Luteolin Regulates the Differentiation of Regulatory T Cells and Activates IL-10-Dependent Macrophage Polarization against Acute Lung Injury

Figure 1

Treatment with luteolin reduces the severity of ALI. (a) Treatment with luteolin reduces the production of IL-1β, IL-6, IL-17A, and TNF-α in serum and BALF of CLP mice, thereby playing an anti-inflammatory role. IL-1β, IL-6, IL-17A, and TNF-α levels in serum and BALF of mice were measured using a mouse cytokine/chemokine magnetic bead panel kit. (b) Luteolin treatment alleviates lung injury in CLP-induced ALI mice. Lungs from each experimental group were stained with H&E and processed for histological examination. CLP-induced ALI mice exhibited obvious lung injury. The CLP+Lut group exhibited a significant reduction in the thickness of the alveolar wall, alveolar hemorrhage and collapse, and inflammatory cell infiltration relative to the CLP group. Lung injury in the CLP+Lut group was milder than that in the CLP group. (c, d) Luteolin reduced the proportion of MPO producing neutrophils and IL-17A protein levels in the lungs of CLP mice, thereby playing a protective role in ALI. Immunohistochemical staining for MPO and IL-17A was performed on paraffin-embedded, formalin-fixed lung tissue slices as described in Materials and Methods. (e) Luteolin alleviates pulmonary edema in the CLP-induced mouse model. Pulmonary edema was measured by the lung weight ratio. (f) Luteolin reduced the nuclear translocation of NF-κB (p65) and NF-κB (p65) phosphorylation activation in lungs of CLP mice. p65 protein levels were measured by western blotting. Each group , experiments are repeatable, and the most representative one was shown. Data of the column graphs are presented as . NS: not significant. , , , and by the one-way ANOVA followed by LSD multiple comparison test, compared between the control, CLP, and CLP+Lut groups.

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