Elucidation of the percutaneous absorption of chromium compounds by functional proteomics

Abstract

Chromium compounds are known to be associated with cytotoxicity and carcinogenicity when applied via a skin route. The aim of this study was to evaluate the skin permeability and toxicological profiles of four chromium species. Chromium permeation across the skin, as determined by an in vitro Franz cell, decreased in the order of sodium chromate>potassium chromate>potassium dichromate>chromium nitrate. The uptake of chromium species within the skin generally showed a contrary trend to the results of permeation, although differences among the various compounds were not large. Levels of in vivo skin deposition of the four compounds showed no statistically significant differences. Potassium chromate produced the greatest disruption of the skin structure as determined by HE staining, followed in order by sodium chromate, potassium dichromate, and chromium nitrate. This indicates that hexavalent chromium elicited greater toxicity to the skin compared to trivalent chromium. A similar result was observed for the viability of skin fibroblasts. To improve our understanding of the molecular mechanisms leading to functional changes in proteins, proteomic tools, including 2-DE and MS techniques combined with sequence database correlations, were applied to identify target proteins altered by pathologic states. Eight protein spots, corresponding to cutaneous enzymes involved in energy metabolism and chaperon proteins, which were identified and discussed in this study, were associated with skin cytotoxicity, immunity, and carcinogenesis. In addition, functional proteomics of skin tissues may provide a promising tool for developing therapeutic strategies and can serve as the basis for further research.

Functional proteomics reveals hepatotoxicity and the molecular mechanisms of different forms of chromium delivered by skin administration

“…All samples were diluted appropriately into a measurable range before being introduced to an atomic absorption spectrometry (AAS) (Hitachi Z‐5000, Japan). The diluted samples were investigated according to the methods described before 20 with a graphite furnace and Zeeman background correction system for Cr with wavelength of 359.3 nm. The remaining samples were processed for the other experiments including histopathology, proteomic analysis, and Western blotting.…”

“…The sample was sectioned at 4‐μm‐thick and stained with hematoxylin and eosin (H&E) and Masson's trichrome. Immunohistochemstry with pan‐cytokeratin or α‐SM actin (1:100 dilution by PBS) was treated to specimens as described in a previous study 20. For every sample, three sites were examined and evaluated by light microscopy (Olympus BX51, Tokyo, Japan).…”

Functional proteomics reveals the protective effects of saffron ethanolic extract on hepatic ischemia‐reperfusion injury

“…Each spot intensity volume (%) was determined by background subtraction and total spot volume normalization; the resulting spot volume percentage was used for comparison between groups. More than twofold alterations at 95% confidence interval (p < 0.05) were considered as statistically significant [29,30]. All experiments were repeated three times to confirm the reproducibility.…”

Dermatologic Toxicities and Biological Activities of Chromium

“…There are many factors involved in the penetration process including concentration of chromium species, medium (solvent and pH), intrinsic properties of chromium species (molecular volume of chromium species, counter ion, nature of chemical bond and polarity, solubility, and valence), reactivity towards protein, previous penetration or accumulation, skin characteristics (gender and race, age skin, density of sebaceous gland, thickness of skin, and anatomy of skin), and environmental factors (temperature, humidity, and UV radiation) [21,22]. In a normal skin condition, Cr(VI) ions tend to have higher solubility [23] and percutaneous permeability than Cr(III) ions [24,25]. However, Cr(III) have higher protein affinity to form metal-protein complex which tends to make it retain in the skin epidermis [26].…”