Synthesis of ellagic acid O-alkyl derivatives and isolation of ellagic acid as a tetrahexanoyl derivative from Fragaria ananassa.

Ellagic acid [1] is a gallic acid dimer that occurs in plants, fruits, and nuts, either in its free form, or in a series of ellagitannins, or as a glucoside. It has been shown to inhibit cancer induced by several types of chemical carcinogens including polycyclic aromatic hydrocarbons, N-nitrosamines, aflatoxin, and aromatic amines. It has been extracted from a number of fruits, including strawberries; however, its presence in the extracts was determined only by hplc connected with a diode array detector.

Ellagic acid protects rat embryos in culture from the embryotoxic effects of N-methyl-N-nitrosourea.

Ellagic acid is a naturally occurring plant phenol that has demonstrated anticarcinogenic and antimutagenic activity in several test systems. Given the common proposed etiopathogenic processes of mutagenesis, carcinogenesis, and teratogenesis induced by genotoxic chemicals, the present study was initiated to determine whether ellagic acid would protect rat embryos in culture from the teratogenic effects of N-methyl-N-nitrosourea (MNU). Ellagic acid alone (as used in these experiments; 50 microM in DMSO) was not embryotoxic.

Inhibitory effects of phenethyl isothiocyanate on N-nitrosobenzylmethylamine carcinogenesis in the rat esophagus.

F-344 rats fed diets containing phenethyl isothiocyanate (PEITC; 3 and 6 mumol/g diet), a naturally occurring constituent of cruciferous vegetables, before and during treatment with the carcinogen N-nitrosobenzylmethylamine (NBMA), developed 99-100% fewer esophageal tumors than NBMA-treated control rats. PEITC exhibited inhibitory effects against both preneoplastic lesions (acanthosis and hyperkeratosis, leukoplakia, leukokeratosis) and neoplastic lesions (papilloma, carcinoma). Tumors were not observed in rats treated with PEITC alone.

Deuterium isotope effect on the toxicokinetics of monomethylamine in the rat.

The single-dose toxicokinetics of monomethylamine has been characterized in the rat by HPLC assay of serial blood samples. Biphasic first-order elimination was observed following an iv bolus dose of 19 mumol/kg with a terminal half-life of 19.1 +/- 1.

Metabolic denitrosation of N-nitrosodimethylamine in vivo in the rat.

Enzymatic denitrosation is a potentially inactivating metabolic route that has been shown to convert carcinogenic N-nitrosodimethylamine (NDMA) to methylamine (MA) in vitro. To investigate its quantitative course in vivo, groups of 8-week-old male Fischer rats have been given small (8-15 mumol/kg) p.o.