Study on the pharmacokinetics and metabolism of paeonol in rats treated with pure paeonol and an herbal preparation containing paeonol by using HPLC-DAD-MS method

Protective mechanism of Paeonol on central nervous system

Cerebrovascular diseases involve neuronal damage, resulting in degenerative neuropathy and posing a serious threat to human health. The discovery of effective drug components from natural plants and the study of their mechanism are a research idea different from chemical synthetic medicines. Paeonol is the main active component of traditional Chinese medicine Paeonia lactiflora Pall. It widely exists in many medicinal plants and has pharmacological effects such as anti-atherosclerosis, antiplatelet aggregation, anti-oxidation, and anti-inflammatory, which keeps generally used in the treatment of cardiovascular and cerebrovascular diseases. Based on the therapeutic effects of Paeonol for cardiovascular and cerebrovascular diseases, this article reviewed the pharmacological effects of Paeonol in Alzheimer's disease, Parkinson's disease, stroke, epilepsy, diabetes encephalopathy, and other neurological diseases, providing a reference for the research of the mechanism of Paeonol in central nervous system diseases.

Paeonol ameliorates hippocampal neuronal damage by inhibiting GRM5/GABBR2/β-arrestin2 and activating the cAMP-PKA signaling pathway in premenstrual irritability rats

Premenstrual dysphoric disorder (PMDD) is a periodic psychiatric disorder with high prevalence in women of childbearing age, seriously affecting patients' work and life. Currently, the international first-line drugs for PMDD have low efficiency and increased side effects. Paeonol, a major component of the traditional Chinese medicine Cortex Moutan, has been applied in treating PMDD in China with satisfactory results, but the therapeutic mechanism is not fully understood. This study aims to evaluate the therapeutic effects and pharmacological mechanisms of paeonol on the main psychiatric symptoms and hippocampal damage in PMDD. We established a premenstrual irritability rat model by the resident-intruder paradigm and performed elevated plus maze and social interactions. And we employed the HE and Nissl staining techniques to observe the therapeutic effect of paeonol on hippocampal damage in PMDD rats. Subsequently, Elisa, qRT-PCR Array, Western Blotting, and cell models were utilized to elucidate the underlying molecular mechanisms through which paeonol intervenes in treating PMDD. In this study, we demonstrated the therapeutic effects of paeonol on irritability, anxiety, and social withdrawal behaviors in rats. In addition, we found that paeonol significantly reduced the serum corticosterone (CORT) level, improved hippocampal morphological structure and neuron number, and reduced hippocampal neuron apoptosis in PMDD rats. Paeonol reduced GRM5, GABBR2, β-arrestin2, and GRK3 expression levels in hippocampal brain regions of PMDD rats and activated the cAMP/PKA signaling pathway. Inhibitor cell experiments showed that paeonol specifically ameliorated hippocampal injury by modulating the β-arrestin2/PDE4-cAMP/PKA signaling pathway. The present study demonstrates, for the first time, that paeonol exerts a therapeutic effect on periodic psychotic symptoms and hippocampal injury in PMDD through inhibiting GRM5/GABBR2/β-arrestin2 and activating cAMP-PKA signaling pathway. These findings enhance our understanding of the pharmacological mechanism underlying paeonol and provide a solid scientific foundation for its future clinical application.

Pharmacological effects and mechanisms of paeonol on antitumor and prevention of side effects of cancer therapy

Cancer represents one of the leading causes of mortality worldwide. Conventional clinical treatments include radiation therapy, chemotherapy, immunotherapy, and targeted therapy. However, these treatments have inherent limitations, such as multidrug resistance and the induction of short- and long-term multiple organ damage, ultimately leading to a significant decrease in cancer survivors' quality of life and life expectancy. Paeonol, a nature active compound derived from the root bark of the medicinal plant Paeonia suffruticosa, exhibits various pharmacological activities. Extensive research has demonstrated that paeonol exhibits substantial anticancer effects in various cancer, both in vitro and in vivo. Its underlying mechanisms involve the induction of apoptosis, the inhibition of cell proliferation, invasion and migration, angiogenesis, cell cycle arrest, autophagy, regulating tumor immunity and enhanced radiosensitivity, as well as the modulation of multiple signaling pathways, such as the PI3K/AKT and NF-κB signaling pathways. Additionally, paeonol can prevent adverse effects on the heart, liver, and kidneys induced by anticancer therapy. Despite numerous studies exploring paeonol's therapeutic potential in cancer, no specific reviews have been conducted. Therefore, this review provides a systematic summary and analysis of paeonol's anticancer effects, prevention of side effects, and the underlying mechanisms involved. This review aims to establish a theoretical basis for the adjunctive strategy of paeonol in cancer treatment, ultimately improving the survival rate and enhancing the quality of life for cancer patients.

Traditional uses, phytochemistry, pharmacology, and pharmacokinetics of the root bark of Paeonia x suffruticosa andrews: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Moutan Cortex (MC), commonly known as "Mu dan pi", refers to the dried root bark of Paeonia x suffruticosa Andrews and is broadly used as a traditional herbal medication in China, Japan, and Korea. For thousands of years, it has been utilized to treat female genital, extravasated blood, cardiovascular, and stagnant blood disorders.

AIM OF THE REVIEW

The purpose of this review article was to summarize information on the traditional uses, phytochemistry, pharmacology and pharmacokinetics of MC, as well as to outline the further research directions for the development of new drugs and the associations between traditional uses and pharmacological effects.

MATERIALS AND METHODS

The information involved in the study was gathered from a variety of electronic resources, including PubMed, Web of Science, ScienceDirect, SciFinder, China Knowledge Resource Integrated Database, and Google Scholar. The date was from 1992 to 2022.

RESULTS

Approximately 163 chemical compounds have been extracted and identified from MC, including monoterpenes, monoterpene glycosides, triterpenes, phenolics, flavonoids, volatile oils, alkaloids, and others. In these categories, the monoterpene glycosides and phenols being the most common. A wide variety of pharmacological effects have been described for MC crude extracts and active molecules, such as antioxidant, anti-inflammatory, antibacterial and antiviral, antitumor, antidiabetic, organ protection, and neuroprotective activities, as well as treating cardiovascular diseases. Pharmacokinetics has been also used in the study of MC, including its crude extracts or chemical constituents, in order to explore the therapeutic mechanism, direct clinically appropriate application and provide new ideas for the exploitation of innovative medicines.

CONCLUSION

Modern pharmacological research has demonstrated that MC, as a significant therapeutic resource, has the ability to heal a wide range of diseases, particularly female genital and cardiovascular problems. These researches propose therapeutic ideas for the development of novel MC medicines. Furthermore, preclinical and clinical study have verified several observed pharmacological properties related with the traditional usages of MC.

Paeonol for the Treatment of Atherosclerotic Cardiovascular Disease: A Pharmacological and Mechanistic Overview

With improvement in living standards and average life expectancy, atherosclerotic cardiovascular disease incidences and mortality have been increasing annually. Paeonia suffruticosa, a natural herb, has been used for the treatment of atherosclerotic cardiovascular disease for thousands of years in Eastern countries. Paeonol is an active ingredient extracted from Paeonia suffruticosa. Previous studies have extensively explored the clinical benefits of paeonol. However, comprehensive reviews on the cardiovascular protective effects of paeonol have not been conducted. The current review summarizes studies reporting on the protective effects of paeonol on the cardiovascular system. This study includes studies published in the last 10 years. The biological characteristics of Paeonia suffruticosa, pharmacological mechanisms of paeonol, and its toxicological and pharmacokinetic characteristics were explored. The findings of this study show that paeonol confers protection against atherosclerotic cardiovascular disease through various mechanisms, including inflammation, platelet aggregation, lipid metabolism, mitochondria damage, endoplasmic reticulum stress, autophagy, and non-coding RNA. Further studies should be conducted to elucidate the cardiovascular benefits of paeonol.

Paeonol-loaded PLGA nanoparticles as an oral drug delivery system: Design, optimization and evaluation

Herein, we report a novel type of NPs by loading paeonol (Pae) into PLGA NPs, to enhance drug stability and oral bioavailability. The paeonol (Pae)-loaded polylactic-co-Gly-colic acid (PLGA) nanoparticles (Pae-PLGA-NPs) were prepared by nanoprecipitation method. The resultant NPs were in spherical shape with an average particle size around 237.7 ± 4.92 nm, and the PDI and zeta potential were 0.110 ± 0.01 and -25.33 ± 1.37 mV, respectively. The encapsulation efficiency (EE) and drug loading (DL) of the Pae-PLGA-NPs were 86.26 ± 1.12 and 12.74 ± 0.37% respectively. The in vitro drug release, in vivo pharmacokinetics and in situ single-pass intestinal perfusion (SPIPs) of Pae-PLGA-NPs was investigated. In vivo, the AUC_(0-t), C _max, MRT_(0-t), and T_1/2z of the Pae-PLGA-NPs group were 3.79-, 1.89-, 1.40- and 1.49-fold greater than those of the Pae suspension group, respectively. The in situ single-pass intestinal perfusion of NPs results showed the Ka values in the duodenum, jejunum, ileum and colon were 1.12-, 1.40-, 1.52- and 2.21-fold higher than those of Pae solution, respectively. Moreover, the Papp values of the ileum and colon were 1.27- and 1.31-fold higher than those of the solution group. Such findings suggested the Pae-PLGA-NPs can significantly improve the intestinal absorption characteristics, and have a beneficial effect on oral administration as a nanometer-sized carrier.

Genus Paeonia: A comprehensive review on traditional uses, phytochemistry, pharmacological activities, clinical application, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia, which comprises approximately 52 shrubs or herbaceous perennials around the world, is the only genus of the Paeoniaceae and is pervasively distributed in Asia, southern Europe, and North America. Many species of the genus Paeonia have been used for centuries in ethnomedical medical systems.

AIM OF THE REVIEW

The present study aims to summarize the traditional uses, clinical applications, and toxicology of the genus Paeonia, to critically evaluate the state-of-the-art phytochemical and pharmacological studies of this genus published between 2011 and 2020, and to suggest directions for further in-depth research on Paeonia medicinal resources.

MATERIALS AND METHODS

Popular and widely used databases such as PubMed, Scopus, Science Direct, and Google Scholar were searched using the various search strings; from these searches, a number of citations related to the traditional uses, phytochemistry, biological activities, clinical application, and toxicology of the genus Paeonia were retrieved.

RESULTS

The use of 21 species, 2 subspecies, and 7 varieties of the genus Paeonia as traditional herbal remedies has been reported, and many ethnomedicinal uses, such as the treatment of hematemesis, blood stasis, dysmenorrhea, amenorrhea, epilepsy, spasms, and gastritis, have been recorded. The roots and root bark are the most frequently reported parts of the plants used in medicinal applications. In phytochemical investigations, 451 compounds have been isolated from Paeonia plants to date, which contains monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids and steroids, and phenols. Studies of their pharmacological activities have revealed the antioxidant, anti-inflammatory, antitumour, antibacterial, antiviral, cardiovascular protective, and neuroprotective properties of the genus Paeonia. In particular, some bioactive extracts and compounds (total glucosides of peony (TGP), paeonol, and paeoniflorin) have been used as therapeutic drugs or tested in clinical trials. In addition to the "incompatibility" of the combined use of "shaoyao" and Veratrum nigrum L. roots in traditional Chinese medicine theory, Paeonia was considered to have no obvious toxicity based on the available toxicological tests.

CONCLUSION

A large number of phytochemical and pharmacological reports have indicated that Paeonia is an important medicinal herb resource, and some of its traditional uses including the treatment of inflammation and cardiovascular diseases and its use as a neuroprotective agent, have been partially confirmed through modern pharmacological studies. Monoterpenoid glucosides are the main active constituents. Although many compounds have been isolated from Paeonia plants, the biological activities of only a few of these compounds (paeoniflorin, paeonol, and TGP) have been extensively investigated. Some paeoniflorin structural analogues and resveratrol oligomers have been preliminarily studied. With the exception of several species (P. suffruticosa, P. ostii, P. lactiflora, and P. emodi) that are commonly used in folk medicine, many medicinal species within the genus do not receive adequate attention. Conducting phytochemical and pharmacological experiments on these species can provide new clues that may lead to the discovery of medicinal resources. It is necessary to identify the effective phytoconstituents of crude extracts of Paeonia that displayed pharmacological activities by bioactivity-guided isolation. In addition, comprehensive plant quality control, and toxicology and pharmacokinetic studies are needed in the future studies.

Paeonol Derivatives and Pharmacological Activities: A Review of Recent Progress

Paeonol, 2-hydroxy-4-methoxy acetophenone, is one of the main active ingredients of traditional Chinese medicine such as Cynanchum paniculatum, Paeonia suffruticosa Andr and Paeonia lactiflora Pall. Modern medical research has shown that paeonol has a wide range of pharmacological activities. In recent years, a large number of studies have been carried out on the structure modification of paeonol and the mechanism of action of paeonol derivatives has been studied. Some paeonol derivatives exhibit good pharmacological activities in terms of antibacterial, anti-inflammatory, antipyretic analgesic, antioxidant and other pharmacological effects. Herein, the research progress on paeonol derivatives and their pharmacological activities were systematically reviewed.

Nine absorbed components pharmacokinetic of raw and processed Moutan Cortex in normal and blood-heat and hemorrhage syndrome model rats

Raw Moutan Cortex (RMC) and Processed Moutan Cortex (PMC) have a long history of use in China and other Asian countries. In this study, a rapid and accurate ultra-high-pressure liquid chromatography coupled with diode array detector (UHPLC-DAD) method was developed and validated for the simultaneous determination of nine absorbed compounds of RMC/PMC. After extraction by protein precipitation with methanol from plasma, the analytes were separated on an Acquity UPLC® BEH Shield RP₁₈ column (2.1 × 100 mm, 1.7 μm, Waters, USA). Acetonitrile (A) and 0.1% (v/v) formic acid in water (B) were selected as the mobile phase to perform gradient elution. The linearity of nine analytes was >0.9915. The intra- and inter-assay precision (RSD) values were within 11.18%, and accuracy ranged from 91.32 to 101.29%. Suitable stability, matrix effect and extraction recoveries were also obtained. The validated method was applied to compare the pharmacokinetics of RMC and PMC in Blood-Heat and Hemorrhage Syndrome Model and normal rats. The results revealed that processing and the pathological state could influence the pharmacokinetic characteristics of compounds in RMC/PMC. The study willbe useful for further studies on pharmacokinetics and clinical application of raw and processed Moutan Cortex.

Pharmacokinetics, Tissue Distribution and Excretion of Paeonol and Its Major Metabolites in Rats Provide a Further Insight Into Paeonol Effectiveness

Paeonol is a major bioactive ingredient in Moutan Cortex (the root barks of Paeonia suffruticosa Andrews) and exhibited a wide range of bioactivities such as anti-inflammation, anti-oxidation, hypoglycemic effect, analgesic, and others. Even though paeonol has been proven to possess significant pharmacological and therapeutic effects, its pharmacokinetic properties are not satisfactory since it has been found to have a rapid clearance in vivo. In the present study, the pharmacokinetics, tissue distribution and excretion of paeonol and its major metabolites were investigated in rats by an efficient and specific UPLC-MS/MS method. The results indicated that paeonol was rapidly absorbed, extensively metabolized, and widely distributed in various tissues without long-term accumulation after oral administration to rats. The major distribution tissues of paeonol and its metabolites were kidney, liver, and heart. Paeonol was able to cross the blood-brain barrier but rapidly decreased after 10 min. The total excretion of four metabolites in urine, bile, and feces was approximately 35.0% within 24 h, and the metabolites were mainly excreted through the urine. In addition, the hypoglycemic activities of paeonol and its metabolites were investigated by a glucose uptake assay on TNF-α mediated insulin resistance in 3T3-L1 adipocytes. The results showed that paeonol and its major metabolites displayed hypoglycemic activities. This is the first comprehensive and systematic report on the pharmacokinetics of paeonol and its metabolites. This research provides an important basis for the clinical development and application of active metabolites.

Design, synthesis, and antitumor activity of novel paeonol derivatives containing the 1,4-benzoxazinone and 1,2,3-triazole moieties

A new series of paeonol derivatives containing the 1,4-benzoxazinone and 1,2,3-triazole moieties were synthesized and evaluated for their cytotoxicity in vitro against human non-small cell lung cancer NCI-H1299 cells and human cervical carcinoma HeLa cells. Among them, compared with that of paeonol, compounds 8-acetyl-4-{[(1-(5-chloro-2-nitrophenyl)-1 H-1,2,3-triazol-4-yl]methyl}-5-methoxy-2 H-1,4-benzoxazin-3(4 H)-one, 8-acetyl-4-[(1-mesityl-1 H-1,2,3-triazol-4-yl)methyl]-5-methoxy-2 H-1,4-benzoxazin-3(4 H)-one, and 8-acetyl-5-methoxy-4-{[(1-(naphthalen-1-yl)-1 H-1,2,3-triazol-4-yl]methyl}-2 H-1,4-benzoxazin-3(4 H)-one exhibited significant inhibitory activity toward the human non-small cell lung cancer NCI-H1299 cells (IC50 = 13.36 ± 0.003, 19.75 ± 0.3, 15.79 ± 0.05 μg mL−1). The last compound also exhibited significant inhibitory activity toward the human cervical carcinoma HeLa cells (IC50 = 19.73 ± 1.0 μg mL−1).

Involvement of a Novel Organic Cation Transporter in Paeonol Transport Across the Blood-Brain Barrier

Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (V_D) of [³H]paeonol in rat brain was about 6-fold higher than that of [¹⁴C]sucrose, the vascular space marker of BBB. The uptake of [3H]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [³H]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

An Available Strategy for Nasal Brain Transport of Nanocomposite Based on PAMAM Dendrimers via In Situ Gel

Polyamidoamine (PAMAM) dendrimers are efficient drug carriers. The presence of a physiological pathway for nasal brain transport provides a potential path for direct brain-targeted delivery of dendrimer nanocomposites. In this study, we synthesized PAMAM dendrimer composites with a nanoscale size; the particle size of PAE (Paeonol)/mPEG (the heterofunctional PEG polymer with a methoxy)-PAMAM G5.NHAc and mPEG-PAMAM G5.NH₂-FITC were 72.41 ± 11.58 nm and 96.51 ± 7.77 nm, and the zeta potential of PAE/mPEG-PAMAM G5.NHAc and mPEG-PAMAM G5.NH₂-FITC were + 0.57 ± 0.11 mv and + 9.60 ± 0.41 mv, respectively. The EE% and DL% of PAE in PAE/mPEG-PAMAM G5.NHAc were 53.77% and 13.92%, respectively. PAE/mPEG-PAMAM G5.NHAc/DGG ionic-sensitive in situ gel was prepared, the viscosity of solution and gel state were 112 ± 3.2 mPa and 1403 ± 38.5 mPa, respectively. The in vitro goat mucoadhesive strength of the gel was 4763.36 ± 85.39 dyne/cm². In situ gel system was proven to be a non-Newtonian pseudo-plastic fluid with shear thinning, thixotropy and yield stress. The optimal model of PAE released from PAE/mPEG-PAMAM G5.NHAc and PAE/mPEG-PAMAM G5.NHAc/DGG were the Higuchi equation and the Korsmeyer-Peppas equation, respectively. The cytotoxicity of the nanocomposites showed a concentration-dependence, and the cell viabilities of PAE/mPEG-PAMAM G5.NHAc were both higher than 95% between 0.0001 μM and 10 μM. mPEG-PAMAM G5.NH₂-FITC was efficiently taken up by cells and exhibited strong fluorescence in the cytoplasm and nucleus. Significant accumulation of nanocomposites was observed in the brain after administration of the in situ gel group, and maximum accumulation was reached at 12 h. A small amount of accumulation was observed in the nanocomposite solution group only at 2 h. Therefore, the direct nasal brain transport efficiency of PAMAM dendrimer nanocomposites can be significantly improved after combining with in situ gel. PAMAM dendrimer nanocomposite/DGG is a potential drug delivery system for nasal brain transport.

Pharmacokinetics and Brain Distribution of the Active Components of DA-9805, Saikosaponin A, Paeonol, and Imperatorin in Rats

DA-9805 is a botanical anti-Parkinson’s drug candidate formulated from ethanol extracts of the root of Bupleurum falcatum, the root cortex of Paeonia suffruticosa, and the root of Angelica dahurica. The pharmacokinetics (PKs) and brain distribution of active/representative ingredients of DA-9805, Saikosaponin a (SSa; 1.1–4.6 mg/kg), Paeonol (PA; 14.8–59.2 mg/kg), and Imperatorin (IMP; 1.4–11.5 mg/kg) were evaluated following the intravenous or oral administration of each pure component and the equivalent dose of DA-9805 in rats. All three components had greater dose-normalized areas under the plasma concentration-time curve (AUC) and slower clearance with higher doses, following intravenous administration. By contrast, dose-proportional AUC values of SSa, PA, and IMP were observed following the oral administration of each pure component (with the exception of IMP at the highest dose) or DA-9805. Compared to oral administration of each pure compound, DA-9805 administration showed an increase in the AUC of SSa (by 96.1–163%) and PA (by 155–164%), possibly due to inhibition of their metabolism by IMP or other component(s) in DA-9805. A delay in the absorption of PA and IMP was observed when they were administered as DA-9805. All three components of DA-9805 showed greater binding values in brain homogenates than in plasma, possibly explaining why the brain-to-plasma ratios were greater than unity following multiple oral administrations of DA-9805. By contrast, their levels in cerebrospinal fluid were negligible. Our results further our understanding of the comprehensive PK characteristics of SSa, PA, and IMP in rats and the comparative PKs between each pure component and DA-9805.

Advancement in the chemical analysis of Paeoniae Radix (Shaoyao)

Paeoniae Radix Alba (baishao or white peony root) and Paeoniae Radix Rubra (chishao or red peony root) are two highly valuable traditional Chinese medicines (TCMs) usually indicated for painful conditions, menstrual disorders and viral infections. These two TCMs are collectively referred to as shaoyao (Paeoniae Radix) due to their close origins and similar chemical compositions. Modern research indicates that monoterpene glycosides, polyphenols and paeonols are the three main types of compounds related to the pharmacological activities of Paeoniae Radix. This review summarizes recent advances in the chemical analysis of Paeoniae Radix and the related traditional Chinese medicine formulas/preparations, including methods used for sample pretreatment, qualitative analysis, quantitative analysis and biological sample analysis. More than 120 papers are discussed in this review, focusing on the chemical analysis of Paeoniae Radix, and various analytical techniques (such as HPLC, LC-MS, IR, near IR and quantitative NMR), as well as their advantages/disadvantages, are described. It is our hope that this paper can provide necessary information for improving the quality evaluation methods currently available for Paeoniae Radix and offer a scientific basis for the future in-depth study of the pharmacokinetics and pharmacodynamics of Paeoniae Radix.

Systematic characterization of the metabolites of paeonol in rats using ultra performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry with an integrative strategy

Paeonol, an active constituent in the root bark of Paeonia suffruticosa Andrews, is used to treat inflammation, headache and other diseases in clinic. Though the data on pharmacological researches of paeonol abounds, its metabolic profile is not so clear. It is essential to systematically characterize the in vivo metabolites in order to better understand its mechanism of action. In this study, ultra performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q/TOF-MS) with an integrative strategy was developed for analysis of paeonol metabolites. As a result, based on seven reference substances isolated or synthesized, twenty-five metabolites were detected and identified in urine, feces, bile and plasma of rats after oral administration of paeonol. To the best of our knowledge, 14 of these metabolites have not been reported previously. In addition, the dominating metabolic fates were oxidation, demethylation, hydrogenation, glucuronic acid and sulfate conjugations, and hydrogenation of paeonol was reported for the first time. This research provides scientific and reliable support for full understanding of the metabolic profiling of paeonol.

Evaluation of paeonol-loaded transethosomes as transdermal delivery carriers

Paeonol shows effective anti-allergic, anti-inflammatory and analgesic activities. However, because of its poor solubility in water and high volatility at room temperature, the application of this drug is restricted in the clinic. The objective of this research was to develop a biocompatible paeonol formulation with improved stability, skin delivery and pharmacokinetic efficiency. In this paper, paeonol-loaded vesicles were prepared using an ethanol injection method. Nano-vesicles were characterized for their physical properties and encapsulation efficiency (EE). Drug permeation behavior in vitro and deposition quantity in porcine ear skin were measured with a Valia-Chien (V-C) diffusion device. Additionally, a validated and sensitive high performance liquid chromatography (HPLC) method was developed to analyze paeonol concentrations in rat plasma after transdermal administration. The results showed that the particle-size order of the nano-vesicles was the following: transethosomes (122.5±7.5nm)<transfersomes (256.5±8.9nm). Compared to the paeonol transfersomes, the transethosomes had a higher EE (85.5±5.2%), and they showed a spherical morphology with a smooth surface when viewed under a transmission electron microscope (TEM). In an in vitro permeation study, the paeonol transethosomes showed an enhanced transdermal flux of 95.7±8.8μg/cm²/h and a higher deposition quantity in porcine ear skin compared to the transfersomes. A one-compartment first-order absorption model could be used to describe the pharmacokinetics of paeonol in rats after transdermal administration. The AUC of the paeonol transethosomes was approximately 1.57- and 3.52-fold higher than those of the transfersomes and a saturated solution of paeonol in 35% ethanol, respectively. The results demonstrated that the paeonol transethosomes had a narrow size distribution, high encapsulation efficiency, and long residence in the plasma. This formulation remarkably enhanced the bioavailability of paeonol.

Anti-inflammatory and Anti-oxidative Activities of Paeonol and Its Metabolites Through Blocking MAPK/ERK/p38 Signaling Pathway

The possible protective and curative effects of paeonol on carrageenan-induced acute hind paw edema in rats and dextran sulfate sodium (DSS)-induced colitis in mice have been evaluated. After oral administration, paeonol (20 and 40 mg/kg) reduced the edema increase in paw volumes and also the development of DSS-induced murine colitis. Furthermore, anti-inflammatory and anti-oxidant activities of paeonol (1) together with its 10 metabolites (M2~M11) were investigated by using in vitro anti-inflammatory and anti-oxidant assays. M3 and M11 exhibited significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities (with EC50 values of 93.44 and 23.24 μM, respectively). All the metabolites except M8 showed hydroxyl radical scavenging activities, and M3 and M11 were the most potent agents (with EC50 values of 336.02 and 124.05 μM, respectively). Inhibitory effects of paeonol, M2~M11 on the overproduction of nitric oxide (NO), and the release of TNF-α were also tested. M3 and M11 potently inhibited lipopolysaccharide (LPS)-induced overproduction of NO in macrophage RAW 264.7. Western blot results demonstrated that paeonol, M3, and M11 downregulated the high expression of inducible nitric oxide synthase (iNOS) and COX-2 proteins, and the effects of M3 and M11 were more potent when compared with paeonol. These findings indicated that paeonol may play anti-inflammatory and anti-oxidant roles by changing to its active metabolites after absorption. In addition, further investigations on the mechanism showed that paeonol, M3, and M11 blocked the phosphorylation of MAPK/ERK 1/2 and p38, whereas they showed no effect on the phosphorylation of JNK. The above results suggested that pre-treatment with paeonol might be an effective therapeutic intervention against inflammatory diseases including colitis.

Anti-proliferative effects of paeonol on human prostate cancer cell lines DU145 and PC-3

Paeonol (Pae) is the main active ingredient from the root bark of Paeonia moutan and the grass of Radix Cynanchi Paniculati. Numerous reports indicate that Pae effectively inhibits several types of cancer lines. In this study, we report that Pae hinders prostate cancer growth both in vivo and in vitro. Human prostate cancer lines DU145 and PC-3 were cultured in the presence of Pae. The xenograft tumor in mice was established by subcutaneous injection of DU145 cells. Cell growth was measured by MTT, and the apoptosis was detected by the flow cytometry. Expression of Bcl-2, Bax, Akt, and mTOR were tested by western blotting assay. DU145 and PC-3 showed remarkable sensitivity to Pae, and exposure to Pae induced dose-and time-dependent growth inhibitory responses. Moreover, treatment of Pae promoted apoptosis and enhanced activities of caspase-3, caspase-8, and caspase-9 in DU145. Further work demonstrated Pae reduced expression of Bcl-2 and increased expression of Bax in DU145. Interestingly, we observed that Pae significantly decreased phosphorylated status of Akt and mTOR, and inhibitory effects of Pae and PI3K/Akt inhibitor on DU145 proliferation were synergistic. Finally, we confirmed that oral administration of Pae to the DU145 tumor-bearing mice significantly lowered tumor cell proliferation and led to tumor regression. Pae possesses inhibitory effects on prostate cancer cell growth both in vitro and in vivo, and the anti-proliferative effect may be closely related to its activation of extrinsic and intrinsic apoptotic pathway and inhibition of the PI3K/Akt pathway.

Integrated identification, qualification and quantification strategy for pharmacokinetic profile study of Guizhi Fuling capsule in healthy volunteers

Guizhi Fuling capsule (GZFL), a traditional Chinese medicine formulation, is widely used in China to relieve pain from dysmenorrhea and is now in a Phase II clinical trial in the USA. Due to the low exposure of the five main medicative ingredients (amygdalin, cinnamic acid, gallic acid, paeoniflorin and paeonol) of GZFL in human, a strategy was built to qualitatively and quantitatively identify the possible metabolites of GZFL and to describe the pharmacokinetic profiles of GZFL in human. In this strategy, LC-Q-TOF/MS was used to identify and structurally elucidate the possible metabolites of GZFL in vivo; and a time-based metabolite-confirming step (TBMCs) was used to confirm uncertain metabolites. The simultaneously quantitation results by LC-MS/MS showed low exposure of the five medicative ingredients. According to the strategy we built, a total of 36 metabolites were found and structurally elucidated. The simultaneously semi-quantitative analysis by LC-MS/MS showed that obvious time-concentration curves could be established for 12 of the metabolites, and most of them showed a relatively higher exposure. This study provides a better understanding of the metabolic processes of GZFL in human.

A comparison of the delayed outward potassium current between the nucleus ambiguus and hippocampus: sensitivity to paeonol

Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2'-hydroxy-4'-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100μM did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300μM increased the frequency of spontaneous action potentials in hippocampal CA1 neurons. Paeonol (300μM) significantly decreased the tetraethylammonium-sensitive outward current in hippocampal CA1 neurons, but had no effect upon the fast-inactivating potassium current (IA). Extracellular application of paeonol at 300μM did not affect action potentials or the delayed outward currents in NA neurons. Paeonol (100μM) reduced the Kv2.1 current in H1355 cells, but not the Kv1.2 current. The inhibitor of Kv2, guangxitoxin-1E, reduced the delayed outward potassium currents in hippocampal neurons, but had only minimal effects in NA neurons. We demonstrated that paeonol decreased the delayed outward current and increased excitability in hippocampal CA1 neurons, whereas these effects were not observed in NA neurons. These effects may be associated with the inhibitory effects on Kv2.1 currents.

Comparison of pharmacokinetic profiles of Terminalia phenolics after intragastric administration of the aqueous extracts of the fruit of Terminalia chebula and a Mongolian compound medicine-Gurigumu-7

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit of Terminalia chebula (fructus chebulae) is an important Traditional Medicine used for intestinal and hepatic detoxification. Gurigumu-7 which is made of fructus chebulae and 6 other traditional medicines is one of the most frequently used compound Mongolian and Tibet medicines for liver diseases. Terminalia phenolics are considered as the bioactive constituents of fructus chebulae and consequently of Gurigumu-7.

AIM OF THE STUDY

To compare the pharmacokinetic profiles of Terminalia phenolics after intragastric administration of the aqueous extracts of fructus chebulae and Gurigumu-7 and to evaluate the possible influence of intestinal bacterial metabolism on these pharmacokinetic profiles.

MATERIALS AND METHODS

An ultra performance liquid chromatography with triple quadrupole mass spectrometry method was established and validated for simultaneously determining the pharmacokinetic profiles of seven Terminalia phenolics after intragastric administration of pure compounds, fructus chebulae extract, and Gurigumu-7 extract. In vitro rat fecal lysates experiments were carried out to explore the metabolic discrepancy between fructus chebulae and Gurigumu-7.

RESULTS

Seven Terminalia phenolics were detected in rat plasma after intragastric administration of the aqueous extracts of fructus chebulae and Gurigumu-7. Administration of Gurigumu-7 could promote the absorption and increase the Cmax and AUC values of these phenolic constituents compared to fructus chebulae administration. The fecal lysates studies showed that the Terminalia phenolics in Gurigumu-7 were less rapidly bio-transformed than those in fructus chebulae. This may be a contributing factor to the pharmacokinetic discrepancy between the phenolics in fructus chebulae and Gurigumu-7.

CONCLUSION

Administration of Gurigumu-7 could increase the absorption of Terminalia phenolics through slowing down the intestinal bacteria metabolism. These results provide, in part, an in vivo rationale for the formulation of the traditional Mongolia / Tibet medicine, Gurigumu-7.

Simultaneous determination of thirteen major active compounds in Guanjiekang preparation by UHPLC-QQQ-MS/MS

An ultra high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS) method has been developed to evaluate the quality of a pharmaceutical herbal preparation, Guanjiekang (GJK), through a simultaneous determination of 13 major active compounds with a huge difference in level of content. Chromatographic separation was achieved on a Waters Acquilty UPLC C18 column (2.1 × 100 mm, 1.7 μm) with a mobile phase consisting of acetonitrile and buffer solution (10mM ammonium acetate containing 0.1% acetic acid) under a gradient elution manner. A triple quadrupole mass spectrometer was operated in positive ionization mode with multiple reaction monitoring for the detection of the 13 compounds. All calibration curves showed excellent linear regressions (R(2)>0.999) within the test range. The precision, repeatability and stability of the 13 compounds were below 5.0% in terms of RSD. The recoveries were 99.2-103.9% with RSD of 0.23-3.30% for GJK samples. The method was successfully used for the analysis of samples of GJK preparation and showed that the lowest level was in aconitine (0.582 ± 0.143 ng/g) and the highest was in paeoniflorin (16.80 ± 0.886 mg/g), with a 41800 folds of difference. In conclusion, a rapid, sensitive, precise, accurate, and reliable UHPLC-QQQ-MS/MS method has been developed for the simultaneous detection of 13 active compounds with massive difference in level of content in the pharmaceutical samples of GJK preparation, which can be applied for the quality control of GJK product.

A novel stearic acid-modified hirudin peptidomimetic with improved pharmacokinetic properties and anticoagulant activity

A novel hirudin isoform 3 mimetic peptide, named peptide S2, has been prepared by introduction of a stearic acid modification. Peptide S2 exhibited superior inhibitory activity to hirulog-1 (Bivariludin) and showed significantly higher anticoagulant potency in vivo. Peptide S2 elevated the thrombin time, prothrombin time and activated partial thromboplastin time of rat and human plasma more efficiently than hirulog-1 and the unmodified form of peptide S2 (peptide 1). Furthermore, peptide S2 inhibited arterial thrombosis and inferior vena cava in rat model 8 h after administration, and was 10-fold more potent than hirulog-1 300 min after administration of 0.1 μmol/kg peptide. The enhanced antithrombotic activity could be attributed to its long half-life (T_1/2 = 212.2 ± 58.4 min), which was 13.1 and 14.7-fold longer than those of hirulog-1 (T_1/2 = 15.1 ± 1.3 min) and peptide 1 (T_1/2 = 13.5 ± 2.6 min), respectively. Further enzymatic degradation and binding assay with human serum albumin (HSA) demonstrated that the longer duration time should be originated from the slowing of trypsin or thrombin–mediated degradation, as well as its binding to HSA. The improved pharmacokinetic properties observed for peptide S2 has made it a promising therapeutic agent for the treatment of thrombi-related diseases.

A study of pharmacokinetic interactions among co-existing ingredients in Viscum coloratum after intravenous administration of three different preparations to rats

Background:

Viscum coloratum (Komar) Nakai, known as Hujisheng in china, has been widely used as a herb medicine to treat a variety of diseases, including cardiovascular diseases, cancer, hypertension, hepatitis and hemorrhage.

Objective:

The aim was to investigate pharmacokinetic interactions among co-existing ingredients in V. coloratum after intravenous administration of three different preparations (four monomer solutions, the mixture of them and Viscum coloratum extracts) to rats.

Materials and Methods:

After protein precipitation pretreatment with plasma samples, high performance liquid chromatographic methods were developed and applied to quantitatively determinate the four components [syringin (Syri), homoeriodictyol-7-O-β-D-glycoside (Hedt-III), homoeriodictyol-7-O-β-D-apiose (1 → 2)-β-D-glycoside (Hedt-II) and homoeriodictyol-7-O-β-D-apiosiyl-(1 → 5)-β-D-apiosyl-(1 → 2)-β-D-glycoside (Hedt-I)]. The pharmacokinetic parameters (Area under the curve [AUC_(0-t)], AUC_(0-∞), t_1/2) were calculated using DAS 2.1 software (Chinese Pharmacological Society, Shanghai, China) and compared statistically by One-way analysis of variance using SPSS software (18.0, Chicago, IL, USA) with P < 0.05 considered statistically significant.

Results:

Good linearities were achieved in the measured concentration range with R² it0.9920. Precision, accuracy and extraction recovery were all within the acceptable range. For Syri, there was a significant difference only on t_1/2 among three treatment groups. For Hedt-I, Hedt II and Hedt-III, three flavonoid glycosides, the change of AUC_(0-t), AUC_(0-∞) and t_1/2 were markedly distinctive and even converse.

Conclusion:

Complex, extensive pharmacokinetic interactions were observed among these components in V. coloratum. They were mutually influenced by the in vivo absorption, distribution, metabolism and elimination. The result suggested traditional Chinese medicine was a complicated system, and we should take a scientific and dialectic view in the research and development processes.

Pharmacokinetic profile of phytoconstituent(s) isolated from medicinal plants-A comprehensive review

Herbal medicine, the backbone of traditional medicine, has played an important role in human health and welfare for a long period. Traditional therapeutic approaches of regional significance are found in Africa, South and Central America, China, India, Tibet, Indonesia, and the Pacific Islands. The considerable scientific significance and commercial potential of traditional medicines have resulted in increased international attention and global market demands for herbal medicines, especially Chinese herbal medicines. Herbal medicines currently are the primary form of health care for the poor in the developing countries, and also are widely used as a supplement or substitute for conventional drugs in developed countries. These traditional medicines have a pivotal role in the treatment of various ailments and more than 50% of drugs used in Western pharmacopoeia are isolated from herbs or derived from modifications of chemicals found in plants. Herbal medicines usually contain a complex mixture of various bioactive molecules, which make its standardization complicated, and there is little information about all compounds responsible for pharmacological activity. Several research papers have been published that claim pharmacological activity of herbal medicines but few are discussing the role of the exact phytoconstituent. Understanding the pharmacokinetic profile of such phytoconstituents is essential. Although there are research papers that deal with pharmacokinetic properties of phytoconstituents, there are a number of phytoconstituents yet to be explored for their kinetic properties. This article reviews the pharmacokinetic profile of 50 different therapeutically effective traditional medicinal plants from the year 2003 onward.

Revealing metabolomic variations in Cortex Moutan from different root parts using HPLC-MS method

INTRODUCTION

The distribution of metabolites in the different root parts of Cortex Moutan (the root bark of Paeonia suffruticosa Andrews) is not well understood, therefore, scientific evidence is not available for quality assessment of Cortex Moutan.

OBJECTIVE

To reveal metabolomic variations in Cortex Moutan in order to gain deeper insights to enable quality control.

METHODS

Metabolomic variations in the different root parts of Cortex Moutan were characterised using high-performance liquid chromatography combined with mass spectrometry (HPLC-MS) and multivariate data analysis. The discriminating metabolites in different root parts were evaluated by the one-way analysis of variance and a fold change parameter.

RESULTS

The metabolite profiles of Cortex Moutan were largely dominated by five primary and 41 secondary metabolites . Higher levels of malic acid, gallic acid and mudanoside-B were mainly observed in the second lateral roots, whereas dihydroxyacetophenone, benzoyloxypaeoniflorin, suffruticoside-A, kaempferol dihexoside, mudanpioside E and mudanpioside J accumulated in the first lateral and axial roots. The highest contents of paeonol, galloyloxypaeoniflorin and procyanidin B were detected in the axial roots. Accordingly, metabolite compositions of Cortex Moutan were found to vary among different root parts.

CONCLUSION

The axial roots have higher quality than the lateral roots in Cortex Moutan due to the accumulation of bioactive secondary metabolites associated with plant physiology. These findings provided important scientific evidence for grading Cortex Moutan on the general market.

Low-dose paeonol derivatives alleviate lipid accumulation

Here, we present a series of novel paeonol derivatives that prevent lipid accumulation at lower doses.

Exploring the ligand-protein networks in traditional chinese medicine: current databases, methods and applications

While the concept of "single component-single target" in drug discovery seems to have come to an end, "Multi-component-multi-target" is considered to be another promising way out in this field. The Traditional Chinese Medicine (TCM), which has thousands of years' clinical application among China and other Asian countries, is the pioneer of the "Multi-component-multi-target" and network pharmacology. Hundreds of different components in a TCM prescription can cure the diseases or relieve the patients by modulating the network of potential therapeutic targets. Although there is no doubt of the efficacy, it is difficult to elucidate convincing underlying mechanism of TCM due to its complex composition and unclear pharmacology. Without thorough investigation of its potential targets and side effects, TCM is not able to generate large-scale medicinal benefits, especially in the days when scientific reductionism and quantification are dominant. The use of ligand-protein networks has been gaining significant value in the history of drug discovery while its application in TCM is still in its early stage. This article firstly surveys TCM databases for virtual screening that have been greatly expanded in size and data diversity in recent years. On that basis, different screening methods and strategies for identifying active ingredients and targets of TCM are outlined based on the amount of network information available, both on sides of ligand bioactivity and the protein structures. Furthermore, applications of successful in silico target identification attempts are discussed in details along with experiments in exploring the ligand-protein networks of TCM. Finally, it will be concluded that the prospective application of ligand-protein networks can be used not only to predict protein targets of a small molecule, but also to explore the mode of action of TCM.

Novel effect of paeonol on the formation of foam cells: promotion of LXRα-ABCA1-dependent cholesterol efflux in macrophages

Paeonol, a phenolic component purified from Paeonia suffruticosa (Cortex Moutan), is used in traditional Chinese medicine to treat inflammatory diseases. However, little is known about the effect of paeonol on cholesterol metabolism. We investigated the efficacy of paeonol on cholesterol metabolism and the underlying mechanism in macrophages and apolipoprotein E deficient (apoE(-/-)) mice. Treatment with paeonol markedly attenuated cholesterol accumulation induced by oxidized LDL in macrophages, which was due to increased cholesterol efflux. Additionally, paeonol enhanced the mRNA and protein expression of ATP-binding membrane cassette transport protein A1 (ABCA1) but did not alter the protein level of ABCG1 or other scavenger receptors. Inhibition of ABCA1 activity with a pharmacological inhibitor, neutralizing antibody or small interfering RNA (siRNA), negated the effects of paeonol on cholesterol efflux and cholesterol accumulation. Furthermore, paeonol induced the nuclear translocation of liver X receptor α (LXRα) by increasing its activity. siRNA knockdown of LXRα abolished the paeonol-induced upregulation of ABCA1, promotion of cholesterol efflux and suppression of cholesterol accumulation. Moreover, atherosclerotic lesions, hyperlipidemia and systemic inflammation were reduced and the protein expression of ABCA1 was increased in aortas of paeonol-treated apoE(-/-) mice. Paeonol may alleviate the formation of foam cells by enhancing LXRα-ABCA1-dependent cholesterol efflux.

Exploring the ligand-protein networks in traditional chinese medicine: current databases, methods, and applications

The traditional Chinese medicine (TCM), which has thousands of years of clinical application among China and other Asian countries, is the pioneer of the “multicomponent-multitarget” and network pharmacology. Although there is no doubt of the efficacy, it is difficult to elucidate convincing underlying mechanism of TCM due to its complex composition and unclear pharmacology. The use of ligand-protein networks has been gaining significant value in the history of drug discovery while its application in TCM is still in its early stage. This paper firstly surveys TCM databases for virtual screening that have been greatly expanded in size and data diversity in recent years. On that basis, different screening methods and strategies for identifying active ingredients and targets of TCM are outlined based on the amount of network information available, both on sides of ligand bioactivity and the protein structures. Furthermore, applications of successful in silico target identification attempts are discussed in detail along with experiments in exploring the ligand-protein networks of TCM. Finally, it will be concluded that the prospective application of ligand-protein networks can be used not only to predict protein targets of a small molecule, but also to explore the mode of action of TCM.

LC-MS/MS determination of pogostone in rat plasma and its application in pharmacokinetic studies

Pogostone is an important constituent of Pogostemon cablin (Blanco) Benth., and possesses various known bioactivities. A rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of pogostone in rat plasma using chrysophanol as internal standard (IS). The analytes were extracted with methanol and separated using a reversed-phase YMC-UltraHT Pro C18 column. Elution was achieved with a mobile phase consisting of methanol-water (75:25, v/v) for 5 min at a flow rate of 400 μL/min. The precursor/product transitions (m/z) under MS/MS detection with negative electrospray ionization (ESI) were 223.0 → 139.0 and 253.1 → 224.9 for pogostone and IS, respectively. The calibration curve was linear over the concentration range 0.05-160 µg/mL (r = 0.9996). The intra- and inter-day accuracy and precision were within ±10%. The validated method was successfully applied to the preclinical pharmacokinetic investigation of pogostone in rats after intravenous (5, 10 and 20 mg/kg) and oral administration (5, 10 and 20 mg/kg). Finally, the oral absolute bioavailability of pogostone in rats was calculated to be 70.39, 78.18 and 83.99% for 5, 10 and 20 mg/kg, respectively.

The Predicted Proteomic Network Associated with the Antiarthritic Action of Qingfu Guanjieshu in Collagen-II-Induced Arthritis in Rats

Qingfu Guanjieshu (QFGJS) is an herbal preparation for treating rheumatoid arthritis (RA). Previous studies revealed that QFGJS significantly inhibited experimental arthritis and acute inflammation, accompanied by reduction of proinflammatory cytokines and elevation of anti-inflammatory cytokines. This study aims to identify the targeted proteins and predict the proteomic network associated with the drug action of QFGJS by using 2D gel and MALDI-TOF-MS/MS techniques. Thirty female Wistar rats were evenly grouped as normal and vehicle- and QFGJS-treated CIA rats. The antiarthritic effect of QFGJS was examined with a 19-day treatment course, and the knee synovial tissues of animals from each group were obtained for 2D gel and MALDI-TOF-MS/MS analysis. Results showed that QFGJS significantly ameliorated collagen II-induced arthritis when administrated at 2.8 g/kg body weight for 19 days. 2D gel image analysis revealed 89 differentially expressed proteins in the synovial tissues among the normal and vehicle- and QFGJS-treated CIA rats from over 1000 proteins of which 63 proteins were identified by MALDI-TOF-MS/MS analysis, and 32 proteins were included for classification of functions using Gene Ontology (GO) method. Finally, 14 proteins were analyzed using bioinformatics, and a predicted proteomic network related to the anti-arthritic effect of QFGJS was established, and Pgk1 plays a central role.

Network-based drug discovery by integrating systems biology and computational technologies

Network-based intervention has been a trend of curing systemic diseases, but it relies on regimen optimization and valid multi-target actions of the drugs. The complex multi-component nature of medicinal herbs may serve as valuable resources for network-based multi-target drug discovery due to its potential treatment effects by synergy. Recently, robustness of multiple systems biology platforms shows powerful to uncover molecular mechanisms and connections between the drugs and their targeting dynamic network. However, optimization methods of drug combination are insufficient, owning to lacking of tighter integration across multiple '-omics' databases. The newly developed algorithm- or network-based computational models can tightly integrate '-omics' databases and optimize combinational regimens of drug development, which encourage using medicinal herbs to develop into new wave of network-based multi-target drugs. However, challenges on further integration across the databases of medicinal herbs with multiple system biology platforms for multi-target drug optimization remain to the uncertain reliability of individual data sets, width and depth and degree of standardization of herbal medicine. Standardization of the methodology and terminology of multiple system biology and herbal database would facilitate the integration. Enhance public accessible databases and the number of research using system biology platform on herbal medicine would be helpful. Further integration across various '-omics' platforms and computational tools would accelerate development of network-based drug discovery and network medicine.

Isolation and identification of the metabolites of paeonol in human urine

Paeonol, a major component of Paeonia suffruticosa Andrews, is used in clinical situations in China as a natural anti-inflammatory agent. The aim of the present study is to investigate the metabolism of paeonol in humans. Six metabolites were isolated from human urine after oral administration of paeonol, and their structures were elucidated as resacetophenone (M1), resacetophenone-2-O-sulfate (M2), 2-hydroxy-4-methoxyacetophenone-5-O-sulfate(M3), 2-hydroxy-4-methoxyacetophenone-5-O-glucopyranuronoside (M4), 2-hydroxyacetophenone-4-O-glucopyranuronoside (M5) and 2,5-dihydroxy-4-methoxyacetophenone(M6) by a series of analyses involving mass spectrometry, (1)H NMR, (13)C NMR and NOESY spectra. In addition, three more metabolites 2,4-dihydroxyacetophenone-5-O-sulfate (M7), paeonol-2-O-glucopyranuronoside (M8) and paeonol-2-O-sulfate (M9), were identified in human urine by using a UPLC/Q-TOF-MS/MS method. This is the first study of paeonol metabolism in humans. Based on the identified metabolites, possible metabolic pathways of paeonol in humans are proposed. Paeonol is metabolized mainly by hydroxylation and demethylation to give the corresponding phase I metabolites, M1, M6 and 2,4,5-trihydroxyacetophenone, and which then underwent conjugation with glucuronic acid or sulfuric acid to form phase II metabolites.

Paeoniflorin reduced acute toxicity of aconitine in rats is associated with the pharmacokinetic alteration of aconitine

ETHNOPHARMACOLOGICAL RELEVANCE

To investigate the influence of paeoniflorin (major bioactive component of Paeonia lactiflora Pall.) on the pharmacokinetic behavior of aconitine (major toxic and bioactive component of Aconitum carmichaeli Debx.) and potential detoxifying effect of paeoniflorin on the acute toxicity of aconitine, which may provide in depth understanding to the toxicity reduction effect of Paeonia lactiflora to Aconitum carmichaeli.

MATERIALS AND METHODS

Ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometer (UHPLC-MS/MS) was employed to determine the plasma content of aconitine. Aconitine was administrated by oral to SD rats at the dosage of 200 μg/kg with or without paeoniflorin given by intraperitoneal injection at the dosage of 20 mg/kg. Plasma samples were collected for determination and analysis of pharmacokinetic parameters of aconitine. The LD(50) of aconitine and acute animal death induced by aconitine were examined when aconitine was given alone or jointly with paeoniflorin in ICR mice.

RESULTS

A sensitive, accurate, precise, reliable and repeatable UHPLC-MS/MS method was successfully established for determination of the plasma content of aconitine in 12.5 μL plasma sample. The lower limit of quantification of aconitine was 0.01 ng/mL. Compared with the SD rats that were orally administrated with aconitine alone, the rats received aconitine and co-administrated with paeoniflorin by peritoneal injection showed a remarkably lower C(max) (5.69 ng/mL vs 9.66 ng/mL, P<0.05) and delayed T(max) (70 min vs 46 min, P<0.05), as well as a trend of reduction in AUC(0-t) (1082.75 ng-min/mL vs 1650.27 ng-min/mL, P=0.395). The LD(50) values of aconitine coadministered with 120 or 240 mg/kg of paeoniflorin were obviously increased to 2.30 and 2.15 mg/kg against 1.80 mg/kg of aconitine by oral administration alone. Mice treated with paeoniflorin (240 mg/kg) and aconitine (1.8 mg/kg) together revealed a significant decreased death rate than that received aconitine treatment alone (15% vs 50%, P<0.05).

CONCLUSIONS

The acute oral toxicity of aconitine in rats was significantly reduced by paeoniflorin; this might result from the alterations of pharmacokinetic behavior of aconitine in the animals by coadministration of paeoniflorin.

Applications of HPLC/MS in the analysis of traditional Chinese medicines

In China, traditional Chinese medicines (TCMs) have been used in clinical applications for thousands of years. The successful hyphenation of high-Performance liquid chromatography (HPLC) and mass spectrometry (MS) has been applied widely in TCMs and biological samples analysis. Undoubtedly, HPLC/MS technique has facilitated the understanding of the treatment mechanism of TCMs. We reviewed more than 350 published papers within the last 5 years on HPLC/MS in the analysis of TCMs. The present review focused on the applications of HPLC/MS in the component analysis, metabolites analysis, and pharmacokinetics of TCMs etc. 50% of the literature is related to the component analysis of TCMs, which show that this field is the most populär type of research. In the metabolites analysis, HPLC coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry has been demonstrated to be the powerful tool for the characterization of structural features and fragmentation behavior patterns. This paper presented a brief overview of the applications of HPLC/MS in the analysis of TCMs. HPLC/MS in the fingerprint analysis is reviewed elsewhere.

Determination of asperosaponin VI in rat plasma by HPLC-ESI-MS and its application to preliminary pharmacokinetic studies

Asperosaponin VI (also named akebia saponin D) is a typical bioactive triterpenoid saponin isolated from the rhizome of Dipsacus asper Wall (Dipsacaceae). In this work, a sensitive high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) assay has been established for determination of asperosaponin VI in rat plasma. With losartan as the internal standard (IS), plasma samples were prepared by protein precipitation with methanol. Chromatographic separation was performed on a C(18) column with a mobile phase of 10 mm ammonium acetate buffer containing 0.05% formic acid-methanol (32 : 68, v/v). The analysis was performed on an ESI in the selected ion monitoring mode using target ions at m/z 951.4 for asperosaponin VI and m/z 423.2 for the IS. The calibration curve was linear over the range 3-1000 ng/mL and the lower limit of quantification was 3.0 ng/mL. The intra- and inter-assay variability values were less than 9.5 and 7.8%, respectively. The accuracies determined at the concentrations of 3.0, 100.0, 300.0 and 1000 ng/mL for asperosaponin VI were within +/-15.0%. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of asperosaponin VI.