Background: Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease. Buyang Huanwu Tang (BYHWT), a classical traditional Chinese medicine formula, has been widely utilized for the treatment of PF in China. This present study aimed to explore the mechanism of BYHWT in the treatment of PF in vitro. Methods: TGF-β1 stimulated human alveolar epithelial A549 cells were used as in vitro model for PF. Post the treatment of BYHWT, cell viability was measured by MTT assay, and cell morphology was observed under microscope. The epithelial-to-mesenchymal transition (EMT) markers (E-cadherin, Vimentin) and collagen I (Col I) were detected by western blot, immunofluorescence staining and real-time quantitative polymerase chain reaction. With the co-administration of activators (IGF-1, SC79) and inhibitors (LY294002, MK2206), the effect of BYHWT on PI3K/Akt pathway was analyzed by western blot. Results: BYHWT inhibited cell growth, and prevented cell morphology changed from epithelial to fibroblasts in TGF-β1 induced A549 cells. BYHWT decreased Vimentin and Col I, while increased E-cadherin at both protein and mRNA levels. Moreover, phosphorylation of PI3K (p-PI3K) and phosphorylation of Akt (p-Akt) were significantly down-regulated by BYHWT in TGF-β1 stimulated A549 cells. Conclusion: These results indicate that BYHWT suppressed TGF-β1-induced collagen accumulation and EMT of A549 cells by inhibiting the PI3K/Akt signaling pathway. These findings suggest that BYHWT may have potential for the treatment of PF.

Objective. To establish and validate a simple, sensitive, and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of methotrexate (MTX) and its major metabolite 7-hydroxy-methotrexate (7-OH-MTX) in human plasma. Method. The chromatographic separation was achieved on a Zorbax C₁₈ column (3.5 μm, 2.1 × 100 mm) using a gradient elution with methanol (phase B) and 0.2% formic acid aqueous solution (phase A). The flow rate was 0.3 mL/min with analytical time of 3.5 min. Mass spectrometry detection was performed in a triple-quadruple tandem mass spectrometer under positive ion mode with the following mass transitions: m/z 455.1/308.1 for MTX, 471.0/324.1 for 7-OH-MTX, and 458.2/311.1 for internal standard. The pretreatment procedure was optimized with dilution after one-step protein precipitation. Results. The calibration range of methotrexate and 7-OH-MTX was 5.0-10000.0 ng/mL. The intraday and interday precision and accuracy were less than 15% and within ±15% for both analytes. The recovery for MTX and 7-OH-MTX was more than 90% and the matrix effect ranged from 97.90% to 117.60%. Conclusion. The method was successfully developed and applied to the routine therapeutic drug monitoring of MTX and 7-OH-MTX in human plasma.

Little is known about the effects of Buyang Huanwu decoction on pulmonary fibrosis. Herein, 144 healthy SD rats were randomly divided into six groups: blank control group (B), model control group (M), positive medicine control group (Mp), and high‐, moderate‐, and low‐dose Buyang Huanwu decoction groups (Hd, Md, and Ld). A pulmonary fibrosis model was established by endotracheal injection of bleomycin. On the second day of modeling, the corresponding saline, methylprednisolone suspension, and the three doses of Buyang Huanwu decoction were used to treat the 6 groups of rats by intragastric administration for 7, 14, and 28 consecutive days. After 7, 14, and 28 days of treatment, the mRNA expression of CTGF and AKT, the protein level of CTGF, p‐AKT, and collagen types I and III were tested. Finally, we found that the serum collagen type I and III level in Hd, Md, and Ld rats on the 14th and 28th day and the collagen type I and III level in Hd rats on 7th day were significantly lower than in M rats (P < 0.01). The protein level of p‐AKT and CTGF in Hd and Md rats on the 7th and 14th days and the protein level of p‐AKT in Hd rats on the 28th day were lower than in M rats (P < 0.01, P < 0.05). The level of CTGF mRNA in Hd, Md, and Ld rats and the level of AKT mRNA in Hd and Md rats on the 7th, 14th, and 28th days and the expression level of AKT mRNA in Ld rats on the 14th and 28th days were significantly lower than in M rats (P < 0.01). The study suggests that Buyang Huanwu decoction alleviated pulmonary fibrosis of rats by improvement of lung tissue morphology, low level of serum collagen types I and III, and the reduced expression of CTGF and p‐AKT protein, which might be a result of its downregulated expression of CTGF and AKT mRNA levels.