title: Effects of baicalin on alveolar fluid clearance and α-ENaC expression in rats with LPS-induced acute lung injury.
abstract: Baicalin has been reported to attenuate lung edema in the process of lung injury. However, the effect of baicalin on alveolar fluid clearance (AFC) and epithelial sodium channel (ENaC) expression has not been tested. Sprague-Dawley rats were anesthetized and intratracheally injected with either 1 mg/kg lipopolysaccharide (LPS) or saline vehicle. Baicalin with various concentrations (10, 50, and 100 mg/kg) was injected intraperitoneally 30 min before administration of LPS. Then lungs were isolated for measurement of AFC, cyclic adenosine monophosphate (cAMP) level, and cellular localization of α-ENaC. Moreover, mouse alveolar type II (ATII) epithelial cell line was incubated with baicalin (30 μmol/L), adenylate cyclase inhibitor SQ22536 (10 μmol/L), or cAMP-dependent protein kinase inhibitor (PKA) KT5720 (0.3 μmol/L) 15 min before LPS (1 μg/mL) incubation. Protein expression of α-ENaC was detected by Western blot. Baicalin increased cAMP concentration and AFC in a dose-dependent manner in rats with LPS-induced acute lung injury. The increase of AFC induced by baicalin was associated with an increase in the abundance of α-ENaC protein. SQ22536 and KT5720 prevented the increase of α-ENaC expression caused by baicalin in vitro. These findings suggest that baicalin prevents LPS-induced reduction of AFC by upregulating α-ENaC protein expression, which is activated by stimulating cAMP/PKA signaling pathway.
authors.affiliation: a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Deng
authors.affiliation: b Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Dao-Xin
authors.initials: DX
authors.lastname: Wang
authors.affiliation: a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China.
authors.forename: Ai-Ling
authors.initials: AL
authors.lastname: Liang
authors.affiliation: a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China.
authors.forename: Da-Kai
authors.initials: DK
authors.lastname: Xiang
mesh_terms: D055371:Acute Lung Injury / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D000067956:Adenylyl Cyclase Inhibitors / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology; D053503:Epithelial Sodium Channels / Q000378:metabolism*; D005419:Flavonoids / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D015759:Ionomycin / Q000494:pharmacology; D008070:Lipopolysaccharides; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D051379:Mice; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D014867:Water / Q000378:metabolism
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D000894:Anti-Inflammatory Agents, Non-Steroidal; D002227:Carbazoles; D053503:Epithelial Sodium Channels; D005419:Flavonoids; D008070:Lipopolysaccharides; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D014867:Water; C038044:baicalin; D015759:Ionomycin; C057416:KT 5720; D000242:Cyclic AMP
keywords: acute lung injury; alveolar fluid clearance; baicalin; baicaline; canaux sodiques de la membrane apicale des cellules épithéliales; clairance du liquide alvéolaire; epithelial sodium channel; lésion pulmonaire aiguë