Topical Application of OJI-204 Alleviates Skin Dryness, Dry Skin-Induced Itch, and Mechanical Alloknesis

<b>Background/Objectives</b>: The skin is an important barrier that protects against invasion by foreign substances and retains water in the body. Several skin diseases involve dry skin due to a disrupted skin barrier, and most skin diseases that appear on dry skin are accompanied by itch. Dry skin-induced itch and mechanical alloknesis reduce quality of life. Sulfated hemicellulose (i.e., pentosan polysulfate sodium), similar to heparin, is a compound belonging to the sulfated polysaccharide family; however, in contrast to heparin, it is derived from plant materials. We herein investigate the effects of the topical application of OJI-204, a sulfated hemicellulose made by purifying and chemically synthesizing hemicellulose, on dry skin in a mouse model. <b>Methods</b>: The mouse model of dry skin was generated using a mixture of acetone and ether with water. Either OJI-204 (3% or 10%) or 0.3% heparinoid, PBS (control), was applied twice a day to the <b>a</b>cetone and diethyl <b>e</b>ther/<b>w</b>ater (AEW)-treated area. The degree of skin dryness was evaluated by measuring transepidermal water loss and stratum corneum hydration. Scratching behavior was recorded the day before AEW treatment and the day after the final day, and an alloknesis assay was performed on the day after the final day. <b>Results</b>: We found that 3% or 10% OJI-204 attenuated dry skin conditions (erythema/hemorrhage, scarring/dryness, edema, and excoriation/erosion) and itchiness more effectively than 0.3% heparinoid. Furthermore, the degree of dryness improved to the same degree as that with heparinoid. OJI-204 also significantly reduced dry skin-induced spontaneous itch and mechanical alloknesis. <b>Conclusions</b>: These results suggest the potential of OJI-204 as a therapeutic or preventive agent for dry skin.