DMBA/TPA induced skin tumor

Skin 11 Inhibition of DMBA/TPA induced skin tumors (Oral application) [43]... 

Assay for Iinhibition of DMBA/TPA Induced Skin Tumors in Mice... 

Inhibition of A -nitrobis-(2-hydroxypropyl)amine (BHP) induced pancreatic tumors Inhibition of DMBA/TPA induced skin tumors Inhibition of DMBA/teleocidin B induced skin tumors Inhibition of DMBA/fumonsin-Bl induced skin tumors Inhibition ofNOR-l/TPA induced skin tumors Inhibition of DMBA/okadaic acid induced skin tumors Inhibition of DMBA/mineral oil induced skin tumors... 

Skin 1 Inhibition of 7,12-dimethylbenz[a Janthracene (DMBA 2)/TPA induced skin tumors (Topical application) [8,3739-42]... 

The Protective Effect of DBM on TPA-induced Skin Tumor Promotion in CD-I Mice Previously Initiated with DMBA... 

For the highly inhibitive compounds in the TPA-induced inflammatory assay, we evaluated their antitumor-promoting activity by a standard initiation-promotion protocol [Fig. (3)] [37,40]. Initiation was achieved by a single application of 50 pg of DMBA (2), a well known tumor initiator, to the skin of backs of 8-week-old female ICR mice. From one week after initiation, 1 pg of TPA (1) was applied twice a week until week 20. The test compound (2.0 or 0.2 pM) dissolved in acetone-dimethyl sulfoxide (DMSO) (9 1, 100 pi) was applied 30 min before each TPA treatment. Groups of 15 mice were used. The number of tumors was counted weekly. 

Soyasapogenol B, soyasaponins I and II and wistariasaponins from Wistaria brachybotrys (wistariasaponin C corresponds to astragaloside VIII) decreased (20-30%) the Epstein-Barr Virus (EBV) activation induced by the tumor promoter TPA (12-O-tetradecanoylphorbol-13-acetate) in Raji cells at a concentration of lxlO2 mol ratio [151]. Soyasaponin I from the same plant exhibited remarkable inhibitory effects on mouse skin tumor promotion on the basis of the two-stage DMBA-TPA carcinogenesis test in vivo. Soyasaponin I reduced the number of papillomas per mouse at about 40% even at 20 weeks [152]. 

As already shown, tubeimoside 1 (5) from Bobolstemma paniculatum exhibited a strong anti-tumor activity, but had intriguingly a potent antitumor-promoting effect in two-stage mouse skin tumor formation induced by DMBA+TPA [38]. Its natural analog, tubeimoside III showed also a potent anti-tumor-promoting effect in the same model after topical administration but not after oral administration [39]. 

And, many compounds which showed strong inhibitory effects on the induction of EBV-EA by TPA have been shown to act as inhibitors of tumor promotion on two-stage carcinogenesis test in vivo [15-21, 27-29]. The one of two-stage carcinogenesis test is on mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a... 

When the rosemary extract was administered (i.g.) at lOOmg/kg/day for 5 consecutive days, the number and area of diethylnitrosamine-induced GST placental-form-positive (GST-P) hepatocellular foci were reduced in male F344 rats. A methanol extract of the leaves of rosemary was evaluated for its effects on tumor initiation and promotion in mouse skin carcinogenesis. Topical apphcation of the rosemary extract to mouse skin attenuated the covalent binding of BaP to epidermal DNA and inhibited tumor initiation by BaP and DMBA. Application of rosemary to mouse skin also inhibited TPA-induced ODC activity, inflammation, hyperplasia, and tumor promotion. Likewise, topical application of camosol or ursolic acid isolated from rosemary inhibited TPA-induced ear inflanunation, ODC activity, and tumor promotion. ... 

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