DATE PALM KERNEL EXTRACT ON FACIAL SKIN WRINKLES 285 extremely well tolerated when applied daily on facial skin (no irritation, redness, burn, or itching). This is in contrast with other topical treatments containing compounds such as retinoic acid which provides improvements in skin appearance but at the expense of irritating adverse effects such as skin redness and sensitivity (16). In addition to good tolerability, DPKE is easily formulated, chemically stable, and compatible with other formulation constituents, qualifying it to be an ideal agent for use in cosmetic products. Skin aging is the result of a multifaceted biological phenomenon consisting of two com- ponents: intrinsic (chronologic) aging and extrinsic aging. The pathophysiologic elucida- tion of both components has been well documented in clinical and histologic studies (17). Intrinsic aging is largely a genetic process in which increased production of reactive oxy- gen species (ROS) alongside with progressive damage to mitochondrial DNA causes cell senescence and impairment of skin repair (18). Extrinsic aging is responsible for most skin deteriorations, and is caused by several factors, of which, exposure to ultraviolet (UV) light (photoaging) is the most crucial, and causes DNA damage in a multiplicity of living tissue (19). Photodamage also involves the generation of ROS that breaks the cellular biosynthesis of collagen and glycosaminoglycans in skin along with decreased keratinocyte Figure 3. Percentage change s in relative melanin concentration after 4 and 8 weeks of treatment. Data are presented as mean ± SD. Signifi cance levels: *p 0.05 versus baseline. #p 0.05 versus placebo (paired t-test).

T able IV Collective Data Obtained in Both Male and Female Volunteers at Baseline and after 4 and 8 weeks of Treatment with DPKE Cream Male volunteers (=7) Female volunteers (=29) Baseline 4 weeks 8 weeks Baseline 4 weeks 8 weeks Clinical assessment: Roughness score 2.32 ± 0.83 — 1.86 ± 0.87* 1.72 ± 0.85 — 1.14 ± 0.51* Texture homogeneity score 2.07 ± 0.53 — 1.41 ± 0.63* 2.21 ± 0.75 — 1.59 ± 0.62** Pigmentation score 2.30 ± 0.74 — 2.08 ± 1.08 2.37 ± 0.99 — 1.83 ± 0.80* Redness score 1.81 ± 0.77 — 2.04 ± 0.78 2.10 ± 0.85 — 1.91 ± 0.96 Biophysical measurements: Skin hydration (AU) 43.00 ± 10.56 49.70 ± 9.83** 55.23 ± 9.63** 40.71 ± 9.60 53.74 ± 9.66** 50.93 ± 12.03** TEWL (g/m2/h) 11.75 ± 3.32 10.24 ± 1.57 10.12 ± 1.90 12.33 ± 3.10 10.48 ± 2.54* 10.02 ± 2.90** Skin elasticity (AU) 0.844 ± 0.088 0.910 ± 0.057 0.976 ± 0.113* 0.836 ± 0.093 0.890 ± 0.063* 0.930 ± 0.094** Skin fi rmness (AU) 0.270 ± 0.078 0.199 ± 0.047* 0.171 ± 0.061* 0.277 ± 0.084 0.236 ± 0.057* 0.218 ± 0.054** Skin melanin density (AU) 272.9 ± 21.8 250.6 ± 20.2 264.9 ± 27.3 273.5 ± 29.7 263.4 ± 28.9 254.1 ± 26.3* Erythema (AU) 176.9 ± 62.8 168.6 ± 66.4 155.5 ± 74.2 167.6 ± 60.3 158.9 ± 70.4 151.7 ± 68.4 Multispectral analysis: Wrinkle size (AU) 67.5 ± 19.5 44.0 ± 17.6 41.8 ± 15.9* 54.6 ± 22.1 46.5 ± 22.5 39.2 ± 23.1* Maximal depth (mm) 0.482 ± 0.117 0.315 ± 0.130 0.258 ± 0.157* 0.395 ± 0.194 0.323 ± 0.190 0.287 ± 0.225* Relative indentation index (%) 100.0 ± 18.1 84.9 ± 16.4 78.5 ± 17.5* 100.0 ± 17.8 81.3 ± 16.5** 80.8 ± 15.4*** Relative roughness index (%) 100.0 ± 15.5 82.5 ± 13.0* 74.4 ± 12.8** 100.0 ± 15.2 75.1 ± 15.7** 67.2 ± 13.9*** Relative melanin concentration (%) 100.0 ± 13.7 92.9 ± 14.4 86.7 ± 13.5 100.0 ± 20.6 87.3 ± 20.4* 85.8 ± 25.4* Data are presented as mean ± SD of seven male and 29 female subjects. Signifi cance levels: *p 0.05, **p 0.01, and ***p 0.001 versus baseline values (paired t JOURNAL OF COSMETIC SCIENCE 286