Andrographolide restores steroid sensitivity to block LPS/IFNγ-induced IL-27 and airway hyper-responsiveness in mice

OBJECTIVE Steroid-resistant airway hyper-responsiveness(AHR)has been proposed to be related to the activation of innate host defense pathways such as those induced by LPS,IFN-γ,and LPS/IFN-γ-stimulated essential mediator IL-27.We investigated whether andrographolide,apreviously demonstrated anti-inflammatory bioactive molecule extracted from the plant Andrographis paniculata,could restore steroid sensitivity to block LPS/IFN-γ-induced IL-27 production and AHR viaits anti-oxidative property.METHODS Mouse macrophage cell line Raw264.7,mouse primary pulmonary monocyte/macrophage,and BALB/c mouse were treated with LPS/IFN-γ,in the presence and absence of increasing doses of dexamethasone and/or andrographolide.mRNA and protein levels of IL-27 in vitro and in vivo were examined,and mouse AHR was assessed.RESULTS Dexamethasone alone failed to inhibit LPS/IFN-γ-induced IL-27 and AHR in mice.Andrographolide significantly facilitated the suppressive effect of dexamethasone on LPS/IFN-γ-induced IL-27 level in macrophage cell line and primary monocyte/macrophage,mouse bronchoalveolar lavage fluid and lung tissue,and furthermore on the incurring AHR.LPS/IFN-γdid not impede nuclear translocation of glucocorticoid receptors but diminishthe protein level of histone deacetylase-2(HDAC2),an essential epigenetic enzymeresponsible for steroid anti-inflammatory action.Andrographolide at low doses(5μmol·L-1 in vitro;1mg·kg-1,ip in vivo)restored nuclear HDAC2 protein levels both in cells and in mouse lungs,possibly via suppression of PI3K/Akt signaling pathway and up-regulation of the anti-oxidative transcription factor Nrf-2level.CONCLUSION Our data suggest that andrographolide may resensitize steroid action on blocking LPS/IFN-γ-induced IL-27 and resultant AHR by restoring HDAC2 level.

Non-typeable haemophilus influenzae-induced exacerbation on a cigarette smoke lung injury model:Protective effect of andrographolide

OBJECTIVE To develop a 2-week cigarette smoke(CS)acute lung injury model exacerbated by haemophilus influenzae(NTHi)and study the protective effect of andrographolide in this COPD model.METHODS Female BALB/c mice,6-8-week-old,were exposed to 4% 3R4 FCS delivered using aperistaltic pump daily for 2 weeks to induce an acute lung injury model.After 2 weeks of smoking,mice were inoculated intratracheally with NTHi to induce exacerbation on the model.Mice were sacrificed 48 h after last bacteria challenge and lung samples were collected for various analyses.RESULTS After developing a 2-week CS acute lung injury model exacerbated by NTHi,the CS+NTHi group was shown to have a higher inflammatory response,higher bacterial clearance,an upregulation of MMP12 mRNA levels and decrease in TIMP1 mRNA levels in the lungs.Administration of Andrographolide suppressed BALF lung cellular infiltrates,TNF-α,CXCL1/KC,IL-1βand 8-OHdG protein levels,together with increased HO-1 and GR mRNA levels and decreased MMP-8 and MMP-9 mRNA levels.Andrographolide was able to ameliorate lung histopathology as observed with H&E staining and inflammation scoring.Andrographolide was also shown to reduce Keap-1 level in lungs without affecting DJ-1 level.CONCLUSION This study demonstrates the protective effect of andrographolide in a novel 2-week CS acute lung injury model exacerbated by NTHi and presents it as a potential therapeutic for COPD.