Cytokine induction in the 3D EpiDerm™ skin model used as an in vitro preclinical screening tool for formulations with anti-inflammatory action

Pidathala, Asha; Sheehan, Devin; Pham, Rebecca; Farahmand, Sara; Costin, Gertrude-Emilia

Abnormal cytokine profiles represent the hallmark of inflammatory skin conditions such as psoriasis, acne, atopic dermatitis, irritant and allergic contact dermatitis. Damage to skin keratinocytes induces the release of primary cytokine interleukin (IL)-1α which further stimulates the release of secondary cytokines (e.g., IL-8) involved in the mediation of inflammatory reactions. Animal models have been historically used to assess the potency of formulations designed to intervene in the inflammatory cascade. In recent years, in vitro testing methods based on three-dimensional (3D) reconstructed skin equivalents became a reliable, rapid tool to screen actives and formulations for efficacy claims, including potential anti-inflammatory action. Here we present data generated in a novel in vitro assay based on the EpiDerm™ Human Cell Construct (MatTek Corporation). The EpiDerm™ tissues were exposed topically for 6 hours to materials intended to counteract the inflammation induced by phorbol-12-myristate 13-acetate (PMA) added to the culture media. Two different ingredients with known anti-inflammatory activity formulated as creams were evaluated (OTC-class 7 low potency, and Rx-class 2 high potency, formulated for augmented penetration). The low potency active was also tested as a spray along with an alcohol-based hand sanitizer. To avoid over-prediction of the irritation, the alcohol-based formulations were applied to the tissues at a reduced dosing volume of 30 μL, while the creams were applied as 100 μL doses. The cytokines analyzed were IL-1α and IL-8 (released in the culture media and in the lysed tissues). Our data showed that IL-1α analyzed in the lysed tissues and IL-8 analyzed in the culture media were reliable indicators of anti-inflammatory actions for the materials tested. Both cytokine indicators showed that the Rx cream formulated for augmented penetration was the most effective of the creams in reducing the cytokines’ levels, thus supporting the class 2 high potency. Furthermore, the class 7 active formulated as a spray had a stronger anti-inflammatory action compared to its cream counterpart despite the reduced dosing volume. Our data support the potential use of the Rx class 2 cream and the OTC class 7 spray as reference materials for screening formulations investigated for anti-inflammatory action. 


EpiDerm (EPI-200), cytokine induction, anti-inflammatory action, inflammation, IL-1a, IL-8, phorbol-12-myristate 13-acetate (PMA), 12-O-Tetradecanoylphorbol-13-acetate (TPA), OTC-class 7, Rx-class 2, alcohol-based hand sanitizer, creams, tissue lysates

Materials Tested

phorbol-12-myristate 13-acetate (PMA), 12-O-Tetradecanoylphorbol-13-acetate (TPA), OTC-class 7, Rx-class 2, alcohol-based hand sanitizer

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