Study On Acute Toxicity And Subchronic Nephrotoxicity Of Aristolochic Acid A In Tianfu Broiler

Aristolochic acid（AA）is a common effective component in traditional Chinese medicine,but it has strong toxicity,which makes some traditional Chinese medicine can not be predicted when it is used in poultry breeding industry,and harms poultry breeding industry.Kidney is the target organ of AA damage.However,the toxic mechanism of aristolochic acid to poultry is still unclear.Therefore,the acute toxicity of aristolochic acid A to Tianfu broilers was studied by intraperitoneal injection of different concentrations of aristolochic acid A.Then the LD₅₀of aristolochic acid A to Tianfu broiler was calculated according to the modified Coriolis method.The subchronic toxicity test was carried out in combination with LD₅₀.To determine whether aristolochic acid a can damage the kidney of Tianfu broiler by gross anatomy,renal function and histopathology.Finally,from the perspective of oxidative stress,apoptosis and cell cycle,ROS,apoptosis rate,JC-1 and cell cycle in broiler kidney were examined by flow cytometry,and the related genes were quantified by fluorescence.The mechanism of aristolochic acid A on the subchronic renal toxicity of Tianfu broiler was explored.The results are as follows:（1）Aristolochic acid A can make Tianfu broiler acute poisoning,and after poisoning,the broiler has symptoms of shortness of breath,decreased intake and drinking water,and death.After the broiler died,it was found that there were obvious bleeding points in the kidney,and the kidney became swollen,felt tense and glossiness decreased.Histopathological examination showed that the renal tubular cells in each group had different degrees of damage.Observe and record the test for 14 days.The LD₅₀of aristolochic acid A to Tianfu broiler was 14.52 mg/kg.（2）40 Tianfu broilers were randomly divided into three groups:low dose group(1/100 LD₅₀),medium dose group(1/50 LD₅₀)and high dose group(1/10 LD₅₀).Another group was the blank control group.The subchronic toxicity of aristolochic acid A to Tianfu broilers was tested for 28 days.It was found that kidney swelling and kidney index increased in aristolochic acid a broilers.The results of histopathological examination showed that the renal tissue of broilers in the low,middle and high dose groups had different degrees of pathological changes.The epithelial cells of renal tubules in the high dose group were swollen and denatured,and some areas were necrotic,and the lumen disappeared.The results of biochemical tests showed that the levels of creatinine（CRE）and blood urea nitrogen（BUN）were significantly increased in the high dose group,the activities of superoxide dismutase（SOD）and reduced glutathione（GSH）were significantly decreased in the high dose group,and the content of malondialdehyde（MDA）was increased in the high dose group.（3）The results of flow cytometry showed that ROS,apoptosis rate,JC-1 and S phase cells increased significantly in broiler kidney.Through real-time fluorescence quantitative PCR to detect the m RNA content of antioxidant and apoptosis related genes in renal tissue,we found that the relative expression of antioxidant genes HO-1,NQO1 and Raf-1,which regulate cell proliferation and differentiation,decreased significantly.The relative expression of Bcl-2 decreased significantly and Bax and caspase-3 increased significantly.In conclusion,aristolochic acid a can cause acute and sub chronic poisoning to Tianfu broilers.The mechanism of sub chronic renal toxicity of aristolochic acid A to Tianfu broiler is as follows:Aristolochic acid A can break the normal redox balance of Tianfu broiler,inhibit the expression of NQO1 and HO-1,destroy the antioxidant system,and induce oxidative stress injury of kidney.At the same time,the expression of Raf-1 was inhibited,and the renal cells were blocked from S phase to G2/M phase.It can promote the expression of Bax and Caspase-3,inhibit the expression of Bcl-2,induce apoptosis of renal cells,and finally induce renal injury.