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Anti-malarial drug artesunate attenuates experimental allergic asthma via inhibition of the phosphoinositide 3-kinase/Akt pathway.

Cheng C, Ho WE, Goh FY, Guan SP, Kong LR, Lai WQ, Leung BP, Wong WS - PLoS ONE (2011)

Bottom Line: Anti-inflammatory effect of artesunate was further confirmed in a house dust mite mouse asthma model.Artesunate ameliorates experimental allergic airway inflammation probably via negative regulation of PI3K/Akt pathway and the downstream NF-κB activity.These findings provide a novel therapeutic value for artesunate in the treatment of allergic asthma.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore.

ABSTRACT

Background: Phosphoinositide 3-kinase (PI3K)/Akt pathway is linked to the development of asthma. Anti-malarial drug artesunate is a semi-synthetic derivative of artemisinin, the principal active component of a medicinal plant Artemisia annua, and has been shown to inhibit PI3K/Akt activity. We hypothesized that artesunate may attenuate allergic asthma via inhibition of the PI3K/Akt signaling pathway.

Methodology/principal findings: Female BALB/c mice sensitized and challenged with ovalbumin (OVA) developed airway inflammation. Bronchoalveolar lavage fluid was assessed for total and differential cell counts, and cytokine and chemokine levels. Lung tissues were examined for cell infiltration and mucus hypersecretion, and the expression of inflammatory biomarkers. Airway hyperresponsiveness was monitored by direct airway resistance analysis. Artesunate dose-dependently inhibited OVA-induced increases in total and eosinophil counts, IL-4, IL-5, IL-13 and eotaxin levels in bronchoalveolar lavage fluid. It attenuated OVA-induced lung tissue eosinophilia and airway mucus production, mRNA expression of E-selectin, IL-17, IL-33 and Muc5ac in lung tissues, and airway hyperresponsiveness to methacholine. In normal human bronchial epithelial cells, artesunate blocked epidermal growth factor-induced phosphorylation of Akt and its downstream substrates tuberin, p70S6 kinase and 4E-binding protein 1, and transactivation of NF-κB. Similarly, artesunate blocked the phosphorylation of Akt and its downstream substrates in lung tissues from OVA-challenged mice. Anti-inflammatory effect of artesunate was further confirmed in a house dust mite mouse asthma model.

Conclusion/significance: Artesunate ameliorates experimental allergic airway inflammation probably via negative regulation of PI3K/Akt pathway and the downstream NF-κB activity. These findings provide a novel therapeutic value for artesunate in the treatment of allergic asthma.

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Related in: MedlinePlus

Effects of artesunate on OVA-induced inflammatory gene expression, PI3K/Akt activation and NF-κB DNA-binding activity in allergic airway inflammation.(A) Lung tissues were collected 24 hours after the last OVA aerosol challenge. Total mRNA was extracted using TriZol reagent and the quantitative real time PCR was performed. All reactions were run in triplicate and three independent experiments for each target. The relative quantity of target gene expression was automatically normalized by GADPH as an internal control and values shown were the ratios of various treatments to saline group. (B) Immunoblotting of Akt, tuberin, p70S6K and 4E-BP1 in protein extracts of lung tissues isolated from mice 24 hours after the last saline aerosol or OVA aerosol challenge pretreated with either DMSO or 30 mg/kg artesunate. β-actin was used as an internal control. The experiments were repeated for three times (n = 3 mice) with similar pattern of results. (C) Nuclear p65 DNA-binding activity was determined using a TransAM™ p65 transcription factor ELISA kit. Values shown are the mean ± SEM of four separate experiments. *Significant difference from DMSO control, p<0.05.
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pone-0020932-g005: Effects of artesunate on OVA-induced inflammatory gene expression, PI3K/Akt activation and NF-κB DNA-binding activity in allergic airway inflammation.(A) Lung tissues were collected 24 hours after the last OVA aerosol challenge. Total mRNA was extracted using TriZol reagent and the quantitative real time PCR was performed. All reactions were run in triplicate and three independent experiments for each target. The relative quantity of target gene expression was automatically normalized by GADPH as an internal control and values shown were the ratios of various treatments to saline group. (B) Immunoblotting of Akt, tuberin, p70S6K and 4E-BP1 in protein extracts of lung tissues isolated from mice 24 hours after the last saline aerosol or OVA aerosol challenge pretreated with either DMSO or 30 mg/kg artesunate. β-actin was used as an internal control. The experiments were repeated for three times (n = 3 mice) with similar pattern of results. (C) Nuclear p65 DNA-binding activity was determined using a TransAM™ p65 transcription factor ELISA kit. Values shown are the mean ± SEM of four separate experiments. *Significant difference from DMSO control, p<0.05.

Mentions: OVA aerosol challenge markedly up-regulated lung mRNA level of Muc5ac, which is essential for mucus hypersecretion [25]; inducible nitric oxide synthase (iNOS), the enzyme responsible for nitric oxide (NO) production in allergic airway inflammation [26]; thymic stromal lymphopoietin (TSLP), a cytokine key to the initiation of Th2 immune response [27]; IL-17 and IL-33, two effector cytokines that have recently been shown essential for airway inflammation and remodeling [28], [29]; of chitinase family members including acidic mammalian chitinase (AMCase), Ym2 and YKL-40, which have recently been shown to play critical roles in airway inflammation and remodeling [30], [31], [32]; and of adhesion molecules such as ICAM-1, VCAM-1 and E-selectin, which are pivotal for pulmonary recruitment of inflammatory cells like eosinophils and lymphoctyes [7], [33]. Pretreatment with artesunate (30 mg/kg) demonstrated strong suppression of Muc5ac, iNOS, TSLP, IL-17, IL-33, AMCase, Ym-2, YKL-40, ICAM-1, VCAM-1 and E-selectin, in the allergic airways (Figure 5A).


Anti-malarial drug artesunate attenuates experimental allergic asthma via inhibition of the phosphoinositide 3-kinase/Akt pathway.

Cheng C, Ho WE, Goh FY, Guan SP, Kong LR, Lai WQ, Leung BP, Wong WS - PLoS ONE (2011)

Effects of artesunate on OVA-induced inflammatory gene expression, PI3K/Akt activation and NF-κB DNA-binding activity in allergic airway inflammation.(A) Lung tissues were collected 24 hours after the last OVA aerosol challenge. Total mRNA was extracted using TriZol reagent and the quantitative real time PCR was performed. All reactions were run in triplicate and three independent experiments for each target. The relative quantity of target gene expression was automatically normalized by GADPH as an internal control and values shown were the ratios of various treatments to saline group. (B) Immunoblotting of Akt, tuberin, p70S6K and 4E-BP1 in protein extracts of lung tissues isolated from mice 24 hours after the last saline aerosol or OVA aerosol challenge pretreated with either DMSO or 30 mg/kg artesunate. β-actin was used as an internal control. The experiments were repeated for three times (n = 3 mice) with similar pattern of results. (C) Nuclear p65 DNA-binding activity was determined using a TransAM™ p65 transcription factor ELISA kit. Values shown are the mean ± SEM of four separate experiments. *Significant difference from DMSO control, p<0.05.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3111464&req=5

pone-0020932-g005: Effects of artesunate on OVA-induced inflammatory gene expression, PI3K/Akt activation and NF-κB DNA-binding activity in allergic airway inflammation.(A) Lung tissues were collected 24 hours after the last OVA aerosol challenge. Total mRNA was extracted using TriZol reagent and the quantitative real time PCR was performed. All reactions were run in triplicate and three independent experiments for each target. The relative quantity of target gene expression was automatically normalized by GADPH as an internal control and values shown were the ratios of various treatments to saline group. (B) Immunoblotting of Akt, tuberin, p70S6K and 4E-BP1 in protein extracts of lung tissues isolated from mice 24 hours after the last saline aerosol or OVA aerosol challenge pretreated with either DMSO or 30 mg/kg artesunate. β-actin was used as an internal control. The experiments were repeated for three times (n = 3 mice) with similar pattern of results. (C) Nuclear p65 DNA-binding activity was determined using a TransAM™ p65 transcription factor ELISA kit. Values shown are the mean ± SEM of four separate experiments. *Significant difference from DMSO control, p<0.05.
Mentions: OVA aerosol challenge markedly up-regulated lung mRNA level of Muc5ac, which is essential for mucus hypersecretion [25]; inducible nitric oxide synthase (iNOS), the enzyme responsible for nitric oxide (NO) production in allergic airway inflammation [26]; thymic stromal lymphopoietin (TSLP), a cytokine key to the initiation of Th2 immune response [27]; IL-17 and IL-33, two effector cytokines that have recently been shown essential for airway inflammation and remodeling [28], [29]; of chitinase family members including acidic mammalian chitinase (AMCase), Ym2 and YKL-40, which have recently been shown to play critical roles in airway inflammation and remodeling [30], [31], [32]; and of adhesion molecules such as ICAM-1, VCAM-1 and E-selectin, which are pivotal for pulmonary recruitment of inflammatory cells like eosinophils and lymphoctyes [7], [33]. Pretreatment with artesunate (30 mg/kg) demonstrated strong suppression of Muc5ac, iNOS, TSLP, IL-17, IL-33, AMCase, Ym-2, YKL-40, ICAM-1, VCAM-1 and E-selectin, in the allergic airways (Figure 5A).

Bottom Line: Anti-inflammatory effect of artesunate was further confirmed in a house dust mite mouse asthma model.Artesunate ameliorates experimental allergic airway inflammation probably via negative regulation of PI3K/Akt pathway and the downstream NF-κB activity.These findings provide a novel therapeutic value for artesunate in the treatment of allergic asthma.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore.

ABSTRACT

Background: Phosphoinositide 3-kinase (PI3K)/Akt pathway is linked to the development of asthma. Anti-malarial drug artesunate is a semi-synthetic derivative of artemisinin, the principal active component of a medicinal plant Artemisia annua, and has been shown to inhibit PI3K/Akt activity. We hypothesized that artesunate may attenuate allergic asthma via inhibition of the PI3K/Akt signaling pathway.

Methodology/principal findings: Female BALB/c mice sensitized and challenged with ovalbumin (OVA) developed airway inflammation. Bronchoalveolar lavage fluid was assessed for total and differential cell counts, and cytokine and chemokine levels. Lung tissues were examined for cell infiltration and mucus hypersecretion, and the expression of inflammatory biomarkers. Airway hyperresponsiveness was monitored by direct airway resistance analysis. Artesunate dose-dependently inhibited OVA-induced increases in total and eosinophil counts, IL-4, IL-5, IL-13 and eotaxin levels in bronchoalveolar lavage fluid. It attenuated OVA-induced lung tissue eosinophilia and airway mucus production, mRNA expression of E-selectin, IL-17, IL-33 and Muc5ac in lung tissues, and airway hyperresponsiveness to methacholine. In normal human bronchial epithelial cells, artesunate blocked epidermal growth factor-induced phosphorylation of Akt and its downstream substrates tuberin, p70S6 kinase and 4E-binding protein 1, and transactivation of NF-κB. Similarly, artesunate blocked the phosphorylation of Akt and its downstream substrates in lung tissues from OVA-challenged mice. Anti-inflammatory effect of artesunate was further confirmed in a house dust mite mouse asthma model.

Conclusion/significance: Artesunate ameliorates experimental allergic airway inflammation probably via negative regulation of PI3K/Akt pathway and the downstream NF-κB activity. These findings provide a novel therapeutic value for artesunate in the treatment of allergic asthma.

Show MeSH
Related in: MedlinePlus