No abstract

8-hydroxydeoxyguanosine (8-OHdG) is one of the products which are excreted in urine as a result of oxidative damage to DNA. We investigated the feasibility of using 8-OHdG in urine as an index for oxidative damage to DNA in atopic dermatitis (AD). Seventeen patients with long-standing AD and 17 healthy volunteers were enrolled in this study. The severity of AD was evaluated by SCORAD index. Eosinophils, total IgE and lactate dehydrogenase-5 in peripheral blood were measured as clinical parameters for AD. A newly developed enzyme-linked immunosorbent assay method was used to measure urine 8-OHdG. The AD patients showed significantly higher levels (P < 0.0001) of 8-OHdG in their urine than corresponding controls. Urine 8-OHdG levels showed as strong a positive correlation as other haematological parameters did using the SCORAD index. Thus, we conclude that the urine 8-OHdG levels can also serve as a biochemical index of tissue damage and can act as a useful tool in the clinical evaluation of AD.

Recently the application of crude drugs in cosrnetics has produced a keen interest. We learned from ancient Chinese rnedical books that crude drugs were applied as cosmetics with medical efficacy for increasing the beauty of ladies [I]; arnong which it was noted that many prescriptions were for the purpose of treating hyperpigrnentation such as melasrna and ephelides. However, the reasons'why such crude drugs were applied an also their pharmacological effects are lntroduction

Many patients with atopic dermatitis are dissatisfied with conventional treatments based on topical steroids and have experienced some traditional remedies and alternative therapies. However, most of such therapies have not been evaluated scientifically and clinically by specialists. This study was designed to assess whether a certain vegetarian diet might be effective for atopic dermatitis and if so, to identify the mechanisms of this remedy through analyses of immunological parameters. An open-trial study was carried out in twenty patients with atopic dermatitis. An improvement of dermatitis was evaluated by SCORAD index and serological and immunological parameters were monitored. After a twomonth treatment, the severity of dermatitis was strikingly inhibited, as assessed by SCORAD index and serological parameters including LDH5 activity and a number of peripheral eosinophils. A sharp reduction in eosinophils and neutrophils was observed prior to improvement in the skin inflammation. In addition, PGE2 production by peripheral blood mononuclear cells was reduced by this treatment. In contrast, serum IgE levels did not change during the same period. Although this study is an open-trial one, it suggests that this treatment may be useful for the treatment of adult patients with severe atopic dermatitis.

Coumarins are widely distributed in plants and are especially abundant in the bark, leaves, and roots of Umbelliferae and Rutaceae plants. So far more than 1300 types of coumarin have been identified as natural or synthesized compounds. Coumarins have recently been reported to have interesting pharmacologic and biochemical properties such as antioxidative, 1,2) antiinflammatory, and antiallergic effects, 3,4) inhibition of platelet aggregation 5) and protein kinase, 6) induction of apoptosis, 7) and antiviral, 8) antidifferentiative, 9) and antimutagenic activity. 10)Melanin pigment is a heteropolymer of indole compounds synthesized within melanocytes in the epidermis. Inhibitory compounds on melanogenesis are useful as skin-whitening agents used in cosmetics and as treatment of hyperpigmentation. Tyrosinase is known to play a critical regulatory role in melanin biosynthesis. 11) Therefore, many tyrosinase inhibitors that suppress melanogenesis in epidermal layers have been actively studied in cosmetics and pharmaceuticals. [12][13][14][15] These observations led us to search for naturally occurring tyrosinase inhibitors.Recently, we have isolated esculetin from the seeds of Euphorbia lathyris L. as a mushroom tyrosinase inhibitory compound.16) To the best of our knowledge, this is the first report of the tyrosinase-inhibitory effects of esculetin. In this study, 18 coumarins and four cinnamic acid derivatives were examined for antityrosinase activity and study of the structure-activity relationship. We evaluated further the inhibitory effect on melanin synthesis in B16 melanoma cells and guinea pig epidermal sheets of esculetin, which showed the strongest inhibitory activity among these compounds. MATERIALS AND METHODS MaterialsCoumarin, 4-hydroxycoumarin, umbelliferone, 7-methoxycoumarin, 6-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, esculin, esculetin, scopoletin, 7-hydroxycoumarin-4-acetic acid, and 7-hydroxycoumarin-3-carboxylic acid were purchased from Aldrich Chemical Co. (Milwaukee, WI, U.S.A.). 4-Methylesculetin, 5,7-dihydroxy-4-methylcoumarin, isoscopoletin, and fraxetin were obtained from Extrasynthese Co. (Genay, France). Daphnetin, daphnin, and daphnetin-8-glucoside were isolated from Daphne odora. The chemicals purchased were used as received.Assay of Tyrosinase-Inhibitory Activity The assay was performed as previously described.16) One milliliter of a 1.5 mM L-3,4-dihydroxyphenylalanine (DOPA) solution, 0.1 ml of dimethyl sulfoxide (DMSO) with or without sample, and 1.8 ml of 1/15 M phosphoric acid buffer solution (pH 6.8) were mixed. The mixtures were preincubated at 25°C for 10 min. Then, 0.1 ml of the aqueous solution of mushroom tyrosinase (1000 U/ml, Sigma Chemical Co., St. Louis, MO, U.S.A.) was added, and the reaction was monitored at 475 nm. A control reaction was conducted with DMSO. The percentage of inhibition of tyrosinase activity was calculated as follows: inhibition (%)ϭ(AϪB)/Aϫ100, where A represents the difference in the absorbance of the control sample between the incub...