Pharmacokinetic studies of phellodendrine in rat plasma and tissues after intravenous administration using ultra-high performance liquid chromatography–tandem mass spectrometry

Biological Importance of Phellodendrine in Traditional and Modern Medicines: An Update on Therapeutic Potential in Medicine

BACKGROUND

Herbal medicines have been used for the preparation of numerous pharmaceutical products for the treatment of human disorders. Plant-derived products have been used in medicine, nutraceuticals, perfumery, beverages, and cosmetics industries for different purposes. Herbal medicines are mainly derived from different parts of plant materials. Phellodendron bark has been widely known as one of the fundamental herbs of traditional Chinese medicine. Phellodendron bark contains phellodendrine as a main active phytochemical. Phellodendrine ((7S,13aS)-3,10-dimethoxy-7-methyl-6,8,13,13atetrahydro-5H-isoquinolino[2,1-b]isoquinolin-7- ium-2,11-diol), is a quaternary ammonium alkaloid.

METHODS

This present study aimed to investigate the biological potential and therapeutic effectiveness of phellodendrine in medicine through scientific data analysis of different research works on phellodendrine. The therapeutic value of phellodendrine was analyzed in the present work through scientific data available in Google, Google Scholar, ScienceDirect, and PubMed. All the scientific data on phellodendrine were collected from these databases using the terms herbal drugs and phellodendrine. Pharmacological and analytical data of phellodendrine were analyzed in the present work in order to know the medicinal importance of phellodendrine.

RESULTS

Scientific data analysis of phellodendrine in the present work signified the biological importance of phellodendrine in medicine. Phellodendrine has numerous beneficial aspects in medicine due to its potential benefits in ulcerative colitis, inflammation, pancreatic cancer, nephritis, immune response, acetylcholinesterase activity, psoriasis, arthritis, atopic dermatitis, and oxidative stress. However, it also has significant effects on eicosanoid generation, neuraminidase-1, inflammasome generation, cytochrome p450, taste receptors, and hepatic gluconeogenesis. Furthermore, scientific data has indicated the presence of phellodendrine in different natural sources, including Phellodendri cortex. Analytical data on phellodendrines has signified their importance in the isolation and separation of pure phytochemicals in medicine. Pharmacokinetic parameters have highlighted the tissue distribution of phellodendrine in different tissue of human beings and higher animals.

CONCLUSION

In the present work, scientific data analysis has indicated the biological importance, pharmacological activities, and analytical aspects of phellodendrine in medicine.

Discovery of a novel class of benzoxazole derivatives as histamine H3 receptor ligands for the treatment of neuropathic pain

To discover effective analgesics, we summarize the synthesis, optimization, and pharmacological anti-nociceptive effects of a novel series of benzoxazole derivatives targeting H₃ receptor (H₃R). The new benzoxazoles were assayed in vitro for histamine H₃R and H₁R binding affinity. The best compound 8d (2-methyl-6-(3-(4-methylpiperazin-1-yl)propoxy)benzo[d]oxazole) exhibited high affinity for H₃R (K_i = 19.7 nM), high selectivity for ten other off-target receptors, and negligible effects on human ether-a-go-go-related gene (hERG, cardiac ion channel). In rodent animals, compound 8d dose-dependently reversed formalin-evoked pain (Phase I, ED₅₀ = 6.0 mg/kg; Phase II, ED₅₀ = 7.8 mg/kg) and CCI-induced neuropathic pain (chronic constriction injury, ED₅₀ = 15.6 mg/kg). Furthermore, compound 8d showed an excellent safety profile in acute toxicity test (LD₅₀ > 2000 mg/kg) with a therapeutic index (TI = LD₅₀/ED₅₀) > 250 and showed a desirable drug-like pharmacokinetic profile. Above characteristics indicate that compound 8d represents a promising candidate analgesic for the treatment of neuropathic pain.

The discovery of berberine erythrocyte-hemoglobin self-assembly delivery system: a neglected carrier underlying its pharmacokinetics

Berberine (BBR) has extremely low concentration and high tissue distribution. However, current pharmacokinetic studies predominantly focus on its concentration in plasma, which could hardly make a comprehensive understanding of its pharmacokinetic process. This study made a pioneering endeavor to explore the erythrocyte-hemoglobin (Hb) self-assembly system of BBR by exploring the interaction of BBR with erythrocyte and the combination of BBR with Hb. Results showed that BBR had a low bioavailability (C₀ = 2.833 μg/mL via intravenous administration of 2.5 mg/kg BBR and C_max = 0.260 μg/mL via oral administration of 400 mg/kg BBR). Besides, BBR achieved higher concentrations in erythrocytes than plasma, and the erythrocytes count and Hb content were significantly decreased after intravenous administration. Hemolysis rate indicated the BBR-erythrocyte system (with 2% erythrocytes) was relatively stable without hemolysis at the concentration of 1.00 mg/mL. And the maximum percentage of drug loading was 100% when the BBR-erythrocyte concentration was 0.185 μg/mL. Furthermore, incubation of BBR and erythrocytes resulted in internalization of the erythrocyte membrane and the formation of intracellular vacuoles. The thermodynamic parameters indicated that the binding process of bovine hemoglobin (BHB) and BBR was spontaneous. UV-vis absorption spectra, synchronous fluorescence, circular dichroism and Raman spectra collectively indicated that BBR showed strong binding affinity toward BHB and affected the molecular environment of residues like tryptophan and tyrosine in BHB, resulting in the conformational changes of its secondary and tertiary structure. Molecular docking indicated BBR interacted with Arg-141 residue of BHB via hydrogen bond with the bond length of 2.55 Å. The ΔG value of the BHB-BBR system was −31.79 kJ/mol. Molecular dynamics simulation indicated the root mean square derivation of BBR-BHB was <0.025 nm, suggestive of stable conformation. Cumulatively, there was an erythrocyte-Hb self-assembled drug delivery system after oral or intravenous administration of BBR, which conceivably gained novel insight into the discrepancy between the extremely low plasma concentration and relatively high tissue concentration of BBR.

Comparative pharmacokinetics, intestinal absorption and urinary excretion of six alkaloids from herb pair Phellodendri Chinensis cortex-Atractylodis Rhizoma

Phellodendri Chinensis Cortex (PCC) and Atractylodis Rhizoma (AR) are frequently used as herb pair to treat eczema and gout owing to their synergistic effects. Alkaloids are the major ingredients from PCC and the effect of their combination on the in vivo processing of alkaloids remains unclear. In this study, a simple and reliable UPLC-MS/MS method for simultaneous determination of six alkaloids in rat plasma was developed. This method was applied to a comparative pharmacokinetic study between PCC and PCC-AR in rats. Effect of AR on absorption of alkaloids was investigated by a single-pass intestinal perfusion study. The effect of AR on urinary excretion of alkaloids was studied. Pharmacokinetic studies showed that the values of rea under the concentration-time curve of phellodendrine, magnoflorine and palmatine were greater in the PCC-AR group than in the PCC group. The intestinal absorptive parameters absorption rate constant and effective permeability of phellodendrine and jatrorrhizine in PCC-AR groups were higher than those in the PCC group. Urinary excretion studies revealed that the excreted amount of alkaloids in the PCC-AR group was lower than that in the PCC group. The results revealed that the combination of PCC and AR improves intestinal absorption of alkaloids and reduces their urinary excretion, which enhances their systemic exposure. This study may explain the synergetic effects of PCC and AR in clinical applications.

Characterization of metabolic fate of phellodendrine and its potential pharmacological mechanism against diabetes mellitus by ultra-high-performance liquid chromatography-coupled time-of-flight mass spectrometry and network pharmacology

RATIONALE

Characterizing the functional mechanism of quality control marker (Q-marker) was of great importance in revealing the primary pharmacological mechanism of herbs or the other complex system, and drug-related metabolites always contribute to the pharmacological functions. Cortex Phellodendri was used as a core herb in the treatment of diabetes mellitus (DM). As a Q-marker of Cortex Phellodendri, the role of phellodendrine in DM was still unclear. Thus, the characterization of phellodendrine-related metabolites in vivo and the subsequent induced functional mechanism exerted great importance in elucidating the anti-DM mechanism of Cortex Phellodendri.

METHODS

An ultra-high-performance liquid chromatography-coupled time-of-flight mass spectrometry (UHPLC/Q-TOF MS) method was developed to profile metabolites of phellodendrine in rats. The potential pharmacological mechanism against DM was predicted by network pharmacology.

RESULTS

A total of 19 phellodendrine-related metabolites were screened out in rats for the first time. Among them, M4, M5, M9, and M12 were regarded as the primary metabolites. Meanwhile, phase I metabolic reactions of hydroxylation, demethylation, and isomerization and phase II reactions of glucuronidation and sulfation occurred to phellodendrine; glucuronidation and hydroxylation were the two main metabolic reactions. Moreover, the potential targets of phellodendrine and three main metabolites (M4, M5, and M12) were predicted by a network pharmacological method, and they mainly shared 52 targets, including PDE5A, CHRNA3, SIGMAR1, F3, ESR1, DRD1, DRD2, DRD3, and DRD4. Furthermore, Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that calcium signaling pathway, cGMP-PKG signaling pathway, and cAMP signaling pathway were regarded as the core mechanism of phellodendrine to treat DM.

CONCLUSION

The metabolic feature of phellodendrine in vivo was revealed for the first time, and its anti-DM mechanism information for further pharmacological validations was also supplied. It also gave a direction to further elucidation of pharmacological mechanism of Cortex Phellodendri in treating DM.

Identification of anti-inflammatory compounds from Zhongjing formulae by knowledge mining and high-content screening in a zebrafish model of inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic relapsing intestinal inflammations with increasing global incidence, and new drug development remains in urgent demand for IBD management. To identify effective traditional Chinese medicine (TCM) formulae and compounds in IBD treatment, we innovatively combined the techniques of knowledge mining, high-content screening and high-resolution mass spectrometry, to conduct a systematic screening in Zhongjing formulae, which is a large collection of TCM prescriptions with most abundant clinical evidences.

METHODS

Using Word2vec-based text learning, the correlations between 248 Zhongjing formulae and IBD typical symptoms were analyzed. Next, from the top three formulae with predicted relationship with IBD, TCM fractions were prepared and screened on a transgenic zebrafish IBD model for their therapeutic effects. Subsequently, the chemical compositions of the fraction hits were analyzed by mass spectrometry, and the major compounds were further studied for their anti-IBD effects and potential mechanisms.

RESULTS

Through knowledge mining, Peach Blossom Decoction, Pulsatilla Decoction, and Gegen Qinlian Decoction were predicted to be the three Zhongjing formulae mostly related to symptoms typical of IBD. Seventy-four fractions were prepared from the three formulae and screened in TNBS-induced zebrafish IBD model by high-content analysis, with the inhibition on the intestinal neutrophil accumulation and ROS level quantified as the screening criteria. Six herbal fractions showed significant effects on both pathological processes, which were subsequently analyzed by mass spectrometry to determine their chemical composition. Based on the major compounds identified by mass spectrometry, a second-round screen was conducted and six compounds (palmatine, daidzin, oroxyloside, chlorogenic acid, baicalin, aesculin) showed strong inhibitory effects on the intestinal inflammation phenotypes. The expression of multiple inflammatory factors, including il1β, clcx8a, mmp and tnfα, were increased in TNBS-treated fish, which were variously inhibited by the compounds, with aesculin showing the most potent effects. Moreover, aesculin and daidzin also upregulated e-cadherin's expression.

CONCLUSION

Taken together, we demonstrated the regulatory effects of several TCM formulae and their active compounds in the treatment of IBD, through a highly efficient research strategy, which can be applied in the discovery of effective TCM formulae and components in other diseases.

A comparative investigation of the interaction and pharmacokinetics of hemoglobin with berberine and its oxymetabolite

Berberine (BBR), isolated from Coptis chinensis, is one type of isoquinoline alkaloids. BBR exerts numerous of bioactivities but the plasma concentration is really low. In our previous study, a new oxymetabolite (OBB) has been discovered and showed superior anti-inflammatory effect comparing with BBR. The aim of this study is to investigate the interaction, metabolite and pharmacokinetics of BBR with hemoglobin. Sprague-Dawley rats were used to carry out the interaction, metabolite and pharmacokinetics of BBR and OBB in vivo. Fluorescence spectra were used to analyse the interaction in vitro. Results showed that OBB could be generated after intravenous injection or incubating with BBR in vitro and in vivo; Both BBR and OBB exerted much stronger binding interaction with hemoglobin than plasma and affect the conformation of bovine hemoglobin and change the fluorescence spectral properties; BBR and OBB were mainly presented and transported in the proteins-bound form. These results provide a new insight to understand the dynamic equilibrium of BBR and OBB within body from the perspective of new metabolic pathways.

Phellodendri Cortex: A Phytochemical, Pharmacological, and Pharmacokinetic Review

Background

Phellodendri Cortex (PC) or Huang Bai. According to the scientific database of China Plant Species and Chinese pharmacopeia 2015 edition, PC has two main species which are Phellodendron amurense Rupr (PAR) or “Guan Huang bai” in Chinese and Phellodendron chinense Schneid (PCS) or “Chuan Huang bai” in Chinese. The crude drugs of PAR and PCS are also called Phellodendri amurensis cortex (PAC) and Phellodendri chinense cortex (PCC), respectively. The medicinal part of the plant is the dried trunk bark. PC has comprehensive therapeutic effects which include anti-inflammatory, antimicrobial, anticancer, hypotensive, antiarrhythmic, antioxidant, and antipyretic agents. The exact ingredients in PC and its species are not fully summarised.

Aim of the Study

This study was designed to review and evaluate the pharmacological actions of compounds and to explore the pharmacokinetic knowledge of PC and its species and to also identify the chemical compound(s) with a potential therapeutic effect on atopic dermatitis.

Methods

“Huang Bai” and its English, botanical, and pharmaceutical names were used as keywords to perform database search in Encyclopaedia of traditional Chinese Medicines, PubMed, EMBASE, MEDLINE, Science Direct, Scopus, Web of Science, and China Network Knowledge Infrastructure. The data selection criteria included all the studies that were related to the phytochemical, pharmacological, and pharmacokinetic perspectives of PC and its species or their active constituents. More importantly, the voucher number has been provided to ensure the genuine bark of PC used as the medicinal part in the studies.

Results

140 compounds were summarized from PC and its species: specifically, 18 compounds from PCC, 44 compounds from PCS, 34 compounds from PAC, and 84 compounds from PAR. Obacunone and obaculactone are probably responsible for antiatopic dermatitis effect. PC and its species possess a broad spectrum of pharmacological actions including anti-inflammatory effect, antibacterial effect, antiviral effect, antitumor effect, antigout effect, antiulcer effect, neuroprotective effect, and antiatopic dermatitis effect. PC could widely distribute in plasma, liver, spleen, kidney, and brain. Berberine may be responsible for the toxic effect on the susceptible users with hemolytic disease or in the peripartum and neonatal period.

Conclusions

The compounds of the crude bark of PC and its subspecies have showcased a wide range of pharmacological effects. Pharmacological efficacies of PC are supported by its diverse class of alkaloid, limonoid, phenolic acid, quinic acid, lignan, and flavonoid. Obacunone and obaculactone could be the bioactive compounds for atopic dermatitis management. PC and its subspecies are generally safe to use but extra care is required for certain conditions and group of people.

A LC-MS/MS method for simultaneous determination of seven alkaloids in rat plasma after oral administration of Phellodendri chinensis cortex extract and its application to a pharmacokinetic study

A sensitive and rapid liquid chromatography with tandem mass spectrometry method has been developed for simultaneous determination of berberine (I), jateorhizine (II), palmatine (III), tetrahydropalmatine (IV), phellodendrine (V), protopine (VI) and columbamine (VII) in rat plasma after oral administration of Phellodendri chinensis cortex extraction. The plasmas were extracted by liquid-liquid extraction. The tandem mass spectrometric detection was performed in the multiple reaction monitoring mode in the positive ionization. The intra- and interday precisions and accuracies were in range from -12.18 to 13.21%. Mean absolute recoveries of all analytes and internal standard were between 78.6 and 98.9%. The seven alkaloids were proven to be stable during sample storage and analysis procedures. The established method was validated and successfully applied to pharmacokinetics study in rat plasma after oral administration of Phellodendri chinensis cortex extract. The t_1/2 of palmatine, columbamine, pellodendrine, berberine, tetrahydropalmaine, jatrorrhizine, and protopine were 5.16, 5.96, 7.18, 19.84, 6.28, 7.08, 6.90 h, respectively. The seven compounds could be rapidly absorbed into blood (time for maximal concentration, 1.80-1.93 h). This study could establish a foundation for further research of Phellodendri chinensis cortex and might provide more useful information to guide the clinical usage.

Treatment effects and mechanisms of Yujin Powder on rat model of large intestine dampness-heat syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Yujin Powder (YJP), an old prescription, is one of the most classical prescription for treating the large intestine dampness-heat syndrome (LIDHS). However, its potential modern pharmacological mechanisms remain unclear.

AIM OF THE STUDY

The present study was designed to explore the essence of LIDHS and treatment mechanisms of the YJP on the LIDHS.

METHODS

The rat model of LIDHS was established by such complex factors as high-sugar and high-fat diet, improper diet, high temperature and humidity environment (HTHE), drinking and intraperitoneal injection of Escherichia coli., which imitated the inducing conditions of LIDHS. Then the clinical symptoms and signs, blood routine, blood biochemistry, whole blood viscosity (WBV), serum inflammatory cytokines levels and the histopathological changes of main organs were detected and observed, respectively.

RESULTS

The results showed that the clinical symptoms and signs of the model rats were consistent with the diagnostic criteria of LIDHS, moreover, there were obvious systemic inflammatory response and extensive congestion. And after treatment with YJP in different dosages, the clinical symptoms and signs of the rats with LIDHS were improved; the indexes of blood routine and blood biochemistry and inflammatory cytokines levels tended to be normal; the WBV decreased and histopathological changes of major organs were alleviated or returned to normal. There was an obvious dose-effect relationship, and the high dose of YJP (HD-YJP) had the best treatment effects.

CONCLUSIONS

These results suggested that in LIDHS, diarrhea was the major clinical manifestation; the large intestine was the main lesion area; mucosa injury, inflammation and congestion of the large intestine with systemic inflammatory response and congestion were the most typical pathological characteristics. Meanwhile, YJP exhibited the comprehensive effects of anti-diarrhea, anti-inflammation, lowering blood lipid, relieving blood stasis, repairing intestinal mucosa and regulation and protection of multiple organs on LIDHS. These findings provided not only important information for understanding the essence of LIDHS but also the theoretical basis for developing new-drugs for treating dampness-heat type of diarrheal diseases.