Differing energy densities with laser 670nm InGaP controls inflammation and collagen reorganization in burns.

PURPOSE: This study compared different energy densities of laser on second degrees burns in rats aiming to determine the most effective dosimetry in stimulation of the healing process. METHODS: Burns were induced in the dorsal skin of 54 animals divided into three groups (n: 18): 1-without treatment; 2-irradiated lesions by the Indium Gallium Phosphide (InGaP) 670nm (4.93J/cm2) laser; 3-irradiated lesions by the InGaP-670nm (9.86J/cm2) laser. Samples were collected on the 2, 10 and 18 days after injury for structural, morphometry, biochemical analysis and Western blotting. RESULTS: The energy densities examined were effective in significantly increasing the total number of fibroblasts and blood vessels and reduce the number of inflammatory cells particularly in irradiated lesions with 9.86J/cm2. This same energy density significantly increased the amount of GAGs (Glycosaminoglycans), decreased the TGF-ß1 (Transforming Growth Factor ß1) and increased the VEGF (Vascular and Endothelial Growth Factor) during the experimental period. This energy density also significantly increased the Collagen type I and decreased Collagen type III and the active isoform of metalloproteinase 9 (MMP-9). CONCLUSIONS: The energy density of 9.86J/cm2 was more effective in promoting cellular responses related to neoangiogenesis, decreasing inflammation and collagen fibers reorganization.

Vigna angularis water extracts protect against ultraviolet b-exposed skin aging in vitro and in vivo.

Exposure to ultraviolet (UV) radiation induces various pathological changes, such as thickened skin and wrinkle formation. In particular, UVB irradiation increases matrix metalloproteinase (MMP)-1 production and collagen degradation, leading to premature aging, termed photoaging. The azuki bean (Vigna angularis; VA) has been widely used as a food product as well as a traditional medicine. However, its activity needs additional study to confirm its functional application in foods and cosmetics for protecting skin. In this study, hot-water extract from VA (VAE) and its active component, rutin, were investigated to determine their antiphotoaging effects. VAE was found to have antioxidant activity. In UVB-exposed normal human dermal fibroblasts cells with VAE and rutin treatments, MMP-1 production was significantly suppressed (90% and 47%, respectively). The effects of both topical and oral administration of VAE were tested in UVB-irradiated hairless mice. VAE suppressed wrinkle formation and skin thickness by promoting elastin, procollagen type I, and TGF-ß1 expression (118%, 156%, and 136%, respectively) and by diminishing MMP-1 production. These results suggest that VAE may be effective for preventing skin photoaging accelerated by UVB radiation.

[Effect of intense pulsed light on transforming growth factor-beta1 mRNA expression in rat skin].

OBJECTIVE: To observe the effect of intense pulsed light (IPL) on transforming growth factor-beta1 mRNA (TGF-beta1 mRNA) expression in rat skin and explore the molecular mechanisms of photorejuvenation. METHODS: Fifteen SD rats were exposed to IPL in 3 dermal regions with triple pulses (duration of 4, 5, and 6 ms) at the energy density of 34 J/cm2 and pulse delay of 20 or 25 ms. On days 1, 3, 5, 7, 15, and 30 after the treatment, skin specimens from the treated and non-treated areas were obtained to detect TGF-beta1 mRNA expression with in situ hybridization. RESULTS: In the UPL-exposed skin areas, TGF-beta1 mRNA expression was detected in the epidermal keratinocytes and dermal cells 1 day after the exposure, reaching the highest expression level on day 7 followed by gradual decrement since day 15, and till day 30, only weak expression was found in the dermal cells. In the non-exposed regions, the cells remained negative for TGF-beta1 mRNA. CONCLUSION: IPL can enhance TGF-beta1 mRNA expression in the skin, suggesting that TGF-beta1 plays an important role in dermal remodeling in photorejuvenation.

Flashlamp pulsed-dye laser suppressed TGF-beta1 expression and proliferation in cultured keloid fibroblasts is mediated by MAPK pathway.

BACKGROUND AND OBJECTIVES: Our previous clinical study indicated that transforming growth factor-beta1 (TGF-beta1) and mitogen-activated protein kinases (MAPK) are both involved in keloid regression following flashlamp pulsed-dye laser (PDL). To further characterize of this involvement, this work examined whether PDL suppression of TGF-beta1 expression was mediated through MAPK pathway in cultured keloid fibroblasts (KF). STUDY DESIGN/MATERIALS AND METHODS: Primary culture of KF harvested from keloid patients received various dosages of PDL treatment in 585-nm wavelength. TGF-beta1 expressions in KF following various dosages of PDL were assessed. Additionally, MAPK pathway activities were studied using the PD98059 (an ERK inhibitor), SB203580 (a p38 kinase inhibitor), and SP600125 (a JNK inhibitor), to determine the role in keloid following PDL treatment. Activator protein-1 (AP-1), a transcription factor of TGF-beta, was analyzed by electrophoretic mobility shift assay (EMSA). Phosphorylated c-Jun, one of the components of AP-1, was also detected. RESULTS: The observation results demonstrated that optimal dosages of PDL significantly suppressed KF proliferation and TGF-beta1 expression. EMSA study identified PDL downregulation of super-shift of AP-1. Three subtypes of MAPK cascades were augmented between 30 minutes and 4 hours following PDL treatment, particularly phosphorylation of ERK1/2 and p38. Pre-treatment with PD98059, SB203580, but not SP600125, markedly inhibited the downregulating effects of TGF-beta1 and phosphorylated c-Jun expression following PDL treatment. CONCLUSION: PDL induced keloid regression is mediated by triggering MAPK cascades and blockade of AP-1 transcription and TGF-beta expression. Modulation of TGF-beta and MAPK interaction in keloids may provide specific targets for therapeutic intervention.