In vivo evaluation of insect wax for hair growth potential.

Jinju Ma,Hong Zhang,Youqiong Wang,Xiaoming Chen,Zhongquan Zhang,Kai Li,Liyi Ma,Meijia Zhang

doi:10.1371/journal.pone.0192612

Abstract

Insect wax is secreted by Ericerus pela Chavanness. It has been traditionally used to treat hair loss in China, but few reports have been published on the hair growth-promoting effect of insect wax. In this work, we examined the hair growth-promoting effects of insect wax on model animals. Different concentrations of insect wax were topically applied to the denuded backs of mice, and 5% minoxidil was applied topically as a positive control. We found that insect wax significantly promoted hair growth in a dose-dependent manner, 45% and 30% insect wax both induced hair to regrow, while less visible hair growth was observed in blank controls on the 16th day. The experimental areas treated with 45% and 30% insect wax exhibited significant differences in hair scores compared to blank controls, and hair lengths in the 45% and 30% insect wax group was significantly longer than in blank controls on the 16th and 20th days. There were no new hair follicles forming in the treated areas, and the hair follicles were prematurely converted to the anagen phase from the telogen phase in experimental areas treated with 45% and 30% insect wax. Both 45% and 30% insect wax upregulated vascular endothelial growth factor expression. The results indicated that 45% and 30% insect wax showed hair growth-promoting potential approximately as potent as 5% minoxidil by inducing the premature conversion of telogen-to-anagen and by prolonging the mature anagen phase rather than increasing the number of hair follicles, which was likely related to the upregulation of VEGF expression. The dissociative policosanol in insect wax was considered the key ingredient most likely responsible for the hair growth promoting potential.

Highlights

Hair growth is a complex and cyclically controlled process characterized by a finite period of hair fiber production, a brief regression phase, and a resting period [1,2,3,4]
On the 16th day, we observed that 45% and 30% insect wax induced the hair to regrow in the denuded skin of the experimental areas, with less visible hair growth in the corresponding blank control areas
The whole denuded skin in experimental areas had been covered by re-growth hairs when treated with 45% and 30% insect wax on the 20th day, while the regrowth hairs in the corresponding blank control areas of above two groups were very sparse on the 20th day (Fig 2A, Fig 2B)

Summary

Introduction

Hair growth is a complex and cyclically controlled process characterized by a finite period of hair fiber production (anagen), a brief regression phase (catagen), and a resting period (telogen) [1,2,3,4]. The hair follicles are remodeled during the cyclical periods [1]. A common disorder of hair growth is alopecia, a generic term for hair loss resulting in a diminution of visible hair [5,6,7]. Hair loss profoundly impacts social interactions and the psychological well-being of an increasing number of men and women [8,9,10], and the consumer cosmetics and pharmaceutics market for hair re-growth and the protection of hair loss have markedly grown. Insect wax and hair growth and analysis, decision to publish, or preparation of the manuscript

Methods

Results

Conclusion