Improved immune functions with administration of a low-fat diet in a burn animal model

The purpose of this study was to characterize the impact of a low-fat (LF; 1% fat) diet, a high-fat (HF; 25% fat) diet, and a standard (SD; 5% fat) di et on immune and oxidative parameters in a 20% body surface area burn anima l model fed nd libitum for 10 days postinjury. Although the mechanisms are poorly understood, the amount of dietary lipid in nutritional support has b een shown to have immunomodulatory effects after burn injury. Burned mice f ed the LF diet showed a normal response in activated splenocyte proliferati on compared to burned animals that received the SD or HF diet. Animals fed the SD and HF diets presented increased production of nitric oxide and pros taglandin E-2 response after burn injury, which is associated with inhibite d splenocyte proliferation. The total thiol concentration in spleen cells f rom burned animals kept on the HF diet was significantly higher than that i n unburned animals, while no increase in these oxidative parameters was obs erved in LF-fed burned animals. Moreover, the LF diet significantly reduced hepatic lipid peroxidation, as measured by malonaldehyde concentration, co mpared to the other two diets. These results suggest that the administratio n of a LF diet in mice after a burn injury prevents inhibition of in vitro splenocyte proliferation and reduces the intensity of oxidative stress. (C) 2000 Academic Press.