◍Materials-Hydrolyzed soy protein (hSP)：Mixture of peptides

(Average molecular weight 700 Da, Many basic amino acid residues such as Lys,Concentration 20%)TOFUPRO® U, IKEDA CORPORATION

◍ SC collection- The inside of the upper arms by tape-stripping

◍ Carbonylation (induce SCCP)- UV (LAX-C100 solar simulator (Asahi Spectra Co., Ltd.), SQ + UV, Acr

◍ Evaluation of SCCP- Fluorescein-5-thiosemicarbazide (FTSC),

EVOS-FL fluorescence microscope (Thermo Fisher Scientific)

◍Wash out- Soaking the SC in 2 mol/L NaCl

Establishment and application of a novel experimental model of stratum corneum carbonylation induced by UV and sebum

Omoi M1, 2, Arai Y1, Inamura K1, Suzuki N1, Hirao T2

1 IKEDA CORPORATION, MM Park Building 12F, 3-6-3 Minatomirai, Nishi-ku, Yokohama, 220-0012 Japan.2 Faculty of Pharmacy, Chiba Institute of Science, 15-8 Shiomi-cho, Choshi, Chiba, 288-0025 Japan.

Poster-No. P-S2-283

40

50

60

70

80

0 30 120

None SQ

Mean±SDN=3

*: p<0.05Car

bo

nyl

pro

tein

leve

l （A

U)

**

*

UV irradiation (J/cm2)

SCCP was successfully induced by UV irradiation in a dose-dependent manner. We established a novel experimental model of SC carbonylation induced by UV + sebum component.

Promotion of UV-induced SCCP by SQ

We established an experimental stratum corneum carbonyl protein (SCCP) induction model mimicking oxidative modification at the skin surface using

a tape-stripped stratum corneum (SC) irradiated with ultraviolet (UV) + squalene (SQ). This experimental system made it possible to evaluate the efficacy of cosmetic ingredients in suppressing SCCP to shield healthy skin.

Materials and Methods

Conclusion

Results

Loss of the inhibitory effect of hSP on SCCP induction by SQ + UV following removal of hSP

prior to SCCP induction

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None hSP Hydrolyzedsilk

Lys

Mean± SDN=3

**:p<0.01

Car

bo

nyl

pro

tein

leve

l (A

U)

SQ + UV (120J/cm2)

**

hSP exhibited an excellent inhibitory effect against the SCCP induction as compared with hydrolyzed silk or L-Lys.

Effect of UV irradiation on SQ peroxide value

SQ was irradiated with different amounts of UV. Peroxides were consistently produced in SQ irradiated with UV.

Inhibitory effect of hSP on Acr-induced SCCP induction

SC was treated with deionized water or hSP , then treated without or with 1 mmol/L Acr. hSP showed an excellent inhibitory effect against SCCP induction by Acr.

None No hSP + Acr

Induction of SCCP by UV-irradiated SQ

The SCCP level was increased in a dose-dependent manner by application of UV-irradiated SQ.

SQ with UV

30 J/cm2

SQ with UV

120 J/cm2

SQ without UV

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0 30 120

None hSP

Mean±SDN=4

*: p<0.05

* *

*

Car

bo

nyl

pro

tein

leve

l （A

U)

UV irradiation (J/cm2)

SC was treated without or with hSP, then irradiated with UV + SQ. hSP application to the tape-stripped SC prior to UV + SQ resulted in significant inhibition of SCCP generation.

without UV with UV with SQ + UV

hSP + Acr

Introduction

Typical images of SCCP following treatment without UV, with 120 J/cm2 UV , or 120 J/cm2 UV + SQ.UV promoted greater SCCP induction in the presence of SQ.

DetectionCarbonylationInhibitor Wash outSebum

SC

Observation

SCCPhSP SQ UV 2M NaCl FTSC

Tape-stripping

020406080

0 20 40 60 80 100 120UV irradiation (J/cm2)

Per

oxi

de

valu

e(m

eq/k

g)

Stratumcorneum

hSPUV

Shielded skin

CarbonylationSqualene Aldehydes

UV

Squalene*

*Hydrolyzed soy protein

①Unsaturated lipids (such as SQ)

②Aldehydes

Carbonyl protein (CP) is formed by various oxidative stimuli, including UV radiation.

SC proteins

→ SCCP

We need an experimental system① + ②

→ Lipid peroxides

Various aldehydes (such as acrolein (Acr))Degradation

Targets basic amino acid residues

Include many basic amino acid residues

Pre-wash Post-washhSP + +Wash + -

SQ + UV(30J/cm2)

+ +

Wash - +

No SQ + UV SQ + UV

Detection of carbonyl protein by Acr antibody

SC was treated without or with SQ, then irradiated with UV.Acr adduct was generated in the SC treated with SQ + UV.

without hSP with hSP

Negative control

Inhibitory effect of hSP on UV-induced SCCP induction in the presence of SQ

Inhibitory effect of cosmetic ingredients on UV-induced SCCP induction in the presence of SQ

Removal of adsorbed hSP prior to SCCP induction (pre-wash) eliminated the inhibitory effect of hSP against UV-induced SCCP induction in the presence of SQ.