Effect of Topically Applied Multi-lamellar Emulsion Containing Linoleic Acid on Experimentally Induced Comedones

Lee, Sang Eun; Jeong, Se Kyoo; Youm, Jong Kyung; Lee, Seung Hun

Abstract

BACKGROUND: Disturbed keratinization of the follicular infundibulum is the earliest change in comedo formation. The relative decrease in linoleic acid in the sebum could be responsible, in part, for this abnormal keratinization.
OBJECTIVE
This study was conducted to evaluate the effects of topically applied multi-lamellar emulsion containing linoleic acid (MLE/LA) on experimentally induced comedones.
METHODS
To induce comedo formation, 50% oleic acid (OL) in macrogol 400 was applied to the ventral surface of both ears of New Zealand white rabbits. Twenty ears of ten rabbits were randomly divided into four treatment groups (5 ears in each group). Four groups (OL only, OL and MLE/LA, OL and MLE, OL and control vehicle containing LA) were treated twice daily for 2 weeks. The relative increase in areas of the comedo was evaluated by digital image analysis. The morphologic changes around the epithelial lining of the comedo were observed by light microscopy and scanning electron microscopy.
RESULTS
After 2 weeks of application, only the OL and MLE/LA combined treated group showed significantly less (by 1.23-fold, p<0.05) increase in comedo size when compared to the OL treated group (by 1.86-fold). Upon light microscopy and scanning electron microscopy examination, the MLE/LA treated ears showed a lesser degree of epidermal hyperplasia and hyperkeratosis in the follicular infundibulum compared with the OL treated ears.
CONCLUSION
Topical MLE/LA might have an inhibitory effect on the formation of OL induced comedones.