Topical treatment with coenzyme Q10-containing formulas improves skin's Q10 level and provides antioxidative effects.

Ubiquinone (coenzyme Q10, Q10) represents an endogenously synthesized lipid-soluble antioxidant which is crucial for cellular energy production but is diminished with age and under the influence of external stress factors in human skin. Here, it is shown that topical Q10 treatment is beneficial with regard to effective Q10 replenishment, augmentation of cellular energy metabolism, and antioxidant effects. Application of Q10-containing formulas significantly increased the levels of this quinone on the skin surface. In the deeper layers of the epidermis the ubiquinone level was significantly augmented indicating effective supplementation. Concurrent elevation of ubiquinol levels suggested metabolic transformation of ubiquinone resulting from increased energy metabolism. Incubation of cultured human keratinocytes with Q10 concentrations equivalent to treated skin showed a significant augmentation of energy metabolism. Moreover, the results demonstrated that stressed skin benefits from the topical Q10 treatment by reduction of free radicals and an increase in antioxidant capacity.

Damage at the root of cell renewal--UV sensitivity of human epidermal stem cells.

BACKGROUND: The epidermis harbors adult stem cells that reside in the basal layer and ensure the continuous maintenance of tissue homeostasis. Various studies imply that stem cells generally possess specific defense mechanisms against several forms of exogenous stress factors. As sun exposition is the most prevalent impact on human skin, this feature would be of particular importance in terms of sensitivity to UV-induced DNA damage. OBJECTIVE: To investigate whether human epidermal stem cells are susceptible to UV-induced DNA damage and subsequent functional impairment. METHODS: A method to isolate human epidermal stem cells from suction blister epidermis was established and validated. Volunteers were treated with solar-simulated irradiation on test areas of the forearm and stem cells were isolated from suction blister material of this region. DNA damage was analyzed by staining for cyclobutane thymidine dimers. The functional consequences of UV-induced damages were assessed by colony forming efficiency assays and gene expression analyses. RESULTS: Compared to an unirradiated control, stem cells isolated from areas that were exposed to solar-simulated radiation showed significantly more DNA lesions. Although the number of stem cells was not reduced by this treatment, a functional impairment of stem cells could be shown by reduced colony forming efficiency and altered gene expression of stem cell markers. CONCLUSIONS: Despite their essential role in skin maintenance, epidermal stem cells are sensitive to physiological doses of UV irradiation in vivo.

A novel treatment option for photoaged skin.

BACKGROUND: DNA damage as a result of ultraviolet (UV) exposure plays an important role in the progression of cutaneous aging. Both folic acid and creatine have been linked to the process of DNA protection and repair. AIMS: This study aims to investigate the effects of a commercially available folic acid- and creatine-containing formulation to fight the clinical signs of premature skin aging. PATIENTS/METHODS: Both in vitro and in vivo home-in-use studies using a folic acid- and creatine-containing formulation were performed aiming to elucidate the efficacy in terms of improvement of skin regeneration, protection from UV-induced DNA damage (Comet assay), reduction of wrinkle volume, and skin visco-elasticity. Furthermore, clinical evaluation and photography were carried out to determine the improvement of clinically graded parameters after treatment. RESULTS: Cultured full-thickness epidermal skin models supplemented with folic acid and creatine after epithelial perturbation showed an accelerated skin regeneration compared to untreated control models. Similarly, application of a folic acid- and creatine-containing formulation significantly improved epidermal turnover in vivo as evidenced by smaller corneocytes derived from the treated sites relative to the vehicle-treated sides. In addition, topical in vivo application of this formulation significantly protected from UV-induced DNA lesions, increased skin firmness, and reduced wrinkle volume compared to untreated control areas. Expert grading confirmed a significant decrease of fine and coarse wrinkles in the periocular region as well as overall wrinkles, tactile roughness, and laxity. CONCLUSIONS: Taken together, these results show that the combination of folic acid and creatine significantly accelerates epidermal skin regeneration in vitro and in vivo. Together with the finding of improved biomechanical skin properties, we conclude that the described topical formulation provides an effective treatment option for (photo)-aged skin.

Natural Arctium lappa fruit extract improves the clinical signs of aging skin.

BACKGROUND: Subclinical, chronic tissue inflammation involving the generation of cytokines (e.g., interleukin-6 and tumor necrosis factor-alpha) might contribute to the cutaneous aging process. AIMS: This study aims to screen for an active ingredient with anti-inflammatory (i.e., reduction of interleukin-6 and tumor necrosis factor-alpha) and matrix-stimulating efficacy which improves the clinical signs of skin aging in vivo. PATIENTS/METHODS: In vitro studies with pure Arctiin were performed investigating the inhibition of cytokine induction and stimulation of collagen neo-synthesis. In vivo home-in-use studies using an Arctium lappa fruit extract-containing formulation were carried out to determine procollagen and hyaluronan synthesis, hyaluronan synthase-2 gene expression, and reduction of wrinkle volume after treatment. RESULTS: In vitro studies on human dermal fibroblasts and monocyte-derived dendritic cells supplemented with pure Arctiin showed relative to untreated control cells a stimulation of collagen synthesis and a decrease in interleukin-6 and tumor necrosis factor-alpha concentration, respectively. In addition, topical in vivo application of an A. lappa fruit extract-containing formulation for 12 weeks significantly stimulated procollagen synthesis and increased hyaluronan synthase-2 expression as well as hyaluronan levels compared to vehicle-treated control areas. Similarly, after a 4-week treatment with an A. lappa fruit extract-containing formulation, wrinkle volume in the crow's feet area was significantly reduced as compared to treatment with the vehicle. CONCLUSIONS: Our data show that topical treatment with a natural A. lappa fruit extract significantly improves the metabolism of the dermal extracellular matrix and leads to a visible wrinkle reduction in vivo. In conclusion, A. lappa fruit extract represents a targeted means to regenerate dermal structures and, thus, offers an effective treatment option for mature skin.

Novel aspects of intrinsic and extrinsic aging of human skin: beneficial effects of soy extract.

Biochemical and structural changes of the dermal connective tissue substantially contribute to the phenotype of aging skin. To study connective tissue metabolism with respect to ultraviolet (UV) exposure, we performed an in vitro (human dermal fibroblasts) and an in vivo complementary DNA array study in combination with protein analysis in young and old volunteers. Several genes of the collagen metabolism such as Collagen I, III and VI as well as heat shock protein 47 and matrix metalloproteinase-1 are expressed differentially, indicating UV-mediated effects on collagen expression, processing and degradation. In particular, Collagen I is time and age dependently reduced after a single UV exposure in human skin in vivo. Moreover, older subjects display a lower baseline level and a shorter UV-mediated increase in hyaluronan (HA) levels. To counteract these age-dependent changes, cultured fibroblasts were treated with a specific soy extract. This treatment resulted in increased collagen and HA synthesis. In a placebo-controlled in vivo study, topical application of an isoflavone-containing emulsion significantly enhanced the number of dermal papillae per area after 2 weeks. Because the flattening of the dermal-epidermal junction is the most reproducible structural change in aged skin, this soy extract appears to rejuvenate the structure of mature skin.