was evaluated by visual observation, particle size measurement, and oleanolic acid content measurement. Polymeric micelles in final product ampoule form were applied around the eyes of 23 female subjects for 8 weeks. Five skin parameters were evaluated by optical profilometry every 4 weeks for 8 weeks. In addition, professionals made visual observations of the skin and a human skin irritation study was conducted. Polymeric micelles of oleanolic acid with a particle size of less than 100 nm were prepared using Capryol 90® and poloxamer. The skin permeation rate of the oleanolic acid in the polymeric micelles was higher than that in the other solutions made of oleanolic acid dispersed in 2 different surfactants. No significant changes in particle size, color, or oleanolic acid content were observed, and the polymeric micelles stored at 40 °C for 3 months did not undergo phase separation. After 8 weeks of application, skin irritation had not developed and all five parameters evaluated by optical profilometry as well as the visual evaluation scores were significantly improved. This study showed that the polymeric micelles of oleanolic acid prepared in this study were stable and effective at alleviating wrinkles in humans as the principal active ingredient. Based on these findings, it is expected that polymeric micelles of oleanolic acid can be widely used in cosmetic applications.

Modulation of Oxidative Status by Normoxia and Hypoxia on Cultures of Human Dermal Fibroblasts: How Does It Affect Cell Aging?

Reactive oxygen species (ROS) production in the skin is among the highest compared to other organs, and a clear correlation exists between ROS production and skin aging. Many attempts are underway to reduce oxidative stress in the skin by topical treatment or supplementation with antioxidants/cosmeceuticals, and cultures of human dermal fibroblasts (HDF) are widely used for these studies. Here, we examined the influence of oxygen tension on cell aging in HDF and how this impacted ROS production, the enzymatic and nonenzymatic antioxidant response system, and the efficacy of this defense system in limiting DNA damage and in modulating gene expression of proteins involved in the extracellular matrix, linked to skin aging. We investigated a selection of parameters that represent and reflect the behavior of cellular responses to aging and oxygen tension. Serial passaging of HDF under normoxia (21%) and hypoxia (5%) leads to cell aging as confirmed by β-galactosidase activity, p16 expression, and proliferation rate. However, in HDF under 21% O₂, markers of aging were significantly increased compared to those under 5% O₂ at matched cell passages despite having lower levels of intracellular ROS and higher levels of CoQ₁₀, total GSH, SOD1, SOD3, and mitochondrial superoxide anion. miRNA-181a, which is known to be upregulated in HDF senescence, was also analyzed, and indeed, its expression was significantly increased in old cells at 21% O₂ compared to those at 5% O₂. Upregulation of MMP1 and downregulation of COL1A1 along with increased DNA damage were also observed under 21% O₂ vs 5% O₂. The data highlight that chronic exposure to atmospheric 21% O₂ is able to trigger hormetic adaptive responses in HDF that however fail, in the long term, to prevent cellular aging. This information could be useful in further investigating molecular mechanisms involved in adaptation of skin fibroblasts to oxidative stress and may provide useful hints in addressing antiaging strategies.

Redox-dependent induction of antioxidant defenses by phenolic diterpenes confers stress tolerance in normal human skin fibroblasts: Insights on replicative senescence

Mild stress-induced hormesis represents a promising strategy for targeting the age-related accumulation of molecular damage and, therefore, for preventing diseases and achieving healthy aging. Fruits, vegetables, and spices contain a wide variety of hormetic phytochemicals, which may explain the beneficial health effects associated with the consumption of these dietary components. In the present study, the induction of cellular antioxidant defenses by the phenolic diterpenes carnosic acid (CA) and carnosol (CS) were studied in normal human skin fibroblasts, and insights into the aging process at the cellular level investigated. We observed that CA and CS induced several cytoprotective enzymes and antioxidant defenses in human fibroblasts, whose induction was dependent on the cellular redox state for CS and associated with Nrf2 signaling for both compounds. The stress response elicited by preincubation with CS conferred a cytoprotective action against a following oxidant challenge with tert-butyl hydroperoxide, confirming its hormetic effect. Preincubation of normal fibroblasts with CS also protected against hydrogen peroxide-induced premature senescence. Furthermore, cultivation of middle passage normal human skin fibroblasts in the presence of CS ameliorated the physiological state of cells during replicative senescence. Our results support the view that mild stress-induced antioxidant defenses by CS can confer stress tolerance in normal cells and may have important implications in the promotion of healthy aging.

Use of p38 MAPK Inhibitors for the Treatment of Werner Syndrome

Werner syndrome provides a convincing model for aspects of the normal ageing phenotype and may provide a suitable model for therapeutic interventions designed to combat the ageing process. Cultured primary fibroblast cells from Werner syndrome patients provide a powerful model system to study the link between replicative senescence in vitro and in vivo pathophysiology. Genome instability, together with an increased pro-oxidant state, and frequent replication fork stalling, all provide plausible triggers for intracellular stress in Werner syndrome cells, and implicates p38 MAPK signaling in their shortened replicative lifespan. A number of different p38 MAPK inhibitor chemotypes have been prepared rapidly and efficiently using microwave heating techniques for biological study in Werner syndrome cells, including SB203580, VX-745, RO3201195, UR-13756 and BIRB 796, and their selectivity and potency evaluated in this cellular context. Werner syndrome fibroblasts treated with a p38 MAPK inhibitor reveal an unexpected reversal of the accelerated ageing phenotype. Thus the study of p38 inhibition and its effect upon Werner pathophysiology is likely to provide new revelations into the biological mechanisms operating in cellular senescence and human ageing in the future.

Comparison of gene expression profiles of conjunctival cell lines with primary cultured conjunctival epithelial cells and human conjunctival tissue

Human conjunctival cell lines are useful tools for modeling ocular surface disease and evaluation of ocular drugs and cosmetics. However, gene expression in these cells may not be comparable to primary cultured cells, raising doubts that they could be used as a substitute. We aimed to ascertain the similarities of global gene expression between commonly used cell lines and primary cells using a microarray approach. The Affymetrix U133A chip (>22,000 genes) was used to investigate conjunctival tissue (CT), primary conjunctival epithelial cells (PCEC), two conjunctival epithelial cell lines (IOBA-NHC and ChWK), and HCEC-T, a human corneal epithelial cell line (control). Using principal component analysis, the PCEC profile was clustered more closely to conjunctival tissue than either of the two cell lines. Certain extracellular matrix genes were differentially upregulated in CT compared to PCEC, suggesting presence of fibroblasts in addition to epithelial cells in CT. Overall, 67.3% (95% CI: 66.7-67.9) of transcripts in IOBA-NHC were within 1.5-fold of the corresponding transcripts in PCEC, but only 62.2% (95% CI: 61.5-62.9) in the case of ChWK. In HCEC-T, the proportion was only 58.8% (95% CI 58.1-59.4), suggesting less resemblance to PCEC than the conjunctival epithelial cell lines. The IOBA-NHC profile was more similar to PCEC than ChWK, for all genes and genes concerned with membrane association, communication, development, and regulation of metabolism, especially protein and nucleic acid metabolism. The correlation of normalized gene expression levels was high between either the IOBA-NHC or ChWK and PCEC for genes concerned with cell defense, viral life cycle, antigen presentation, antioxidation, or ubiquitin ligation. In order to evaluate the functional significance of the altered gene expression in IOBA-NHC cells, we evaluated a few proteins important for epithelial differentiation or defense, corresponding to the transcripts for S100A9, TGM2, and TLR4. Protein levels of S100A9 and TGM2 were indeed raised, and TLR4 decreased, in IOBA-NHC compared to PCEC. Gene expression in conjunctival cell lines differs from primary cells, but the profile varies according to functional gene categories. Depending on the methodology of proposed studies, if there is limited availability of PCEC, NHC-IOBA may be more suitable than ChWK, but even then, epithelial differentiation and innate immunity functions in NHC-IOBA may differ from primary cells.

Werner Syndrome as an Example of Inflamm-aging: Possible Therapeutic Opportunities for a Progeroid Syndrome?

Werner syndrome (WS) is a premature aging disorder that is widely used as a model for some aspects of the normal human aging process. Individuals with WS have several of the characteristics of normal aging, such as cataracts, hair graying, and skin aging, but manifest these at an early age. In addition, WS is associated with high levels of inflammatory diseases such as atherosclerosis and type II diabetes. Recent data have indicated that fibroblasts derived from individuals with WS have activated a major molecular pathway involved in inflammation. This observation ties in with the presence of high plasma levels of inflammatory cytokines in individuals with WS. In this paper, the authors discuss the possibility that WS is an example of "inflamm-aging," in that many of the phenotypic manifestations may result from an increased inflammatory state. Moreover, drugs that specifically block this inflammation pathway may be possible candidates for therapeutic intervention in WS.