High-performance liquid chromatographic method for the determination and pharmacokinetic study of dehydrotumulosic acid in the plasma of rats having taken the traditional chinese medicinal preparation Ling-Gui-Zhu-Gan decoction

Spectrum-effect relationship analysis based on HPLC-FT-ICR-MS and multivariate statistical analysis to reveal the pharmacodynamic substances of Ling-Gui-Zhu-Gan decoction on Alzheimer's disease

Alzheimer's disease (AD) threatens elderly human health and still lacks effective treatment. Our previous work showed that LGZGD possessed a neuroprotective effect on the Aβ25-35-induced neurotoxicity in differentiated PC12 cells, indicating that LGZGD may be a potential drug for treatment of AD. However, its pharmacodynamic substances which show anti-inflammatory and anti-oxidant stress activities are still unrevealed. This research aims to reveal the pharmacodynamic substances of LGZGD on Aβ25-35-induced PC12 cell model of AD based on a spectrum-effect relationship study by using HPLC-FT-ICR-MS method and multivariate statistical analysis. Firstly, the chemical composition spectra of different combinations of LGZGD were recorded by HPLC-FT-ICR MS. Subsequently, Aβ25-35-induced PC12 cell model of AD was established and pharmacodynamic experiments were conducted to evaluate their anti-inflammatory and anti-oxidant activities, respectively. Finally, the potential pharmacodynamic substances were screened out through spectrum-effect relationship study accompanied by multivariate statistical analysis including bivariate correlation analysis (BCA), grey relational analysis (GRA), principal component analysis (PCA), partial least squares regression analysis (PLSR). As a result, a total of 96 chemical consistents in different combinations of LGZGD were discovered. Among them, 7 components such as isoglabrolide, licorice saponin E2, licorice saponin N2 and licoisoflavanone were directly linked with the anti-inflammatory effects, and 14 constituents such as tumulosic acid, polyporenic acid C, dehydrotumulosic acid, dehydropachymic acid, and pachymic acid were directly correlated with the anti-oxidative stress activities. In conclusion, we combined the HPLC-FT-ICR-MS spectra with pharmacodynamic indicators to develop the spectrum-effect relationships of LGZGD for the first time, and successfully revealed its potential pharmacodynamic substances in the treatment of AD from the anti-inflammatory and antioxidant pathways in the cell model.

Comparison of pharmacokinetic profiles of seven major bioactive components in normal and non-alcoholic fatty liver disease (NAFLD) rats after oral administration of Ling-Gui-Zhu-Gan decoction by UPLC-MS/MS

A sensitive and rapid ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was hereby developed for the determination of seven components, namely, glycyrrhizic acid, glycyrrhetinic acid, dehydrotumulosic acid, isoliquiritin, liquiritin, atractylenolide III, and cinnamic acid, in the plasma of rats after the oral administration of Ling-Gui-Zhu-Gan decoction (LGZGD). Besides, this very method was methodologically validated for specificity, linearity, inter-day and intra-day precision, accuracy, matrix effect, extraction recovery, and stability. It was also successfully used for the first time to compare the pharmacokinetic characteristics of the seven components after oral administration of LGZGD to normal rats and non-alcoholic fatty liver disease (NAFLD) rats. The results indicated significant differences between the pharmacokinetic characteristics of normal and NAFLD rats. To further reveal the different pharmacokinetic behaviors, the expressions of enzymes and transporters in the liver of normal and NAFLD rats were detected using UPLC-MS/MS. In the NAFLD rats, UDP-glucuronosyltransferase 1-1 (UGT1A1) and nine transporters were significantly inhibited and a positive correlation was observed between them and the AUC of the major components. The present results indicate that the pharmacokinetic differences between the normal and NAFLD rats might be attributed to the significant lower expression levels of both the metabolic enzyme UGT1A1 and nine transporter proteins in the NAFLD rats than in the normal rats. Meanwhile, UGT1A1 and the nine transporter proteins might be used as potential biomarkers to assess the ameliorative effect of LGZGD on NAFLD, which could provide useful information to guide the clinical application of LGZGD.

Lingguizhugan decoction protects PC12 cells against Aβ25-35-induced oxidative stress and neuroinflammation by modulating NF-κB/MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD) is recognized as one of the most prevalent neurodegenerative diseases. Lingguizhugan decoction (LGZGD) is a classical traditional Chinese medicine (TCM). Many studies have shown that LGZGD can alleviate the symptoms of AD.

AIM OF THE STUDY

The aim of this study was to assess the neuroprotective effects of LGZGD and elucidate its molecular mechanism on Aβ_25-35-induced PC12 cells.

MATERIALS AND METHODS

PC12 cells were used MTT assays, ELISA, fluorescence probe analyses, Hoechst 33342 staining, immunofluorescent staining and western blot analyses were systematically conducted to evaluate the underlying mechanisms of LGZGD.

RESULTS

In Aβ_25-35-induced PC12 cells, LGZGD remarkably increased cell viability, reduced the generation of TNF-α, IL-1β, IL-6, MDA and ROS, increased the activity of GSH-Px, inhibited cell apoptosis, downregulated the expression of Bax and cleaved caspase-3, and upregulated the expression of Bcl-2. Moreover, LGZGD modulated the NF-κB/MAPK signaling pathways by upregulating the levels of IκBα and phospho-ERK, while downregulating the levels of phospho-p65, phospho-IκBα, and phospho-p38. Furthermore, LGZGD repressed the nuclear translocation activity of NF-κB p65. Meanwhile, LGZGD increased the expression of phospho-GSK-3β and reversed the hyperphosphorylation of Tau proteins by inhibiting the activation of the ERK MAPK pathway.

CONCLUSIONS

Taken together, the present study suggested that LGZGD may be a valuable drug candidate that can attenuate the neurotoxicity induced by Aβ_25-35 by modulating the NF-κB/MAPK signaling pathways in PC12 cells.

Ling-Gui-Zhu-Gan Decoction Protects H9c2 Cells against H2O2-Induced Oxidative Injury via Regulation of the Nrf2/Keap1/HO-1 Signaling Pathway

OBJECTIVES

Ling-Gui-Zhu-Gan decoction (LGZGD) is a potentially effective treatment for heart failure, and it showed significant anti-inflammatory potential in our previous studies. However, its ability to ameliorate heart failure through regulation of oxidative stress response is still unknown. This study was aimed to investigate the protective effect of LGZGD-containing serum on H2O2-induced oxidative injury in H9c2 cells and explore the underlying mechanism.

METHODS

Eighteen rats were randomly divided into two groups: the blank control group and LGZGD group. The LGZGD group rats were administrated with 8.4 g/kg/d LGZGD for seven consecutive days through gavage, while the blank control group rats were given an equal volume of saline. The serum was extracted from all the rats. To investigate the efficacy and the underlying mechanism of LGZGD, we categorized the H9c2 cells into groups: the control group, model group, normal serum control (NSC) group, LGZGD group, LGZGD + all-trans-retinoic acid (ATRA) group, and ATRA group. Malonedialdehyde (MDA) and superoxide dismutase (SOD) were used as markers for oxidative stress. Dichlorodihydrofluorescin diacetate (DCFH-DA) staining was used to measure the levels of reactive oxygen species (ROS). The apoptosis rate was detected using flow cytometry. The expression levels of pro-caspase-3, cleaved-caspase-3, Bcl-2, Bax, Keap1, Nrf2, and HO-1 were measured using western blotting. The mRNA levels of Keap1, Nrf2, and HO-1 were measured using RT-qPCR.

RESULTS

The LGZGD attenuated injury to H9c2 cells and reduced the apoptosis rate. It was also found to upregulate the SOD activity and suppress the formation of MDA and ROS. The expression levels of pro-caspase-3 and Bcl-2 were significantly increased, while those of cleaved-caspase-3 and Bax were decreased in the LGZGD group compared with the model group. As compared with the model group, the LGZGD group demonstrated decreased Keap1 protein expression and significantly increased Nrf2 nuclear expression and Nrf2-mediated transcriptional activity. ATRA was found to reverse the LGZGD-mediated antioxidative and antiapoptotic effect on injured H9c2 cells induced by H2O2.

CONCLUSION

Our results demonstrated that LGZGD attenuated the H2O2-induced injury to H9c2 cells by inhibiting oxidative stress and apoptosis via the Nrf2/Keap1/HO-1 pathway. These observations suggest that LGZGD might prevent and treat heart failure through regulation of the oxidative stress response.

Rapid determination of polysaccharides and antioxidant activity of Poria cocos using near-infrared spectroscopy combined with chemometrics

This study evaluates the feasibility of near-infrared (NIR) spectroscopy combined with chemometrics as a fast and efficient technique to predict the polysaccharide content and antioxidant activity of Poria cocos. The reference values of polysaccharide content were determined by the phenol-sulfuric acid method, and the antioxidant activities were determined by the DPPH scavenge assay, FRAP scavenge assay and ABTS scavenge assay, respectively. The partial least squares regression algorithm was used to relate the spectra to the reference values. Various methods for spectra pretreatment and variable selection were optimized to improve the predictability and stability of the models. As a result, the best models yielded very satisfying results, of which the values of coefficients of determination were all >0.94, and the values of residual predictive deviation were all >4. Such results confirmed that the present method is robust and applicable, and thus has good potential for rapid quality evaluation of Poria cocos.

Effect of Ling-Gui-Zhu-Gan decoction major components on the plasma protein binding of metoprolol using UPLC analysis coupled with ultrafiltration

Using traditional Chinese medicine formula Ling-Gui-Zhu-Gan decoction (LGZGD) plus selective β1-adrenergic receptor inhibitor metoprolol to treat arrhythmia of coronary heart disease can significantly improve efficiency with no adverse reactions. However, the effect of major components of LGZGD on the plasma protein binding of metoprolol is unclear. Firstly, this study aimed to computationally predict the molecular interactions between metoprolol, the major components of LGZGD, and bovine serum albumin (BSA). Secondly, the plasma protein binding of metoprolol combined with major components of LGZGD was investigated by UPLC analysis coupled with ultrafiltration. The MOE (2008.10) software package was used to investigate the molecular interactions among metoprolol, the major components of LGZGD, and BSA. Using in vitro experiments, BSA was separately spiked with a mixtures of metoprolol and the major components of LGZGD. The results showed that metoprolol interacted with BSA mainly through arene-arene interactions, as did cinnamic acid and liquiritin. However, the energy scores of cinnamic acid and liquiritin were lower than that of metoprolol. There were no interactions between metoprolol and the major components of LGZGD. Further studies in vitro showed that the presence of the major components of LGZGD did not change the plasma protein binding of metoprolol. We adopted molecular docking to predict the drug-herb plasma protein binding interactions of metoprolol and then used ultrafiltration to verify the docking results. There were no drug-herb interactions between metoprolol and LGZGD in BSA, which indicated that this combination therapy might be safe and feasible.

A UHPLC-QTOF-MS/MS method for the simultaneous determination of eight triterpene compounds from Poria cocos (Schw.) Wolf extract in rat plasma: Application to a comparative pharmacokinetic study

Poria cum Radix Pini (PRP), White Poria (WP), Rubra Poria (RP), and Poriae Cutis (PC), different parts of the dried sclerotium of Poria cocos (Schw.) Wolf (PCW), have possessed various pharmacological effects and clinical application. In the present study, a novel ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS) method was developed and validated for the simultaneous determination of eight triterpene compounds in rat plasma and then was applied in the comparison of pharmacokinetic characteristics of PRP, WP, RP, and PC extracts. Chromatographic separation was performed on an ACQUITY UPLC® BEH C₁₈ (2.1 × 100 mm, 5 μm) with a mobile phase composed of aqueous solution (containing 0.5‰ formic acid and 0.5 mmol/L ammonium acetate) and acetonitrile in gradient elution. Mass spectrometric of the analytes and internal standard (IS) were conducted in negative electrospray ionization with high-resolution multiple reaction monitoring (MRM^HR) mode. The lower limit of quantification (LLOQ) for the eight analytes were in the range of 2.00-20.16 ng/mL. All calibration curves showed good linearity (r > 0.993). The inter- and intra-batch precision and accuracy for the eight triterpene compounds were acceptable. The results indicated that the eight triterpene compounds displayed different pharmacokinetic characteristics in PRP, WP, RP, and PC, and that poricoic acid B, poricoic acid A, pachymic acid, dehydrotrametenolic acid, dehydrotumulosic acid, polyporenic acid C and dehydropachymic acid may be the major bioactive compounds of PCW contributing to the diuretic effect.