Toxicity lipid hydroperoxides

A more recent view stresses the importance of lipid hydroperoxides in the dietary intake, for their possible toxic and pathogenic effects, as opposed to those produced in. ... 

Cells may show a low level of autofluorescence at 413 nm when irradiated at 324 nm. This fluorescence dramatically increases when d -parinaric acid (159) is incorporated into the cell membrane, either by intercalation or esteriflcation. Exposure to oxidation stress of cells enriched with the 159 fluorescent probe causes diminution of the fluorescence intensity and is directly correlated with formation of lipid hydroperoxides. Addition of antioxidants, such as Vitamin E (21), abates fluorescence diminution. A blanc run of cells enriched with 159 but not subjected to oxidation stress is necessary to follow the degradation of 159 when exposed to UV irradiation. This method was applied to track lipid oxidation during apoptosis and other phenomena, triggered by toxic compounds such as H2O2, f-BuOOH and cumyl hydroperoxide (27)"° 11,424... 

Decadienal has been reported as one of the most toxic lipid hydroperoxide breakdown products to ceUs . Besides l,Ai -etheno-2 -deoxyadenosine (edAdo) (156)... 

Lipid peroxidation (Figure 14.5) is the initiating reaction in a cascade of events, starting with the oxidation of unsaturated fatty acids to form lipid hydroperoxides, which then break down to yield a variety of end products, mainly aldehydes, which can go on to produce toxicity in distal tissues. For this reason cellular damage results not only from the breakdown of membranes such as those of the endoplasmic reticulum, mitochondria, and lysosomes but also from the production of reactive aldehydes that can travel to other tissues. It is now thought that many types of tissue injury, including inflammation, may involve lipid peroxidation. 

The Toxicity of Lipid Hydroperoxides and Their Decomposition Products... 

Firstly, I will discuss recent evidence supporting the hypothesis that free radicals contribute to important chronic diseases in man and exert an important life-shortening effect. Secondly, I will review data on the toxicity of lipid hydroperoxides and their decomposition products, since lipid hydroperoxides can be a source of free radicals in vivo. And lastly, I will review a system under study in our laboratory in which quantitative data on lipid peroxidation and antioxidants is being obtained using linoleic acid in SDS micelles. 

As might be expected, lipid hydroperoxides are more toxic in vitamin E-deficient animals (H). In the rabbit, the LD Q for... 

In conclusion, the toxicity of lipid hydroperoxides suggests that these materials are extremely toxic. These peroxidic materials could be a potent source of free radicals in vivo. 

The major function of SOD, catalase, and glutathione peroxidase is to protect against the Eenton reaction that is, decomposition of H202by Ee +, resulting in the emergence of the most toxic radical, hydroxyl (HO ). In addition, glutathione peroxidase reduces lipid hydroperoxides to alcohols ... 

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