Modulating effects of oatmeal extracts in the sodium lauryl sulfate skin irritancy model

The aim of the present study was to assess the anti-inflammatory activity of two topically applied oatmeal extracts, i.e. Avena sativa and Avena Rhealba, using the sodium lauryl sulfate (SLS) irritation model. At baseline, test areas on the volar surface of the upper arms of 12 healthy individuals were pretreated with the two extracts and their vehicle (petrolatum ointment) under occlusion for 2 h, and one site was left untreated. Then a patch with a 1% SLS solution was applied to the test sites for 24 h. Irritation was determined at each period by measuring by chromametry and laser-Doppler. In a dose-ranging study with the Avena Rhealba extract alone, the 20 and 30% concentrations exerted a slight inhibition of the a* parameter increase and a marked reduction of the blood flow increase (p < 0.05, compared to vehicle). Then, the effects of the two extracts at the concentration of 20% were compared. All extracts displayed a statistically significant counteracting effect on both parameters (p < 0.05), but no statistically significant difference between treatment groups could be demonstrated. In conclusion, this study demonstrates the preventive effects of oatmeal extracts on skin irritation in the SLS model.