Functional and binding studies of gallic acid showing platelet aggregation inhibitory effect as a thrombin inhibitor.

Objective: This study was devoted to identifying natural thrombin inhibitors from traditional Chinese medicine (TCM) and evaluating its biological activity in vitro and binding characteristics. Methods: A combination strategy containing molecular docking, thrombin inhibition assay, surface plasmon resonance (SPR) and molecular dynamics simulation were applied to verify the study result. Results: Gallic acid was confirmed as a direct thrombin inhibitor with IC50 of 9.07 µmol/L and showed a significant inhibitory effect on thrombin induced platelet aggregation. SPR-based binding studies demonstrated that gallic acid interacted with thrombin with a KD value of 8.29 µmol/L. Molecular dynamics and binding free energy analysis revealed that thrombin-gallic acid system attained equilibrium rapidly with very low fluctuations, the calculated binding free energies was -14.61 kcal/mol. Ala230, Glu232, Ser235, Gly258 and Gly260 were the main amino acid residues responsible for thrombin inhibition by gallic acid, providing a mechanistic basis for further optimization. Conclusion: This study proved that gallic acid is a direct thrombin inhibitor with platelet aggregation inhibitory effect, which could provide a basis for the follow-up research and development for novel thrombin inhibitors.

Dihydroflavonoids as Bioactive Components of Penthorum chinense, a Miao Ethnomedicine, against NAFLD through Bile Acid Metabolism Pathway.

Penthorum chinense Pursh. is a traditional herbal medicine of Miao, and its extracts (PCPE) have been used for treatment of liver diseases in the clinic including nonalcoholic fatty liver disease (NAFLD). However, the active components and pharmacological mechanisms of PCPE for treating NAFLD remain unclear. This study aimed to explore potential mechanisms of action through network pharmacology, molecular docking combined with experimental in vitro. A total of five dihydroflavonoids (1-5) with the same parent nucleus of pinocembrin (PCB) from PCPE, were selected as bioactive ingredients and 109 potential targets related to NAFLD were obtained from public databases and literature mining. The core targets related to the bile secretion signaling were selected based on PPI network and KEGG enrichment analysis for exploring the mechanism of PCPE against NAFLD. Molecular docking results showed good interaction between the core targets in bile secretion signaling pathway and the five compounds predicted to be bioactive. With the strong binding activity to retinoid X receptor-alpha (RXRA) and farnesoid X receptor (FXR) protein, pinocembrin-7-O-ß-D-glucoside (PCBG, the highest content in PCPE) and its metabolite PCB, could significantly increase the expression of RXRA, FXR and bile salt export pump (BSEP) in L02 cells, and significantly decrease the expression of cholesterol 7α-hydroxylase (CYP7A1) at mRNA and protein levels. This study provided favorable evidence for mechanism of the main dihydroflavonoids of PCPE against NAFLD, and presented a paradigm for the study of ethnomedicine.

Efficacy of Guizhi Fuling Wan for primary dysmenorrhea: protocol for a randomized controlled trial.

BACKGROUND: Primary dysmenorrhea (PD) is one of the main gynecological complaints in women of child-bearing age, but limited effective treatments are available. Guizhi Fuling Wan (GFW), one of the most widely known traditional Chinese medicine (TCM) formulations, has been commonly used in clinical practice to treat gynecological disorders in China. In recent years, a growing number of studies have shown that GFW is beneficial for patients with PD. However, the quality of evidence is limited, and there are few studies on specific TCM syndromes of GFW for PD. Therefore, we plan to conduct a randomized controlled trial to explore the efficacy and safety of GFW for PD patients with heat-burning blood-stasis syndrome. METHODS AND ANALYSIS: The clinical study is a randomized, double-blinded, placebo-controlled trial. Eligible patients will be randomly assigned to the GFW group (treated with GFW) and the control group (treated with a matching placebo) in a 1:1 ratio for three menstrual cycles with a 3-month follow-up. The primary outcome will be the mean change of pain intensity measured by the visual analog scale (VAS). The secondary outcomes will include the Cox Menstrual Symptom Scale (CMSS), the Self-rating Depression Scale (SDS), the Self-rating Anxiety Scale (SAS), and the TCM syndrome scale. Adverse events will also be reported. DISCUSSION: This randomized trial will be the first rigorous study designed to assess the efficacy and safety of GFW in treating PD with heat-burning blood-stasis syndrome. The finding of this study will provide an objective clinical basis for the use of GFW for PD in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000034118 . Registered on 24 June 2020.

Discovery of natural 15-LOX small molecule inhibitors from Chinese herbal medicine using virtual Screening, biological evaluation and molecular dynamics studies.

Chinese herbal medicines (CHM) are frequently used to treat different types of inflammatory diseases and 15-Lipoxygenase (15-LOX) is a critical target enzyme for treating various inflammatory diseases. In this study, natural 15-LOX inhibitors were identified in CHM using an approach of virtual screening combined with the biological assays. First, an in-house Chinese medicine database containing 360 compounds was screened using a virtual screening approach based on pharmacophore and molecular docking to uncover several novel potential 15-LOX inhibitors. Secondly, the inhibitory effect of virtual screening hits against the 15-LOX enzyme was validated in an in vitro enzyme inhibition assay. Then, a tumor necrosis factor-α (TNF-α) release assay was carried out to explore the anti-inflammatory response of the active compounds. Furthermore, molecular dynamics (MD) simulation and binding free energy calculation were applied to analyze the process of inhibitors binding and also compared the mode of binding of the inhibitors by using the Molecular Mechanics-Generalized Born Surface Area (MM/GBSA) method. Finally, licochalcone B and eriodictyol were confirmed as inhibitors of the 15-LOX enzyme with IC50 values of 9.67 and 18.99 µM, respectively. In vitro cell-based assay showed that licochalcone B and eriodictyol inhibited the release of TNF-α factor in RAW264.7 cells stimulated by lipopolysaccharides (LPS) in a dose-dependent manner. Molecular dynamics and binding free energy analysis showed that the two 15-LOX-ligand systems immediately attained equilibrium with almost 1 Å fluctuation, the calculated binding free energies were found around -18.89 and -12.96 kcal/mol for licochalcone B and eriodictyol, respectively. Thr412, Arg415, Val420, Thr429, Ile602 and Trp606 were the main amino acid residues for the inhibition of 15-LOX enzyme activity. The current study confirms that licochalcone B and eriodictyol are 15-LOX inhibitors and can suppress the release of the TNF-α factor in RAW264.7 cells stimulated by LPS, thus providing a basis for the follow-up research and development for 15-LOX inhibitors.

Comparison of surgical treatments of tumor-induced osteomalacia in different locations in the lower limbs: A retrospective study.

Tumor-induced osteomalacia (TIO) is a rare disease that behaves benignly. Very few reports about the features of the responsible tumors according to anatomical locations have been presented.In this retrospective study of 53 patients with TIO-associated tumors in the foot/ankle, tibia and femur, we compared preoperative, postoperative, and follow-up courses, including alkaline phosphatase, phosphorus, and fibroblast growth factor 23, to compare the characteristics of TIO-associated tumors in these 3 locations (level of evidence: therapeutic level III).Patients in the foot/ankle group had longer disease courses and therefore a significantly higher complication rate (P < .001). All TIO-associated tumors in the foot/ankle group involved soft tissue (P = .021), whereas most lesions in the tibia group involved bone, and therefore had much higher concentrations of alkaline phosphatase (P = .020). Additionally, serum phosphorus took much longer to normalize after surgery in the foot/ankle group than that in the other 2 groups (P = .004). Consequently, symptom remission was much better in the tibia and femur groups (P = .008). Moreover, the Ki 67 index in TIO-associated tumors was significantly higher in the foot/ankle group (P < .001) and the recurrence rate in this group was markedly higher (P = .002).The TIO-associated tumors in the foot/ankle are characteristically of occult onset, more soft-tissue involvement, and more readily recurrence. More knowledge and examinations are necessary to enable early diagnosis, radical treatments, and minimize recurrence. New therapies are welcomed and needed.