Influence of astragaloside on aquaporin 5 in rats with acute lung injury

OBJECTIVE To observe astragaloside(AS) intervention on aquaporin 5 in rats with acute lung injury and to explore its possible mechanism.METHODS SPF level 63 male SD rats were randomly divided into 3 groups:ALI group,NS group and astragaloside group(AS group),with 21 rats in each group respectively.Each rat in ALI group was treated with normal saline 0.2 mL·d-1 orally for 7 days;in NS group,the normal saline 0.2 mL·d-1 orally;and in AS group,4.5% astragaloside(0.6 mg·kg-1·d-1,the concentration of 4.5 mg·mL-1) pretreatment.ALI group and AS group were given with LPS(4 mg·kg-1,concentration 4 mg·mL-1) by sublingual intravenous injection;NS group by sublingual intravenous injection of normal saline 0.2 mL.After injection,dynamic observations were done on the change of wet-dry weight(W/D),histo-pathological changes in lung tissue,bronchoalveolar lavage fluid(BALF) total cells and percentage of neutrophils,immunohistochemical and Western blot method lung tissue AQP5 protein after 2,6 h,and 12 h.RESULTS Compared with the NS group,in ALI group the W/D values,BALF total cells and neutrophil percentage 2 h after sublingual intravenous injection of LPS began to increase,and reached the peak at the 6th hour and the 12th hour;lung tissue AQP5 protein expression decreased 2 hours after sublingual intravenous injection of LPS was given;and at the 6th hour and the 12th hour reduced significantly.The differences between ALI group and NS group at all time points were statistically significant(P0.05).In AS group at different time points the increases in W/D values,BALF total cells and neutrophil percentage were lowered than in ALI group,AQP5 expression in AS group were higher than that in ALI group,with the 6th hour and the 12th hour the most obvious,and they were statistical significance(P0.05).CONCLUSION Astragaloside could ameliorate the LPS-induced acute lung injury inflammatory response,its mechanism may relate to the up-regulation of AQP5 expression.