Transcriptomic analysis of Vibrio alginolyticus challenged by Rhizoma coptidis reveals mechanisms of virulence genes

Rhizoma coptidis, a Chinese herbal medicine widely used to treat various bacterial infections, has the potential to develop antibiotic substitutes to overcome the drug resistance of Vibrio alginolyticus. To study the inhibitory effect of R. coptidis on V. alginolyticus, we sequenced the transcriptomes of three groups of samples of wild-type V. alginolyticus (CK) and V. alginolyticus, which were stressed by 5 mg/mL R. coptidis for 2 h (RC_2 h) and 4 h (RC_4 h). CK was compared with RC_2 h and RC_4 h, respectively, and a total of 1565 differentially expressed genes (DEGs) (988 up-regulated and 577 down-regulated) and 1737 DEGs (1152 up-regulated and 585 down-regulated) were identified. Comparing RC_2 h with RC_4 h, 156 DEGs (114 up-regulated and 42 down-regulated) were identified. The ability of biofilm formation and motility of V. alginolyticus altered upon with different concentrations of R. coptidis. Interestingly, relative expression patterns of virulence genes appeared statistically significantly varied, upon different concentrations of R. coptidis extract. DEGs were annotated to the Gene Ontology (GO) database for function enrichment analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, the results showed that the main enriched pathways, was those related to the virulence of V. alginolyticus. This study provides a new perspective for understanding the complex pathogenic mechanism of V. alginolyticus. R. coptidis could potnetially be used as alternative or complimnetary to antibiotics to treat infections after further research.

Epiberberine inhibits Helicobacter pylori and reduces host apoptosis and inflammatory damage by down-regulating urease expression

ETHNOPHARMACOLOGICAL RELEVANCE

With dramatically increasing antibiotic resistance in Helicobacter pylori (H. pylori), it is urgent to find alternative therapeutic agents. Rhizoma Coptidis is a traditional Chinese medicine for gastrointestinal diseases and shows excellent anti-H. pylori effect. Epiberberine (EPI), as one of the major alkaloids of Rhizoma Coptidis, has been reported to have urease-inhibiting activity, but its scavenging effect on H. pylori and the potential mechanism remain unclear.

AIM OF THE STUDY

To investigate the inhibitory effect of EPI on H. pylori and explore its multi-action on Helicobacter pylori urease (HPU).

MATERIALS AND METHODS

Using minimum inhibitory concentration (MIC) assay, minimum bactericidal concentration (MBC) assay, growth inhibition kinetics assay, bacterial resistance development, transmission electron microscope (TEM) assay, and animal experiments to investigate the inhibitory effect of EPI on H. pylori in vitro and in vivo. Using the Berthelot method, molecular docking and thermal displacement experiments to verify that EPI inhibits urease activity by interacting with HPU. Using transcriptome data, Real-Time PCR (RT-PCR) experiments to investigate the alterations in the expression of urease subunit ureB gene after EPI treatment. Using MTT cell viability assay, Hoechst 33342 staining method, JC-1 reagent detection method, western blot experiments, and Griess method to investigate the anti-apoptosis and anti-inflammation actions of EPI on gastric epithelial cells (GES-1) induced by HPU.

RESULTS

In vitro experiments proved that EPI has significant anti-H. pylori activity without drug resistance, induces H. pylori fragmentation and apoptosis. In vivo experiments showed that EPI has a certain clearance effect of H. pylori, and can reduce gastric inflammation caused by H. pylori infection. Transcriptome data, RT-PCR experiments, and other experiments demonstrate that EPI has a triple effect: (1) inhibiting the expression of HPU subunits ureB, (2) directly inhibiting urease activity by interacting with HPU, and (3) inhibiting HPU-induced apoptosis and inflammation in GES-1.

CONCLUSIONS

EPI is an excellent anti-H. pylori agent and reduces host apoptosis and inflammation by inhibiting the activity of urease and down-regulating the expression of ureB.

Blocking LTB4 signaling-mediated TAMs recruitment by Rhizoma Coptidis sensitizes lung cancer to immunotherapy

BACKGROUND

Immune checkpoint blockade (ICB) induces durable immune responses across a spectrum of advanced cancers and revolutionizes the oncology field. However, only a subset of patients achieves long-lasting clinical benefits. Tumor-associated macrophages (TAMs) usually secrete immunosuppressive cytokines and contribute to the failure of ICB therapy. Therefore, it is crucial to mechanically manipulate the abundance and function of TAMs in the tumor microenvironment (TME), which can offer a promising molecular basis to improve the clinical response efficacy of ICB in cancer patients.

PURPOSE

This study aims to investigate TAMs in the immunosuppressive microenvironment to identify new therapeutic targets, improve the ability to predict and guide responses to clinical immunotherapy, and develop new strategies for immunotherapy of lung tumors.

METHODS

Lewis lung carcinoma (LLC) xenograft-bearing mouse models were established to analyze the antitumor activity of Rhizoma Coptidis (RC) in vivo. A systems pharmacology strategy was used to predict the correlation between RC and M2 macrophages. The effect of RC on the abundance of M2 macrophages was analyzed by flow cytometry of murine samples. Western blot was performed to analyze the expression of Leukotriene A4 hydrolase (LTA4H) and LTB4 receptor 1 (BLT1) in harvested lung cancer tissues. The impact of blocking leukotriene B4 (LTB4) signaling by RC on the recruitment of M2 macrophages was assessed in vitro and in vivo. Transwell migration assays were conducted to clarify the inhibition of macrophage migration by blocking LTB4. Lta4h-/- mice were used to investigate the sensitivity of immunotherapy to lung cancer by blocking the LTB4 signaling.

RESULTS

Here, we report that RC, an herbal medicine from the family Ranunculaceae, suppresses the recruitment and immunosuppressive function of TAMs, which in turn sensitizes lung cancer to ICB therapy. Firstly, a systems pharmacology strategy was proposed to identify combinatorial drugs for ICB therapy with a systems biology perspective of drug-target-pathway-TME phenotype. We predicted and verified that RC significantly inhibits tumor growth and the infiltration of M2-TAMs into TME of LLC tumor-bearing mice. Then, RC inhibits the recruitment of macrophages to the tumor TME via blocking LTB4 signaling, and suppresses the expression of immunosuppressive factors (IL-10, TGF-β and VEGF). As a result, RC enables CD8+ T cells to retain their proliferative and infiltrative abilities within the TME. Ultimately, these events promote cytotoxic T-cell-mediated clearance of tumor cells, which is further enhanced by the addition of anti-PD-L1 therapy. Furthermore, we employed LTA4H deficient mice (Lta4h-/- mice) to evaluate the antitumor efficiency, the results showed that the efficacy of immunotherapy was enhanced due to the synergistic effect of LTB4 signaling blockage and ICB inhibition, leading to remarkable inhibition of tumor growth in a mouse model of lung adenocarcinoma.

CONCLUSIONS

Taken together, these findings suggest that RC enhances antitumor immunity, providing a rationale for combining RC with immunotherapies as a potential anti-cancer treatment strategy.

Obese rats intervened with Rhizoma coptidis revealed differential gene expression and microbiota by serum metabolomics

Background

Integrating systems biology is an approach for investigating metabolic diseases in humans. However, few studies use this approach to investigate the mechanism by which Rhizoma coptidis (RC) reduces the effect of lipids and glucose on high-fat induced obesity in rats.

Methods

Twenty-four specific pathogen-free (SPF) male Sprague–Dawley rats (80 ± 10 g) were used in this study. Serum metabolomics were detected by ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry. Liver tissue and cecum feces were used for RNA-Seq technology and 16S rRNA gene sequencing, respectively.

Results

We identified nine potential biomarkers, which are differential metabolites in the Control, Model and RC groups, including linoleic acid, eicosapentaenoic acid, arachidonic acid, stearic acid, and L-Alloisoleucine (p < 0.01). The liver tissue gene expression profile indicated the circadian rhythm pathway was significantly affected by RC (Q ≤ 0.05). A total of 149 and 39 operational taxonomic units (OTUs), which were highly associated with biochemical indicators and potential biomarkers in the cecum samples (FDR ≤ 0.05), respectively, were identified.

Conclusion

This work provides information to better understand the mechanism of the effect of RC intervention on hyperlipidemia and hypoglycemic effects in obese rats. The present study demonstrates that integrating systems biology may be a powerful tool to reveal the complexity of metabolic diseases in rats intervened by traditional Chinese medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03382-3.

Berberine and Ginsenoside Rb1 Ameliorate Depression-Like Behavior in Diabetic Rats

Rhizoma coptidis (Huang-lian) and Asian ginseng have been widely used in the treatment of diabetes and other concurrent diseases with apparent effects. This study investigated the effects of the active ingredients of R. coptidis and ginseng, berberine and ginsenoside Rb1, on depression-like behavior in a rat diabetes model. The animal model was established via a high-fat diet and intraperitoneal injection of streptozotocin, while the animal's depression-like behavior was induced via chronic unpredictable mild stress. These experimental rats were divided into four groups: control, depression-like behavior (DLB), metformin plus fluoxetine hydrochloride (M+FH), and berberine plus ginsenoside Rb1 (B+GRb1) groups. Glucose metabolism and insulin resistance were evaluated by oral glucose test and glucose clamp study. Depression-like behavior was evaluated via behavioral analyses, including forced swim, sucrose preference, elevated plus maze, and open-field tests. HE and Nissl staining, plasma cortisol expression of adrenocorticotropic hormone, and brain-derived neurotrophic factor (BDNF) levels were assayed to explore the mechanisms of action. Compared with the control, rats in the DLB group had a significant increase in the levels of blood glucose and depression-like behavior. The B+GRb1 group significantly improved glucose metabolism and insulin resistance, reduced depression-like behavior, downregulated levels of plasma cortisol and adrenocorticotropic hormone under stress, and upregulated BDNF protein expression compared to the DLB rats. HE and Nissl staining data revealed that B+GRb1 protected neurons from pathological and morphological changes. Thus, berberine and ginsenoside Rb1 not only improved glucose metabolism in diabetic rats but also ameliorated their depression-like behavior under chronic unpredictable stress. Mechanistically, studied data with plasma hormonal levels and brain neuronal pathological/morphological changes supported the observed effects. The combination of berberine and ginsenoside Rb1 may have a clinical value in the management of diabetic patients with depression.

An integrated network pharmacology and transcriptomic method to explore the mechanism of the total Rhizoma Coptidis alkaloids in improving diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Coptidis (RC) is a traditional Chinese medicine (TCM) used for treating diabetes (Xiao Ke Zheng), which is firstly recorded in Shennong Bencao Jing. Modern pharmacological studies have confirmed that RC has beneficial effects on diabetes and its complications. Alkaloids are the main active pharmacological component of RC. However, the effect and molecular mechanism of total Rhizoma Coptidis alkaloids (TRCA) in improving diabetic nephropathy (DN) are still unclear.

AIM OF THE STUDY

To verify the effect of TRCA in the treatment of DN and clarify the molecular mechanism by combining network pharmacology and transcriptomic.

MATERIALS AND METHODS

Eight-week-old db/db mice were orally administered with normal saline, 100 mg/kg TRCA, and 100 mg/kg berberine (BBR) for 8 weeks. Serum, urine, and kidney samples were collected to measure biological indicators and observe renal pathological changes. Then, the molecular mechanism of TRCA improving DN was predicted by the network pharmacology. Briefly, the main active alkaloids components of TRCA and their targets were collected from the database, as well as the potential targets of DN. Using the Cytoscape software to visualize the interactive network diagram of "ingredient-target". The GO and KEGG pathways enrichment analysis of the core targets were executed by Metascape. Furthermore, RNA-seq was used to get whole transcriptomes from the kidneys of db/m mice, db/db mice, and db/db mice treated with TRCA. The key differentially expressed genes (DEGs) were gathered to conduct the GO and KEGG pathways enrichment analysis. Finally, the potential pathways were validated by western blotting.

RESULTS

The administration of BBR or TRCA for 8 weeks significantly reduced the fasting blood glucose (FBG) and body weight of db/db mice, and improved their renal function and lipid disorders. According to H&E, PAS, and Masson staining, both the BBR and TRCA could alleviate renal damage and fibrosis. The Venn diagram had shown that seven alkaloids ingredients collected from TRCA regulated 85 common targets merged in the TRCA and DN. The results of RNA-seq indicated that there are 121 potential targets for TRCA treatment on DN. Intriguingly, both the AGE-RAGE signaling pathway and the PI3k-Akt signaling pathway were included in the KEGG pathways enrichment results of network pharmacology and RNA-seq. Moreover, we verified that TRCA down-regulated the expression of related proteins in the AGEs-RAGE-TGFβ/Smad2 and PI3K-Akt pathways in the kidney tissues.

CONCLUSIONS

In summary, the renal protection of TRCA on DN may be related to activation of the AGEs-RAGE-TGFβ/Smad2 and PI3K-Akt signaling pathways.

Effective Dose of Rhizoma Coptidis Extract Granules for Type 2 Diabetes Treatment: A Hospital-Based Retrospective Cohort Study

Rhizoma Coptidis is a popular phytomedicine for the treatment of type 2 diabetes in Asia, but its effective dose for diabetes treatment remains confused because of diverse origins. This study aimed to investigate the dose-response effects of Rhizoma Coptidis extract granules (RCEG), produced with standardized quality control, on hypoglycemic effects in patients with type 2 diabetes. We conducted a retrospective analysis of Chang Gung Research Database from January 01, 2008 to November 30, 2017. Outpatients visiting traditional Chinese medicine clinics and receiving RCEG for type 2 diabetes treatment were included. Plasma glucose, lipid, and other parameters were analyzed from 93 patients with a total of 737 visits within 60 weeks. Scatter plots with the LOESS analysis were used to explore the association between RCEG dose and hypoglycemic effect. The minimal effective dose was chosen to divide the study population into the high-dose and low-dose RCEG groups. Non-parametric tests were used for between-group and within-group comparisons. The multivariate nonlinear mixed-effects model was applied to access the effect of treatment length and groups simultaneously on the change of HbA1c and fasting plasma glucose. The “arule” package in R was used to present the network diagram of RCEG and other co-prescriptions. We first discovered a significant relationship between RCEG dose and HbA1c reduction when the dose reached 0.08 g/kg/day or higher. We thus defined 0.08 g/kg/day of RCEG as the minimum effective dose, and a threshold to separate patients into the high-dose (≥0.08 g/kg/d) and low-dose (<0.08 g/kg/d) RCEG groups. In the high-dose RCEG group, a significant decrease in total cholesterol and a trend toward triglyceride reduction were also noted. Patients more effectively responded to RCEG treatment if they had a higher initial HbA1c level, higher heart rates, better liver function tests, and better tolerance to the higher dose and treatment duration of RCEG. In addition, digestive/tonic/dampness draining formulas and blood regulation recipes were two of the most frequent co-prescriptions with RCEG. This study concluded that RCEG at a dose exceeding 0.08 g/kg/d had beneficial effects on glycemic and lipid control, without showing nephro- or hepatotoxicity, in patients with type 2 diabetes.

Active Ingredients and Mechanism of Action of Rhizoma Coptidis against Type 2 Diabetes Based on Network-Pharmacology and Bioinformatics

A pharmacological network of "component/target/pathway" for Rhizoma coptidis against type 2 diabetes (T2D) was established by network-pharmacology, and the active components of Rhizoma coptidis and its mechanism were explored. A literature-based and database study of the components of Rhizoma coptidis was carried out and screened by ADME parameters. The targets of Rhizoma coptidis were predicted by the ligand similarity method. Related pathways were analyzed with databases, and software was used to construct a "component/target/path" network. The mechanism was further confirmed by GEO database with R software. A total of 12 active components were screened from Rhizoma coptidis, involving 57 targets including MAPK1, STAT3, INSR, and 38 signaling pathways were associated with T2D. Related signaling pathways included essential pathways for T2D such as insulin resistance, and pathways that had indirect effect on T2D. It was suggested that Rhizoma coptidis may exert its effects against T2D through multi-component, multi-target, and multi-pathway forms.

Rhizoma coptidis as a Potential Treatment Agent for Type 2 Diabetes Mellitus and the Underlying Mechanisms: A Review

Diabetes mellitus, especially type 2 diabetes mellitus (T2DM), has become a significant public health burden. Rhizoma coptidis (RC), known as Huang Lian, is widely used for treating diabetes in China. The bioactive compounds of RC, especially alkaloids, have the potential to suppress T2DM-induced lesions, including diabetic vascular dysfunction, diabetic heart disease, diabetic hyperlipidemia, diabetic nephropathy, diabetic encephalopathy, diabetic osteopathy, diabetic enteropathy, and diabetic retinopathy. This review summarizes the effects of RC and its bioactive compounds on T2DM and T2DM complications. Less research has been conducted on non-alkaloid fractions of RC, which may exert synergistic action with alkaloids. Moreover, we summarized the pharmacokinetic properties and structure-activity relationships of RC on T2DM with reference to extant literature and showed clearly that RC has potential therapeutic effect on T2DM.

Rhizoma Coptidis for Alzheimer's Disease and Vascular Dementia: A Literature Review

BACKGROUND

Alzheimer's disease (AD) and vascular dementia (VaD) are major types of dementia, both of which cause heavy economic burdens for families and society. However, no currently available medicines can control dementia progression. Rhizoma coptidis, a Chinese herbal medicine, has been used for >2000 years and is now gaining attention as a potential treatment for AD and VaD.

METHODS

We reviewed the mechanisms of the active ingredients of Rhizoma coptidis and Rhizoma coptidis-containing Chinese herbal compounds in the treatment of AD and VaD. We focused on studies on ameliorating the risk factors and the pathological changes of these diseases.

RESULTS

The Rhizoma coptidis active ingredients include berberine, palmatine, coptisine, epiberberine, jatrorrhizine and protopine. The most widely studied ingredient is berberine, which has extensive therapeutic effects on the risk factors and pathogenesis of dementia. It can control blood glucose and lipid levels, regulate blood pressure, ameliorate atherosclerosis, inhibit cholinesterase activity, Aβ generation, and tau hyperphosphorylation, decrease neuroinflammation and oxidative stress and alleviate cognitive impairment. Other ingredients (such as jatrorrhizine, coptisine, epiberberine and palmatine) also regulate blood lipids and blood pressure; however, there are relatively few studies on them. Rhizoma coptidis-containing Chinese herbal compounds like Huanglian-Jie-Du-Tang, Huanglian Wendan Decoction, Banxia Xiexin Decoction and Huannao Yicong Formula have anti-inflammatory and antioxidant stress activities, regulate insulin signaling, inhibit γ-secretase activity, neuronal apoptosis, tau hyperphosphorylation, and Aβ deposition, and promote neural stem cell differentiation, thereby improving cognitive function.

CONCLUSION

The "One-Molecule, One-Target" paradigm has suffered heavy setbacks, but a "multitarget- directed ligands" strategy may be viable. Rhizoma coptidis active ingredients and Rhizoma coptidiscontaining Chinese herbal compounds have multi-aspect therapeutic effects on AD and VaD.

Methanolic Extract of Rhizoma Coptidis Inhibits the Early Viral Entry Steps of Hepatitis C Virus Infection

Hepatitis C Virus (HCV) remains an important public health threat with approximately 170 million carriers worldwide who are at risk of developing hepatitis C-associated end-stage liver diseases. Despite improvement of HCV treatment using the novel direct-acting antivirals (DAAs) targeting viral replication, there is a lack of prophylactic measures for protection against HCV infection. Identifying novel antivirals such as those that target viral entry could help broaden the therapeutic arsenal against HCV. Herein, we investigated the anti-HCV activity of the methanolic extract from Rhizoma coptidis (RC), a widely used traditional Chinese medicine documented by the WHO and experimentally reported to possess several pharmacological functions including antiviral effects. Using the cell culture-derived HCV system, we demonstrated that RC dose-dependently inhibited HCV infection of Huh-7.5 cells at non-cytotoxic concentrations. In particular, RC blocked HCV attachment and entry/fusion into the host cells without exerting any significant effect on the cell-free viral particles or modulating key host cell entry factors to HCV. Moreover, RC robustly suppressed HCV pseudoparticles infection of Huh-7.5 cells and impeded infection by several HCV genotypes. Collectively, our results identified RC as a potent antagonist to HCV entry with potential pan-genotypic properties, which deserves further evaluation for use as an anti-HCV agent.

Cellular stress response mechanisms of Rhizoma coptidis: a systematic review

Rhizoma coptidis has been used in China for thousands of years with the functions of heating dampness and purging fire detoxification. But the underlying molecular mechanisms of Rhizoma coptidis are still far from being fully elucidated. Alkaloids, especially berberine, coptisine and palmatine, are responsible for multiple pharmacological effects of Rhizoma coptidis. In this review, we studied on the effects and molecular mechanisms of Rhizoma coptidis on NF-κB/MAPK/PI3K–Akt/AMPK/ERS and oxidative stress pathways. Then we summarized the mechanisms of these alkaloid components of Rhizoma coptidis on cardiovascular and cerebrovascular diseases, diabetes and diabetic complications. Evidence presented in this review implicated that Rhizoma coptidis exerted beneficial effects on various diseases by regulation of NF-κB/MAPK/PI3K–Akt/AMPK/ERS and oxidative stress pathways, which support the clinical application of Rhizoma coptidis and offer references for future researches.

The Effect of Ginger Juice Processing on the Chemical Profiles of Rhizoma coptidis

Rhizoma coptidis (RC) has been used as an herbal medicine in China for over one thousand years, and it was subjected to specific processing before use as materia medica. Processing is a pharmaceutical technique that aims to enhance the efficacy and/or reduce the toxicity of crude drugs according to traditional Chinese medicine theory. In this study, the chemical profiles of RC, ginger juice processed RC (GRC), and water processed RC (WRC) was determined to reveal the mechanism of processing of RC. UPLC-QTOF-MS analysis of methanol extract of RC, GRC, and WRC has been conducted to investigate the effect of processing on the composition of RC. HPLC-PDA was used to determine the variance of total alkaloids and seven alkaloids of RC during the processing. The volatiles of RC, GRC and ginger juice were separated by distillation, the change of volatiles content was recorded and analyzed, and the qualitative analysis of the volatiles was carried out using GC-MS. The microstructures of RC, GRC and WRC were observed using a light microscope. Results showed that ginger juice/water processing had limited influence on the composition of RC's methanol extract, but significant influence on the content of some alkaloids in RC. Ginger juice processing significantly increased (p < 0.05) the volatiles content of RC and changed the volatiles composition obviously. Processing also had an influence on the microstructure of RC. This research comprehensively revealed the mechanism of ginger juice processing of RC.

Rhizoma Coptidis and Berberine as a Natural Drug to Combat Aging and Aging-Related Diseases via Anti-Oxidation and AMPK Activation

Aging is the greatest risk factor for human diseases, as it results in cellular growth arrest, impaired tissue function and metabolism, ultimately impacting life span. Two different mechanisms are thought to be primary causes of aging. One is cumulative DNA damage induced by a perpetuating cycle of oxidative stress; the other is nutrient-sensing adenosine monophosphate-activated protein kinase (AMPK) and rapamycin (mTOR)/ ribosomal protein S6 (rpS6) pathways. As the main bioactive component of natural Chinese medicine rhizoma coptidis (RC), berberine has recently been reported to expand life span in Drosophila melanogaster, and attenuate premature cellular senescence. Most components of RC including berberine, coptisine, palmatine, and jatrorrhizine have been found to have beneficial effects on hyperlipidemia, hyperglycemia and hypertension aging-related diseases. The mechanism of these effects involves multiple cellular kinase and signaling pathways, including anti-oxidation, activation of AMPK signaling and its downstream targets, including mTOR/rpS6, Sirtuin1/ forkhead box transcription factor O3 (FOXO3), nuclear factor erythroid-2 related factor-2 (Nrf2), nicotinamide adenine dinucleotide (NAD⁺) and nuclear factor-κB (NF-κB) pathways. Most of these mechanisms converge on AMPK regulation on mitochondrial oxidative stress. Therefore, such evidence supports the possibility that rhizoma coptidis, in particular berberine, is a promising anti-aging natural product, and has pharmaceutical potential in combating aging-related diseases via anti-oxidation and AMPK cellular kinase activation.

Comparative Pharmacokinetic Profiles of Three Protoberberine-type Alkaloids from Raw and Bile-processed Rhizoma coptidis in Heat Syndrome Rats

Background:

The Bile-processed Rhizoma coptidis (BRC), which has a colder drug property than Rhizoma coptidis (RC), is widely used for the treatment of heat syndrome. We compared the pharmacokinetics of the protoberberine-type alkaloids in BRC and RC in rats with heat syndrome to elucidate the bile-processing mechanism.

Material and Methods:

We established a rapid and sensitive method for simultaneously determining three alkaloids: berberine, palmatine, and jatrorrhizine, in rat plasma based on ultra-performance liquid chromatography/tandem mass spectrometry. The separation was carried out on a Waters ACQUITY BEA C₁₈ column. The mobile phase consisted of acetonitrile (containing 0.1% formic acid) and water (containing 0.1% formic acid and 10 mmol/L ammonium acetate) and carbamazepine was used as an internal standard. The detection was carried out in a multiple reaction monitoring mode (MRM) using electrospray ionization in the positive ion mode.

Results:

Pharmacokinetic profiles indicated that the C_max of berberine and palmatine increased two times and the T_max of the three alkaloids decreased three times after bile processing. AUC_0→∞ and AUC_0→t of the alkaloids were similar between RC and BRC.

Conclusion:

The results suggest that bile processing could increase the absorption rate of alkaloids. This study broadens our understanding of Chinese herbal medicine processing.

SUMMARY

Contents of berberine, palmatine and jatrorrhizine, in heat syndrome rats’ plasma between the raw and bile-processed Rhizoma coptidis (RC) were determined by UPLC-MS/MS.

The whole pharmacokinetic profiles of three alkaloids in the bile-processed Rhizoma coptidis (BRC) were similar to those of RC.

The shorter T_max and increased 2-fold C_max were obtained after RC bile-processing.

Bile-processing could promote the absorption rate of alkaloids in a certain degree.

Abbreviation Used: RC: Rhizoma coptidis, BRC: Bile-processed Rhizoma coptidis, HPLC: high-performance liquid chromatography, UPLC-MS/MS: ultra-performance liquid chromatography-mass spectrometry/ mass spectrometry, LC-MS: liquid chromatography-mass spectrometry, MRM: multiple reaction monitoring mode, QC: quality control, RE: relative error, RSD: relative standard deviation, C_max: maxium of drug concentration, T_max: time for maxium of drug concentration, AUC: area under concentration-time curve, LLOQ: Linearity and lower limits of quantification, t_1/2: half-life, Clz: body clearance

Analysis of isoquinoline alkaloids using chitosan-assisted liquid-solid extraction followed by microemulsion liquid chromatography employing a sub-2-micron particle stationary phase

A simple, efficient, and green chitosan-assisted liquid-solid extraction method was developed for the sample preparation of isoquinoline derivative alkaloids followed by microemulsion LC. The optimized mobile phase consisted of 0.8% w/v of ethyl acetate, 1.0% w/v of SDS, 8.0% w/v of n-butanol, 0.1% v/v acetic acid, and 10% v/v ACN. Compared to pharmacopoeia method and organic solvent extraction, this new approach avoided the use of volatile organic solvents, replacing them with relatively small amounts of chitosan. Under the optimum conditions, good linearity (r² > 0.9980) for all calibration curves and low detection limits between 0.05 and 0.10 μg/mL were achieved. The presented procedure was successfully applied to determine alkaloids in Rhizoma coptidis with satisfactory recoveries (81.3-106.4%).

Determination of cytotoxicity of traditional Chinese medicine herbs, Rhizoma coptidis, Radix scutellariae, and Cortex phellodendri, by three methods

BACKGROUND

Many herbs are used in traditional Chinese medicine TCM) for treatment of infections but their properties, in particular, their effects on normal cells have received little attention. This study investigated the cytotoxic properties of three TCM herbs with potential use in prevention and treatment of ocular infections, including Acanthamoeba keratitis.

METHOD

The study investigated cytotoxic effects of the herbal extracts of Rhizoma coptidis, Radix scutellariae, and Cortex phellodendri on human corneal epithelial cells using trypan blue staining, MTT production, and flow cytometry. Differences between herbs were determined using repeated measures one-way analysis of variance, followed by paired t-tests where appropriate.

RESULTS

These three herbs appeared to lack cytotoxicity when tested with trypan blue and MTT, but flow cytometry revealed that R. coptidis led to cell membrane damage.

CONCLUSION

Lack of cytotoxicity of R. scutellariae and C. phellodendri extracts suggest that these are potentially suitable for use in ocular preparations. Only flow cytometry was able to accurately predict cytotoxic effects of extracts of TCM herbs on HCEC, demonstrating the importance of using a sensitive method of detection of cytotoxicity.

Expectorant and antitussive effect of Hedera helix and Rhizoma coptidis extracts mixture

PURPOSE

This study aims to investigate the additive effect of the Hedera helix (HH) and Rhizoma coptidis (RC) extracts mixture on antitussive and expectorant activities in animals.

MATERIALS AND METHODS

The expectorant assay was performed with phenol red secretion in mice trachea. Mice or guinea pigs were randomly divided into groups of 8 each, including negative and positive control groups. After gastric administration of the test extracts in mice, 2.5% phenol red solution (0.2 mL) was intraperitoneally injected. Trachea was dissected and optical density of tracheal secretion was measured. After gastric administration of the test extracts in guinea pigs, the antitussive activities were assessed using a citric acid-induced cough measurement.

RESULTS

The extracts of HH and RC significantly increased tracheal secretion and inhibited cough. The mixture of HH and RC extracts in a 1:1 concentration at a dose of 200 mg/kg showed a more potent effect on phenol red secretion (25.25±3.14) and cough inhibition (61.25±5.36) than the individual use of each extracts [phenol red secretion; HH 13.39±4.22 (p=0.000), RC 20.78±2.50 (p=0.010), cough inhibition; HH 9.89±4.14 (p=0.010), RC 30.25±7.69 (p=0.000)]. A 3:1 ratio mixture of HH to RC demonstrated an optimal expectorant effect (p<0.001), and this mixture showed expectorant and antitussive effects in a dose-dependent manner.

CONCLUSION

This study provides evidence for antitussive and expectorant effect of a 3:1 mixture of HH and RC, which may be a useful therapeutic option for respiratory diseases.

Study of the anti-MRSA activity of Rhizoma coptidis by chemical fingerprinting and broth microdilution methods

AIM

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogenic bacterium that causes both hospital- and community-acquired infections, and for which single-drug treatments are becoming less efficient. Rhizoma coptidis has been used for more than two thousand years in China to treat diarrhea, fever, and jaundice. In this study, the anti-MRSA activity of Rhizoma coptidis is examined and its effective components sought.

METHODS

The mecA and norA genes were determined by PCR amplification and sequencing. Drug susceptibility of Staphylococcus aureus ATCC43300 was performed using the VITEK2 compact system. The chemical fingerprint of Rhizoma coptidis was investigated using HPLC and preparative liquid chromatography, and the anti-MRSA activity was determined using an improved broth microdilution method.

RESULTS

The drug susceptibility test revealed that the penicillin-binding protein phenotype of the strain changed in comparison to penicillin-sensitive Staphylococcus aureus. Ten batches of Rhizoma coptidis showed anti-MRSA activity on the norA-negative Staphylococcus aureus strain, as well as the strain that contained a norA gene. The spectrum-effect relationship revealed that the berberine alkaloids were the effective components, within which berberine, coptisine, palmatine, epiberberine, and jatrorrhizine were the major components.

CONCLUSION

This study lays a foundation for in vivo studies of Rhizoma coptidis and for the development of multi-component drugs.

Differential detection of Rhizoma coptidis by capillary electrophoresis electrospray ionization mass spectrometry with a nanospray interface

A lab prototype CE-nanospray-MS platform with a high sensitivity porous sprayer was successfully applied in differential identification of Rhizoma coptidis in this paper. To obtain a stable and reliable nanospray, detailed optimizations about emitter geometry, buffer composition, emitter position, and spray voltage, as well as emitter cleanliness were discussed. Results showed that the reproducibility and sensitivity for separations of alkaloid standards were satisfactory using CE-nanospray-MS, which were also compared to ultra-HPLC (UHPLC)-MS. Their signal responds were at the same order of magnitude (intensities: 0.8 - 1.5 × 10(8) vs. 3.8 - 6.2 × 10(8) ), even though a 2 nL injection for CE was 2500-fold lower than UHPLC (5 μL injection). The absolute LOD results of CE-MS showed a remarkable superiority (18-24 fg), equal to 1000-fold lower than that of UHPLC-MS. Principal component analysis (PCA) of adulterated R. coptidis showed that this protocol had the ability to profile and qualify complex herb medicines, which also created a great potential for evaluation and qualification of rare and valuable Chinese medicines in future.

Optimization of ultrasonic-assisted extraction of bioactive alkaloid compounds from rhizoma coptidis (Coptis chinensis Franch.) using response surface methodology

The optimum extraction conditions for the maximum recovery of total alkaloid content (TAC), berberine content (BC), palmatine content (PC), and the highest antioxidant capacity (AC) from rhizoma coptidis subjected to ultrasonic-assisted extraction (UAE) were determined using response surface methodology (RSM). Central composite design (CCD) with three variables and five levels was employed, and response surface plots were constructed in accordance with a second order polynomial model. Analysis of variance (ANOVA) showed that the quadratic model was well fitted and significant for responses of TAC, BC, PC, and AA. The optimum conditions obtained through the overlapped contour plot were as follows: ethanol concentration of 59%, extraction time of 46.57min, and temperature of 66.22°C. Verification experiment was carried out, and no significant difference was found between observed and estimated values for each response, suggesting that the estimated models were reliable and valid for UAE of alkaloids.

Comparative Pharmacokinetics of Berberine, Palmatine and Jatrorrhizine in Rat Plasma after Oral Administration of Rhizoma coptidis and Zuojinwan Using Liquid Chromatography-Tandem Mass Spectrometry

A selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/ MS) method was developed for the determination of berberine, palmatine and jatrorrhizine in rat plasma. Target compounds, together with the internal standard (metronidazole), were extracted from rat plasma samples by protein precipitation with acetonitrile-methanol (1:2, v/v). Chromatography was carried out using a C18 column (150 × 4.6mm, 5μm) under isocratic elution with water (containing 0.3% formic acid)-acetonitrile (30:70, v/v). The mass spectrometric detection was performed by selected reaction monitoring (SRM) mode via electrospray ionization (ESI) source operating in positive ionization mode. The method was linear over the concentration range of 0.2-100 ng/mL for all components. The intra- and inter-day precision values were less than 14.7% and the deviations were within ± 9.0%. The validated method was applied to the comparative pharmacokinetic studies of berberine, palmatine and jatrorrhizine after oral administration of Rhizoma coptidis and Zuojinwan. The results indicated that the pharmacokinetics of berberine, palmatine and jatrorrhizine were significantly different between different groups.