Synergistic Enhancement of Isoforskolin and Dexamethasone Against Sepsis and Acute Lung Injury Mouse Models

Yan Fang,1,2,* Chuang Xiao,1,* Lueli Wang,1,* Youlan Wang,3 Jun Zeng,1 Yaping Liang,1 Rong Huang,1 Yunke Shi,2 Sha Wu,1 Xiaohua Du,2 Shibo Sun,2 Min Li,2 Yuanyuan Zheng,2 Hongxiang Wu,1 Qiuzhe Guo,4 Weimin Yang1 1School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming, People’s Republic of China; 2The First Affiliated Hospital of Kunming Medical University, Kunming, People’s Republic of China; 3Kunming Institute of Medical Sciences, Kunming, People’s Republic of China; 4Fuwai Yunnan Cardiovascular Hospital, Kunming, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiuzhe Guo; Weimin Yang, Email drguoqz@163.com; ywmbessie@yeah.netBackground: Sepsis is initiated by the dysfunctional response of the host immune system to infection. Septic shock and acute lung injury (ALI) are the main etiology of death caused by sepsis. Glucocorticoids, which are commonly used in clinic to antagonize the inflammatory response of sepsis, may cause serious side effects. Isoforskolin (ISOF) from the plant Coleus forskohlii stimulates adenylyl cyclase, increases the cAMP level and inhibits inflammatory response. The aim of this study was to investigate the synergistic effect of ISOF with dexamethasone (DEX) to prevent and ameliorate septic inflammation.Methods: Lipopolysaccharide (LPS) of 30 and 5 mg/kg (iv.) was used to induce sepsis and ALI mice model respectively in vivo. BEAS-2B cells stimulated by LPS were applied as cell model in vitro. The cumulative survival of mice with LPS-induced sepsis and the histopathological changes of lungs in mice with acute lung injury were observed, and the secretion of pro-inflammatory cytokines was analyzed by ELISA. The expression of RGS2 in BEAS-2B cells was detected by immunoblotting assay and PCR.Results: In the sepsis mice model, ISOF (10 mg/kg) combined with DEX (10 mg/kg.) (ip.) pretreatme