Curcumin alleviates macrophage activation and lung inflammation induced by influenza virus infection through inhibiting the NF-κB signaling pathway.

Yiming Xu,Ling Liu

doi:10.1111/irv.12459

Abstract

BackgroundInfluenza A viruses (IAV) result in severe public health problems with worldwide each year. Overresponse of immune system to IAV infection leads to complications, and ultimately causing morbidity and mortality.ObjectiveCurcumin has been reported to have anti‐inflammatory ability. However, its molecular mechanism in immune responses remains unclear.MethodsWe detected the pro‐inflammatory cytokine secretion and nuclear factor kappa‐light‐chain‐enhancer of activated B cell (NF‐κB)‐related protein expression in human macrophages or mice infected by IAV with or without curcumin treatment.ResultsWe found that the IAV infection caused a dramatic enhancement of pro‐inflammatory cytokine productions of human macrophages and mice immune cells. However, curcumin treatment after IAV infection downregulated these cytokines production in a dose‐dependent manner. Moreover, the NF‐κB has been activated in human macrophages after IAV infection, while administration of curcumin inhibited NF‐κB signaling pathway via promoting the expression of nuclear factor of kappa light polypeptide gene enhancer in B‐cells inhibitor, alpha (IκBα), and inhibiting the translocation of p65 from cytoplasm to nucleus.ConclusionsIn summary, IAV infection could result in the inflammatory responses of immune cells, especially macrophages. Curcumin has the therapeutic potentials to relieve these inflammatory responses through inhibiting the NF‐κB signaling pathway.

Highlights

Influenza A viruses (IAV) cause severe public health problems with worldwide each year, among which the acute respiratory distress syndrome (ARDS) or acute lung injury (ALI) result in the majority of influenza pneumonia associated death.[1,2] It is recorded that in 1918, approximately 50 million people lose their lives worldwide because of reoccurring pandemics.[3]
To further investigate the mechanisms involved in curcumin-regulated cytokine production of IAV-infected macrophages, we conducted Western blotting to detect the expression of associated proteins upon IAV infection and curcumin treatment
Our results demonstrated that upon IAV infection, macrophages might be activated to secret inflammatory cytokines through activation of NF-κB signaling pathway, while the antivirus ability of curcumin might depend on inhibition of NF-κB in macrophages

Summary

Background

Influenza A viruses (IAV) result in severe public health problems with worldwide each year. Methods: We detected the pro-inflammatory cytokine secretion and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB)-related protein expression in human macrophages or mice infected by IAV with or without curcumin treatment. Results: We found that the IAV infection caused a dramatic enhancement of pro- inflammatory cytokine productions of human macrophages and mice immune cells. The NF-κB has been activated in human macrophages after IAV infection, while administration of curcumin inhibited NF-κB signaling pathway via promoting the expression of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα), and inhibiting the translocation of p65 from cytoplasm to nucleus. Conclusions: In summary, IAV infection could result in the inflammatory responses of immune cells, especially macrophages. KEYWORDS acute lung injury, curcumin, inflammation, Influenza A viruses (IAV), nuclear factor kappa-lightchain-enhancer of activated B cells (NF-κB)

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