Efficacy of Ethylvanillin in the Prevention of Mammary Tumors Induced by Methylnitrosourea (MNU) in the Rats
Ethylvanillin is a synthetic flavoring agent that has been shown to have an inhibitory effect against mutagenic agents such as 4-nitroquinoline 1-oxide [Ohta, et al. Fd Chem Toxic 24:51 (1986)]. Ethylvanillin was evaluated in the present study in the MNU-induced mammary cancer model to determine the chemopreventive efficacy of this agent. Prior to this study, a six-week dose selection study confirmed that a dose of 20 grams of ethylvanillin/kg of diet (Teklad) was not toxic. Two dose levels (20 and 10 g/kg of diet) of ethylvanillin were administered in the chemoprevention study to female Sprague-Dawley rats beginning at 43 days of age and continuing until the end of the study. Carcinogen treated rats received one injection of MNU (50 mg/kg BW) via the jugular vein at 50 days of age. Rats were palpated for mammary tumors two times per week and checked daily for signs of toxicity. Diets were analyzed twice during the study to ensure accurate preparation and compound stability. At termination of the study (100 days after MNU), all grossly observed mammary tumors were weighed.