The Effect of Different Water Extracts from Platycodon grandiflorum on Selected Factors Associated with Pathogenesis of Chronic Bronchitis in Rats

The aim of this study was to assess the activity of extracts from Platycodon grandiflorum A. DC (PG) in a model of chronic bronchitis in rats. The research was carried out on three water extracts: E1 - from roots of field cultivated PG; E2 - from biotransformed roots of PG; E3 - from callus of PG. The extracts differed in saponins and inulin levels-the highest was measured in E3 and the lowest in E1. Identification of secondary metabolites was performed using two complementary LC-MS systems. Chronic bronchitis was induced by sodium metabisulfite (a source of SO₂). Animals were treated with extracts for three weeks (100 mg/kg, intragastrically) and endothelial growth factor (VEGF), transforming growth factors (TGF-β1, -β2, -β3), and mucin 5AC (MUC5AC) levels were determined in bronchoalveolar lavage fluid, whereas C reactive protein (CRP) level was measured in serum. Moreover, mRNA expression were assessed in bronchi and lungs. In SO₂-exposed rats, an elevation of the CRP, TGF-β1, TGF-β2, VEGF, and mucin was found, but the extracts' administration mostly reversed this phenomenon, leading to control values. The results showed a strong anti-inflammatory effect of the extracts from PG.

Keywords: Platycodon grandiflorum; bronchitis; cytokines; extracts; mRNA expression; saponins.