56 JOURNAL OF COSMETIC SCIENCE Figure # 1 Figure # 2 0.4! O.2 0 0 Effect ofAntioxidar• m UVB-In:tmed Peroxidatim ffi UV-B Induced IL - 1 a Release From Skin Model uv-a Human skin has been observed to release interleukin-1 alpha after being irradiated with UV light (3). We have observed similar release of interleukin-I alpha from skin models after UVB irradiation (figure # 2). 250 mJ/cm, 500 mJ/cm2 and 1000 mJ/cm2 increased the media levels of interleukin-! alpha from 300 pg/ml to 500 pg/m1475 pg/ml and 675 pg/ml, respectively. Release of infi•ory Cytokit• UV8 • release ofmNF oc 150 -- 0 50 1011 150 •11 Evaluation of the UV-Induced Activation of Proteases UVB Indur. ad elasia• ar•vity UVB indur. ad colla•nase In living s•xJn mndd a•v•y In IMng stdn 0.7 0 • • 1• 0 • • •b {mgc• uvb (mJ/c• Figure # 3 Figure # 4 Tumor necrosis factor alpha (TNF alpha) has also been shown to be released from human skin (4). We observed release from skin models in culture after treatment with UVB doses of 0 - 200 mJ/cm2 (figure # 3). Both interleukin-1 alpha and TNF alpha have catabolic functions in that they cause the degradation of various tissues and extracellular matrix (5). We observed that UVB increase the enzymatic activity for collagenase and elastase in extracts from human skin models (Figure/t4). UVB doses of 250 mJ/cm2, 500 mJ/cm2 and 1000 mJ/cm2 in collagenase activity between 1.5 - 2 fold over unirradiated controls. Elastase activity was increased by 2 fold at the highest doses of UVB. Conclusion: The inflammatory response of human skin to various environmental insults, such as UV light or cigarette smoke, results in the release of messengers with detrimental effects. Interleukin-I and TNF alpha are well know to increase the catabolic metabolism of a tissue. These inflammatory cytokines will contribute to the degradation and atrophy characteristic ofphotoaged skin. In addition, UV and enviroranental pollutants activity the catalytic enzymes ,collagenase and elastase, that will directly cause atrophy and tissue degradation of exposed skin. Therefore a successful cosmetic intervention for photoaging or premature aging must address this catabolic pathway at multilevels to suppress the detrimental effects. The treatment cosmetic design should incorporate the benefits of antioxidants, protease inhibitors, and inflammatory cytokine release inhibitors. Reference: 1. S.Netze!-Arnett, S.K. Mallya, H.Nagase, H.Birkedal-Hansen, H.E.Van Wart.. Anal. Biochem. 195:86-92 (1991). 2. Castillo, M.J., Nakajima, K., Zimmerman, N., Powers, J.C. Anal. Biochem. 99:53-64 (1979) 3. Kupper, T., Chua, A.O., Flood, P., McGuire, J., Gubler, U.. J.Clin. Invest. 80:430-436 (1987) 4. Kock, A., Schwarz, T., Kirnbauer, R., Urbanski, A., Perry, P., Ansel, J.C., Luger, T. (1990) J. Experimental Med. 172: ! 609- ! 6 ! 4 (! 990) 5. Postethwaite, A.E., Lachman, L.B., Mainardi, C., Kang, A.H.,. J.Exp. Med. 157:801-806 (1983)

PREPRINTS OF THE 1997 ANNUAL SCIENTIFIC MEETING 57 SKIN-MOISTURIZING EFFECT OF POLYOLS AND THEIR ABSORPTION INTO HUMAN STRATUM CORNEUM T. Okamoto, Ho Inoue, S. Anzai, and Ho Nakajima Shiseido Basic Research Laboratories, 1050 Nippa-cho, Kohoku-ku, Yokohama-shi, Japan 223 Introduction Lack of water in stratum comeum results in dry and scaly skin. Humechants in skin-care cosmetics play an important role in the moisturizing of stratum cornenm. It is well known that glyceml has excellent skin- improving effects as a humeclant. Bissett and McBride demonstrated the skin-conditioning effects of glyceml on human and pig skinil Batt ct al. reported on the skin improving benefits of glyceml? • Rowlings et al. suggested the important role of glycerol for enhancing desmosome degradation of stratum corneum? However, systematic investigation on the dislribution ofglycerol in stratum corncure and its skin-moisturizing effect had not been conducted. In this work, we investigated (I) the adsorption ofpolyols in stratum comeum and (2) its skin-moisturizing mechanism. Experimental Materials: Glycerol, 1,3-butylene glycol, dipmpylene glycol, erythrilol and dig!ycerin were selected as a model of humectant of polyol and purchased from Tokyo Chemical Industry (Tokyo, Japan). Evaluation of skin-motsturizing effect: Healthy male volunteers were selected for this study. In each individual, 3 or 4 sites of the forearm skin were treated with polyol aqueous solutions. The skin-moisturizing effect was evaluated by skin surface conductance, measun•d with a high-frequency impedance meter, SKIKON-200 {lBS, I-!amamatsu, Japan). These measurements were performed at 23øC and 50% RH. In order to avoid the influence of residual humeclant, perspkation, and sebum, the skin surface was washed with water and soap 30 rain before the measurements. Penetration study of humectants into stratum corneum: Repeated tape-strippings were carried out on the skin treated with polyol aqueous solutions. The weight of collected stratum corneum was estimated from measurement of weight of a sheet of adhesive tape before and after the tape-stripping. The humeclant was extracted with methanol from stratum comeurn on the tape and analyzed by gas-chromatography. Hygroscopiclty of polyols: Water content of the humeelant at various relative humidity was measured with Karl Fischer's method. Results and Discussion In vivo skin-moisturizing effect and amount of polyol absorbed in stratum corneum: Fig. I shows the relationship between skin- moislurizing effect of glyccml or dipropylene glycol and its amount of humeclant in stratum corneum for. The skin-moisturizing effect increased linearly with the amount of absorbed humeelant in stratum corncum in both cases. If the delivered amount of both hum•clants in stratum cornenm was the same, the skin-moisturizing effect of dipropylene glycol was smaller than that of glycerol. The result shows that the moisturizing effect depend on the hygroscopicies of humectants. These results 0 20 40 60 80 100120 Polyol in stratum comeurn (pg/mg of tissue) Fig. I The relationship between skin-moisturizing effect and absorbed polyol The closed square (1) represents glyceml the open circle (O), dipmpylene glycol the open square (D), untreated control. Skin-moisturizing effect (y-axis) was evaluated from following equation. Skin surface conductance after application Skin-moisturizing effect = Skin surface conductance before application The lines wer• regression line, which wascaluclated from data points. suggested that skin-moisturizing effect was due to the amount of polyols in stratum corneum and its hygroscopicity. Time dependence of concentration profile of polyol in stratum corneum: In the case of one time application with 50% glyceml and dipropylane glycol aqueous solutions by a glass tube(3.2 em inner diameter) for 30 rain to the skin, skin-moisturizing effect of glyeerol was comparable to that of dipropylene glycol 30 rain after the application. Although the effect ofdipropylene glycoldecreased with time, no remarkable decrease of the effect of glycerol was observed. In order to clarify this difference, we investigated the time dependence of concentration profide of polyol in stratum corneum the changes in concentration profide ofpolyols with time. Fig. 2 demonstrates the polyol concentration profide across the sttmum corneum at 0, 1, and 6 h after the application, The x-axis, which indicates the integrated weight of stratum comeurn obtained by tape-stripping, corresponds to the depth ofhemy layer. Amount of absorbed dipropylene glycol at various depth of stratum comeurn immediatdy after application was greater than that ofglycerol, but decreased rapidly with time. However, the amount of glycerol absorbed at various depth of stratum cornenm showed no change with time. These results indicate that decrease in skin-moisturizing effect of dipropylene glycol with time is due to its disappearance from stratum comeum.