Antioxidant and Anti-Melanogenic Activities of Heat-Treated Licorice (Wongam, Glycyrrhiza glabra × G. uralensis) Extract.

Min Hye Kang,Hyung Don Kim,Yun-Jeong Ji,Su Ji Choi,Tae Kyung Hyun,Gwi Yeong Jang,Jeong Hoon Lee

doi:10.3390/cimb43020083

Abstract

Melanin is a brown or black pigment that protects skin from ultraviolet radiation and reactive oxygen species (ROS). However, overproduction of melanin is associated with lentigines, melasma, freckles and skin cancer. Licorice has shown antioxidant, anti-tumor, anti-platelet, anti-inflammatory and immunomodulatory activities and is used as a natural treatment for skin whitening. We aimed to confirm the potential of Wongam, a new cultivar of licorice developed by the Rural Development Administration (RDA), as a whitening agent in cosmetics. In addition, we verified the effect of heat treatment on the bioactivity of licorice by comparing antioxidant and anti-melanogenic activities of licorice extract before and after heating (130 °C). The heat-treated licorice extract (WH-130) showed higher radical-scavenging activities in the ABTS+ (2,2′-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. In addition, WH-130 inhibited melanogenesis more effectively due to downregulation of tyrosinase in B16F10 melanoma cells than non-heated licorice extract. Moreover, heat treatment increased total phenolic content. In particular, isoliquiritigenin, an antioxidant and anti-melanogenic compound of licorice, was produced by heat treatment. In conclusion, WH-130, with increased levels of bioactive phenolics such as isoliquiritigenin, has potential for development into a novel skin whitening material with applications in cosmetics.

Highlights

Licorice (Glycyrrhiza species), a perennial herb with medicinal uses in the family Leguminosae, is widely distributed across Central Asia, China, Russia, Manchuria, Mongolia and Europe [1]
We observed that treatment with WH-130 extract at 25, 50 and 100 μg/mL (Figure 4c) resulted in a concentrationdependent decrease in the melanin content of B16F10 melanoma cells. These results show that heating improved the anti-melanogenic activity of licorice extract
kojic acid (KA) reduced cellular TYR activity to 74.07% of the level in IBMX-treated cells. These results show that licorice extracts (WC and WH-130) suppress TYR

Summary

Introduction

Licorice (Glycyrrhiza species), a perennial herb with medicinal uses in the family Leguminosae, is widely distributed across Central Asia, China, Russia, Manchuria, Mongolia and Europe [1]. It has long been utilized as a flavoring and sweetening agent. A new interspecific hybrid cultivar of licorice, was developed by the Rural. Development Administration as a hybrid of Glycyrrhiza glabra x G. uralensis Numerous studies have been conducted on the biological activities of G. uralensis, whereas existing research on Wongam, a new cultivar, is limited to its anti-allergic, immunomodulatory and anti-ulcer activities [1,2]. It is necessary to investigate the broad bioactivity of Wongam

Objectives

Methods

Findings

Discussion

Conclusion