Study On Protective Effect Of Trollius Altaicus Extract Powder On Acute Lung Injury Induced By PM_2.5 In Rats

Objective:To study protective effect of Trollius Altaicus Extract Powder?TAEP?on acute lung injury induced by PM_2.5 in rats.Methods:1.The preliminary safety evaluation of TAEP was carried out using the limit method.Twenty SPF Kunming mice were selected,male and female,weighing 18-22 g,randomly divided into two groups,namely,solvent control group and TAEP group.TAEP was administered once at a dose of 0.35 ml/10 g at a dose of 10 g/kg.After administration,after administration,the toxicity of the animals within 14 days was observed and the death of each group of animals was counted.If there is no animal death during the observation period,it can be judged that the acute toxicity classification is safe and non-toxic;if the animal death occurs during the observation period,the koehler's method is selected to continue the TAEP safety evaluation.2.Sixty SD rats were randomly divided into normal control group,model group,model+TAEP low,medium and high dose groups and dexamethasone positive control group?2 mg/kg?,a total of 6 groups,10 in each group.Except for the normal control group and the model group,distilled water was administered by gavage,and the other groups were given the test substance for 30 days according to the corresponding dose?positive control group was administered for 29 days?.On the 30th day of the experiment,the positive control group was before the modeling.Dexamethasone?2 mg/kg?was given by intragastric administration for 1 hour.Except the normal control group,the other groups underwent tracheal instillation of PM2.5 suspension 14 mg/kg,causing acute lung injury in rats.After modeling for 3 hours,blood was taken from the abdominal aorta,whole blood was taken for white blood cell classification and counting,and serum was separated for detection of lactate dehydrogenase,superoxide dismutase,glutathione,malondialdehyde,nitric oxide,and interleukin-6.Contents of interleukin-1?and tumor necrosis factor-?;alveolar lavage was performed in the left lung of rats,and alveolar lavage fluid was collected to detect the content of interleukin-6,interleukin-1?and tumor necrosis factor-?;The upper right lobe of the rat was examined for histopathology,and the lung wet/dry weight ratio was calculated after weighing the lower lobe.Results:1.The initial safety evaluation period of TAEP was 14 days.After administration,the rats showed no symptoms of vomiting,lethargy and other poisoning,and there was no abnormality in weight gain.It was determined that the toxicity of TAEP was safe and non-toxic.2.Compared with the normal control group,the white blood cell count,lymphocyte count and neutrophil count in the model group were increased?P<0.01?,and the levels of IL-6,IL-1?and TNF-?in serum and BALF were increased.P<0.01),serum SOD and GSH levels decreased?P<0.01?,LDH,MDA,NO levels increased?P<0.01?,lung tissue W/D increased?P<0.01?;compared with the model group,The levels of IL-6,IL-1?and TNF-?in serum and BALF were decreased in the model+TAEP group?P<0.05 or P<0.01?,and the serum SOD and GSH levels were decreased.Elevated?P<0.05 or P<0.01?,LDH,MDA,NO decreased?P<0.05 or P<0.01?,lung tissue W/D decreased?P<0.05 or P<0.01?;model+TAEP high dose The detection indexes of the group were close to those of the dexamethasone group?P<0.05?.The pathological examination showed that the alveolar morphology and structure of the rats decreased with the increase of TAEP dose,and the edema and inflammatory cell infiltration decreased.The rats in the high dose group showed a small amount of inflammation.Cell infiltration,alveolar and bronchial tubes were structurally intact,similar to the dexamethasone positive control group.Conclusion:The acute toxicity of TAEP was classified as safe and non-toxic by preliminary safety evaluation.TAEP can play a better preventive and protective effect on PM2.5-induced acute lung injury in rats by scavenging free radicals,reducing lipid peroxidation and autoimmune regulation.