Abstract C65: Chemopreventive effects of Brazilian traditional medicine Tabebuia avellanedae on in vitro and in vivo carcinogetic systems.

Abstract

Abstract As part of an ongoing project to investigate the antitumor and antitumor promoting properties of Tabebuia avellanedae, its dry powder essence and its active compound, 5-hydroxy-2- {(1-hydroxymethyl)-naphtho 2,3-b} furan-4,9-dione (NQ-801) were carried out. Tabebuia avellanedae (Bignoniaceae) (TA), which is native in South America from Brazil to northern Argentina, is well known in traditional folk medicine used for the treatment of various disease during five hundred years. The inner bark of this plant produced in Brazil is distributed in Asia as a herb tea and healthy purpose. The application of a new screening procedure which utilizes the synergistic effect of short-chain fatty acids and phorbol esters in enabled rapid and easy detection of naturally occurring substances(anti-tumor promoters, chemopreventive agents) with inhibition of Epstein-Barr virus(EBV) activation, using human lymphoblastoid cells. The percentage of the inhibition of TPA-induced EBV-EA activation for these compounds were from 90% to 40%, at experimental concentrations. In addtion, we have now extended these investigations to a new tumorigenesis model in which we initiated the tumors with DMBA initiation and promoted with 1.7 nmol of TPA in two-stage mouse skin test and other models. The control animals exhibited a 100 % papilloma incidence at 20 weeks after promotion. However, treatment with the tested compounds(85 nmol) along with initiator and promoter, reduced the percentage of tumor bearing mice by between 13.3-33.3 at 20 weeks. Employing Western blot analysis studies, we found that H-Ras, MEK and p38 levels observed the effects against carcinogenesis. Base on our data, we suggest that one target of these natural source effect in mouse skin is the modulation of the MAPK signal pathway. These results provide a basis for further development of these botanical supplements for human cancer chemoprevention Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C65.