Study On The Protective Effects And Mechanism Of Selenium On Cadmium-induced Neuron Damage

Heavy metal cadmium is a natural element in the earth's crust,and it is widely used in industry,which eventually lead to environmental,biological and food pollution.For the general population,diet is the main source of exposure to cadmium.Occupational exposure to cadmium mainly occurs through inhalation,and may also be accidentally ingested through contaminated hands and food.Cadmium is a highly toxic metal and is harmful to various tissues and organs.Cadmium is accumulated in the central nervous system,which leads to neuron damage,but few studies are about its intervention and possible mechanisms.Selenium is an essential trace element for the human.Selenium is also the core metal ion of thioredoxin reductase 1.Thioredoxin reductase 1 is an important component of the thioredoxin system and plays an important role in redox in the body.Selenium can maintain normal physiological functions in the body through selenoproteins,and participate in the regulation of oxidative stress and neuron protection.At present,selenium is considered to be an antioxidant in clinic,and it can be antioxidative by mediating thioredoxin reductase 1.Thus,it is widely used as a complementary treatment in many diseases.This project aimed to clarify the role and mechanism of selenium on cadmium-induced neuron damage in vitro.It was divided into two parts.The first part was to clarify the role and mechanism of cadmium in the central nervous system.The human neuroblastoma cell line SH-SY5 Y was selected for the research,and was treated with cadmium chloride in different concentration and time.Then,the cell morphology and vitality,reactive oxygen species content,and the level of thioredoxin reductase 1 were detected.The results showed that cadmium increased reactive oxygen species by down-regulating the level of thioredoxin reductase 1,causing cell damage.The second part was to explore the effect and possible mechanism of selenium on cadmium toxicity.We constructed a cadmium-induced SH-SY5 Y cell model,and added sodium selenite.Then,we detected the cell vitality and morphology by MTT and imaging,and further measured reactive oxygen species content,the level of thioredoxin reductase 1,while using flow cytometry to detect neuron apoptosis.The results clarified that selenium had a protective effect on cadmium-induced neuron damage and increased the level of thioredoxin reductase 1,reduced reactive oxygen species and inhibited neuron apoptosis.This study verified the the new mechanism of cadmium-induced neuron damage,clarified the role and mechanism of selenium on cadmium-induced neuron damage,provided new ideas for the role and prevention of cadmium toxicity,and provided a new theoretical basis for the antioxidation of selenium.