Tumor promotion activity

A, aplysiatoxin, or palytoxin. Therefore, we proposed that okadaic acid binds to its own receptor and induces various biological effects, including tumor promoting activity, through this receptor (27). We are now investigating the nature of its receptor. 

We have shown that TPA-type tumor promoters, such as lyngbyatoxin A and aplysi-atoxins exert tumor promoting activities on mouse skin through different mechanisms from those of non-TPA type tumor promoters such as palytoxin, okadaic acid, and dinophysistoxin-1. 

Lutein produced negative results in several studies of genotoxicity in vitro and in vivo. Although the committee noted that the doses used in these tests were low, it recognized that maximum feasible doses were used. No evidence of tumor-promoting activity was noted in animal models. 

In several studies of toxicity, no adverse effects were documented in monkeys or humans. Taking into account data showing that lutein was not genotoxic, had no structural alert, did not exhibit tumor-promoting activity, and is a natural component of the body (the eye), the Scientific Steering Committee concluded there was no need for a study of carcinogenicity. 

Frenkel, K. and Chrzan, K. (1987). Hydrogen peroxide formation and DNA base modification by tumor promoter-activated polymorphonuclear leukocytes. Carcinogenesis 8, 455-460. 

Nessel, C.S., et al., The role of dermal irritation in the skin tumor promoting activity of petroleum middle distillates, Toxicol. Sci., 49, 48, 1999. 

In animal studies, mirex, was tested at a dermal dose of 3.6 mg/kg 4 weeks in female CD-1 mice for tumor promoter activity and evidence of epidermal hyperplasia after initiation with 200 nmol/day 7,12-dimethyl-benz[a]anthracene (DMBA) for 1 week. Positive control mice were treated with 2 nmol/day of the phorbol ester tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), following initiation with DMBA. A third group of mice were treated with both 3.6 mg/kg mirex and 2... 

Croton f lavens. Analysis of the leaf extract shows the presence of diterpene di- and triesters that are structurally related to TPA (49). The diesters exhibit strong tumor promoting activity in dorsal mouse skin. Each cup of tea contains more tumor promoter than is required to maintain chronic irritation of the human esophagus, a necessary requirement for the promotion of esophageal cancer. 

Slaga TJ et al Sldn tumor-promoting activity of benzoyl peroxide, a widely used free radicalgenerating compound. Science 213 1023-1025, 1981... 

Murakami, A., S. Jiwanjiinda, K. Koshi-mizu, and H. Ohigashi. Screening form vitro anti-tumor promoting activities of edible plants from Thailand. Cancer Lett 1995 95(1/2) 137-146. 

Screening of edible plants against pos- DC230 sible anti-tumor promoting activity. 

Smooth muscle relaxant activity. Tine-ture of the gland, administered to rabbits, was active on the bladder and intestine " . Toxic effect. Gum, administered orally to adults, was active. A case of methemoglobinemia occurred in a 5-week-old male infant, after administration of asafetida preparation to alleviate colic. Treatment was with intravenous methylene blue and the infant recovered . Tumor-promoting activity. Water extract of the dried oleoresin, administered externally to mice at a dose of 200 pL/animal, was active vs 7,12-dimethylbenz[a]anthra-cene and croton oil treatment ". ... 

Epstein-Barr virus early antigen induction. Methanol extract of the dried leaf, in cell culture at a concentration of 1 pg/mL, was inactive. The assay was designed for tumor-promoting activity . Two diastere-oisomers of 2,7,1 l-cembratriene-4,6-diol (a- and 3-CBT) from the neutral fractions of cigarette smoke condensate, in Raji cells, produced potent inhibitory effects on the induction of Epstein-Barr virus (EBV)-EA by 12-0-tetradecanoylphorbol-13-acetate (TPA). The doses of a- and P-CBT required for 50% inhibition of EBV-EA induction by TPA were 7.7 and 6.7 mg/mL, respectively. Application of a- and P-CBT to mouse skin before treatment with TPA, inhibited TPA-induced ornithine decarboxylase activity in a dose-dependent manner. Application of 16.5 pM/mouse of a- and p-CBT resulted... 

Tumor-promoting activity of certain extracts of tobacco. J Natl Cancer Inst 1976 56(5) 1041-1045. 

Screening of edible plants against possible anti-tumor promoting activity. Cancer Lett 1988 39(3) 247-257. Chen, C. P., C. C. Lin, and T. Namba. Development of Natural Crude Drug Resources from Taiwan. VI. In vitro studies of the inhibitory effect on 12 microorganism. Shoyakugaku Zasshi... 

Vimala, S., A. W. Norhahnom, and M. Yadav. Anti-tumor promoter activity in Malaysian ginger rhizobia used in traditional medicine. Brit J Cancer 1999 80(1/2) 110-116. 

DNA viruses that can trigger tumors are found in the classes of the polyomaviruses, the adenoviruses and the papUloma viruses. The polyoma viruses with the SV40 virus as a well studied representative, adenoma virus and human papUloma virus (HPV) are associated with formation of tumors in humans and have genes coding for proteins with the properties of oncoproteins. The oncoproteins of aU three viruses interfere with the pRb function by Ufting its inhibition of transcription factor E2F. It is assumed that the tumor-promoting activity of the proteins is due, in particular, to this property. 

Konoshima, T., M. Takasaki, M. Kozuka, H. Tokuda, H. Nishino, E. Matsuda, and M. Nagai. 1997. Anti-tumor promoting activities of isoflavonoids from Wistaria brachybotrys. Biol. Pharm. Bull. 20 865-868. 

Murakoshi, M., Nishino, H., Tokuda, H., Iwashima, A., Okuzumi, J., Kitano, H., and Iwasaki, R. (1992). Inhibition by squalene of the tumor promoting activity of 12 o-tetradecanoylphorbol-13 acetate in mouse skin carcinogenesis. Int. ]. Cancer 52,950-952. 

Furthermore, we examined the inhibition of the induction of ODC induction by teleocidin in mouse skin. Application of 11.4 nmol morusin (3) caused 43% inhibition of the induction of ODC by 11.4 nmol teleocidin [73]. From the results of these three tests, morusin (3) might inhibit the tumor-promoting activity of teleocidin on mouse skin. 

On the other hand, morusin (3) itself did not show a tumor promoting activity on mouse skin, x in Figs. (10) and (11). From these results, morusin (3) is an anti-tumor promoter judging from its ability to inhibit the short-term effects induced by tumor promoters. 

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