Protective effect mechanism of artesunate on rat kidney with purpuric nephritis through IL-6/ STAT3 signaling pathway

Objective To explore the protective effect mechanism of artesunate on rat kidney with Henoch Schonlein purpuric nephritis（HSPN）through the signaling pathway of interleukin（IL）-6/ signal transducer and activator of transcription 3（STAT3）. Methods After an induction of HSPN， Sprague-Dawley（SD）rats were randomized into four groups of model with random number table methods，low-dose artesunate（15 mg/kg），high-dose artesunate（30 mg/kg）and artesunate（30 mg/kg） plus colivelin（IL-6/STAT3 signaling activator，1 mg/kg）（n=12 each）. Another 12 SD rats were selected as control group. Renal function parameters，pathological morphology of renal tissue，deposition of IgA，serum levels of immunoglobulin A（IgA），circulating immune complex（CIC），IL-18 and IL-6 and the expressions of IL-6/STAT3 pathway-related proteins in renal tissue were recorded. Results As compared with control group，renal tissue of rats in model group manifested severe pathological injuries of obvious hyperplasia of mesangium and basement membrane of glomerulus，glomerular sclerosis，swelling of renal tubules，and a large number of inflammatory cells infiltration，serum levels of（creatinine， Cr），（blood urea nitrogen，BUN），24-hour urine protein，IgA，CIC，IL-18 and IL-6，renal tissue IgA mean fluorescent intensity，protein expression levels of p-STAT3/STAT3 and IL-6 spiked markedly（P<0. 05）；as compared with model group，pathological injury of renal tissue lessoned in low/high-dose artesunate group. serum levels of Cr，BUN，24-hour urine protein，IgA，CIC，IL-18 and IL-6，renal tissue IgA mean fluorescent intensity，protein expression levels of p-STAT3/STAT3 and IL-6 declined（P<0. 05）；high-dose artesunate had more potent effect；as compared with high-dose artesunate group，renal tissue pathological injury worsened in artesunate+colivelin group. Serum levels of Cr and BUN，24-hour urine protein，IgA，CIC，IL-18 and IL-6，renal tissue IgA mean fluorescent intensity and protein expression levels of p-STAT3/STAT3 and IL-6 increased（P<0. 05）. Conclusion Through suppressing the activation of IL-6/STAT3 signaling，artesunate may reduce inflammation，lower the deposition of IgA，alleviate renal injury and exert renal protection in HSPN rats.