Pharmacokinetic interaction between rhynchopylline and pellodendrine via CYP450 enzymes and P-gp.

CONTEXT: Rhynchopylline and pellodendrine are major extractions of commonly used Chinese medicine in gynaecology. The interaction between these two compounds could affect treatment efficiency and even result in toxicity during their co-administration in gynaecological prescription. OBJECTIVE: The pharmacokinetic interaction between rhynchopylline and pellodendrine and the potential mechanism were investigated in this study. MATERIALS AND METHODS: Sprague-Dawley rats were randomly divided into four groups to investigate the pharmacokinetic interaction between rhynchopylline (30 mg/kg) and pellodendrine (20 mg/kg) with single dose of these two drugs as the control. The transport of rhynchopylline was evaluated in the Caco-2 cell model. Additionally, the metabolic stability and the activity of corresponding CYP450 enzymes were assessed in rat liver microsomes. RESULTS: The pharmacokinetic profile of rhynchopylline was dramatically affected by pellodendrine with the increased area under the pharmacokinetic curve (3080.14 ± 454.54 vs. 1728.08 ± 220.598 µg/L*h), Cmax (395.1 ± 18.58 vs. 249.1 ± 16.20 µg/L), prolonged t1/2 (9.74 ± 2.94 vs. 4.81 ± 0.42 h) and the reduced clearance rate (from 11.39 ± 1.37 to 5.67 ± 1.42 L/h/kg). No significant changes were observed in the pharmacokinetics of pellodendrine. The transport of rhynchopylline was significantly inhibited by pellodendrine with a decreasing efflux ratio (1.43 vs. 1.79). Pellodendrine significantly inhibited the activity of CYP1A2 and CYP2C9 with IC50 values of 22.99 and 16.23 µM, which are critical enzymes responsible for the metabolism of rhynchopylline. DISCUSSION AND CONCLUSIONS: The adverse interaction between rhynchopylline and pellodendrine draws attention to the co-administration of these two herbs and provides a reference for further investigations with a broader study population.

Solid lipid nanoparticle delivery of rhynchophylline enhanced the efficiency of allergic asthma treatment via the upregulation of suppressor of cytokine signaling 1 by repressing the p38 signaling pathway.

Allergic asthma is one of the most common chronic airway diseases, and there is still a lack of effective drugs for the treatment of allergic asthma. The purpose of this work is to formulate rhynchophylline (Rhy)-solid lipid nanoparticles (SLNs) to improve their therapeutic efficacy in a mice allergic model of asthma. A solvent injection method was employed to prepare the Rhy-SLNs. Physicochemical characterization of Rhy-SLNs was measured, and the release assessment was investigated, followed by the release kinetics. Next, a model of murine experimental asthma was established. Mice were subcutaneously injected with 20 µg ovalbumin mixed with 1 mg aluminum hydroxide on days 0, 14, 28, and 42 and administrated aerosolized 1% ovalbumin (w/v) by inhalation from day 21 to day 42. Mice were intraperitoneally injected with 20 mg/kg Rhy-SLNs or Rhy at one hour before the airway challenge with ovalbumin. The results showed that Rhy-SLNs revealed a mean particle size of 62.06 ± 1.62 nm with a zeta potential value of -6.53 ± 0.04 mV and 82.6 ± 1.8% drug entrapment efficiency. The release curve of Rhy-SLNs was much higher than the drug released in phosphate buffer saline at 0, 1, 1.5, 2, 4, or 6 h. Moreover, Rhy-SLNs exerted better effects on inhibiting ovalbumin-induced airway inflammation, oxidative stress, airway remodeling (including collagen deposition and mucus gland hyperplasia) than Rhy in murine experimental asthma. Subsequently, we found that Rhy-SLNs relieved allergic asthma via the upregulation of the suppressor of cytokine signaling 1 by repressing the p38 signaling pathway.

Systematic elucidation of the pharmacological mechanisms of Rhynchophylline for treating epilepsy via network pharmacology.

ABSTACT: BACKGROUND: Epilepsy, one of the most common neurological disorders, affects over 70 million people worldwide. Rhynchophylline displays a wide variety of pharmacologic actives. However, the pharmacologic effects of rhynchophylline and its mechanisms against epilepsy have not been systematically elucidated. METHODS: The oral bioavailability and druglikeness of rhynchophylline were evaluated using the Traditional Chinese Medicine Systems Pharmacology Database. Rhynchophylline target genes to treat epilepsy were identified using PharmMapper, SwissTargetPrediction and DrugBank databases integration. Protein-protein interaction analysis was carried out by utilizing the GeneMANIA database. WebGestalt was employed to perform Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. The drug-disease-target-Gene Ontology-pathway network was constructed using Cytoscape. RESULTS: The oral bioavailability and druglikeness of rhynchophylline were calculated to be 41.82% and 0.57, respectively. A total of 20 rhynchophylline target genes related to epilepsy were chosen. Among the 20 genes and their interacting genes, 54.00% shared protein domains and 16.61% displayed co-expression characteristics. Gene ontology, Kyoto Encyclopedia of Genes and Genomes and network analyses illustrate that these targets were significantly enriched in regulation of sensory perception, morphine addiction, neuroactive ligand-receptor interaction and other pathways or biological processes. CONCLUSION: In short, rhynchophylline targets multiple genes or proteins, biological processes and pathways. It shapes a multiple-layer network that exerts systematic pharmacologic activities on epilepsy.

Rhynchophylline Loaded-mPEG-PLGA Nanoparticles Coated with Tween-80 for Preliminary Study in Alzheimer's Disease.

PURPOSE: Alzheimer's disease (AD) is a growing concern in the modern society. The current drugs approved by FDA are not very promising. Rhynchophylline (RIN) is a major active tetracyclic oxindole alkaloid stem from traditional Chinese medicine uncaria species, which has potential activities beneficial for the treatment of AD. However, the application of rhynchophylline for AD treatment is restricted by the low water solubility, low concentration in brain tissue and low bioavailability. And there is no study of brain-targeting therapy with RIN. In this work, we prepared rhynchophylline loaded methoxy poly (ethylene glycol)-poly (dl-lactide-co-glycolic acid) (mPEG-PLGA) nanoparticles (NPS-RIN), which coupled with Tween 80 (T80) further for brain targeting delivery (T80-NPS-RIN). METHODS: Preparation and characterization of T80-NPS-RIN were followed by the detection of transportation across the blood-brain barrier (BBB) model in vitro, biodistribution and neuroprotective effects of nanoparticles. RESULTS: The results indicated T80-NPS-RIN could usefully assist RIN to pass through the BBB to the brain. T80-NPS-RIN treatment regulated the activity of neurons in vitro. CONCLUSION: The presented data confirmed that rhynchophylline encapsulated mPEG-PLGA nanoparticles coated with Tween 80 could across through the BBB and exhibited efficient neuroprotective effects. The T80-NPS-RIN nanoparticles have a chance to be an alternative drug to the therapy of AD.

Site-Specific Conjugation of the Indolinobenzodiazepine DGN549 to Antibodies Affords Antibody-Drug Conjugates with an Improved Therapeutic Index as Compared with Lysine Conjugation.

Antibody-drug conjugates have elicited great interest recently as targeted chemotherapies for cancer. Recent preclinical and clinical data have continued to raise questions about optimizing the design of these complex therapeutics. Biochemical methods for site-specific antibody conjugation have been a design feature of recent clinical ADCs, and preclinical reports suggest that site-specifically conjugated ADCs generically offer improved therapeutic indices (i.e., the fold difference between efficacious and maximum tolerated doses). Here we present the results of a systematic preclinical comparison of ADCs embodying the DNA-alkylating linker-payload DGN549 generated with both heterogeneous lysine-directed and site-specific cysteine-directed conjugation chemistries. Importantly, the catabolites generated by each ADC are the same regardless of the conjugation format. In two different model systems evaluated, the site-specific ADC showed a therapeutic index benefit. However, the therapeutic index benefit is different in each case: both show evidence of improved tolerability, though with different magnitudes, and in one case significant efficacy improvement is also observed. These results support our contention that conjugation chemistry of ADCs is best evaluated in the context of a particular antibody, target, and linker-payload, and ideally across multiple disease models.

Pharmacokinetic Interaction Study of Ketamine and Rhynchophylline in Rat Plasma by Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry.

Eighteen Sprague-Dawley rats were randomly divided into three groups: ketamine group, rhynchophylline group, and ketamine combined with rhynchophylline group (n = 6). The rats of two groups received a single intraperitoneal administration of 30 mg/kg ketamine and 30 mg/kg rhynchophylline, respectively, and the third group received combined intraperitoneal administration of 30 mg/kg ketamine and 30 mg/kg rhynchophylline together. After blood sampling at different time points and processing, the concentrations of ketamine and rhynchophylline in rat plasma were determined by the established ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. Chromatographic separation was achieved using a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 µm) with carbamazepine as an internal standard (IS). The initial mobile phase consisted of acetonitrile and water (containing 0.1% formic acid) with gradient elution. Multiple reaction monitoring (MRM) modes of m/z 238.1 → 179.1 for ketamine, m/z 385.3 → 159.8 for rhynchophylline, and m/z 237.3 → 194.3 for carbamazepine (IS) were utilized to conduct quantitative analysis. Calibration curve of ketamine and rhynchophylline in rat plasma demonstrated good linearity in the range of 1-1000 ng/mL (r > 0.995), and the lower limit of quantification (LLOQ) was 1 ng/mL. Moreover, the intra- and interday precision relative standard deviation (RSD) of ketamine and rhynchophylline were less than 11% and 14%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to pharmacokinetic interaction study of ketamine and rhynchophylline after intraperitoneal administration. The results showed that there may be a reciprocal inhibition between ketamine and rhynchophylline.