Diets Containing High Levels of Corn Oil Suppress Immunoresponsiveness and Exacerbate UV-Carcinogenesis

  • H. S. Black
  • J. Gerguis
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 375)

Abstract

Although ultraviolet radiation (UV) is considered a “complete” carcinogen, an irradiation protocol has been devised that approximates the classic two-stage chemical carcinogenesis protocol, allowing inferences to be made as to the segment of the carcinogenic continuum at which dietary lipid exerts its principal effect upon UV-induced skin cancer. Employing this protocol, we have determined that enhancement of UV-carcinogenesis by high levels of polyunsaturated fat (12% corn oil) occurs during the promotion/progression stage; that replacement with a low fat (0.75% corn oil) diet after initiation will negate the exacerbating effect of high fat; and that an omega-3 fatty acid source (12% menhaden oil) inhibits UV-carcinogenesis even at high dietary levels, although apparently exerting its inhibitory effect during UV-initiation. In addition, both dietary lipid sources (corn oil vs. menhaden oil) and level of corn oil markedly influence delayed-type hypersensitivity (DTH) to the hapten, dinitrochlorobenzene. As level of corn oil also influences tumor expression and prostaglandin E2 levels in a near linear fashion and as PGE2 has been reported to modulate immune hypersensitivity responses, we have examined the influence of low/high corn oil levels on DTH during various time intervals within the UV-carcinogenesis protocol. DTH response was significantly (p < 0.01) suppressed in animals receiving high fat diet prior to irradiation. Although both dietary groups exhibited UV-induced immunosuppression, there remained a significant (p = 0.01) difference in response between the dietary groups through nine weeks of irradiation. These data indicate that level of dietary lipid has a pronounced effect upon immunoresponsiveness during carcinogenesis and may partially explain the exacerbation of carcinogenic expression by high corn oil diets.

Keywords

Dietary Group Dietary Lipid Irradiation Protocol Dietary Lipid Source High Dietary Level 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • H. S. Black
    • 1
  • J. Gerguis
    • 1
  1. 1.Veterans Affairs Medical CenterBaylor College of MedicineHoustonUSA

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