Tianjin Darentang Jingwanhong Pharmaceutical Co. Ltd.

Gout is a crystal-related arthropathy caused by monosodium urate (MSU) deposition, resulting from purine metabolism disorders and hyperuricemia (HUA). Gout belongs to the traditional medicine category of Bi syndrome. Biqi capsules (BQ) is a traditional Chinese medicine formula used to treat Bi syndrome. The BQ prescription is derived from the ancient prescription of Hua Tuo, a famous physician in the Han Dynasty.

To study the effect and mechanism of BQ in treating acute gouty arthritis (AGA) and HUA.

Analyzing BQ's signaling pathways for gout treatment via network pharmacology. The HUA model was induced orally with adenine and potassium oxonate. The rat AGA model was established by MSU injection. In vitro, MH7A and RAW 246.7 cells were treated with LPS and MSU. Serum uric acid, creatinine, and urea nitrogen levels were evaluated. Kidney and ankle joint pathology was observed via HE staining. Inflammatory signaling pathway proteins, epithelial-mesenchymal transition (EMT) pathway proteins, and uric acid metabolism-related proteins were detected by Western blot.

1780 potential targets for gout treatment were identified, and 1039 target proteins corresponding to BQ's active ingredients were obtained. Pathway enrichment analysis revealed BQ improved gout mainly through inflammatory pathways. Experimental results showed BQ could reduce serum uric acid level and increase uric acid clearance rate by regulating the expression of adenosine deaminase (ADA), and organic anion transporter 1 (OAT1) and glucose transporter 9 (GLUT9) in HUA mice. BQ could improve renal function and injury by inhibiting the NLRP3 pathway in HUA mice' kidneys. Additionally, BQ could alleviate ankle joint swelling and synovial injury, inhibit the TLR4/NLRP3 pathway, and reduce levels of inflammatory factors including interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor-alpha (TNF-α) in AGA rats. The main component of BQ, brucine, could inhibit the activation of NLRP3/NF-κB pathway induced by MSU and reduce the expression level of inflammatory factors (IL-6, IL-1β, and TNF-α) in macrophages. Brucine could inhibit the activation of the EMT pathway and reduce the expression level of inflammatory factors (IL-6, TNF-α) in human fibroblast-like synoviocytes (MH7A cells) induced by MSU.

BQ effectively reduced serum uric acid levels, improved kidney and joint damage, and ameliorated the inflammatory response caused by MSU. Its main component, brucine, effectively improved the inflammatory response and reduced the invasive ability of synoviocytes induced by MSU.

Bi qi capsule (BQC) is a traditional Chinese medicine prescription that is clinically used for the treatment of rheumatoid arthritis. Strychnine and brucine, as two typical kinds of alkaloids, are the primary active and neurotoxic constituents of BQC. In this study, a sensitive and reliable rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) quantitative method was used to determine the concentrations of brucine and strychnine in rat brain and blood dialysates. The blood-brain barrier (BBB) penetration of free brucine and strychnine and their pharmacokinetic characteristics were investigated by the validated RRLC-MS/MS method coupled with in vivo microdialysis for the first time. The dialysate brain-blood AUC ratios of brucine were 0.098, 0.44 and 0.40 respectively at 0.4, 0.8 and 1.6 g kg^-1 doses of BQC, and the dialysate brain-blood AUC ratios of strychnine were 0.20, 1.25 and 2.06 respectively at 0.4, 0.8 and 1.6 g kg^-1 doses of BQC. The high brain-blood AUC ratios of brucine and strychnine were observed in medium and high dose groups of BQC. In addition, the effects of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) on brucine and strychnine across BBB were also studied using the above method as well as molecular docking. The results prompted that brucine was the substrate of P-gp, and strychnine might be the inhibitor of P-gp. Brucine and strychnine showed high brain penetration, so it is very important to well control the clinic dosage of BQC and manufactory quality for avoiding the side effects and obtaining good therapeutic efficacy. Our study could be further used in investigating BBB penetration for other drugs caused neurotoxicity.

Objectives: This research aims to explore the therapeutic potential of Bi-Qi capsules in the treatment of gout by identifying crucial drug targets through a multidimensional data analysis strategy. Methods: Bi-Qi capsule drug targets and differentially expressed genes (DEGs) of gout were derived from public databases, such as Swiss Target Prediction, STITCH, and the GEO database. Subsequently, the overlapped targets were analyzed to elucidate the potential therapeutic mechanism and to identify candidate targets of Bi-Qi capsules against gout. Next, Mendelian randomization (MR) analysis was employed to screen and explore the causal relationship between candidate targets and gout. Finally, single-cell RNA sequencing (scRNA-seq), gene set enrichment analysis (GSEA), transcription factor and ceRNA regulatory networks, and molecular docking were performed to validate the role of the crucial targets of Bi-Qi capsules in the treatment of gout. Results: A total of 46 candidate targets were identified, in which KCNA5, PTGS2, and TNF exhibited significant causal relationships with gout (p < 0.05) and were regarded as the crucial targets. Through scRNA-seq and gene labeling, crucial targets were found to be expressed in eighteen cell clusters and eight cell types, which are closely associated with carbohydrate metabolism, nerve conduction, and the innate immunity process. Bi-Qi capsule active compounds such as tanshinone IIA, strychnine, tanshinaldehyde, cryptotanshinone, tumulosic acid, and glycyrrhetic acid exhibit a better binding ability to crucial targets. Conclusions: The results not only elucidate the anti-gout mechanism of Bi-Qi capsules but also provide an insight into multi-target natural medication for metabolic disease treatment, which contributes to guiding the clinical application of Bi-Qi capsules in the future.