Mixed tocopherols inhibit N-methyl-N-nitrosourea-induced mammary tumor growth in rats.

Abstract

Tocopherols are present in significant amounts in vegetable oils used in human foods. The most prevalent tocopherols in foods are the alpha, beta, gamma, and delta variants with (RRR) stereochemistry. Tocopherols are lipophilic phenolic antioxidants, produced by plants. In the United States, gamma-tocopherol is the most prominent dietary tocopherol due to its high amount in the dominant commercially produced vegetable oils such as soybean, corn, and cottonseed. In this report, experiments were designed to study the inhibitory effect of mixed tocopherols against N-methyl-N-nitrosourea-induced mammary tumor growth in female Sprague-Dawley rats. Beginning at 21 days of age, rats were treated with a single intraperitoneal injection of 50 mg/kg body weight of N-methyl-N-nitrosourea. One wk later, the rats were fed experimental diets containing 0 or 0.1% mixed tocopherols containing over 50% gamma-tocopherol. At 9 wk after N-methyl-N-nitrosourea treatment, all rats were evaluated for inhibition of mammary tumor growth and proliferating cell nuclear antigen. Dietary administration of mixed tocopherols significantly suppressed mammary tumor growth (P < 0.05) and proliferating cell nuclear antigen (P < 0.01) and also moderately suppressed tumor multiplicity. The treatment increased the serum levels of gamma- and delta-tocopherols without affecting the body weight. The results of this study suggest that mixed tocopherols may be safe and effective agents for the prevention of breast cancer.

• Authors: Nanjoo Suh, Shiby Paul, Hong Jin Lee, Yan Ji, Mao-Jung Lee, Chung S Yang, Bandaru S Reddy, Harold L Newmark
• Journal: Nutrition and cancer (Nutr Cancer) Vol. 59 Issue 1 Pg. 76-81 ( 2007) ISSN: 0163-5581 [Print] United States
• PMID: 17927505 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Anticarcinogenic Agents
• Antioxidants
• Proliferating Cell Nuclear Antigen
• Methylnitrosourea
• Tocopherols

Topics

• Animals
• Anticarcinogenic Agents (therapeutic use)
• Antioxidants (therapeutic use)
• Dose-Response Relationship, Drug
• Female
• Immunohistochemistry
• Mammary Neoplasms, Experimental (pathology, prevention & control)
• Methylnitrosourea (toxicity)
• Proliferating Cell Nuclear Antigen (analysis)
• Random Allocation
• Rats
• Rats, Sprague-Dawley
• Severity of Illness Index
• Tocopherols (therapeutic use)