Echinochrome A Protects against Ultraviolet B-induced Photoaging by Lowering Collagen Degradation and Inflammatory Cell Infiltration in Hairless Mice.

Jung Eun Seol,Hyoung Kyu Kim,Natalia P Mishchenko,Hyeong Rok Yun,Bomin Seol,Sang Woo Ahn,Valentin A Stonik,Elena A Vasileva,Jin Han,Nammi Park,Sergey A Fedoreyev

doi:10.3390/md19100550

Abstract

Echinochrome A (Ech A, 7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone) has been known to exhibit anti-oxidative and anti-inflammatory effects. However, no study has been carried out on the efficacy of Ech A against skin photoaging; this process is largely mediated by oxidative stress. Six-week-old male SKH-1 hairless mice (n = 36) were divided into five groups. Except for a group that were not treated (n = 4), all mice underwent ultraviolet-B (UVB) exposure for 8 weeks while applying phosphate-buffered saline or Ech A through intraperitoneal injection. UVB impaired skin barrier function, showing increased transepidermal water loss and decreased stratum corneum hydration. UVB induced dermal collagen degeneration and mast cell infiltration. Ech A injection was found to significantly lower transepidermal water loss while attenuating tissue inflammatory changes and collagen degeneration compared to the control. Furthermore, Ech A was found to decrease the relative expression of matrix metalloproteinase, tryptase, and chymase. Taken together, these results suggest that Ech A protects against UVB-induced photoaging in both functional and histologic aspects, causing a lowering of collagen degradation and inflammatory cell infiltration.

Highlights

Echinochrome A (Ech A) is a quinoid pigment (Figure 1A) in the polyhydroxynaphthaquinone family that is extracted from sea urchin shells or spines [1]
We investigated the in vivo therapeutic potential of Ech A against UVBinduced photoaging in a murine model
There was no significant difference in transepidermal water loss (TEWL) and stratum corneum hydration (SCH) in week 2 between any of the groups

Summary

Introduction

Echinochrome A (Ech A) is a quinoid pigment (Figure 1A) in the polyhydroxynaphthaquinone family that is extracted from sea urchin shells or spines [1]. The moiety of Ech A is known to have anti-oxidative and anti-inflammatory effects [2]. In Russia, Echi A has been used as an ingredient in medication called Histochrome®, showing protective effects against oxidative stress in cardiovascular or ocular degenerative disorders [3,4,5]. Ech A has been shown to reduce the level of mitochondrial reactive oxygen species (ROS) in cardiomyocytes [6], exert anti-ulcerogenic effects in a gastric ulcer model [7], attenuate oxidative stress and pro-inflammatory cytokine secretion in an acute uveitis model [8], and correct imbalances in the intestinal immune system in an inflammatory bowel disease model [9]. Several clinical trials have supported the efficacy of Ech A in various diseases such as ophthalmic, cardiovascular, cerebrovascular, inflamma-.

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