138 JOURNAL OF COSMETIC SCIENCE Figure 3. Effects of R. mort extracts on the inhibition of UV-induced pigmentation. (a) Placebo. (b) 1% (v/v) R. mori-extracts-treated skin. (c) 5% (v/v)R. mori-extracts-treated skin. SAFETY TESTS OF R. MORI EXTRACTS Acute toxicity test. We investigated the potential toxicity of the R. mori extracts. Accord- ing to the CTFA guidelines, we assessed acute oral toxicity and acute derreal toxicity of the compound in 60 rats and 24 rabbits, respectively. We examined acute toxicity for 14 days after treatment. No death occurred, and abnormality was not detected at clinical findings in rats and rabbits administered orally with the compound. We did not observe

INHIBITORY EFFECTS OF R. MORI EXTRACTS 139 The flow-chart of Ramulus mori extracts Ramulusmori 10 Kg I 70% EtOH 60 L, after 5 days filter Ethylacetate extraction water fraction IC50=1001• g/ml Ethylacetate Extracts 92.3 g IC5o=10.0 g g/ml I Prep-TLC I ...... Rf=0.23, IC5o=1.35 gg/ml •" Recrystalization with CHC13 dark-brown 45.4 gl IC5o=4.53 la g/ml Silicagel Column Chromatography Fraction 10.2 g IC5o=1.35 l•g/ml Prep-LC 2'-Oxyresveratrol, 1.67g IC5o=0.23 [tg/ml Figure 4. Flow chart of purification of single compound from R. mori extracts. changes of body weight in the test animals or abnormalities of organs from gross findings of necropsy (data not shown). Skin irritation test. The primary skin irritation from R. mori extracts was investigated in six rabbits. We examined skin irritation and clinical signs for 24-72 hours after a seven-day treatment using Draiz's P.I.I. (primary irritation index). We did not observe side effects such as erythema or edema. Eye irritation test. The potential toxicity of the compound was determined according to AFNOR (Association Francaise de Normalization) guidelines in an eye irritation test on nine rabbits. We examined both eyes at one hour, and one, two, three, four, and seven days after treatment. We did not see any clinical signs.