Ultraviolet light lesions induced

Dibenzoylmethane (DBM) is a minor constituent of licorice and an analogue of curcumin. We previously reported that feeding 1% DBM in the diet strongly inhibited 7,12-dimethylbenzyla[a]anthracene (DMBA)-induced mammary tumorigenesis and formation of leukemias/lymphomas in Senear mice). In this report, we show that topical application of DBM to the backs of mice inhibited chemical- and ultraviolet light (UV)-induced inflammation, sunburn lesions, and formation of skin tumors in mice. Topical application of DBM inhibited TPA-induced edema of mouse ears and skin tumor promotion in CD-I mice in a dose-dependent manner. Topical application of 3 - 10 pmol DBM with 5 nmol TPA twice weekly for 16 weeks in CD-I mice previously treated with DMBA inhibited the number of skin tumors per mouse by 65 - 93%, and percent of mice with tumors was inhibited by 29 - 50%.. Topical application of 10 pmol DBM with mirex (a non-TP A type tumor promoter) 3 times a week for 18 weeks in... 

Table IV. Inhibitory Effect of DBM and PABA on Ultraviolet Light (UV)-induced Skin Sunburn Lesions in SKH-1 Mice...

C4. Casciola-Rosen, L., and Rosen, A., Ultraviolet light-induced keratinocyte apoptosis A potential mechanism for the induction of skin lesions and autoantibody production in LE. Lupus 6, 175—... 

In contrast to the results with SAB, when cells were exposed to the monofunctional alkylating agent, N-methyl-N -nitro-N-nitrosoguanidine (MNNG), SCE frequency remained low in those cells exposed in mid to late S phase and was highest in cells exposed in Gi or early S phase. Thus, as has been shown by others with ultraviolet light or 8-methoxypsoralen-induced DNA lesions (12, IS), MNNG exposure resulted in lesions that lead to SCE formation only when the lesions were produced prior to the replication of the chromosome, i.e., ahead of the repUcation foik. 

N. Uchida, H. Mitani, A. Shima (1995). Multiple effects of fluorescent light on repair of ultraviolet-B-induced DNA lesions in cultured goldfish cells. Photochem. Photobiol., 61,79-83. 

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