fumonisin-b1 and Skin-Neoplasms

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Eucalyptus plants were screened. Consequently, the phlorogrucinol-monoterpene derivative, euglobal-G1 (EG-1), was obtained from the leaves of Eucalyptus grandis as an active constituent. EG-1 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA) as an initiator and fumonisin-B1, which has been known as one of mycotoxins produced by Fusarium monifliforme, as a promoter. Further, EG-1 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumor using 4-nitroquinoline-N-oxide (4-NQO) as an initiator and glycerol as a promoter.

Topics: 4-Nitroquinoline-1-oxide; 9,10-Dimethyl-1,2-benzanthracene; Animals; Anticarcinogenic Agents; Antiviral Agents; Body Weight; Carboxylic Acids; Carcinogens; Carcinogens, Environmental; Eucalyptus; Female; Fumonisins; Glycerol; Lung Neoplasms; Mice; Mice, Inbred SENCAR; Neoplasms, Experimental; Phloroglucinol; Phytotherapy; Plants, Medicinal; Skin Neoplasms; Terpenes; Time Factors

An extract of the roots of Taraxacum japonicum (Compositae) exhibited strong anti-tumor-promoting activities on the two-stage carcinogenesis of mouse skin tumor induced by dimethylbenz[a] anthracene (DMBA) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter, as well as on that induced by DMBA and fumonisin B1. Further, the extract exhibited anti-tumor-initiating activity on the two-stage carcinogenesis of mouse skin tumor induced by (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexen amide (NOR-1) as an initiator and TPA as a promoter. These results suggested that an extract of the roots of the Taraxacum plant could be a valuable chemopreventive agent against chemical carcinogenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Anticarcinogenic Agents; Antineoplastic Agents, Phytogenic; Carboxylic Acids; Female; Fumonisins; Humans; Mice; Mice, Inbred ICR; Papilloma; Plant Extracts; Plants, Medicinal; Skin Neoplasms; Tetradecanoylphorbol Acetate

Seven saponins (1-7) isolated from the rhizomes and roots of Panax vietnamensis were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), in Raji cells as a primary screening test for anti-tumor-promoters (cancer chemopreventive agents). The ocotillol-type saponin, majonoside-R2 (2), which is the major and characteristic constituent of this plant, exhibited a significant inhibitory effect on EBV-EA activation. Furthermore, the cell cycle analysis of 2 on Raji cells was also examined and strong inhibition was observed on the effect of the cell cycle induced by TPA. Compound 2 showed potent anti-tumor-promoting activity in two-stage carcinogenesis tests of mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA or fumonisin B1 as a promoter. Consequently, these results suggest that majonoside-R2 (2) could be a valuable chemopreventive agent against chemical carcinogenesis.

Topics: Animals; Anticarcinogenic Agents; Antigens, Viral; Carboxylic Acids; Fumonisins; Ginsenosides; Male; Mice; Mice, Inbred ICR; Papilloma; Saponins; Skin Neoplasms; Tetradecanoylphorbol Acetate