Tumor promoter-like activity of the molluscicidal latex of 'Crown-of-Thorns' (Euphorbia milii var. hislopii) in the V79 metabolic cooperation assay
Cruz, C.M.; Kasper, P.; Cataldo, A.; Zamith, H.P.; Paumgartten, F.J.
Brazilian Journal of Medical and Biological Research 29(11): 1519-1523
1996
ISSN/ISBN: 0100-879X PMID: 9196556 Document Number: 456651
The latex of Euphorbia milii var. hislopii (syn. E. splendens) has been shown to be a potent plant molluscicide that could be used against the intermediate hosts of Schistosoma. A comprehensive toxicological evaluation of the latex is necessary before its large-scale use in schistosomiasis control because of the presence of tumour-promoting phorbol esters in several plants of the Euphorbiaceae family. Phorbol esters, together with a number of other known tumour promoters, share the common property of inhibiting metabolic cooperation (the exchange of low molecular weight molecules via gap junctions) between Chinese hamster V79 cells in monolayer cultures. In order to determine whether latex of E. milii presents tumour promoter-like activity in this short-term in vitro assay, samples of lyophilized latex were tested at a noncytotoxic concentration range (1, 10, 50 and 100 micro g/ml) in 3 independent experiments. 12-O-Tetradecanoylphorbol-13-acetate (10 ng/ml) was used as positive control. In all 3 assays, E. milii latex consistently inhibited metabolic cooperation between V79 cells at concentrations >=10 micro g/ml. The results indicate that E. milii latex contains tumour-promoting substances and suggest that the use of crude latex as a molluscicide may pose a carcinogenic hazard to people who are continuously exposed to the product.