Tissue-specific accumulation of tocopherols and tocotrienols in turkey tissues during embryonic development and their susceptibility to lipid peroxidation were investigated. Fertile turkey eggs were incubated using standard commercial conditions. Embryonic tissues were collected at 16, 22, 25 d of incubation and from day-old poults (referred to as day 29) and alpha-; beta- + gamma- and delta-tocopherols and respective tocotrienolswere analysed by HPLC. A turkey diet provided to the parent hens contained the complete range of tocopherols and tocotrienols. Between days 16 and 22 of embryo development, the alpha-tocopherol concentration in the liver remained constant and then increased significantly (P<0.01) reaching a maximum just after hatching. Similar changes were observed for the other tocopherols and tocotrienols. The accumulation of alpha-tocopherol in the yolk sac membrane (YSM) started after day 20 of development and at hatching the alpha-tocopherol concentration in the YSM was twice that of beta- + gamma-tocopherols and 15 times greater than that of alpha-tocotrienol. In the kidney, heart, lung, muscle and adipose tissues a gradual increase in tocopherol and tocotrienol concentrations took place between days 20 and 25 of development with a sharp increase in particular of alpha-tocopherol between days 25 and 29. There was a discrimination between tocopherols and tocotrienols during their assimilation from the diet by the parent hen and during metabolism by the developing turkey embryo. Tissue-specific features in the susceptibility to lipid peroxidation were found with the brain being the most susceptible to lipid peroxidation at day 25 and in day-old poults.
Monthly Archives: September 1999
Although scientific evidence is relatively limited, rice bran oil (RBO) is tenaciously believed to be a healthy vegetable oil in Asian countries. It exerts hypocholesterolemic activity in relation to more commonly used vegetable oils and is characterized by a relatively high content of non-fatty acid components, some of which are known to have beneficial health effects. Components specific for RBO such as gamma-oryzanol and tocotrienolscould participate in its hypocholesterolemic effects. In addition, blending RBO with safflower oil, but not with sunflower oil, may magnify the hypocholesterolemic efficacy. This observation is of particular interest with regard to dietary intervention with RBO. The possible mechanism underlying this effect may at least in part be related to the specific triglyceride structure of safflower oil, differing from that of sunflower oil.