The use of antisense strategy to modulate human melanogenesis.

BACKGROUND AND OBJECTIVES: Skin without significant dyschromia is an aesthetic goal of people worldwide. Current options for lightening skin could have significant drawbacks. The antisense strategy may be a viable alternative. The reactions in melanogenesis are catalyzed mainly by tyrosinase, tyrosinase-related protein 1 (TRP-1), and TRP-2. Activation of tyrosinase is associated with phosphorylation by protein kinase C-betaI (PKC-betaI) and formation of a complex between phosphorylated tyrosinase and TRP-1. The aim of this study was to use 2 antisense oligonucleotides to modulate the synthesis of the tyrosinase/TRP-1 complex, PKC-beta, or both by interacting with the targeted mRNA, thus whitening skin by interfering with melanogenesis at the translational level. METHODS/STUDY DESIGN: In the in vitro study, the effect of the antisense oligonucleotides was evaluated by measuring the rate at which dihydroxyphenylalanine (DOPA) oxidase transforms L-DOPA to DOPAchrome in the pathway for melanin biosynthesis. A reduction in the reaction rate compared to the controls corresponded to a decrease in the enzyme activity and, consequently, to a reduction of the formation of melanin pigments. To evaluate the in vivo lightening effect of the antisense oligonucleotides, 30 Asian women volunteers with pigmented spots on both hands applied the test product twice daily for 8 weeks. The test product was applied to 2 marked-off areas of the hand: a pigmented spot (to evaluate the effect of the test product on the color of the spot) and a nonpigmented spot area (to evaluate the effect of the test product on normal skin pigmentation). The lightening effect was evaluated by comparing chromametric and mexametric parameters before treatment, after 4 weeks, and after 8 weeks. RESULTS: In vitro DOPA-oxidase activity was inhibited by 13% in melanocytes treated with the antisense sequence for PKC-BI alone, by 16% with the antisense sequence for TRP-1 alone, and by 36% with the association of 2 sequences. The inhibiting effect with both sequences required the specific sequences with nonreversed polarities. In vivo clinical results showed statistically significant whitening in both pigmented spots and nonpigmented spots when the test product was applied twice daily for 8 weeks by up to 30 Asian women. CONCLUSIONS: The association of TRP-1 and PKC-betaI antisense molecules significantly increased the inhibition of tyrosinase activity on human melanocytes. Antisense oligonucleotides are a new generation of active cosmetic ingredients that offer unprecedented specificity, biological stability, and safety in lightening skin. This is the first report of positive results in a cosmetic based on the use of these new active agents.

In vivo skin antioxidant effect of a new combination based on a specific Vitis vinifera shoot extract and a biotechnological extract.

BACKGROUND AND OBJECTIVES: Ultraviolet (UV) light produces reactive oxygen species (ROS) in skin, which accelerate aging by damaging DNA, proteins, lipids, and other cellular constituents. The aims of this study were to 1) evaluate the antioxidant properties of a Vitis vinifera shoot extract on cultured normal human keratinocytes, 2) compare the in vivo antioxidant of this extract in combination with a biotechnological extract (Ronacare Hydroine), and 3) evaluate the efficacy on photoaging skin of a serum based on a combination (Vitis vinifera shoot extract in hydroglycolic solution, or Sarmentine, and Ronacare Hydroine) after a 4-week application, and to quantify the additional improvement given by applying a cream with the serum. METHODS/STUDY DESIGN: An in vitro study was conducted to evaluate the antioxidant properties of Vitis vinifera shoot extract added to cultured normal human keratinocytes. A fluorescent probe was used to quantify cytoplasmic endogenous species formed in response to oxidative stress induced by H2O2. The antioxidant activity of Vitis vinifera shoot extract was compared to that of a solvent control and 2 positive controls, vitamin E and vitamin C. In the first in vivo study, 2 test products were included in a comparative, randomized, single-blind trial in which 27 subjects acted as their own (untreated) controls. Products were applied 4 times to randomized areas of the inner surface of the forearm for one day. The following day, treated and untreated (control) areas of stratum corneum were sampled for fluorimetric analysis. A decrease in fluorescence compared with untreated control reflected a decrease in the level of ROS, in which case the product had a scavenging effect. The 2 products contained a combination of Sarmentine and Ronacare Hydroine, whose antioxidant properties were under investigation. Other products were known antioxidants. In the second in vivo study, 60 female subjects applied either serum or serum plus cream twice daily for 28 days for clinical evaluation. Overall improvement was rated on a quartile scale (0%-25%, 26%-50%, 51%-75%, 76%-100%) and changes in firmness, radiant glow, evenness, smoothness, wrinkles, fine lines, hydration, texture, and softness were rated on a negative to positive scale (-5=worse to +5=greatly improved). RESULTS AND CONCLUSIONS: Vitis vinifera shoot extract appears to have significantly stronger in vitro antioxidant capacity than vitamin C or vitamin E. In the same vehicle (placebo emulsion), ascorbic acid (0.5%), Sarmentine (1%), and the Sarmentine (1%) plus Ronacare Hydroine (1%) combination had a significant in vivo antioxidant effect versus a nontreated area. The combination Sarmentine (1%) plus Ronacare Hydroine (1%) showed a higher efficacy than Sarmentine alone. The dermatologic evaluation showed that a 4-week twice-daily application of a serum containing the combination improved the main clinical signs of photoaged skin. The addition of the cream with the serum appears to enhance the serum-induced improvement of most of the skin characteristics.

Modulation of gene expression as a new skin anti-aging strategy.

BACKGROUND/OBJECTIVES: [corrected] The signs of aging may originate from natural processes or from exposure to the sun, wind, or other environmental factors. To evaluate the anti-aging effects of potential agents researchers must first identify and be able to quantify epidermal markers that change with aging. This paper summarizes the results of studies conducted to evaluate the transcriptional effects of an Aframomum angustifolium seed extract and Malva Sylvestris extract, and the antiaging efficacy of a skin care product containing the Aframomum angustifolium seed extract. METHODS: The transcriptional effect of an Aframomum angustifolium seed extract on normal human keratinocytes (NHKs) and normal human fibroblasts (NHF) was evaluated in vitro with the use of a low-density DNA array technology. The Malva Sylvestris extract was studied with a commercial DNA macroarray and by a real-time quantitative reverse transcriptase-polymerase chain reaction. The in vitro anti-aging activities of the Malva sylvestris extract were compared with those of all-trans retinoic acid (RA), a well-established topical therapy for photodamage and wrinkles. The genes studied were known to be modified by RA. The anti-aging efficacy of a facial skin care product containing Aframomum angustifolium seed extract was evaluated in a single-center study using image processing analysis and in a 2-center study by evaluation of the photographs by the investigator, independent evaluators, and subjects. RESULTS: In general, the Aframomum angustifolium seed extract strongly modified the gene expression profiles of NHKs and weakly modified the gene expression profiles of NHFs. After incubation with Aframomum angustifolium seed extract, the expressions of 3 antioxidant genes (metallothionein 1, metallothionein 2, and thioredoxin) were increased in NHKs, while expressions of 1 antioxidant gene (glutathione peroxidase) was increased in NHFs. Concerning the Malva sylvestris extract, a cDNA macro-array technology experiment with the reconstructed human epidermis model showed that some genes modulated by treatment with the Malva sylvestris extract are also regulated by RA treatment indicating a similar activity at the mRNA level. In the single-center study, a facial skin care product containing the Aframomum angustifolium seed extract significantly improved the homogeneity of the skin. The areas of the detected objects (skin imperfections) decreased significantly on each studied area of the face and the variance decreased significantly over the entire face. In the 2-center study, 28% percent of the subjects reported a greater than 50% overall global improvement in their skin by the end of the study compared to 11% of the subjects after 4 weeks of treatment. Seventy-six percent of subjects said they would purchase the cream. CONCLUSIONS: The authors developed a low-density DNA chip method that permitted the study of the transcriptional effect of Malva Sylvestris extract and of Aframomum angustrifolium seed extract. The gene expression profiles obtained demonstrate the anti-aging properties of these compounds. An in vivo single-center study, performed and analyzed with an assay based on image processing analysis, demonstrated the antiwrinkle activity of a formulation containing the Aframomum angustifolium seed extract. The data obtained in the 2-center study suggests that the cosmeceutical containing Aframomum angustifolium seed extract produces a global rejuvenation effect in terms of redness, pigmentation, and fine lines similar to that noted utilizing an intense pulse light source.

Transcriptional effect of an Aframomum angustifolium seed extract on human cutaneous cells using low-density DNA chips.

BACKGROUND: Studying photoexposed and photoprotected skin biopsies from young and aged women, it has been found that a specific zone, composed of the basal layers of the epidermis, the dermal epidermal junction, and the superficial dermis, is major target of aging and reactive oxygen species. We showed that this zone is characterized by significant variations at a transcriptional and/or protein levels. AIMS: Using low-density DNA chip technology, we evaluated the effect of a natural mixture of Aframomum angustifolium seed extract containing labdane diterpenoids on these aging markers. METHODS: Expression profiles of normal human fibroblasts (NHF) were studied using a customized cDNA macroarray system containing genes covering dermal structure, inflammatory responses, and oxidative stress defense mechanisms. For normal human keratinocyte (NHK) investigations, we chose OLISA technique, a sensitive and quantitative method developed by BioMérieux specifically designed to investigate cell death, proliferation, epidermal structure, differentiation, and oxidative stress defense response. RESULTS: We observed that this extract strongly modified gene expression profiles of treated NHK, but weakly for NHF. This extract regulated antioxidant defenses, dermal-epidermal junction components, and epidermal renewal-related genes. CONCLUSION: Using low-density DNA chip technology, we identified new potential actions of A. angustifolium seed extract on skin aging.

HNF-4-dependent induction of apolipoprotein A-IV gene transcription by an apical supply of lipid micelles in intestinal cells.

Apolipoprotein (apo) A-IV, a component of triglyceride-rich lipoproteins secreted by the small intestine, has been shown to play an important role in the control of lipid homeostasis. Numerous studies have described the induction of apoA-IV gene expression by lipids, but the molecular mechanisms involved in this process remain unknown. In this study, we have demonstrated that a lipid bolus induced transcription of the apoA-IV gene in transgenic mice and that the regulatory region of the apoA-IV gene, composed of the apoC-III enhancer and the apoA-IV promoter (eC3-A4), was responsible for this induction. In enterocyte Caco-2/TC7 cells, a permanent supply of lipids at the basal pole induced expression of the apoA-IV gene both at the transcriptional level and through mRNA stabilization. ApoA-IV gene transcription and protein secretion were further induced by an apical supply of complex lipid micelles mimicking the composition of duodenal micelles, and this effect was not reproduced by apical delivery of different combinations of micelle components. Only induction of the apoA-IV gene by lipid micelles involved the participation of hepatic nuclear factor (HNF)-4, as demonstrated using a dominant negative form of this transcription factor. Accordingly, lipid micelles increased the DNA binding activity of HNF-4 on the eC3-A4 region. These results emphasize the importance of physiological delivery of dietary lipids on apoA-IV gene expression and the implication of HNF-4 in this regulation.