title: Evaluation of EpiDerm full thickness-300 (EFT-300) as an in vitro model for skin irritation: studies on aliphatic hydrocarbons.
abstract: The aim of this study was to understand the skin irritation effects of saturated aliphatic hydrocarbons (HCs), C9-C16, found jet fuels using in vitro 3-dimensional EpiDerm full thickness-300 (EFT-300) skin cultures. The EFT-300 cultures were treated with 2.5microl of HCs and the culture medium and skin samples were collected at 24 and 48h to measure the release of various inflammatory biomarkers (IL-1alpha, IL-6 and IL-8). To validate the in vitro results, in vivo skin irritation studies were carried out in hairless rats by measuring trans epidermal water loss (TEWL) and erythema following un-occlusive dermal exposure of HCs for 72h. The MTT tissue viability assay results with the EFT-300 tissue show that 2.5microl/tissue ( approximately 4.1microl/cm(2)) of the HCs did not induce any significant changes in the tissue viability for exposure times up to 48h of exposure. Microscopic observation of the EFT-300 cross-sections indicated that there were no obvious changes in the tissue morphology of the samples at 24h, but after 48h of exposure, tridecane, tetradecane and hexadecane produced a slight thickening and disruption of stratum corneum. Dermal exposures of C12-C16 HCs for 24h significantly increased the expression of IL-1alpha in the skin as well as in the culture medium. Similarly, dermal exposure of all HCs for 24h significantly increased the expression of interleukin-6 (IL-6) and IL-8 in the skin as well as in the culture medium in proportion to the HC chain length. As the exposure time increased to 48h, IL-6 concentrations increased 2-fold compared to the IL-6 values at 24h. The in vivo skin irritation data also showed that both TEWL and erythema scores increased with increased HCs chain length (C9-C16). In conclusion, the EFT-300 showed that the skin irritation profile of HCs was in the order of C9C10C11C12<C13 approximately C14 approximately C16 and that the tissue was an excellent in vitro model to predict in vivo irritation and to understand the structural activity relationship of HCs.
authors.affiliation: College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA.
authors.forename: Ramya
authors.initials: R
authors.lastname: Mallampati
authors.forename: Ram R
authors.initials: RR
authors.lastname: Patlolla
authors.forename: Saurab
authors.initials: S
authors.lastname: Agarwal
authors.forename: R Jayachandra
authors.initials: RJ
authors.lastname: Babu
authors.forename: Patrick
authors.initials: P
authors.lastname: Hayden
authors.forename: Mitchell
authors.initials: M
authors.lastname: Klausner
authors.forename: Mandip S
authors.initials: MS
authors.lastname: Singh
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D006838:Hydrocarbons / Q000633:toxicity*; D007249:Inflammation; D007509:Irritants / Q000633:toxicity*; D008954:Models, Biological; D051381:Rats; D054772:Rats, Hairless; D023422:Skin Irritancy Tests / Q000379:methods*; D046509:Tissue Culture Techniques
chemical_list: D016207:Cytokines; D006838:Hydrocarbons; D007509:Irritants