The Study On In Vitro Bioactivity Of Linoleic Acid Oxidation Product And Its Pro-inflammatory Effect

Linoleic acid, which content is affluent in the human body, is one of the essential fattyacids. It has the function that reduces the blood fat and blood pressure, and plays an importantrole in body circulation and immunoregulation. Because of the unsaturated double bond, itcan be oxidated easily, and the oxidation product may lead to atherosclerosis(AS)、cancer andneurodegenerative disease to some extent. However, the study on the bioactivity of oxidationproduct of linoleic acid is very limited. The purpose of this essay was to find out the effect ofoxidation on biomacromolecule. The pro-inflammation effect was also detected by usingmacrophagocyte cells RAW264.7. Moreover, the MAPK cell signal pathway was investigatedto verify the regulation effect of the linoleic acid oxidation product.In this study, Fe2+and ascorbic acid were used to induce the oxidation reaction, thechange during the oxidation process was detected by measuring conjugated diene and TBARS.The results showed that as time passed, the value of conjugated diene rised at first and falledlater, while the TBARS kept increasing all the time. This suggested that in the beginning ofthe reaction, lots of lipid hydroperoxide were generated, but they broke down to aldehydesfinally. For the influence to the biomacromolecular, we mixed the lipid oxidation with proteinand DNA. After electrophoresis, we found that the oxidation could induce the crosslink andcarbonylation, the3day’s product and5day’s product both have a remarkable effect.5day’sproduct could bring oxidation damage to DNA, and mainly made it fracture.Moreover，weather linoleic acid oxidation could induce the inflammation on RAW264.7was also investigated. The pro-inflammation effect was measured by ROS and COX-2, theresults showed that5day’s product had the most powful effect on boosting the generation ofROS and the expression of COX-2. Then5day’s product was used to figure out the signalpathway, found that it could not only induce ROS and COX-2in the dose-depend manner, butalso activated the ERK, JNK and p38in the MAPK pathway. In addition, it could promote theexpression of HO-1. On the other hand, the product noteworthly suppressed the NO, whichwas quite different from LPS, but we still can’t explain it.In brief, this research proved that linoleic acid have strong in vitro bioactivities and couldinduce the inflammation in RAW264.7cells, all the data indicate that linoleic acid oxidationproduct could be harmful to the body. This study could provide the theory data for the research of nutrition and function of linoleic acid.