Validation of a HPLC-tandem MS/MS method for pharmacokinetics study of (+)-pinoresinol-di-β-D-glucopyranoside from Eucommia ulmoides Oliv extract in rats' plasma

Characterization of the metabolites of Eucommiae Cortex in rats provides a further insight into its estrogen-like effective substances

Eucommiae Cortex is one of important traditional Chinese medicines (TCMs) used in Asia for preventing and treating osteoporosis induced by estrogen deficiency. However, the low exposure of prototype components in Eucommiae Cortex in vivo is difficult to interpret its efficacy. Under the guidance of UPLC-Q/TOF-MS, 42 metabolites including 32 lignans and 10 phenolics, 21 of which were new compounds, were isolated from rat urine and feces after oral administration of aqueous extract of E. ulmoides Oliv. by various chromatographic techniques. Their structures were determined based on extensive physicochemical analyses and spectral data. Their absolute configurations were determined by experimental and calculated ECD spectra, along with the calculated NMR with DP4 evaluation. Additionally, all isolated metabolites were evaluated for their estrogen-like activities, and there are 15 metabolites having estrogen-like effects after assessing influences in MCF-7 cells. Further, Dual Luciferase Reporter Gene Assay was used to determine their activation with estrogen receptor, M10 and M11 mixtures, M14, M19, M33, M27, M31, M38-M41 could activate ERα, and M19 and M41 could activate ERβ. These results not only clarify the pharmacological substances of Eucommiae Cortex, but also provide a basis for guiding its clinical application.

Research Progress of Eucommia ulmoides Oliv and Predictive Analysis of Quality Markers Based on Network Pharmacology

Du Zhong is a valuable Chinese medicinal herb unique to China. It is a national second- class precious protected tree, known as "plant gold", which has been used to treat various diseases since ancient times. The main active ingredients are lignans, phenylprophetons, flavonoids, iridoids and steroids and terpenoids, which have pharmacological effects such as lowering blood pressure, enhancing immunity, regulating bone metabolism, protecting nerve cells, protecting liver and gallbladder and regulating blood lipids. In this paper, a comprehensive review of Eucommia ulmoides Oliv. was summarized from the processing and its compositional changes, applications, chemical components, pharmacological effects, and pharmacokinetics, and the Q-marker of Eucommia ulmoides Oliv. is preliminarily predicted from the aspects of traditional efficacy, medicinal properties and measurability of chemical composition, and the pharmacodynamic substance basis and potential Q-marker of Eucommia ulmoides Oliv. are further analyzed through network pharmacology. It is speculated that quercetin, kaempferol, β-sitosterol, chlorogenic acid and pinoresinol diglucoside components are selected as quality markers of Eucommia ulmoides Oliv., which provide a basis for the quality control evaluation and follow-up research and development of Eucommia ulmoides Oliv.

Comparative Study on the Absorption and Metabolism of Pinoresinol and Pinoresinol-4-O-β-D-Glucopyranoside in Mice

SCOPE

Lignans are a group of phenolic compounds commonly found in plants, often in the form of glycosides. This study investigates the differences in the digestion, absorption, and metabolism of lignans and their glucosides using pinoresinol (PIN) and pinoresinol-4-O-β-D-glucopyranoside (PMG).

METHODS AND RESULTS

After oral administration mice PIN and PMG with a dose of 0.1 µmol kg-1 . The results showed that the stomach and small intestine rapidly absorbe PIN and PMG in their prototype form. After oral administration of 0.25 h, serum levels of PIN and PMG reach peak values of 61.14 and 52.97 ng mL-1 , respectively. This indicates a faster PIN absorption rate than PMG, likely due to the glycosides attach to the parent compound, with concentrations of 1574.14 and 876.75 ng g-1 , respectively. Pharmacokinetic analysis reveals that PIN has a greater area under the curve and a longer half-life than PMG in serum and liver. Moreover, mice in the PIN group exhibit higher metabolite levels in the serum and liver compared to those in the PMG group.

CONCLUSION

The deglycosylation process that occurs during the pickling of white radish facilitates the absorption and metabolism of the lignans fraction in the body.

Rapid identification of the geographical origin of Eucommia ulmoides by using excitation-emission matrix fluorescence combined with chemometric methods

Eucommia ulmoides is an important and valuable traditional Chinese medicine with various medical functions, and has been widely used as health food in China, Japan, South Korea and other Asian countries for many years. The efficacy and quality of E. ulmoides are closely associated with the geographical origin. In this work, the potential of excitation-emission matrix (EEMs) fluorescence coupled with chemometric methods was investigated for simple, rapid and accurate for identification E. ulmoides from different geographical origins. Parallel factor analysis (PARAFAC) was applied for characterizing the fluorescence fingerprints of E. ulmoides samples. Moreover, k-nearest neighbor (kNN), principal component analysis-linear discriminant analysis (PCA-LDA) and partial least squares discriminant analysis (PLS-DA) models were used for the classification of E. ulmoides samples according to their geographical origins. The results showed that kNN model was more suitable for identification of E. ulmoides samples from different provinces. The kNN model could identify E. ulmoides samples from eight different geographical origins with 100% accuracy on the training and test sets. Therefore, the proposed method was available for conveniently and accurately determining the geographical origin of E. ulmoides, which can expect to be an attractive alternative method for identifying the geographic origin of other traditional Chinese medicines.

Traditional application and modern pharmacological research of Eucommia ulmoides Oliv

As a Traditional Chinese Medicine, Eucommia ulmoides Oliv. has been used for the treatment of various diseases since ancient times, involving lumbar pain, knee pain, osteoporosis, hepatoprotection, paralysis, intestinal haemorrhoids, vaginal bleeding, abortion, spermatorrhoea, foot fungus, anti-aging etc. With the developing discovery of E. ulmoides extracts and its active components in various pharmacological activities, E. ulmoides has gained more and more attention. Up to now, E. ulmoides has been revealed to show remarkable therapeutic effects on hypertension, hyperglycemia, diabetes, obesity, osteoporosis, Parkinson's disease, Alzheimer's disease, sexual dysfunction. E. ulmoides has also been reported to possess antioxidant, anti-inflammatory, neuroprotective, anti-fatigue, anti-aging, anti-cancer and immunoregulation activities etc. Along these lines, this review summarizes the traditional application and modern pharmacological research of E. ulmoides, providing novel insights of E. ulmoides in the treatment of various diseases.

Comparative absorption kinetics of seven active ingredients of Eucommia ulmoides extracts by intestinal in situ circulatory perfusion in normal and spontaneous hypertensive rats

Eucommia ulmoides Oliv. (E. ulmoides) is a valuable and nourishing medicinal herb in China that has been used in the treatment of hypertension. Given the fact that most traditional Chinese medicine is mainly used to treat disease, investigating the pharmacokinetics of traditional Chinese medicines in the pathological state is more useful than that in the normal state. However, the differences in the absorption kinetics of active ingredients of E. ulmoides extract between pathological and physiological conditions have not been reported. Therefore, in this study, the rat intestinal in situ circulatory perfusion model was used to investigate the differences in absorption kinetics of seven active ingredients of E. ulmoides extract in normal and spontaneously hypertensive rats, namely, genipinic acid, protocatechuic acid, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, (+)-pinoresinol di-O-β-D-glucopyranoside and (+)-pinoresinol 4'-O-β-D-glucopyranoside. Our results indicate that the pathological state of spontaneous hypertension may change the absorption of active components of E. ulmoides extracts, and these findings may provide a reference for improving the rational use of E. ulmoides in the clinic.

A UPLC-MS Method for Simultaneous Determination of Geniposidic Acid, Two Lignans and Phenolics in Rat Plasma and its Application to Pharmacokinetic Studies of Eucommia ulmoides Extract in Rats

The bark of Eucommia ulmoides is a well-known Chinese herbal medicine that is used to regulate blood pressure and reduce blood sugar and fats, as well as an antioxidant and antimicrobial agent. Here we describe the development of a sensitive ultrahigh performance liquid chromatography-tandem mass spectrum method for the simultaneous determination of five major active ingredients of E. ulmoides bark extract, namely, geniposidic acid (GA), protocatechuic acid (PCA), chlorogenic acid (CA), (+)-pinoresinol di-O-β-D-glucopyranoside (PDG) and (+)-pinoresinol 4'-O-β-D-glucopyranoside (PG), in rat plasma. The preliminary steps in the plasma analysis were the addition of an internal standard and acidification (0.1 % formic acid), followed by protein precipitation with methanol. Separation of the active ingredients was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm; internal diameter 1.7 µm) at a flow rate of 0.35 mL/min, with acetonitrile/water containing 0.1 % formic acid as the mobile phase. Detection was performed on a triple quadrupole tandem mass spectrometer via electrospray ionization source with positive and negative ionization modes. All calibration curves showed good linearity (r ≥ 0.997) over the concentration range with the low limit of quantification between 4.45 and 54.9 ng/mL. Precision was evaluated by intra- and inter-day assays, and the percentages of the relative standard deviation were all within 15 %. Extraction efficiency and matrix effect were 84.3-102.4 % and 98.1-112.2 %, respectively. The validated method was successfully applied to the pharmacokinetic study in rats after oral administration of E. ulmoides extract. The results indicate that the pharmacokinetic properties of GA differ from those of PCA, CA, PDG and PG, respectively.

A Comprehensive Review on Pharmacokinetic Profile of Some Traditional Chinese Medicines

Herbal medicines are the oldest and most widely used form of treatment for welfare of mankind. Herbal medicines possess strong reputation as complementary treatment across the globe due to their easy accessibility and safety. Particularly traditional Chinese medicines (TCM) are very popular due to their desirable therapeutic effects. They already have been proven for their remarkable potential in treatment of wide range of disease ailments. The major drawback in using herbal medicines is lack of standardisation aspects due to the complexity of chemical constituents. Pharmacokinetics study of such medicines helps forecast a range of events related to efficacy, safety, and toxicity profile of them. Apart from this, pharmacokinetics studies also recommended by various regulatory agencies during diverse stages of herbal drug development. Thus it is highly essential to have knowledge about the pharmacokinetic properties of any herbal drug. Thus it was thought that it will be worthwhile to compile the pharmacokinetic data of TCM which will be helpful for the researchers involved in further research on TCM. To portray entire picture about absorption, distribution, metabolism, and excretion (ADME) of some TCM, this well-designed scientific review covers the pharmacokinetic profile of 50 TCM available from 2003 and onwards.

Simultaneous quantitation and validation of method for the quality evaluation of Eucommiae cortex by HPLC/UV

A new HPLC/UV method has been developed for the simultaneous quantitative determination of four major components in Eucommiae cortex, namely geniposidic acid (1), geniposide (2), pinoresinol di-O-β-D-glucopyranoside (3), and liriodendrin (4). Simultaneous separations of these four components were achieved on a J'sphere ODS C(18) column (250 × 4.6 mm, 4 µm). The elution was done using water with 0.1% phosphoric acid (A) and acetonitrile with 0.1% phosphoric acid (B) in a two-step elution of the mobile phase at a flow rate of 1.0 mL/min and a wavelength of 230 nm. The method was validated for linearity, recovery, precision, accuracy, stability and robustness. All calibration curves showed good linear regression (r(2) > 0.999) within the test ranges. This method showed good recovery and reproducibility for the quantification of these four components in 85 species of Eucommiae cortex. The intra-day and inter-day precisions were lower than 0.53% (as a relative standard deviation, RSD) and accuracies between 93.00 and 106.28% for all standards. The results indicate that the established HPLC/UV method is suitable for quantitation and quality evaluation of Eucommiae cortex.

UPLC-MS/MS determination and gender-related pharmacokinetic study of five active ingredients in rat plasma after oral administration of Eucommia cortex extract

ETHNOPHARMACOLOGICAL RELEVANCE

Eucommiae cortex (EC), the bark of Eucommia ulmoides Oliv., has been traditionally used to treat many diseases in China for more than 2000 years. The pharmacological effects are primarily attributed to the presence of lignans, iridoids and phenolics, which are main active ingredients in EC.

AIM OF THE STUDY

First, to investigate the active ingredients that can be absorbed into the rat plasma according to which ingredients exhibit significant correlation of drug concentration-time curve. Second, to establish an efficient ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of ingredients absorbed in rat plasma. Finally, to investigate gender effect on the pharmacokinetics of the ingredients absorbed in male and female rats plasma after oral administration with EC extract.

MATERIALS AND METHODS

18 ingredients from EC were detected by UPLC-MS/MS, 9 out of 18 ingredients were absorbed into rat plasma. And 5 ingredients exhibit significant correlation of drug concentration-time curve. They were pinoresinol di-O-β-d-glucopyranoside (PDG), geniposide (GE), geniposidic acid (GA), aucubin (AN) and chlorogenic acid (CA). The analytes were extracted from rat plasma via a simple protein precipitation procedure and osalmid was used as the internal standard. Chromatographic separation was achieved on a Waters ACQUITY HSS T3 column (2.1mm×100mm, 1.8μm) using a gradient elution program with acetonitrile and 0.1% formic acid water as the mobile phase, with a flow rate of 0.3mLmin(-1). The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reactions monitoring (MRM) mode in a positive ion mode via electrospray ionization (ESI). The transition monitored were /z 683.00[M+H](+)→235.10 for PDG, / z 389.00[M+H](+)→208.80 for GE, m/z 375.00[M+H](+)→194.79 for GA, m/z 364.00[M+NH4](+)→148.81 for AN, m/z 355.10[M+H](+)→162.84 for CA and m/z 230.03[M+H](+)→120.77 for internal standard.

RESULTS

The developed method showed good linearity over a wide concentration range, the lower limits of quantification and higher accuracy and precision for determination of the 5 analytes. Then the method was applied to study the pharmacokinetics in rats, and the results indicated that there were significant differences in pharmacokinetic parameters of the analytes between the male and female rats, and absorptions of these analytes in male group were all significantly higher than those in female group.

CONCLUSION

This study established an efficient, sensitive and selective UPLC-MS/MS method for simultaneous determination of the five ingredients in rat plasma, and it could be successfully applied to the comparative pharmacokinetic studies in male and female rats after oral administration with EC extract.

LC/MS/MS determination and pharmacokinetic studies of six compounds in rat plasma following oral administration of the single and combined extracts of Eucommia ulmoides and Dipsacus asperoides

AIM

To establish and apply a new LC/MS/MS method for the simultaneous, quantitative determination of six ingredients, aucubin (AU), geniposide (GP), geniposidic acid (GPA), pinoresinol diglucoside (PDG), secologanin (SLG), and loganin (LG) in single and combined extracts of Eucommia ulmoides and Dipsacus asperoides.

METHOD

Using the LC/MS/MS-ESI(-)-MRM mode to detect the six compounds, chromatographic separation was achieved on an Agilent Eclipse plus C18 column, and the mobile phase consisted of solvent A (CH3CN) and solvent B (H2O containing 0.01% CH3COOH V/V).

RESULTS

This method was successfully applied to quantify the six compounds in rat plasma after oral administration, and showed good precision, accuracy, reproducibility, and linear regression (r(2)>0.99).

CONCLUSION

The results showed that following the use of the two medicinal plants, for AU and GP, the values of Cmax markedly increased, and the values of cmax markedly decreased. It was found that the compatibility of the medicinal plants might affect their pharmacokinetic properties of their constituents.

Lignans from the bark of Eucommia ulmoides inhibited Ang II-stimulated extracellular matrix biosynthesis in mesangial cells

Background

Tree bark of Eucommia ulmoides Oliv., (commonly well-known as “Du-zhong” in China), has been used to treat hypertension, hypercholesterolemia, hyperglycemia, hepatic fibrosis and renal injury. This study aims to investigate the effects of lignans extracted from the bark of Eucommia ulmoides Oliv. on Ang II-induced proliferation and extracellular matrix biosynthesis in rat mesangial cells.

Methods

Rat mesangial cells (RMCs) were cultured in vitro and divided into six groups (control, Ang II, losartan, and low, middle and high concentration lignans groups). RMC proliferation was measured by MTT assay. RT-qPCR and western blotting were used to detect mRNA and protein expression of collagen type I (Col I), collagen type III (Col III), collagen type IV (Col IV), fibronectin and aldose reductase (AR).

Results

Cellular proliferation induced by Ang II was significantly suppressed by Eucommia lignans of different concentrations (P = 0.034, P < 0.001, and P < 0.001). Treatment of cells with Ang II increased Col I, Col III, Col IV, and fibronectin mRNA expression, which was observed at the protein level (P < 0.001, P < 0.001, P = 0.004, and P = 0.004, respectively). The increased mRNA expression and protein levels of Col I, Col III, Col IV, and fibronectin were diminished remarkably with by treatment Eucommia lignans, and elevated AR expression stimulated by Ang II was significantly inhibited by Eucommia lignans.

Conclusions

Eucommia lignans (Du-zhong) inhibited Ang II-stimulated extracellular matrix biosynthesis in mesangial cells.

Recent developments in the field of the determination of constituents of TCMs in body fluids of animals and human

Although traditional Chinese medicines (TCMs) play important role in drug discovery and human health, the actual value of TCMs has not been fully recognized worldwide due to its complex components and uncontrollable quality. For the modernization and globalization of TCMs, it is important to establish selective, sensitive and feasible analytical methods for determination and quantification of bioactive components of TCMs in body fluids primarily due to the low concentration, the complex nature of the biological matrices, and multi-components and their metabolites present in biological fluids. The present review summarizes the current extraction techniques, chromatographic separation and spectroscopic (especially mass spectrometric) analysis methods and new trends on the analysis of bioactive components and metabolites of TCMs in biological fluids. In addition, the importance of establishment of pharmacokinetics and bioavailability profiles and simultaneous determination of multi-active components in TCMs is discussed to provide proper examples of analytical methods for pharmacological and clinical studies of TCMs.