. EGF receptor-dependent JNK activation is involved in arsenite-induced p21Cip1/Waf1 upregulation and endothelial apoptosis. Am J Physiol Heart Circ Physiol 289: H99 -H107, 2005. First published February 25, 2005 doi:10.1152/ajpheart.00901.2004.-Arsenic exposure is associated with an increased risk of atherosclerosis and vascular diseases. Although endothelial cells have long been considered to be the primary targets of arsenic toxicity, the underlying molecular mechanism remains largely unknown. In this study, we sought to explore the signaling pathway triggered by sodium arsenite and its implication for endothelial phenotype. We found that sodium arsenite produced timeand dose-dependent decreases in human umbilical vein endothelial cell viability. This effect correlated with the induction of p21Cip1/Waf1 (up to 10-fold), a regulatory protein of cell cycle and apoptosis. We also found that arsenite-stimulated EGF (ErbB1) and ErbB2 receptor transactivation, manifest as receptor tyrosine phosphorylation, appeared to be a proximal signaling event leading to p21Cip1/Waf1 induction, because both pharmacological inhibitors and knockdown of receptors by RNA interference blocked arsenite-induced p21Cip1/Waf1 upregulation. Arsenite-induced activation of JNK and p38 MAPK was distinct, with only JNK as a downstream target of the EGF receptor. Moreover, inhibition of JNK with SP-600125 or dominant negative MKK7 inhibited only p21Cip1/Waf1
Hydrogel patches are some of the most effective dressings for wound healing. In this study, the Gantrez® S-97 (Gan)/xyloglucan (XG) hydrogel patches were formulated by using a full central composite design (CCD). The optimized hydrogel patches consisted of 17.78% w/w of Gan and 0.1% w/w of XG. Honey and D. bulbifera extract were loaded in the Gan/XG hydrogel patches. The physical properties of the hydrogel patches, including water content, water absorption, rate of water vapor transmission, and mechanical properties, were examined. The D. bulbifera extract/honey-loaded patch exhibited a higher value of water absorption, tensile strength, and elongation than the honey-loaded patch and the unloaded patch, respectively. The biological activities of the patches were also investigated. All hydrogel patches protected wounds from external bacterial infection. The D. bulbifera extract/honey-loaded patch exhibited stronger antioxidant activity than the honey-loaded patch and the unloaded patch. Besides, all the hydrogel patches with concentrations of 0.5–2.5 mg/mL showed that they were nontoxic to fibroblast cells. The combination of D. bulbifera extract and honey in the patch affected fibroblast proliferation. In addition, all Gan/XG hydrogel patches significantly induced recovery of the scratch area. Therefore, the Gan/XG hydrogel patches could be candidates as wound dressings.
Porcine placenta extract (PPE) contains many water-soluble macromolecular compounds, such as proteins and growth factors, which have limited transportation through the skin. This study aimed to assess the effect of porcine-placenta-extract (PPE)-loaded nano-transdermal systems for skin repair and hair growth promotion. The potentials of the nanoformulation for cytotoxicity, cell proliferation, intracellular reactive oxygen species (ROS) reduction, lipoxygenase inhibition, intracellular inflammatory cytokine reduction, and cell aggregation were evaluated. PPE-entrapped niosome nanovesicles were produced by thin-film hydration and probe-sonication methods, followed by incorporation in a skin serum formulation. The physicochemical properties of the formulation were examined, and the efficacy of the serum formulation was elucidated in humans. The results showed that PPE had no toxicity and was able to induce cell growth and cell aggregation. In addition, PPE significantly decreased intracellular ROS, inhibited lipoxygenase activity, and reduced the production of intracellular tumor necrosis factor-α. In the in vivo human study, the PPE nanovesicles-loaded serum could improve skin properties by increasing skin hydration. Moreover, it was capable of promoting hair growth by increasing hair elongation and melanin index after application for one month. Consequently, the PPE nanovesicles-loaded serum was effective for skin anti-aging and hair rejuvenation.
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