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

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.

Effects of Sargassum thunbergii Extract on Skin Whitening and Anti-Wrinkling through Inhibition of TRP-1 and MMPs

“…Melanogenesis is a physiological process that leads to the synthesis of melanin pigments [ 1 ]. Melanin is a black or brown pigment secreted from the melanocytes present in the basal layer of the epidermis and determines the skin, eyes, and hair color [ 2 ]. However, excessive generation of melanin pigments can lead to hyperpigmentation-related diseases, such as malignant melanomas [ 3 ].…”

Combined Protocol of Micro Needling with Chemical Peelings for Intimate Skin Whitening

“…PIH is chronic and multifactorial, therefore, treatment success depends on to combine the in-office procedure with home care treatment [21,22]. Therefore, the use of topical bleaching agents, such as alpha arbutin an important tyrosinase inhibitor and kojic acid, a copper chelating agent, are crucial for a good response in skin lightening [23,24]. Two actives present in serum and topical home care formulations deserve to be highlighted: TGF beta 3, which promotes an improvement in the quality of the dermal matrix, stimulating the synthesis of more extra cellular matrix and fluocinolone, a potent fluorinated corticoid that reduces inflammation local caused by friction of the skin [25][26][27].…”

Efficacy and safety of a facial serum containing snail secretion filtrate, Calendula officinalis, and Glycyrrhiza glaba root extract in the treatment of maskne: A randomized placebo‐controlled study

“…An earlier study also addressed its antioxidant and anti-melanogenic effects. 9 The data suggest that the product, the formulated serum with triple medicinal natural ingredients, might have a beneficial or therapeutic effect on maskne. However, no clinical trials have proven this serum's efficacy.…”

“…The last additive ingredient is licorice or Glycyrrhiza glabra ( G. glabra ) which is composed of flavonoids. An earlier study also addressed its antioxidant and anti‐melanogenic effects 9 …”