Effect Of Emodin On Inflammatory Response And Expression Of P38MAPK In Lung Tissue Of Streptococcus Pneumoniae Pneumonia Mice

objective:To investigate the effects of emodin on lung inflammation and expression of mitogen-activated protein kinase p38?p38MAPK?in Streptococcus pneumoniae pneumonia mice.Methods:Thirty-two female BALB/c mice were divided into control,pneumonia model,emodin,and cefuroxime groups.All mice were anesthetized with 5%chloral hydrate 5 ul/g intraperitoneally.After anaesthesia in mice of the pneumonia model group,emodin group,and cefuroxime group,these its nasal mucosa was pierced with a sterile needle,and a 0.5 Maxwell unit of bacterial suspension was slowly instilled into the rat nasal cavity?50 uL?.The control group mice,instead of normal saline.Pre-experimentation confirmed that the model was successfully established.Then,the emodin group was treated with emodin 25mg·kg^-1·d^-1,and the cefuroxime group was treated with cefuroxime 50mg·kg^-1·d^-1,once a day,7 days in total.The control group andmodel group was given the same mount of normal saline instead.After the last gavage,opened the chest of the mouse and taked the lung tissue.The left lung was used for HE staining.The right lung was assayed for interleukin-1??IL-1??,interleukin-6?IL-6?,tumor necrosis factor-a?TNF-??and mitogen-activated protein kinase p38?p38MAPK?.Results:1.Behavioral observation of mice:The control group mice had good mental appetite,slightly increased body weight and occasional cough after 50 UL nasal drip with saline,but no irritability,faster respiratory rate,nasal runny nose,sneezing,lip mucosa cyanosis and fecal incontinence.After 50 UL nasal drip with Streptococcus pneumoniae suspension,the mice in the model group had poor appetite,dirty hair,less movement,weight loss,restlessness,running away in the cage,rapid breathing,slightly cyanosis of lip mucosa,occasional nasal runny,sneezing and fecal incontinence.While in emodin group and in cefuroxime group,the behavioral observation of mice is between the above two.2.Emodin alleviates lung pathological changes in Streptococcus pneumoniae pneumonia mice:In the control group,the alveolar structure was intact,and there was no obvious inflammatory cell infiltration in the alveolar septum.A large number of inflammatory cells infiltrated in the model group,and the inflammatory cell infiltration of the emodin group and the cefuroxime group was between the above two.3.Emodin decreases the contents of interleukin-1??IL-1??,interleukin-6?IL-6?and tumor necrosis factor-a?TNF-??in lung tissue of Streptococcus pneumoniae pneumonia mice:Compared with the control group,the contents of interleukin-1??IL-1??,interleukin-6?IL-6?,tumor necrosis factor-a?TNF-??in lung tissue of mice were increased significantly in model group,emodin group and cefuroxime group?P<0.05?.While compared with model group,the contents of interleukin-1??IL-1??,interleukin-6?IL-6?and tumor necrosis factor-??TNF-??in lung tissue of mice were decreased significantly in emodin group and cefuroxime group content?P<0.05?.3.Emodin decreases the expression of mitogen-activated protein kinase p38?p38MAPK?gene in lung tissue of Streptococcus pneumoniae pneumonia mice:Compared with the control group,the expression levels of p38MAPK gene were higher in model group,emodin group and cefuroxime group?P<0.05?.While compared with model group,the expression levels of pP38MAPK gene were lower in emodin group and cefuroxime group?P<0.05?.5.Emodin decreases the expression of mitogen-activated protein kinase p38?p38MAPK?protein in lung tissue of Streptococcus pneumoniae pneumonia mice:Compared with the control group,the expression levels of p38MAPK protein were higher in model group,emodin group and cefuroxime group?P<0.05?.While compared with model group,the expression levels of p38MAPK protein were lower in emodin group and cefuroxime group?P<0.05?.Conclusion:1.Intranasal drip of 50 UL?0.5 McFahrenheit unit?of Streptococcus pneumoniae suspension can induce the formation of Streptococcus pneumoniae pneumonia model in mice,increase the contents of interleukin-1??IL-1??,interleukin-6?IL-6?,tumor necrosis factor-??TNF-??in lung tissue of mice,and up-regulate the expression of mitogen-activated protein kinase p38?p38MAPK?gene and protein in lung tissue of mice.2.Emodin can reduce the contents of interleukin-1??IL-1??,interleukin-6?IL-6?,tumor necrosis factor-??TNF-??in lung tissue of Streptococcus pneumoniae pneumonia mice,and down-regulate the expression of mitogen-activated protein kinase p38?p38MAPK?gene and protein,so as to alleviate the inflammatory reaction in lung tissue of Streptococcus pneumoniae pneumonia mice.