Lowbush blueberry extract protects normal human (Homo sapiens L.) epidermal keratinocytes from damage by UV-B irradiation

Seiji Yamasaki,Naohiro Kodama,Joji Iseki,Kenji Mizoguchi

doi:10.17628/ecb.2018.7.162-167

Abstract

To search for natural materials that protect human skin from damage caused by ultraviolet-B (UV-B) irradiation, we prepared water extracts of the following four dry berries: lowbush blueberry (LBB) ( Vaccinium angustifolium L.), highbush blueberry (HBB) ( Vaccinium corymbosum L.), cranberry (CB) ( Vaccinium macrocarpon Ait.) and grape ( Vitis vinifera L.). Normal human epidermal keratinocytes (NHEKs) were pretreated with each of the extracts and then subjected to transient UV-B irradiation (15.0 W m -2 ) for 80 s. The results showed that pretreatment of NHEKs with LBB extract significantly attenuated UV-B-induced damage. The concentrations of proanthocyanidins, total flavonoids and total polyphenols in LBB extract were higher than those in the other three berry extracts. Therefore, these compounds might mediate the protection of NHEKs from UV-B-induced damage.

Highlights

Chlorofluorocarbons cause continual depletion of the stratospheric ozone layer, which increases the amount of solar ultraviolet-B (UV-B; 280−320 nm) irradiation [UV-B (+)] passing through to the earth’s surface.[1]
We determined the maximum concentrations of berry extracts that did not reduce Normal human epidermal keratinocytes (NHEKs) cell viability more than 70 % of the value in control NHEKs under UV-B (−)
The decrease in cell viability of NHEKs pretreated with berry extracts (Figures 3Ab−Db) suggests that these four berry extracts are toxic to cells

Summary

Introduction

Chlorofluorocarbons cause continual depletion of the stratospheric ozone layer, which increases the amount of solar ultraviolet-B (UV-B; 280−320 nm) irradiation [UV-B (+)] passing through to the earth’s surface.[1] UV-B (+) is harmful to living organisms. UV-B is the chief cause of skin reddening and sunburn, which damages the skin’s more superficial epidermal layers. Sunscreen contains UV-light absorbers and UV-light scattering agents. UV-light absorbers are usually phenolic compounds found in various oils whereas UV-light scattering agents are minerals such as titanium oxide or zinc oxide. It is essential to identify natural and safe compounds that do not cause allergies and that still protect skin from UV-Bmediated damage

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Results

Conclusion