Protective effect of (-)-epigallocatechin gallate on ultraviolet b-induced skin damage in hairless mice

Chang Liu,Li-Ping Xiang,Curt Anthony Polito,Yue-Rong Liang,Xin-Qiang Zheng,Jian-Liang Lu

doi:10.4314/tjpr.v15i6.10

Chang Liu, Li-Ping Xiang + Show 4 more

Open Access

https://doi.org/10.4314/tjpr.v15i6.10

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Abstract

Purpose : To investigate the protective effect of green tea (-)-epigallocatechin gallate (EGCg) on ultraviolet B (UV-B)-induced skin damages in hairless mice in order to develop a natural sunscreen compound for use in skin care products and cosmetics. Methods : EGCg was dissolved in acetone at concentrations of 1.0, 10.0 and 50.0 mg/mL, and topically applied to the skin of hairless mice at doses of 0.2 mL/cm2, with acetone as control. The mice were then irradiated by 100 μW/cm2 UV-B for 30 min daily. EGCg treatment and UV-B irradiation were carried out daily for 28 consecutive days. The mice were then sacrificed and their dorsal skin examined by transmission electron microscopy (TEM) on the 28th day. Results : UV-B irradiation induced severe macroscopic skin damage including chapping, cracking and abnormal desquamation in the treated hairless mice. EGCg showed dose-dependent protective effects against UV-B induced damage on the skin. Treatments with 10.0 and 50.0 mg/mL EGCg alleviated UVB- induced skin damage by suppressing both keratinocyte apoptosis and mitochondrial dysfunction, along with inhibiting the production of melanin pigment. Conclusion : Topical application of green tea EGCg shows dose-dependent protective effect against UV-B-induced damage on hairless mouse skin. Thus, the plant compound can potentially be used as an alternative agent for photoprotection against UV-B exposure. Keywords : UV-B, Green tea EGCg, Photoprotection, Stratum corneum, Mitochondrion, Melanosome

Highlights

Skin is an organ of the integumentary system, made up of multiple layers of ectodermal tissue, which serves as a protective barrier over the body's surface
Topical application of UV defense agent (KIEHL’S ultra light daily UV defense (SPF50 PA+++)) showed good protective effect on the hairless mice skin exposed to ultraviolet B (UV-B) irradiation (Figure 1, PC)
Treatments of medium (10.0 mg/mL) and high (50.0 mg/mL) levels of EGCg produced protective effects similar to that of the positive control group (Figure 1, PC, ML and high level EGCg (HL)). These results suggest that EGCg produces protective effects on the skins of hairless mice exposed to UV-B radiation in a dose dependent manner

Summary

INTRODUCTION

Skin is an organ of the integumentary system, made up of multiple layers of ectodermal tissue, which serves as a protective barrier over the body's surface. Tests using HaCaT cells concluded that green tea polyphenols afforded protection against UV-B induced stress by interacting with UV-B induced reactive oxygen species (ROS) and attenuating mitochondrion-mediated apoptosis [8]. These mechanisms need to be evaluated and verified in animal models and/or clinical studies [7,9]. The present study was designed to investigate the photoprotective effect of EGCg on UV-Binduced skin damages in hairless mice by using acetone as a vehicle solvent for delivering EGCg. Ultrastructural changes in the skin tissues induced by UV-B were observed by transmission electron microscopy (TEM).

RESULTS

DISCUSSION

CONCLUSION