[Effect of different parts of Pinelliae Rhizoma Decoction against airway inflammation and analysis of effective components].

ABSTRACT

This study investigated the material basis and mechanism of Pinelliae Rhizoma Decoction in the treatment of airway inflammation. The cigarette smoke combined with lipopolysaccharide(LPS) was used to induce an airway inflammation model in mice. The expression levels of IL-6 and IL-8 in the bronchoalveolar lavage fluid(BALF) and the phosphorylation levels of p38 and IκB in the lungs of mice were taken as indexes to screen the effective extracts by system solvent extraction from Pinelliae Rhizoma Decoction(dichloromethane extract, ethyl acetate extract, n-butanol extract, etc.). Meanwhile, the human bronchial epithelial(16-HBE) cell model of cigarette smoke extract(CSE)-induced injury was established, and the mRNA expression levels of IL-6 and IL-8 and the phosphorylation levels of p38 and IκB proteins were also taken as indexes to evaluate the anti-inflammatory effect of different extracts of Pinelliae Rhizoma Decoction. The results showed that Pinelliae Rhizoma Decoction significantly antagonized airway inflammation in mice by down-regulating the expression levels of IL-6 and IL-8 in mice with airway inflammation and 16-HBE cells with CSE-induced injury and inhibiting the phosphorylation levels of p38 and IκB. The dichloromethane and ethyl acetate extracts of Pinelliae Rhizoma Decoction showed significant anti-inflammatory effects, while such effects of other extracts were not prominent. Furthermore, the database of Pinelliae Rhizoma composition was constructed, and the components in effective extracts were analyzed by HPLC-TOF-MS and Nano-LC-MS/MS. As revealed by the results, the compositions of the two effective extracts were similar with 36 common components. They were combined and then divided into Pinelliae Rhizoma alkaloids(PTAs) and Pinelliae Rhizoma non-alkaloids(PTNAs) by 732 cation-exchange resin. Further in vitro investigation confirmed the significant anti-inflammatory effect of PTNAs, while such effect of PTAs was not manifest. The MS analysis showed 172 peptides and 7 organic acids in PTNAs. The peptide content in PTNAs was 63.5% measured by quantitative analysis of BCA assay, and the organic acid content was 9.92% by potentiometric titration method. The findings of this study suggested that Pinelliae Rhizoma Decoction could antagonize airway inflammation in mice by inhibiting phosphorylation of p38 and IκB and blocking the activation of MAPK and NF-κB signaling pathways, and the effective components were related to the peptides and organic acids in PTNAs. The above results lay a foundation for the research on the mechanism and material basis of Pinelliae Rhizoma in antagonizing airway inflammation.