488 JOURNAL OF COSMETIC SCIENCE � rlJ 200 ....... ·-= p0.01 = 180 = - ....... � 160 = '-"' � ·- 140 rlJ = � 120 rlJ rlJ Q -- C, 100 - =·- 80 Placebo Eucalyptus Figure 4. Hair gloss intensity after three months of half-head use test of continuous application of Eucalyptus extract lotion and placebo lotion (Group 1). Figure 8 displays the results for Caucasian panelists who live in Japan (Group 4), after two months of use of 3% EL. The Caucasian panelists also confirmed the perception of increases in hair bending stiffness and hair gloss intensity using the 3% Eucalyptus extract. As described above, Eucalyptus extract has an effect on improving hair properties, regardless of gender difference, age, and race. ANALYSIS BY ATOMIC FORCE MICROSCOPE (AFM) In order to analyze the improvement factor of the bending elasticity, Young's modulus at the new-growth part of the cortex of the hair treated with Eucalyptus extract and the placebo was measured by AFM. A flat and smooth hair section was made in epoxy resin by ultramicrotome and the AFM nano-indentation measurement was carried out. The measurement data were analyzed by the Hertz model according to the method of Parbhu (25). The calculation results indicated that the Young's modulus of the Eucalyptus extract-treated hair was significantly higher than that of the placebo-treated hair in all samples from two panelists (Figure 9). ANALYSIS BY MICROSCOPIC IR SPECTRUM METHOD Secondary structural analysis of the hair cortex was carried out to test whether the

EUCALYPTUS EXTRACT-INDUCED HAIR CHANGES 489 Eucalyptus Extract 0.5wt% Eucalyptus Extract 1.0wt¾ Eucalyptus Extract 3.0wt¾ 12.0 -------�-------- 12.0 12.0 I'll = "'a 11.0 I'll "'� 10.5 = 10.0 9.5 Placebo Eucalyptus 11.5 11.5 11.0 11.0 10.5 10.5 10.0 ! 10.0 9.5 9.5 Placebo Eucalyptus Placebo Eucalyptus Figure 5. Results of 2.5 months of half-head use tests of scalp lotions containing 0.5%, 1 %, and 3% Eucalyptus extract lotion vs placebo lotion (Group 3 ). 30% - ·- == c.. Q 208/o rll rll Q-' J9 ·- r:I.J. = ·- Q-' rll = Q-' - y = Iii-I 10% 0% -10% l .. .___ ________________________________J Figure 6. Change in the bending stiffness of the hair shaft by application of Eucalyptus extract lotion (3wt%) for three months (Group 2). This includes the results from panelists using the placebo lotion. changes in gloss and Young's modulus at the new-growth part of the hair treated with Eucalyptus extract were related to changes in the hair microstructure. Solid-NMR, CD, XRD, and IR had been considered for analysis of the secondary structure of the hair protein. Solid-NMR could not be applied, since we could not prepare enough samples for measurement by solid-NMR from this survey (26). Since the sample condition should be a solution state in the case of CD measurement, preprocessing is needed for the analysis of the secondary protein structure of the hair (27). Such preprocessing changes the secondary structure of hair protein. For this reason, CD measurement was not used, in order to avoid the denaturation of protein.