JOURNAL OF COSMETIC SCIENCE 110 E. angustifolium extract. Thus, E. angustifolium extract can act directly on sebocytes to reduce sebum production. As seen in Figure 2, when skin explants were exposed to a mixture of Malassezia strains (M. furfur, M. globosa, and M. restricta) for 24 h, morphological alterations appeared after 5 days following exposure. Using histological techniques, we consequently observed an important number of cells showing pyknotic nuclei in the suprabasal layer of the epidermis (Figure 2B) compared to unchallenged skin (Figure 2A). Treatment of unchallenged skin with E. angustifolium extract (1.5%) had no effect (not shown). Treatment of yeast-challenged skin explants with the same concentration extract had a positive impact on protecting epidermis morphology, as a clear reduction of the number of cells undergoing pyknosis was observed (Figure 2C). Skin explants challenged in the same fungal mixture and method described earlier were stained for hBD2, hBD3, and TLR2. Expressions of all three immunological response markers increased noticeably (middle column) compared to unchallenged skin explant (left column). As seen in Figure 3, TLR2 was very lightly expressed in normal skin (Figure 3A). When challenged with Malassezia mixture, the receptor was moderately expressed in superfi cial epidermal layers (Figure 3B) and inhibited when yeast-challenged explants were treated with E. angustifolium extract (1.5%). Same results were observed concerning hBD2 (Figure 3D–F). Finally, hBD3 was slightly expressed in normal skin (Figure 3G). Figure 2. Epilobium angustifolium extract protects skin explants from Malassezia-induced morphological changes. (A) Unchallenged skin. (B) Presence of numerous cells with pyknotic nuclei in the suprabasal layer. (C) Reduction in the number of cells with pyknotic nuclei in the suprabasal layer. Figure 3. Epilobium angustifolium extract modulates TLR2, hBD2, and hBD3 expression in skin explants.

BATTLE AGAINST DANDRUFF 111 Although challenge with the Malassezia mixture induced a clear overexpression of the protein in the superfi cial epidermal layers (Figure 3H), treatment of the challenged skin with E. angustifolium clearly inhibited yeast-induced overexpression of hBD3 (Figure 3I). In this aspect, E. angustifolium extract treatment helps keeping a tight control of beta- defensins expression. CLINICAL STUDIES The Adherent Scalp Flaking Score (ASFS) method is a reliable and relevant clinical scoring protocol to quantitate dandruff severity (15). Accordingly, in our study, ASFS was per- formed by qualifi ed technicians to measure the effi cacy of antidandruff shampoos contain- ing our extract (1.5%). As shown in Figure 4, both adherent and nonadherent dandruff scorings were signifi cantly reduced ( p 0.0001) after the third treatment shampooing (D9) compared to initial scoring (D0). Number of both adherent and nonadherent dandruff scoring continued to decrease over the length of the study (D30) to reach a fi nal reduction of -54% and -48%, respectively. Results indicate that E. angustifolium extract treatment was effective in controlling both types of dandruff fl akes in real-life conditions. Figure 4. Epilobium angustifolium extract inhibits formation of adherent and non-adherent dandruff in vivo. Figure 5. Epilobium angustifolium extract improves sebum regulation in vivo.