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KR-102962438-B1 - Compositions for moisturizing skin or enhancing skin barrier comprising extracts of Salix alba or high-molecular fraction thereof

KR102962438B1KR 102962438 B1KR102962438 B1KR 102962438B1KR-102962438-B1

Abstract

The present invention relates to a composition for strengthening the skin barrier and/or moisturizing the skin, comprising a white willow bark extract and/or a polymer fraction thereof. Specifically, the present invention relates to a composition for strengthening the skin barrier or moisturizing the skin, comprising a white willow bark extract or a polymer fraction thereof, which strengthens skin barrier function by increasing keratinocyte membrane formation (CE formation) and the expression of Claudin 1 and Filaggrin, which are keratinocyte outer membrane structural proteins, and exhibits excellent moisturizing power due to the promotion of hyaluronic acid synthesis.

Inventors

  • 전수원
  • 지향기
  • 조은애
  • 정은선
  • 박덕훈

Assignees

  • 바이오스펙트럼 주식회사

Dates

Publication Date
20260511
Application Date
20231012

Claims (6)

  1. A cosmetic composition for strengthening the skin barrier or moisturizing, comprising a polymer fraction of white willow ( Salix alba ) bark extract as an active ingredient, wherein the polymer fraction comprises a polymer having a molecular weight of 10 kDa or more.
  2. A cosmetic composition according to claim 1, characterized in that the polymer fraction is prepared by a method comprising the steps of adding ethanol to the white willow bark extract to precipitate it, and recovering a polymer material with a molecular weight of 10 kDa or more from the precipitate.
  3. A topical skin composition for strengthening the skin barrier or moisturizing, comprising a polymer fraction of white willow bark extract as an active ingredient, wherein the polymer fraction comprises a polymer having a molecular weight of 10 kDa or more.
  4. A skin external preparation composition according to claim 3, characterized in that the polymer fraction is prepared by a method comprising the steps of precipitating the white willow bark extract with ethanol and recovering a polymer with a molecular weight of 10 kDa or more from the precipitate.
  5. A food composition for strengthening the skin barrier or moisturizing, comprising a polymer fraction of white willow bark extract as an active ingredient, wherein the polymer fraction comprises a polymer having a molecular weight of 10 kDa or more.
  6. A food composition according to claim 5, characterized in that the polymer fraction is prepared by a method comprising the steps of precipitating the white willow bark extract with ethanol and recovering a polymer with a molecular weight of 10 kDa or more from the precipitate.

Description

Compositions for moisturizing skin or enhancing skin barrier comprising extracts of Salix alba or high-molecular fraction thereof The present invention relates to a composition for strengthening the skin barrier or moisturizing, comprising a white willow bark extract or a fraction thereof. More specifically, the present invention relates to a composition for strengthening the skin barrier or moisturizing the skin, comprising a white willow bark extract or a high molecular weight fraction thereof, which strengthens skin barrier function by increasing keratinocyte membrane formation (CE formation) and the expression of Claudin 1 and Filaggrin, which are keratinocyte outer membrane structural proteins, and exhibits excellent moisturizing power due to the promotion of hyaluronic acid synthesis. The skin is the outermost organ of the human body and serves as an essential barrier that prevents harmful substances from the external environment from entering the body, while simultaneously preventing the loss of biological components such as body moisture. The skin is broadly divided into three layers: the epidermis, dermis, and subcutaneous fat. The moisture content of the skin is approximately 70% in the dermis and decreases towards the epidermis, with the stratum corneum retaining 10 to 20% moisture. In particular, the epidermis functions to prevent the evaporation of body moisture and block the excessive penetration of external substances. The epidermis is composed of four layers: the basal layer (stratum basale), the spinous layer (stratum spinosum), the granular layer (stratum granulosum), and the stratum corneum. Water in the dermis eventually moves to the stratum corneum by passive diffusion and is expelled to the outside; this transepidermal water loss (TEWL) is maintained at an appropriate level by the cornified protein envelope and cornified lipid envelope surrounding the stratum corneum. The cornified lipid envelope acts as a scaffold that forms a multilayered structure of intercellular lipids, thereby enabling the formation of a complete skin barrier structure. Keratinocytes differentiate from the basal layer through the granular layer to the stratum corneum, a process involving transformation into nucleusless keratinocytes through differentiation, and the formation of an outer membrane surrounding the keratinocytes through cross-linking of proteins within the keratin hyaline granules containing keratin with other proteins in the cytoplasm. Proteins whose expression increases in relation to differentiation include transglutaminase 1 and 3, involucrin, loricrin, and filaggrin. When differentiation begins, transglutaminase binds structural proteins such as involucrin and loricrin to the inside of the cell membrane, forming a cornified envelope (CE), which plays the most important role in the stratum corneum performing skin barrier functions. Structural proteins of the keratinocyte membrane are cross-linked through covalent bonds, forming a mature cornified envelope of 5–10 nm around the cell membrane. These formed keratinocyte membrane proteins combine with keratin and lipids within the stratum corneum to form a framework, serving as the foundation for the stratum corneum structure and constituting the skin barrier. Along with the stratum corneum, tight junctions (TJs) constitute the skin barrier, playing a crucial role in preventing moisture loss and protecting the body from external stimuli. TJs forming the skin barrier in the stratum granulosum refer to intercellular junctions and are primarily composed of ocludin and claudin. Claudin 1, a transmembrane protein, is a major component of TJs and is found on the outer layers of the basal layer and suprabasal layer of the epidermis. A deficiency in Claudin 1 is known to increase transepidermal water loss (TEWL). Filaggrin, a protein responsible for connecting the outer membrane of keratinocytes with keratin fibers, exists within keratin hyaline granules in the form of its precursor, profilagrin. It is then degraded by proteases and subsequently converted into filaggrin through dephosphorylation. Filaggrin acts to bind keratin molecules together, contributing to the strong physical support of the skin barrier. When filaggrin undergoes deamination by proteases, it breaks down into amino acids such as PCA (pyrrocarboxylic acid) or UCA (trans-urocanic acid). As a natural moisturizing factor, it functions to maintain skin hydration, preserve the slightly acidic pH of the stratum corneum, and protect against skin damage caused by external stimuli. When filaggrin levels are reduced due to genetic mutations or acquired factors, it can disrupt skin barrier function, leading to moisture loss and impaired protective capabilities. In the case of dry skin, the cohesiveness between keratinocytes is often weakened, or moisture loss fails due to abnormalities in the lipid membrane components of the stratum corneum. This breakdown of the skin barrier leads to dryness. Hyalu