Studies On The Toxicological Effect Of Graphene Combined With Triphenyl Phosphate On Mussel Mytilus Galloprovincialis And Its Mechanism

In the natural environment,organisms are frequently exposed to complex mixtures of pollutants.These pollutants usually enter organisms simultaneously,which leads to joint toxicological effect.With excellent adsorption properties,graphene nanomaterials can interact with other pollutants when they are released into the environment,which may affect the environmental behavior of these pollutants.The molecule structure of triphenyl phosphate(TPP)contains three benzene rings,which leads to that TPP interact with graphene easily.With the mass demand and production of graphene and TPP,it is of great significance to study the joint toxicological effects of graphene and TPP,which will provide theoretical basis and data support for ecological risk assessment.In this study,electrochemical methods were used to study the effect of graphene and TPP on the cell membrane,and spectroscopic methods were used to study the interaction of graphene and TPP with the promoter region segment of p53 gene(p53-DNA).Techniques of tissue sections,antioxidant enzyme activities assay and real-time quantitative reverse transcription PCR(qRT-PCR)were applied to study the individual and combined toxicological effects of graphene and TPP on mussel Mytilus galloprovincialis.The main results were as follows:(1)Both graphene and TPP led to a significant decrease in the impedance of the gold electrode modified by the phospholipid bilayer membrane,indicating that both of them had a certain effect on the integrity of the biomembrane.With the combined effects of graphene and TPP,the damage of simulated biomembrane was increased,which showed a synergistic effect.(2)Graphene could be combined with p53-DNA through intercalation and groove action,which might change the conformation of p53-DNA and affect the stability of p53-DNA.TPP could be combined with p53-DNA through groove action,but the interaction force was weaker compared with graphene.Graphene and TPP had a synergistic effect when they existed simultaneously,and TPP might promote the combination of graphene and p53-DNA.(3)Graphene exposure caused slight damage to the gill and digestive gland tissues of mussel M.galloprovincialis,while TPP exposure did not cause significant damage.Both graphene and TPP induced oxidative stress in digestive gland tissues and had inhibitory effects on some antioxidant enzymes,while combined exposure reduced the oxidative stress,showing a certain antagonism.Both graphene and TPP could cause significant changes in expression of genes associated with immune response,stress response,cytoskeleton and signal transduction in digestive gland tissues of M.galloprovincialis,while combined exposure was antagonistic about gene expression.In addition,TPP exposure led to significant changes in the expression of genes associated with reproduction,indicating that TPP had a certain reproductive toxicity,while graphene exposure and joint exposure had no significant effect on it.(4)These above results showed that graphene and TPP mighy destroy and enter the cell membrane and interacted with DNA synergistically,but there was an antagonistic effect on the level of oxidative stress and gene expression when they enter mussel.