Abstract
BACKGROUND: The fatty acid composition of horse oil is similar to human sebum and contains a large amount of linoleic acid and α-linolenic acid; therefore, its topical application is expected to improve the skin function and microcirculation. METHOD: To confirm the effectiveness of topical horse oil application, we conducted three kinds of experiments using hairless mice. As a control, we did not apply any ointment. First, we administered percutaneously horse oil, olive oil and petrolatum on the dorsal skin and evaluated transepidermal water loss (TEWL) and hydration during 4 hours. Second, we measured vascular diameters and blood flow velocity by using Dorsal Skinfold Chamber during 4 hours. Third, two small burn injuries were made on the dorsal area. On the right side, we applied horse oil every day for a week, on the left side was used as a control. TEWL and Hydration were evaluated at 0,1,3,5 and 7days. RESULTS: First, the application of horse oil and petrolatum caused significant decrease in TEWL vs. control (p<0.05 and p<0.01, respectively). Second, there was a significant vasodilation of arterioles after 10 minutes of horse oil application (p<0.01). On the other hand, there was vasoconstriction by application of olive oil (p<0.01). Third, horse oil application on burn decreased TEWL vs. control (p<0.01) at 1 day or later. CONCLUSION: Horse oil as a preparation for local external use is suitable to maintain and improve the humidity and microcirculation of the skin. Finally, we consider that horse oil might be also useful for the prevention and treatment of conditions like dry skin and skin ulcer. [J Physiol Sci. 2007;57 Suppl:S244]
