Biophysical Assessment of Persistent Effects of Moisturizers after Their Daily Applications: Evaluation of Corneotherapy

Abstract

Background: Although effective moisturizers can improve xerotic skin changes immediately, their effects are only transient, because the materials applied to the stratum corneum (SC) are easily shed from the skin surface by the daily desquamation process. However, there are a few lines of clinical as well as experimental evidence suggesting that, once application of effective moisturizers is repeated daily, they may produce persistent effects without being influenced by the desquamation of the skin surface. If we can expect such pharmacological effects by simple repeated applications of moisturizers on the skin surface, it will provide a great motivation for the introduction of corneotherapy into the treatment of xerotic skin problems. Objective: This study was designed not only to confirm the feasibility of corneotherapy but to propose a practical method to assess such long-lasting effects of moisturizers by using biophysical methods. Methods: We conducted applications of various moisturizers twice daily to different areas of the flexor surface of the forearms for the initial 5 days of the first week. Thereafter, we performed biophysical measurements of the SC of these areas in the second week, namely 3, 5 and 7 days after their last applications. Results: Daily repeated applications of moisturizers did not induce any change in the water barrier function of the SC or in the size of desquamating corneocytes, a parameter for turnover rate of the SC. However, they substantially increased high-frequency conductance, a parameter for the hydration state of the skin surface, for several days in both normal individuals and patients with atopic xerosis, although the lasting effects were shorter in the latter. The obtained data enabled us to rank the efficacy of moisturizers either according to the duration of the lasting effects or the magnitude of an increase in the hydration levels of the SC. Conclusion: The present results confirmed the feasibility of corneotherapy, in which even simple application of moisturizers targeted at the SC can produce unexpected persistent clinical effects after their repeated treatments. The method described in this study constitutes a practical assay system to evaluate the efficacy of topical agents used for dry skin problems objectively and quantitatively.

Randomized, Double-blind Study with Glycerol and Paraffin in Uremic Xerosis

“…The mechanism of the action of glycerol has been ascribed to modulation of Aquaporin-3 channels (21). In contrast, paraffin has no effect on skin hydration and only a limited effect on transepidermal water loss (22,23) but preserves the barrier function against irritants (24). The combination of glycerol and paraffin is therefore of potential benefit in the treatment of uremic xerosis patients to rapidly compensate for the main defects that characterize this condition, i.e.…”

The Effect of Gromwell (Lithospermum erythrorhizon) Extract on the Stratum Corneum Hydration and Ceramides Content in Atopic Dermatitis Patients

“…AD has been shown to be accompanied by impairement in the epidermal barrier function including reduced water content and an augmentation in TEWL due to the alteration of SC lipid profile. In mild and moderate AD, moisturizing and emollient creams are known to be effective through an increase of skin hydration and improvement of barrier function [19][20][21][22] . Tabata et al 21 indeed demonstrated that repeated daily applications of moisturizers, without any pharmacologically active agent, can induce long-lasting hydration effects in AD patients.…”

Novel anti-aging composition for topical skin care

“…A more popular approach is to apply a cosmetic formulation to the skin to counter the effects of aging (Baumann 2007). Treatments designed to prolong or promote youthful appearance include topical applications of cosmetic preparations, lotions and moisturizers, electrical stimulation, and collagen injections (Tabata et al 2000). Several cosmetic ingredients, such as Botox ® (botulinum toxin), have been used to improve the appearance of the skin via their skin-beneficiary effects that include skin resurfacing, skin wrinkle reduction, and anti-aging effects.…”