Fig. 3

H&E staining of lung tissue in each group. A ×100; B ×400. (a₁, b₁) Control group, normal lung morphology: thin lined interalveolar septa with well-organized alveolar space. (a₂, b₂) Exposure group, distorted lung morphologies: collapsed alveolar space with inflammatory exudates, wider and thickened interalveolar septa, initial formation of silicon nodules. (a₃, b₃) Vehicle group, similar to exposure group. (a₄, b₄) Treatment group, ameliorative lung morphology: lessoned collapsed alveolar space with inflammatory exudate, less widened and thickened alveolar septum, reduced pronounced nodules of silicon. Arrows point out pathological changes of lung tissue