Objective Recent findings showed that skin ageing preferentially affects human papillary dermal fibroblasts suggesting that the papillary dermis represents a critical zone altered by skin ageing. Based on these findings, we investigated the potential anti‐ageing effect of rhamnose. Methods We investigated the potential anti‐ageing effect of rhamnose using in vitro reconstructed skin containing fibroblasts obtained either from young or old donors, and in vivo clinical investigation. Results We detected positive effects of rhamnose in both epidermal and dermal compartments of in vitro reconstructed skin. Moreover, we were able to show that such in vitro findings were also obtained in vivo including an effect on collagen IV and procollagen I production. Conclusion We provide evidence that rhamnose has a potentially beneficial effect on papillary dermis and dermal–epidermal junction, both of the areas which are affected by skin ageing.

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Skin aging is the result of superimposed intrinsic (individual) and extrinsic (e.g., UV exposure or nutrition) aging. Previous works have reported a relationship between UV irradiation and glycation in the aging process, leading, for example, to modified radical species production and the appearance of AGEs (advanced glycosylation end products) in increasing quantities, particularly glycoxidation products like pentosidine. In addition, the colocalization of AGEs and elastosis has also been observed. We first investigated the combination of the glycation reaction and UVA effects on a reconstructed skin model to explain their cumulative biological effect. We found that UVA exposure combined with glycation had the ability to intensify the response for specific markers: for example, MMP1 or MMP3 mRNA, proteases involved in extracellular matrix degradation, or proinflammatory cytokine, IL1α, protein expression. Moreover, the association of glycation and UVA irradiation is believed to promote an environment that favors the onset of an elastotic-like phenomenon: mRNA coding for elastin, elastase, and tropoelastin expression is increased. Secondly, because the damaging effects of UV radiation in vivo might be more detrimental in aged skin than in young skin due to increased accumulation of pentosidine and the exacerbation of alterations related to chronological aging, we studied the biological effect of soluble pentosidine in fibroblasts grown in monolayers. We found that pentosidine induced upregulation of CXCL2, IL8, and MMP12 mRNA expression (inflammatory and elastotic markers, respectively). Tropoelastin protein expression (elastin precursor) was also increased. In conclusion, fibroblasts in monolayers cultured with soluble pentosidine and tridimensional in vitro skin constructs exposed to the combination of AGEs and UVA promote an inflammatory state and an alteration of the dermal compartment in relation to an elastosis-like environment.

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Objective: During aging, skin undergoes structural, cellular and molecular changes, which not only alter skin mechanical properties but also biological and physiological functions. Structurally the epidermis becomes thinner, the dermal epidermal junction flattens and the extra-cellular matrix component of the dermis is disorganized and degraded. The dermis is composed of two compartments: The Reticular dermis is the deepest and thickest part while the upper layer, the papillary dermis, which is much thinner and is in close contact with epidermis, plays an important role in the structure and function of the skin. We have recently shown that the papillary dermis was preferentially affected by skin aging because the activity of fibroblasts in this region was especially altered as a function of age. The purpose of this study was to investigate the capacity of a flax extract as anti-aging component. Method: We investigated the capacity of a flax extract to stimulate or restore the activity of papillary fibroblasts from young and old donors in cultured monolayers and in reconstructed skin. Several biological markers of extracellular matrix homeostasis and mechanical properties were investigated. Results: The tested flax extract seemed to improve parameters known to change with age: I/ In monolayers after treatment the number of aged fibroblasts increased II/ In reconstructed skin the flax extract appears to positively regulate some biological activities; particularly in aged fibroblasts where the deposition of laminin 5, fibrillin 1, procollagen I were increased in the dermis and the secretion of specific soluble factors like MMP1, MMP3 and KGF were regulated to levels similar to those observed in young fibroblasts III/ Mechanical properties were improved particularly for elastics parameters (R5, R2 and R7). Conclusion: The flax extract is a promising anti-aging compound. The treatment of aged papillary fibroblasts resulted in a return to a younger-like profile for some of the studied parameters.