Simultaneous determination of seven alkaloids in rat plasma by UFLC-MS/MS and its application to a pharmacokinetic study after oral administration of Cerebralcare Granule

An integrated strategy for the establishment of a protoberberine alkaloid profile: Exploration of the differences in composition between Tinosporae radix and Fibraurea caulis

INTRODUCTION

Accurate species and content identification of major active components in herbals are the guarantee of the safety and effectiveness for medical and commodity purposes.

OBJECTIVES

In this study, an integrated strategy used to establish the protoberberine alkaloid profile was applied to explore the differences in composition between the pieces of Tinosporae radix and Fibraurea caulis, both of which had morphological similarities.

MATERIALS AND METHODS

First, an in-house library including possible protoberberine alkaloids based on different substituents was predicted by systematic literature survey. Meanwhile, diagnostic fragments of protoberberine alkaloids were investigated using the corresponding standards. Second, ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) was used to obtain multidimensional mass spectral data. Then, the identifications were confirmed by targeted filter of the acquired data based on the library.

RESULTS

As a result, 10 protoberberine alkaloid molecules including 46 isomers were identified or characterised. The qualitative distribution and relative content of protoberberine alkaloids revealed the fundamental difference between Tinosporae radix and Fibraurea caulis. 25 alkaloids were present in both herbals, while five compounds were detected only in Tinosporae radix. Furthermore, the contents of four alkaloids in Tinosporae radix were significantly higher than those in its adulterant, Fibraurea caulis.

CONCLUSION

The five unique ingredients in Tinosporae radix can be used as a better indicator for distinguishing the pieces of Tinosporae radix and Fibraurea caulis. The protoberberine alkaloid profile established in this study can be applied to quality evaluation of the two herbals or other herbals containing major protoberberine alkaloids.

Cerebralcare Granule® enhances memantine hydrochloride efficacy in APP/PS1 mice by ameliorating amyloid pathology and cognitive functions

Background

Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by memory deficits and cognitive decline. Current drugs can only relieve symptoms, but cannot really cure AD. Cerebralcare Granule® (CG) is a Traditional Chinese medicine (TCM) containing a variety of biologically active compounds. In our previous studies, CG has shown a beneficial effect against memory impairment in mice caused by d-galactose. However, whether CG can be used as a complementary medicine for the treatment of AD remains unexplored. Here, we use a combination of CG and memantine hydrochloride (Mm) to treat Alzheimer-like pathology and investigate the effects and mechanisms in vivo.

Methods

The histology of brain was examined with Hematoxylin–eosin (HE) staining, Golgi staining and Thioflavin S staining. ELISA was applied to assess the expression levels or activities of CAT, SOD, GSH-Px, MDA, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL) in serum, as well as the levels of IL-6, IL-1β, and TNF-α in the mice brain. Western blotting was used to assess the expression of β-secretase (BACE1), amyloid precursor protein (APP), APPβ, APPα, synaptophysin (SYN), growth-associated protein 43 (GAP43), and postsynaptic density 95 (PSD95).

Results

In the present study, the combination group (CG + Mm) significantly attenuated Alzheimer-like behavior without adverse effects in APP/PS1 mice, indicating its high degree of safety and efficacy after long-term treatment. CG + Mm reduced AD pathological biomarker Aβ plaque accumulation by inhibiting BACE1 and APP expression (P < 0.05 or P < 0.001). Besides, the combination group markedly inhibited the levels of IL-1β, IL-6, and TNF-α in hippocampus (P < 0.001), as well as activities of SOD, CAT, and GSH-Px in serum (P < 0.001). By contrast, the combination group improved synaptic plasticity by enhancing SYN, PSD95, and GAP43 expression.

Conclusions

Taken together, these data supported the notion that CG combined with Mm might ameliorate the cognitive impairment through multiple pathways, suggesting that CG could play a role as complementary medicine to increase anti-AD effect of chemical drugs by reducing Aβ deposition, neuroinflammation, oxidative damage, and improving synaptic plasticity.

Characterization of in vitro metabolites of three tetrahydroprotoberberine alkaloids in rat liver S9 by high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Tetrahydroberberine (THB), tetrahydrocoptisine (THCP) and tetrahydrocolumbamine (THCB) belong to the tetrahydroprotoberberine (THPB) alkaloids. Most of them have been extensively studied because of their pharmacological activities such as anti-hypertension, anti-arrhythmia, antimicrobial activity and antioxidant. However, limited information on the pharmacokinetics and metabolism of the three alkaloids has been reported. The purpose of this study was to investigate the in vitro metabolism of THB, THCP and THCB in rat liver S9 by using a rapid and accurate high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC/QqTOF-MS) method.

METHODS

The incubation mixture was processed with 15% trichloroacetic acid. Chromatographic separation of the three THPB alkaloids and their metabolites was achieved by HPLC/QqTOF-MS and accurate mass measurements of metabolites were automatically performed through data-dependent acquisition in only a 30-min analysis. The detailed structural elucidations of these metabolites were performed by comparing the changes in their accurate molecular masses, elemental compositions and product ions with those of the parent drug.

RESULTS

Five, five and four metabolites of THB, THCP and THCB were identified in rat liver S9, respectively. The results show that O-demethylenation of the 9,10-vicinal methoxyl group was the main metabolic pathway of THB and THCB and that demethylenation of the two methylenedioxy groups was the main metabolic pathway of THCP. In addition, minor oxidation and methylation reactions could occur for these alkaloids in rat liver S9.

CONCLUSIONS

This was the first investigation of the in vitro metabolism of THB, THCP and THCB in rat liver S9 by using a sensitive and accurate HPLC/QqTOF-MS method. The tentatively proposed metabolic pathways of the three alkaloids will provide a basis for further studies of the in vivo metabolism of the three compounds in animals and humans.

Development and Validation of a HPLC-ESI-MS/MS Method for Simultaneous Quantification of Fourteen Alkaloids in Mouse Plasma after Oral Administration of the Extract of Corydalis yanhusuo Tuber: Application to Pharmacokinetic Study

The tuber of Corydalis yanhusuo is a famous traditional Chinese medicine and found to have potent pharmacological effects, such as antinociceptive, antitumor, antibacterial, anti-inflammatory, and anti-depressive activities. Although there are several methods to be developed for the analysis and detection of the bioactive ingredients’ alkaloids, so far, only few prominent alkaloids could be quantified, and in vitro and in vivo changes of comprehensive alkaloids after oral administration are still little known. In this study, we first developed a simple and sensitive high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to quantify the comprehensive alkaloids of extracts of C. yanhusuo in mouse plasma, using nitidine chloride as an internal standard. As results, at least fourteen alkaloids, including an aporphine (oxoglaucine), a protopine (protopine), five tertiary alkaloids (corydaline, tetrahydroberberine, tetrahydropalmatine, tetrahydrocolumbamine, and tetrahydrocoptisine) and seven quaternary alkaloids (columbamine, palmatine, berberine, epiberberine, coptisine, jatrorrhizine, and dehydrocorydaline) could be well quantified simultaneously in mouse plasma. The lower limits of quantification were greater than, or equal to, 0.67 ng/mL, and the average matrix effects ranged from 96.4% to 114.3%. The mean extraction recoveries of quality control samples were over 71.40%, and the precision and accuracy were within the acceptable limits. All the analytes were shown to be stable under different storage conditions. Then the established method was successfully applied to investigate the pharmacokinetics of these alkaloids after oral administration of the extract of Corydalis yanhusuo in mice. To the best of our knowledge, this is the first document to report the comprehensive and simultaneous analyses of alkaloids of C. yanhusuo in mouse plasma. It was efficient and useful for comprehensive pharmacokinetic and metabolomic analyses of these complex alkaloids after drug administration.

Cerebralcare Granule(®), a Chinese Herb Compound Preparation, Attenuates D-Galactose Induced Memory Impairment in Mice

Cerebralcare granule(®) (CG) is a preparation of Traditional Chinese Medicine that widely used in China. It was approved by the China State Food and Drug Administration for treatment of headache and dizziness associated with cerebrovascular diseases. In the present study, we aimed to investigate whether CG had protective effect against D-galactose (gal)-induced memory impairment and to explore the mechanism of its action. D-gal was administered (100 mg/kg, subcutaneously) once daily for 8 weeks to induced memory deficit and neurotoxicity in the brain of aging mouse and CG (7.5, 15, and 30 g/kg) were simultaneously administered orally. The present study demonstrates that CG can alleviate aging in the mouse brain induced by D-gal through improving behavioral performance and reducing brain cell damage in the hippocampus. CG prevents aging mainly via suppression of oxidative stress response, such as decreasing NO and MDA levels, renewing activities of SOD, CAT, and GPx, as well as decreasing AChE activity in the brain of D-gal-treated mice. In addition, CG prevents aging through inhibiting NF-κB-mediated inflammatory response and caspase-3-medicated neurodegeneration in the brain of D-gal treated mice. Taken together, these data clearly demonstrates that subcutaneous injection of D-gal produced memory deficit, meanwhile CG can protect neuron from D-gal insults and improve memory ability.