ObjectiveTo investigate the effect of the Buyang Huanwutang （BHT）-containing serum on the bleomycin-induced senescence of A549 cells and explore the potential mechanism by which BHT ameliorates pulmonary fibrosis. MethodsA549 cells were cultured in vitro and modeled for senescence through the application of bleomycin. SD rats were administrated with BHT by gavage for the preparation of BHT-containing serum， and the effect of BHT-containing serum on the viability of the cell model was studied through a cell experiment designed with the following groups： blank group， model group， 2.5%， 5%， and 10% BHT-containing serumgroups. The effect of BHT-containing serum on the BLM-induced senescence of A549 cells was studied by the experiment designed with blank group， model group， positive group （PC，pirfenidone，600 mg·L^-1）， 2.5%， 5%， 10% BHT-containing serum groups. SA-β-Gal staining was used to reveal the area of senescence-positive cells， and flow cytometry was employed to analyze the cell cycle distribution. Real-time PCR and the immunofluorescence assay were adopted to determine the mRNA and protein levels of cell senescence markers p16 and p21. Western blot was employed to quantify the protein levels of senescence-associated secretory phenotype （SASP） molecules interleukin （IL）-1β， IL-6， matrix metalloproteinase （MMP）-3， chemokine ligand （CCL）2， tumor necrosis factor （TNF）-α， and transforming growth factor-β （TGF-β）/Smad pathway molecules TGF-β₁， Smad2， phosphorylated （p）-Smad2， Smad3， and p-Smad3. ResultsCompared with the blank group， the model group showed a decrease in cell survival rate （P<0.01）， increases in the SA-β-Gal-positive area， the proportion of cells in G₀/G₁ phase， the mRNA and protein levels of P16 and P21， and the protein levels of IL-1β， IL-6， TNF-α， MMP-3， CCL2， TGF-β₁， p-Smad2， and p-Smad3 （P<0.05，P<0.01）. Compared with the model group， the BHT-containing serum at each dose increased the cell survival rate （P<0.01） and decreased the SA-β-Gal-positive area， the proportion of cells in G₀/G₁ phase， the mRNA and protein levels of p16 and p21， and the protein levels of IL-1β， IL-6， TNF-α， MMP-3， and CCL2 （P<0.05， P<0.01）. Moreover， the inhibitory effect of BHT-containing serum on cell senescence showed a dose-dependent manner， with the 10% BHT-containing serum showing the most obvious effects and inhibiting the expression of TGF-β₁， p-Smad2， and p-Smad3 （P<0.01）. The effect of 10% BHT-containing serum was comparable to that of pirfenidone， and the serum even outperformed pirfenidone in inhibiting the expression of TNF-α and Smad2 （P<0.05）. ConclusionThe BHT-containing serum can inhibit BLM-induced senescence of A549 cells in a dose-dependent manner by regulating the TGF-β/Smad signaling pathway.

In order to provide basic information for the utilization and development of famous classical formulas containing Bletillae Rhizoma， this article systematically analyzes the historical evolution of the name， origin， harvesting and processing of Bletillae Rhizoma by reviewing the ancient materia medica， prescription books， medical books and modern literature. The research results showed that Baiji（白及） was the main name， some scholars took Baiji（白芨） as its main name， and there were many other names such as Baiji（白给）， Baigen（白根）， Baiji（白苙）. The mainstream source of Bletillae Rhizoma was the tubers of Bletilla striata， and drying， large， white， solid， root-free and skin removed completely were the good quality standards. With the promotion of wild to cultivated medicinal materials， there were certain differences between their traits， and the quality evaluation indexes should be adjusted accordingly. The origin of records in the past dynasties was widely distributed， with Guizhou and Sichuan having high production and good quality in modern times. The harvesting period is mostly in spring and autumn， and harvested in autumn was better. The processing and processing technology is relatively simple， and it was used fresh or powdered in past dynasties， while it is mainly sliced for raw use in modern times. Based on the results， it is suggested that the tubers of Bletilla striata of Orchidaceae should be used in the famous classical formulas， and it should be uniformly written as Baiji（白及）. And if the original formula indicates the requirement of processing， it should be operated according to the requirement， if the requirement of processing is not indicated， it can be used in raw form as medicine.