|Merrill Jr, Alfred|
Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/1996
Publication Date: N/A
Citation: N/A Interpretive Summary: Sphingolipids are a class of fat that are known to play an important role in regulating the growth, function, and health of many cell types. All foods contain these lipids. Some foods such as milk and soybeans contain them in relatively large amounts. Thus, each day humans and animals consume these lipids and yet we know very little about how they contribute to animal and human health. Recent studies indicate that these lipids, isolated from milk, can reduce some forms of cancer in mice. In addition, we now know that there are toxic chemicals, called fumonisins, in foods that alter the amount of these lipids in animals that consume contaminated feeds. For example, the rodent chows fed to rats and mice used in animal feeding studies have been found to contain these toxic chemicals which are produced by certain molds. This is a cause for concern since feeding studies with rodents are used to determine the safety of many chemicals and drugs. These findings underscore the importance of sphingolipids and raise a warning flag for the selection of animal diets for nutritional and toxicological studies.
Technical Abstract: Sphingolipids are highly bioactive compounds that participate in the regulation of cell growth, differentiation, diverse cell functions, and apoptosis. They are present in both plant and animal foods in appreciable amounts, but little is known about their nutritional significance. Recent studies have shown that feeding sphingomyelin to female CF1 mice treated with a colon carcinogen (1,2-dimethylhydrazine) reduced the number of aberrant colonic crypt foci; longer term feeding also affected the appearance of colonic adenocarcinomas. Therefore, dietary sphingolipids should be considered in studies of the relationships between diet and cancer. Sphingolipids have also surfaced as important factors in understanding the mechanism of action of a recently discovered family of mycotoxins, termed fumonisins. Fumonisins are produced by fungi that are commonly found on maize and a few related foods, and their consumption can result in equine leukoencephalomalacia, porcine pulmonary edema and a number of other diseases of veterinary animals and, perhaps, humans. A cellular target of fumonisins is the enzyme ceramide synthase, and disruption of sphingolipid metabolism by fumonisins has been established by studies with both cells in culture and animals that have consumed these toxic mycotoxins. These findings underscore the ways in which sphingolipids and agents that affect sphingolipid utilization should be given consideration in selecting animal diets for nutritional and toxicological studies.