Pharmacology of skin aging. Stimulation of glycosaminoglycan biosynthesis by L-fucose and fucose-rich polysaccharides, effect of in vitro aging of fibroblasts

Vascular biomechanical properties in mice with smooth muscle specific deletion of Ndst1

Heparan sulfate proteoglycans act as co-receptors for many chemokines and growth factors. The sulfation pattern of the heparan sulfate chains is a critical regulatory step affecting the binding of chemokines and growth factors. N-deacetylase-N-sulfotransferase1 (Ndst1) is one of the first enzymes to catalyze sulfation. Previously published work has shown that HSPGs alter tangent moduli and stiffness of tissues and cells. We hypothesized that loss of Ndst1 in smooth muscle would lead to significant changes in heparan sulfate modification and the elastic properties of arteries. In line with this hypothesis, the axial tangent modulus was significantly decreased in aorta from mice lacking Ndst1 in smooth muscle (SM22αcre(+)Ndst1(-/-), p < 0.05, n = 5). The decrease in axial tangent modulus was associated with a significant switch in myosin and actin types and isoforms expressed in aorta and isolated aortic vascular smooth muscle cells. In contrast, no changes were found in the compliance of smaller thoracodorsal arteries of SM22αcre(+)Ndst1(-/-) mice. In summary, the major findings of this study were that targeted ablation of Ndst1 in smooth muscle cells results in altered biomechanical properties of aorta and differential expression of myosin and actin types and isoforms.

Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.

Photoaging: Mechanisms and repair

Aging is a complex, multifactorial process resulting in several functional and esthetic changes in the skin. These changes result from intrinsic as well as extrinsic processes, such as ultraviolet radiation. Recent advances in skin biology have increased our understanding of skin homeostasis and the aging process, as well as the mechanisms by which ultraviolet radiation contributes to photoaging and cutaneous disease. These advances in skin biology have led to the development of a diversity of treatments aimed at preventing aging and rejuvenating the skin. The focus of this review is the mechanism of photoaging and the pathophysiology underlying the treatments specifically designed for its prevention and treatment.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be familiar with the mechanism of photoaging, the treatments for photoaging, and the data that supports the use of these treatments.

Effect of a preparation containing a fucose-rich polysaccharide on periorbital wrinkles of human voluntaries

BACKGROUND

Skin aging is accompanied by wrinkle formation. At some sites, as the periorbital skin, this is a relatively early phenomenon, variable from one woman to the other and even between the right and left eye.

PURPOSE

We tested the effect of a preparation with fucose-rich oligo- and polysaccharide (FROP-3) on periorbital wrinkles (crow's feet) on a team of voluntaries.

METHOD

The efficiency of a preparation containing as active principle a fucose-rich polysaccharide in a base-cream for the treatment of temporal periorbital wrinkles on 20 voluntary women was tested as follows: the women applied the cream twice a day for 4 weeks. Negative replicas were taken on the periorbital skin before and after 4 weeks of application of the cream. The results were evaluated by semi-automated morphometry on the plastic replicas and expressed as the 'wrinkle-factor' obtained by multiplying total wrinkle length in millimeters by the average wrinkle width.

RESULTS

After 4 weeks of treatment, there was a significant improvement of the periorbital wrinkles for the majority of the voluntary team who tested the cream. On the 29 periocular wrinkles examined 65% showed an improvement at the end of the treatment. In two cases, the improvement was 100% on one eye (disappearance of the crow's feet) and of 75% and 79% on the other eye. On six eyes, there was no significant change after the end of the treatment, and on four eyes a worsening was observed. The age-dependent modifications showed that improvement was independent of age and was the result of individual skin reactions to the cream. The occurrence and the severity of crow's feet is highly individual, and differs from one side of the face to the other for the same person. These strong individual variations explain the highly variable results, not only from one woman to the other but also comparing one side of the face to the other for the same person.

CONCLUSION

Under the effect of 4 weeks of treatment with the FROP-3-containing cream, most of the voluntaries had their periorbital wrinkles attenuated and some women showed a total regression of crow's feet on one of their eyes.