Vitamin E isoform γ-tocotrienol alleviates cigarette smoke-induced chronic obstructive pulmonary disease

OBJECTIVE Cigarette smoke-induced chronic obstructive pulmonary disease(COPD)is a leading cause of death,where inflammation and oxidative stress are involved in the pathogenesis.Vitamin E isoformγ-tocotrienol possesses both anti-oxidative and anti-inflammatory properties.We hypothesized thatγ-tocotrienol may have protective effects against COPD.METHODS BALB/c mice were exposedto cigarette smoke daily for 2 weeks with oralγ-tocotrienol treatment in the second week.Bronchoalveolar lavage(BAL)fluid was assessed for total and differential cell counts,oxidative damage biomarkers,and cytokine levels.Lung tissues were examined for the expression of antioxidants and pro-inflammatory biomarkers.In order to measure changes in lung functions in COPD,another set of mice was exposed to cigarette smoke for 2 months with oralγ-tocotrienol treatment in the last 2 weeks.RESULTSγ-Tocotrienol dose-dependently abated cigarette smoke-induced elevation of BAL fluid total and neutrophil cell counts,cytokine and chemokine(IL-1β,IL-6,IL-17,LIX,G-CSF,KC,RANTES and VEGF)levels,as well as oxidative/nitrosative damage biomarker(advanced oxidation of protein products,8-isoprostane,8-hydroxy-2-deoxyguanosine and 3-nitrotyrosine)levels.γ-Tocotrienol promoted total lung antioxidant capacity and endogenous antioxidant activities of superoxide dismutase,catalase and glutathione peroxidase.More importantly,γ-tocotrienol markedly restored work of breathing and lung functions(total lung capacity,static compliance and FEV100/FVC)in chronic experimental COPD.Furthermore,γ-tocotrienol demonstrated better anti-oxidative,anti-inflammatory,and restoration of lung functions in COPD than prednisolone.CONCLUSION We have shown for the first time the efficacy of vitamin E isomerγ-tocotrienol in protection against cigarette smoke-induced COPD by direct neutralization of free radicals,abating oxidative damage,and restoring antioxidants activities,coupled with anti-inflammatory actions in the inflamed airways.

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.

Anti-malaria drug artesunate protects bronchial epithelium from DNA damage induced by asthma

OBJECTIVE To investigate the genome protective effects of anti-malaria drug,artesunate in an experimental allergic asthma model.METHODS Mice were sensitized on day 0 and 7 and challenged on day 14 with 100μg house dust mite(HDM)via intratracheal administration.Artesunate(30mg·kg-1)was administered intra-peritoneally on day 6,7,8,13,14 and 15.Samples were collected on day 1,3 and 5 post last HDM-challenge for analysis of air way inflammation and DNA damage.Lung sections were immunofluorescence(IF)-stained for DNA double strand breaks(DSBs)markers,γH2AX and 53BP1.Levels of DNA repair proteins Ku70 and Rad51,which are involved in non-homologous end joining(NHEJ)and homologous recombination(HR)DNA DSB repair pathways respectively,were measured.To quantify cell death in asthmatic lung,TUNEL staining was performed.Comet assay,a single cell gel electrophoresis was employed to detect DNA damage induced by HDM in BEAS-2Bhuman bronchial epithelial cell line,in vitro.RESULTS Artesunate treatment significantly reduces immune cells infiltration in BAL fluid of asthmatic mice,collected on day 3 and 5 post-challenge.Importantly,artesuante is able to protect bronchial epithelium from DNA DSBs induced by asthma,as detected by the reduced level of γH2AX and 53BP1 foci formation in the nucleus.This genome protective effect is evident even on day 1 post-challenge,when immune cells infiltration remained high.This indicates that artesunate confers protection on bronchial epithelium in the presence of inflammation.Additionally,artesunate is also able to reduce cell death in asthmatic lung revealed by TUNEL assay and cleaved caspase 3 level.Interestingly,the levels of DNA repair proteins in artesuante-treated asthmatic mice are unchanged as compared to HDM-only mice,suggesting that artesunate treatment does not augment the level of DNA repair proteins.When human bronchial epithelial BEAS-2 Bcells were exposed to HDMin vitro,we observed an increase in the levels of DNA damage.Artesunate(60μmol·L-1)co-incubated with HDM is not able to prevent direct DNA damage induced by the allergen.Together,these studies suggest that the genome protective effect of artesunate in vivo may be attributed to physiological effects(such as its anti-inflammatory effects)rather than serving to directly prevent DNA damage.CONCULSION This study highlights a novel role for artesunate in protecting bronchial epithelial cells from asthma-induced DNA damage.

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.