The Anti-radiation Effect And Mechanism Of Ferulic Acid

Purpose:With the development of society, nuclear technology is widely used andpromoted, while the damage caused by radiation is greatly exacerbated. Radiation cancause various types of radiation sickness, such as intestinal, cerebral, etc. Delay orimproper treatment will lead to disastrous consequences. Although some drugs havebeen proved effective in radiation therapy, it is hard to popularize their applicationdue to the strong toxic side effects. To find low toxicity and high efficiency ofradiation protective agent from the natural medicine has become the hot spot ofradiation research. This experiment is established on the deeper study of Si-Wu-Tang,by screening out the active ingredient—Ferulic acid (FA), and research on theanti-radiation effects of FA with modern biology techniques. We evaluate itsanti-radiation activity in vitro and in vivo through discussing the mechanism fromcellular level, molecular level and the overall level.Methods:Our research focused on the anti-radiation effects of FA by observing itsprotection to HUVECs, lymphocytes and mice after being radiated and discussing itsmechanism on cellular, molecular and over all level.Radiation causes peroxidative damage in human umbilical vascular endothelialcells (HUVECs). We detected the intracellular ROS and GSH content, and theexpression of NAPDH after radiation (10Gy). The influence of FA on expression ofantioxidant factors (glutamate-cysteine ligase catalytic subunit (GCLC),glutamate-cysteine ligase regulatory subunit (GCLM), NADPH quinoneoxidoreductase-1(NQO1) and heme oxygenase-1(HO-1)) was observed on bothprotein and genetic level by means of biological methods such as Western blot andRT-PCR. Meanwhile the signal pathway and molecular targets were also studied.Radiation induces inflammation in HUVECs, which will lead to vascularchanges. Anti-adhesion effect of FA was studied by taking adhesion between U937cells and HUVECs as the evaluation index after radiation(10Gy). We conductedthe research on its mechanism of anti-radiation by testing the changes of expression ofICAM-1(ICAM-1), VCAM-1(VCAM-1) with modern biological techniques.lymphocyte is extremely sensitive to radiation. The protection mechanism of FAwas tentatively analyzed by building the model of lymphocytes apoptosisi afterradiation(3Gy). The suppression effect to apoptosis of FA was tested quantitativelywith Hoechst33342and Annexin V-FITC-PI, the mitochondrial pathway of apoptosisand changes in the signal pathway of caspase family were investigated at the sametime.Low-dose radiation causes a series of changes to the hematopoietic function ofmouse. FA enhanced hematopoietic progenitor cell activity resulting in acceleratedblood cell recovery, and increased the levels of granulocyte-colony stimulating factorand erythropoietin.Results:1. FA significantly increased the transcription of antioxidant related genes suchas GCLC(glutamate-cysteine ligase catalytic subunit), GCLM(glutamate-cysteineligase regulatory subunit), NQO1(NADPH quinone oxidoreductase-1) and hemeoxygenase-1(HO-1) mRNA in radiated cells, and these are involved in a significantincrease the intracellular GSH content and the expression of NAPDH. FA evidentlypromoted Nrf2translocation into nuclei and increased the intracellular GSH andNADPH levels in radiated cells. Phosphatidylinositol3-kinase (PI3K) andextracellular signal regulated kinase (ERK) pathways were associated withFA-induced Nrf2activation.2. The result of cell adhesion assay showed FA inhibited radiation-induced U937adhesion to HUVECs. FA prevented induction of ICAM-1and VCAM-1expressionin a concentration-dependent manner after stimulation with radiation at the level ofmRNA and protein. The inhibitory effect of FA on adhesion molecules expression wasmediated by the blockade of JNK.3. Lymphocytes were pretreated for12h with FA and then exposed to3Gyradiation.FA significantly reversed apoptotic induced by radiation and attenuated the ROS generation. Furthermore, several anti-apoptotic characteristics of FA weredetermined, including the ability to diminish cytosolic Ca2+concentration, inhibitcaspase-3activation and cytochrome C translocation, upregulate B-cell lymphoma2(Bcl-2) and downregulate Bcl-2-associated X protein (Bax) in3Gy-irradiatedlymphocytes. signal pathway analysis showed FA decreased the activation ofextracellular regulated kinase (ERK), which had been activated by radiation.4. FA treatment enhanced hematopoietic progenitor cell activity resulting inaccelerated blood cell recovery. FA administration increased levels ofgranulocyte-colony stimulating factor (G-CSF) and erythropoietin.Conclusion:In brief, we verified the anti-radiation effect of FA in vivo and vitro. FA caninhibit the radiation-induced cell damage through increasing cell viability andsuppressing cell apoptosis. The anti-radiation mechanisms of FA including:①FAcan inhibit the peroxidative damage, regulate the expression of anti-oxidative genesand promote Nrf2translocation into nuclei, suggesting the mechanism may beinvolved in Nrf2-ARE mediated antioxidant action;②FA can inhibit adhesiondamage, decrease the expression of adhesion molecule, the results suggesting that theeffect of FA may be through regulateing AP-1activation by modulating JNK activity;③FA regulate the mitochondrial function and Bcl-2and Bax expression. FA depressJNK and ERK pathways but keep little influence on p38MAPK;④FA recover theperipheral blood cells and colony-forming cell assays, play a good anti-radiationeffect in vivo. FA might become a promising candidate for radio-protector.