Biotransformation and tissue distribution of protopine and allocryptopine and effects of Plume Poppy Total Alkaloid on liver drug-metabolizing enzymes

Protopine ameliorates OVA-induced asthma through modulatingTLR4/MyD88/NF-κB pathway and NLRP3 inflammasome-mediated pyroptosis

BACKGROUND

Chronic airway inflammation and hyperresponsiveness are characteristics of asthma. The isoquinoline alkaloid protopine (PRO) has been shown to exert anti-inflammatory effects, but its mechanism of action in asthma is not known.

PURPOSE

Investigate the protective properties of PRO upon asthma and elucidate its mechanism.

STUDY DESIGN AND METHODS

The effects of PRO in asthma treatment were assessed by histology, biochemical analysis, and real-time reverse transcription-quantitative polymerase chain reaction. Then, we integrated molecular docking, western blotting, cellular experiments, immunohistochemistry, immunofluorescence analysis, flow cytometry, and metabolomics analysis to reveal its mechanism.

RESULTS

In vivo, PRO therapy reduced the number of inflammatory cells (eosinophils, leukocytes, monocytes) in bronchoalveolar lavage fluid (BALF), ameliorated pathologic alterations in lung tissues, and inhibited secretion of IgG and histamine. Molecular docking showed that PRO could dock with the proteins of TLR4, MyD88, TRAF6, TAK1, IKKα, and TNF-α. Western blotting displayed that PRO inhibited the TLR4/NF-κB signaling pathway. PRO regulated expression of the pyroptosis-related proteins NLR family pyrin domain containing 3 (NLRP3) inflammasome, gasdermin D, caspase-1, and drove caspase-1 inactivation to affect inflammatory responses by inhibiting the NLRP3 inflammasome. In vitro, 24 h after treatment with PRO, cell activity, as well as levels of reactive oxygen species (ROS) and interleukin (IL)-1β and IL-18, decreased significantly. Immunofluorescence staining showed that PRO decreased expression of TLR4 and MyD88 in vitro. PRO decreased nuclear translocation of NF-κB p65. Twenty-one potential biomarkers in serum were identified using metabolomics analysis, and they predominantly controlled the metabolism of phenylalanine, tryptophan, glucose, and sphingolipids.

CONCLUSION

PRO reduced OVA-induced asthma. The underlying mechanism was associated with the TLR4/MyD88/NF-κB pathway and NLRP3 inflammasome-mediated pyroptosis.

Alkaloids in commercial preparations of California poppy - Quantification, intestinal permeability and microbiota interactions

California poppy products are commonly used for the treatment of nervousness, anxiety and sleeping disorders. Pharmacologically relevant constituents include the main alkaloids californidine, escholtzine and protopine. However, only limited information is available about the alkaloid content in commercial preparations and their intestinal absorption. Moreover, a possible metabolization of these alkaloids by the gut microbiota, and their impact on microbial activity and viability have not been investigated. Californidine, escholtzine and protopine were quantified by UHPLC-MS/MS in eight commercial California poppy products. The intestinal permeability of alkaloids was studied in Caco-2 cell as a model for absorption in the small intestine. The gut microbial biotransformation was explored in artificial gut microbiota from the in vitro PolyFermS model. In addition, the impact of these alkaloids and a California poppy extract on the microbial production of short-chain fatty acids (SCFAs) and the viability of microbiota was investigated. Contents of californidine, escholtzine and protopine in California poppy products were in the ranges of 0.13-2.55, 0.05-0.63 and 0.008-0.200 mg/g, respectively. In the Caco-2 cell model, californidine was low-to-moderately permeable while escholtzine and protopine were highly permeable. An active transport process was potentially involved in the transfer of the three alkaloids. The three compounds were not metabolized by the artificial gut microbiota over 24 h. Neither the California poppy extract nor the alkaloids markedly impacted microbial SCFA production and bacterial viability.

Safety and efficacy of a feed additive consisting of Macleaya cordata (Willd.) R. Br. extract and leaves (Sangrovit® extra) for all poultry species (excluding laying and breeding birds) (Phytobiotics Futterzusatzstoffe GmbH)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Macleaya cordata (Willd.) R. Br. extract and leaves (Sangrovit® Extra) when used as a zootechnical feed additive (functional group: other zootechnical additives) for all poultry species (excluding laying and breeding birds). The additive is standardised to contain a concentration of the sum of the four alkaloids sanguinarine, chelerythrine, protopine and allocryptopine of 1.25%, with 0.5% sanguinarine. Owing to the presence of the DNA intercalators sanguinarine and chelerythrine, a concern for genotoxicity was identified. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) had no safety concerns when the additive is used at the recommended level of 150 mg/kg complete feed (corresponding to 0.750 mg sanguinarine/kg complete feed) for chickens for fattening and other poultry species for fattening. No conclusion can be drawn for poultry reared for laying/breeding. The use of Sangrovit® Extra in poultry species for fattening at the maximum recommended level was considered of low concern for consumers. The additive was shown to be irritant to the eyes but not irritant to skin or a skin sensitiser. The FEEDAP Panel could not exclude the potential of the additive to be a respiratory sensitiser. When handling the additive, exposure of unprotected users to sanguinarine and chelerythrine may occur. Therefore, to reduce the risk, the exposure of users should be reduced. The use of Sangrovit® Extra as a feed additive under the proposed conditions of use was considered safe for the environment. The additive Sangrovit® Extra had the potential to be efficacious in improving performance of chickens for fattening at 45 mg/kg complete feed. This conclusion was extended to chickens reared for laying/breeding and extrapolated to all poultry species for fattening or reared for laying/breeding.

Anti-Inflammatory Effects of Allocryptopine via the Target on the CX3CL1-CX3CR1 axis/GNB5/AKT/NF-κB/Apoptosis in Dextran Sulfate-Induced Mice

Allocryptopine (ALL) is an isoquinoline alkaloid extracted from Macleaya cordata(Willd). R. Br., which has been claimed to have anti-inflammatory and neuroprotection properties. However, the mechanism by which ALL ameliorates inflammatory bowel disease (IBD) remains unclear. Here, we used network pharmacology and quantitative proteomic approaches to investigate the effect of ALL on IBD pathogenesis. Network pharmacology predicted potential targets and signaling pathways of ALL's anti-IBD effects. As predicted by network pharmacology, gene ontology (GO) analysis, in terms of the proteomic results, showed that the immune response in mucosa and antimicrobial humoral response were enriched. Further study revealed that the ALL-related pathways were the chemokine signaling pathway and apoptosis in the Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, we identified AKT1 as a hub for the critical pathways through protein-protein interaction (PPI) network analysis. Similar to mesalazine (MES), Western blot verified that ALL downregulated upstream chemokine CX3CL1 and GNB5 content to reduce phosphorylation of AKT and NF-κB, as well as the degree of apoptosis, to improve inflammatory response in the colon. Our research may shed light on the mechanism by which ALL inhibits the CX3CL1/GNB5/AKT2/NF-κB/apoptosis pathway and improves the intestinal barrier to reduce colitis response and act on the CX3CL1-CX3CR1 axis to achieve neuroprotection.

Sex differences in the pharmacokinetics and tissue residues of Macleaya cordata extracts in rats

Macleaya cordata extracts (MCE) are listed as feed additives in animal production by the European Food Authority. The core components of MCE are mainly sanguinarine (SA) and chelerythrine (CHE). This study aims to investigate sex differences in the pharmacokinetics and tissue residues of MCE in rats.Male and female rates were intragastrically administered MCE (1.25 mg·kg^-1 body weight and 12.5 mg·kg^-1 body weight dose for 28 days). SA and CHE concentrations were determined using high-performance liquid chromatography/tandem mass spectrometry.The peak plasma concentration (C_max) and area under the curve (AUC) of both CHE and SA were higher in female than in male rats (12.5 mg·kg^-1 body weight group), whereas their half-life (T_1/2) and apparent volume of distribution (V_d) was lower (p < 0.05). Tissue rfesidue analysis indicated that SA and CHE were more distributed in male than in female rats and were highly distributed in the cecum and liver. SA and CHE were completely eliminated from the liver, kidney, lung, heart, spleen, leg muscle, and cecum after 120 h, indicating they did not accumulate in rats for a long time.Overall, we found that the pharmacokinetics and tissue residues of SA and CHE of male and female rats showed sex differences.

Identification and Quantification, Metabolism and Pharmacokinetics, Pharmacological Activities, and Botanical Preparations of Protopine: A Review

Through pharmacological activity research, an increasing number of natural products and their derivatives are being recognized for their therapeutic value. In recent years, studies have been conducted on Corydalis yanhusuo W.T. Wang, a valuable medicinal herb listed in the Chinese Pharmacopoeia. Protopine, one of its components, has also become a research hotspot. To illustrate the identification, metabolism, and broad pharmacological activity of protopine and the botanical preparations containing it for further scientific studies and clinical applications, an in-depth and detailed review of protopine is required. We collected data on the identification and quantification, metabolism and pharmacokinetics, pharmacological activities, and botanical preparations of protopine from 1986 to 2021 from the PubMed database using “protopine” as a keyword. It has been shown that protopine as an active ingredient of many botanical preparations can be rapidly screened and quantified by a large number of methods (such as the LC-ESI-MS/MS and the TLC/GC-MS), and the possible metabolic pathways of protopine in vivo have been proposed. In addition, protopine possesses a wide range of pharmacological activities such as anti-inflammatory, anti-platelet aggregation, anti-cancer, analgesic, vasodilatory, anticholinesterase, anti-addictive, anticonvulsant, antipathogenic, antioxidant, hepatoprotective, neuroprotective, and cytotoxic and anti-proliferative activities. In this paper, the identification and quantification, metabolism and pharmacokinetics, pharmacological activities, and botanical preparations of protopine are reviewed in detail to lay a foundation for further scientific research and clinical applications of protopine.

Potential Toxicity Evaluation of Protopine in Macleaya cordata (Willd.) R. Br.-A Bioactivity Guided Approach

Macleaya cordata (Willd.) R. Br. (M. cordata) is a perennial herb known for its chemotherapeutic properties, strong feeding additive, and potential antidiarrheal drug. Despite its therapeutic potentials, its clinical applications are hindered by an apparent lack of toxicity data. In this study, the toxic ingredients of this plant were investigated using a bioactivity-guided approach. Two compounds, protopine and allocryptopine, were purified and elucidated by LC-MS, ¹H-NMR, and ¹³C-NMR. Protopine, a primary component in M. cordata, had an LD₅₀ of 313.10 mg/kg i.e., which was considered toxic. An autopsy was performed on protopine-administered mice, and the histopathology of the kidney, liver, brain, heart, lung, and spleen was determined. Autopsy findings included hemorrhage in the respiratory system, lung congestion, and hemorrhage and edema in the parenchymatous organs (heart, liver, kidney, and brain). Histopathology confirmed the pathological changes in the brain, liver, and kidney. Protopine is one of the principal bioactive constituents of many phytopreparations used in veterinary and human medicine, such as Sangrovit and Iberogast. Our findings indicated that phytopreparations containing protopine might pose a serious health threat to humans and animals.

Metabolism and Tissue Distribution of Chelerythrine and Effects of Macleaya Cordata Extracts on Liver NAD(P)H Quinone Oxidoreductase

Background:Macleaya cordata (Willd.) (Papaveraceae) is listed as a feed additive in animal production by the European Food Authority.

Methods: The metabolites of chelerythrine in rats were measured in vitro and in vivo by rapid and accurate high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC/QqTOF-MS). The structures of CHE metabolites were elucidated by comparing their changes in accurate molecular masses and fragment ions with those of parent ion or metabolite. The metabolic enzymes that were involved in chelerythrine reduction were investigated using an inhibition method. The tissue distribution of chelerythrine and the effects on NQO1 following intragastric administration with M. cordata extracts in rats were examined.

Results: A total of twelve metabolites of chelerythrine were characterized by this approach in rat liver S9 and in vivo. The reduction of the iminium bond of chelerythrine and subsequent O-demethylation was the main metabolic pathway of chelerythrine in rat liver S9 while the reduction of the iminium bond of chelerythrine was the main metabolic pathway of chelerythrine in rats in vivo. After the rats were given intragastric administration, the low concentration residues of sanguinarine and chelerythrine in different rat tissues were found at 48 h after the last dose, suggesting that both compounds could be widely distributed in tissues. The results also indicated that XO, NQO1, NQO2, and carbonyl reductase are involved in chelerythrine reduction. Macleaya cordata extracts treated female and male rats, respectively, showed different responses, inhibiting NQO1 activity in males, but inducing NQO1 activity in females. Chelerythrine had a weak impact on NQO1 activity, but sanguinarine inhibited NQO1 activity

Conclusion: Through studying the effects of cytosolic reductase inhibitors on chelerythrine reduction and the impact of chelerythrine and sanguinarine on the activity of NQO1 in vitro and in vivo, we clarified the potential drug interaction of Macleaya cordata extract in clinical application, so as to provide theoretical guidance for clinically safe medication. In addition, it provided a reference basis for the metabolic mechanism of chelerythrinein rats.

Protopine/Gemcitabine Combination Induces Cytotoxic or Cytoprotective Effects in Cell Type-Specific and Dose-Dependent Manner on Human Cancer and Normal Cells

The natural alkaloid protopine (PRO) exhibits pharmacological properties including anticancer activity. We investigated the effects of PRO, alone and in combination with the chemotherapeutic gemcitabine (GEM), on human tumor cell lines and non-tumor human dermal fibroblasts (HDFs). We found that treatments with different PRO/GEM combinations were cytotoxic or cytoprotective, depending on concentration and cell type. PRO/GEM decreased viability in pancreatic cancer MIA PaCa-2 and PANC-1 cells, while it rescued the GEM-induced viability decline in HDFs and in tumor MCF-7 cells. Moreover, PRO/GEM decreased G1, S and G2/M phases, concomitantly with an increase of subG1 phase in MIA PaCa-2 and PANC-1 cells. Differently, PRO/GEM restored the normal progression of the cell cycle, altered by GEM, and decreased cell death in HDFs. PRO alone increased mitochondrial reactive oxygen species (ROS) in MIA PaCa-2, PANC-1 cells and HDFs, while PRO/GEM increased both intracellular and mitochondrial ROS in the three cell lines. These results indicate that specific combinations of PRO/GEM may be used to induce cytotoxic effects in pancreatic tumor MIA PaCa-2 and PANC-1 cells, but have cytoprotective or no effects in HDFs.