Pharmacokinetics, bioavailability, and metabolism of Notoginsenoside Fc in rats by liquid chromatography/electrospray ionization tandem mass spectrometry

Notoginsenoside Fc, a novel renoprotective agent, ameliorates glomerular endothelial cells pyroptosis and mitochondrial dysfunction in diabetic nephropathy through regulating HMGCS2 pathway

BACKGROUND

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease (ESRD), and the therapeutic strategies for DN are limited. Notoginsenoside Fc (Fc), a novel saponin isolated from Panax Notoginseng (PNG), has been reported to alleviate vascular injury in diabetic rats. However, the protective effects of Fc on DN remain unclear.

PURPOSE

To investigate the beneficial effects and mechanisms of Fc on DN.

METHODS

Db/db mice were treated with 2.5, 5 and 10 mg·kg-1·d-1 of Fc for 8 weeks. High glucose (HG) induced mouse glomerular endothelial cells (GECs) were treated with 2.5, 5 and 10 μM of Fc for 24 h.

RESULTS

Our data found that Fc ameliorated urinary microalbumin level, kidney dysfunction and histopathological damage in diabetic mice. Moreover, Fc alleviated the accumulation of oxidative stress, the collapse of mitochondrial membrane potential and the expression of mitochondrial fission proteins, such as Drp-1 and Fis1, while increased the expression of mitochondrial fusion protein Mfn2. Fc also decreased pyroptosis-related proteins levels, such as TXNIP, NLRP3, cleaved caspase-1, and GSDMD-NT, indicating that Fc ameliorated GECs pyroptosis. In addition, 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) expression was increased in diabetic group, which was partially abrogated by Fc. Our data further proved that knockdown of HMGCS2 could restrain HG-induced GECs mitochondrial dysfunction and pyroptosis. These results indicated that the inhibitory effects of Fc on mitochondrial damage and pyroptosis were associated with the suppression of HMGCS2.

CONCLUSION

Taken together, this study clearly demonstrated that Fc ameliorated GECs pyroptosis and mitochondrial dysfunction partly through regulating HMGCS2 pathway, which might provide a novel drug candidate for DN.

An online preparative high-performance liquid chromatography system with enrichment and purification modes for the efficient and systematic separation of Panax notoginseng saponins

In this study, an online preparative high-performance liquid chromatography (prep-HPLC) system based on the combination of the enrichment and purification modes for the efficient and systematic separation of Panax notoginseng saponins (PNS) was achieved. Five separation columns were used for the first and second separation of target components, eighteen trap columns were used to capture the effluents from the first separation or loading the trapped sample effluents, and a two-position eight-port valve was used to switch between the first and second separations. The conditions for the first and second separation of PNS were simulated and optimized with the online prep-HPLC system. Then, the PNS were separated using optimized chromatographic conditions. Notably, 14 monomer compounds with >90% purity (11 compounds with purity >97%) were simultaneously isolated from PNS using the above self-developed device, and their chemical structures were identified. Moreover, the separation time was less than 33.0 h. After 6 repeated enrichment and purification, the weight of each compound obtained was more than 5.0 mg, with compound 2 weighing over 900 mg. In brief, the self-developed prep-HPLC system, which integrated enrichment and purification, is suitable for the efficient and systematic separation of PNS and has broad application prospects, especially for the separation of complex chemical components in natural products.

Optimization of Extraction and Separation Process of Notoginsenoside Fc from Panax notoginseng Leaves

Response surface methodology (RSM) was used to determine the optimal conditions for ultrasound-assisted extraction (UAE) of Notoginsenoside Fc (Fc) from panax notoginseng leaves. The experiment utilized a Box-Behnken design (BBD) and separation conditions were optimized. The optimum extraction conditions were as follows: extraction time = 1.5 h, ethanol concentration = 86%, liquid-to-solid ratio = 19:1. The experimentally obtained values were in accordance with the values predicted by the RSM model. We determined that the RSM model was able to successfully simulate the optimal extraction of Fc from the leaves. Further, Fc was enriched from Panax notoginseng through nine macroporous resins, and HPD-100 macroporous resins were selected for preliminary enrichment of Fc due to its economic costs and benefits. Subsequently, octadecyl silane (ODS) column chromatography was used to improve the purity of Fc to over 90% after separation by ODS column chromatography. Fc with a purity greater than 95% can be obtained by recrystallization. This is the first study that has focused on the extraction and enrichment of Fc from Panax notoginseng leaves using macroporous resin combined with ODS column chromatography, which provides the possibility for further application of Fc.

Natural products in attenuating renal inflammation via inhibiting the NLRP3 inflammasome in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and severe complications of diabetes and serves as the primary cause of end-stage kidney disease (ESKD) globally. Increasing evidence indicates that renal inflammation is critical in the pathogenesis of DKD. The nucleotide - binding oligomerization domain (NOD) - like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most extensively researched inflammasome complex and is considered a crucial regulator in the pathogenesis of DKD. The activation of NLRP3 inflammasome is regulated by various signaling pathways, including NF- κB, thioredoxin-interacting protein (TXNIP), and non-coding RNAs (ncRNA), among others. Natural products are chemicals extracted from living organisms in nature, and they typically possess pharmacological and biological activities. They are invaluable sources for drug design and development. Research has demonstrated that many natural products can alleviate DKD by targeting the NLRP3 inflammasome. In this review, we highlight the role of the NLRP3 inflammasome in DKD, and the pathways by which natural products fight against DKD via inhibiting the NLRP3 inflammasome activation, so as to provide novel insights for the treatment of DKD.

Notoginsenoside Fc ameliorates renal tubular injury and mitochondrial damage in acetaminophen-induced acute kidney injury partly by regulating SIRT3/SOD2 pathway

Introduction

Mitochondria dysfunction is one of the primary causes of tubular injury in acute kidney injury (AKI). Notoginsenoside Fc (Fc), a new saponin isolated from Panax notoginseng, exhibited numerous pharmacological actions. However, the beneficial effects of Fc on renal tubular impairment and mitochondrial dysfunction in AKI have not been fully studied.

Methods

In this study, we established acetaminophen (APAP)-induced AKI model in mice to examine the therapeutic impacts of Fc on AKI.

Results

Our results showed that Fc could decrease the levels of the serum creatinine (Scr), blood urea nitrogen (BUN) and Cystatin C in mice with AKI. Fc also ameliorated renal histopathology, renal tubular cells apoptosis and restored expression of apoptosis-related proteins such as Bax, Bcl-2 and caspase3 (C-caspase3). Additionally, Fc increased the protein expression of SIRT3 and SOD2 in kidneys from mice with AKI. In vitro studies further showed Fc reduced the apoptosis of HK-2 cells exposure to APAP, attenuated the loss of mitochondrial membrane potential and decreased the formation of mitochondrial superoxide. Fc also partly restored the protein expression of Bax, Bcl-2, C-Caspase3, SIRT3, and SOD2 in HK-2 cells exposure to APAP.

Conclusion

In summary, Fc might reduce renal tubular injury and mitochondrial dysfunction in AKI partly through the regulation of SIRT3/SOD2 pathway.

Identification of Protosappanoside D from Caesalpinia decapetala and Evaluation of Its Pharmacokinetic, Metabolism and Pharmacological Activity

Protosappanoside D (PTD) is a new component isolated from the extract of Caesalpinia decapetala for the first time. Its structure was identified as protosappanin B-3-O-β-D-glucoside by ¹H-NMR, ¹³C-NMR, 2D-NMR and MS techniques. To date, the pharmacological activities, metabolism or pharmacokinetics of PTD has not been reported. Therefore, this research to study the anti-inflammatory activity of PTD was investigated via the LPS-induced RAW264.7 cells model. At the same time, we also used the UHPLC/Q Exactive Plus MS and UPLC-MS/MS methods to study the metabolites and pharmacokinetics of PTD, to calculate its bioavailability for the first time. The results showed that PTD could downregulate secretion of the pro-inflammatory cytokines. In the metabolic study, four metabolites were identified, and the primary degradative pathways in vivo involved the desaturation, oxidation, methylation, alkylation, dehydration, degradation and desugarization. In the pharmacokinetic study, PTD and its main metabolite protosappanin B (PTB) were measured after oral and intravenous administration. After oral administration of PTD, its T_max was 0.49 h, t_1/2z and MRT_(0–t) were 3.47 ± 0.78 h and 3.06 ± 0.63 h, respectively. It shows that PTD was quickly absorbed into plasma and it may be eliminated quickly in the body, and its bioavailability is about 0.65%.

Efficacy and Safety of Shenqisuxin Granule for Non-ST-segment Elevation Acute Coronary Syndrome: Study Protocol for a Randomized, Double-Blinded, Placebo-Controlled Trial

Introduction

The Chinese herbal compound formula, Shenqisuxin granule (SQSX), promotes neovascularization and prevents in-stent restenosis in modern pharmaceutical studies and is expected to provide an effective strategy for non-ST-segment elevation acute coronary syndrome (NSTEACS). Thus, this study aims to examine the efficacy and safety of SQSX for NSTEACS and initially reveal its mechanism.

Methods/Design

The study is a randomized, double-blinded and placebo-controlled trial. A total of 66 participants will be randomly allocated to one of the following two groups. Participants in the SQSX group will receive conventional treatment plus SQSX, while the placebo group will receive conventional treatment plus placebo, both for 14 days. The primary outcome, hs-CRP, and secondary outcome the Seattle Angina Questionnaire (SAQ) will be assessed at baseline, 7 ± 3 days and 14 ± 3 days. At all visit windows, other indicators including creatine kinase (CK), creatine kinase-myocardial band (CK-MB), cardiac troponins I (cTnI), 12-lead electrocardiograph and the syndrome scores of Qi deficiency and blood stasis will be tested and metagenomic sequencing for intestinal flora will be performed. Echocardiography and safety assessment will be performed at baseline and 14 ± 3 days. Adverse events will be monitored during the trial.

Discussion

The purpose of the study is to examine the efficacy and safety of SQSX to improve NSTEACS and initially reveal its mechanism.

Trial Registration

China Clinical Trial Registry, ChiCTR2000029226. Registered on January 19, 2020.

Advances and challenges in ginseng research from 2011 to 2020: the phytochemistry, quality control, metabolism, and biosynthesis

Covering: 2011 to the end of 2020Panax species (Araliaceae), particularly P. ginseng, P. quinquefolius, and P. notoginseng, have a long history of medicinal use because of their remarkable tonifying effects, and currently serve as crucial sources for various healthcare products, functional foods, and cosmetics, aside from their vast clinical preparations. The huge market demand on a global scale prompts the continuous prosperity in ginseng research concerning the discovery of new compounds, precise quality control, ADME (absorption/disposition/metabolism/excretion), and biosynthesis pathways. Benefitting from the ongoing rapid development of analytical technologies, e.g. multi-dimensional chromatography (MDC), personalized mass spectrometry (MS) scan strategies, and multi-omics, highly recognized progress has been made in driving ginseng analysis towards "systematicness, integrity, personalization, and intelligentization". Herein, we review the advances in the phytochemistry, quality control, metabolism, and biosynthesis pathway of ginseng over the past decade (2011-2020), with 410 citations. Emphasis is placed on the introduction of new compounds isolated (saponins and polysaccharides), and the emerging novel analytical technologies and analytical strategies that favor ginseng's authentic use and global consumption. Perspectives on the challenges and future trends in ginseng analysis are also presented.

Pharmacokinetics, plasma protein binding, and metabolism of a potential natural chemosensitizer from Marsdenia tenacissima in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Marsdenia tenacissima (Roxb.) Wight et Arn is a medicinal plant mainly distributed in southwest China. It is used in folk medicine for the treatment of tumors and is synergistic with chemotherapies. In our previous study, 11α-O-2-methybutyryl-12β-O-tigloyl-tenacigenin B (MT2), a main steroid aglycone isolated from the total aglycones of M. tenacissima, significantly enhanced the in vivo antitumor effect of paclitaxel in mice bearing human tumor xenografts, showing its potential as a chemosensitizer. However, the pharmacokinetic characteristics, plasma protein binding rate, and metabolic profile of MT2 remain unclear.

AIM OF THE STUDY

To elucidate the pharmacokinetic characteristics, plasma protein binding rate, and metabolic profile of MT2 in rats.

MATERIALS AND METHODS

MT2 in rat plasma and phosphate-buffered saline was quantified using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method, while the MT2 metabolites in rat liver microsomes were analyzed using UPLC-triple time-of-flight MS/MS.

RESULTS

For intravenously administered MT2, the maximum plasma concentration and the area under the plasma concentration-time curve indicated dose dependency, while the elimination half-life time, the mean residence time, apparent volume of distribution and total apparent clearance values remained relatively unchanged in both the 5 mg/kg and 10 mg/kg groups. For orally administered MT2, the bioavailability was 1.08-1.11%. In rat plasma, MT2 exhibited a protein binding rate of 93.84-94.96%. In rat liver microsomes, MT2 was metabolized by oxidation alone or in combination with demethylation, and five MT2 metabolites were identified.

CONCLUSION

MT2 has low oral bioavailability and a high plasma protein binding rate in rats. After administration, MT2 is transformed into oxidative metabolites in the liver. To achieve a high blood concentration of MT2, it should be administered intravenously. These findings would serve as a reference for further MT2-based pharmacological study and drug development.

In vitro modulatory effects of ginsenoside compound K, 20(S)-protopanaxadiol and 20(S)-protopanaxatriol on uridine 5'-diphospho-glucuronosyltransferase activity and expression

We explored the inhibitory effect of ginsenoside compound K (CK), 20(S)-protopanaxadiol (PPD), and 20(S)-protopanaxatriol (PPT) on six uridine 5'-diphospho-glucuronosyltransferase (UGT) enzyme (UGT1A1, 1A3, 1A4, 1A6, 1A9, and 2B7) activities in human liver microsomes (HLMs) and 10 UGT enzyme (UGT1A1, 1A3, 1A4, 1A6, 1A9, 2B4, 2B7, 2B10, 2B15, and 2B17) activities in recombinant UGT isoforms.PPD was a potent inhibitor of UGT1A3 activity with half-maximal inhibitory concentration values of 5.62 and 3.38 μM in HLMs and recombinant UGT1A3, respectively. UGT1A3 inhibition by CK and PPD was competitive with inhibitory constant (K_i) values of 17.4 and 1.21 μM, respectively, and inhibition by PPT was non-competitive with a K_i value of 8.07 μM in HLMs. PPD exhibited more than 3.4-fold selectivity for UGT1A3 inhibition compared with other UGT isoforms inhibition, while CK and PPT showed more than 2.16- and 2.21-fold selectivity, respectively.PPD did not significantly increase the mRNA expression of UGT1A1, 1A3, 1A4, 1A9, and 2B7 in hepatocytes.Given the low plasma concentrations of PPD in healthy human subjects and the absence of induction potential on UGT isoforms, we conclude that PPD cause no pharmacokinetic interactions with other co-administered drugs metabolised by UGT1A3.

Pharmacokinetic and metabolism study of ginsenoside Rb2 in rat by liquid chromatography combined with electrospray ionization tandem mass spectrometry

In this study, a simple and rapid ultra-fast liquid chromatography tandem mass spectrometry method was established and validated to determine ginsenosides Rb2 in rat plasma. Acetonitrile-mediated protein precipitant was applied to the sample preparation. Chromatographic separation was carried out on an Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 μm). The analytes were monitored using multiple reactions monitoring mode with precursor-to-product ion transitions at m/z 1077.4-945.3 and m/z 799.8 → 637.8 for ginsenoside Rb2 and internal standard, respectively. The mobile phase was composed of 0.1% formic acid aqueous solution and acetonitrile. The assay showed excellent linearity over the concentration range of 2-1,000 ng/ml, with correlation coefficient >0.995. The method was further validated for selectivity, precision, accuracy, recovery, and stability according to the US Food and Drug Administration guidelines. The validated method was successfully applied to pharmacokinetic and bioavailability studies of ginsenoside Rb2 in rat plasma. Based on the pharmacokinetic results, ginsenoside Rb2 showed slow clearance and low oral bioavailability (0.15%). In addition, the metabolites of ginsenoside Rb2 in rat urine and feces were characterized according to their accurate masses and fragment ions. The proposed metabolic pathway was deglycosylation.

Pharmacokinetic studies of ginsenosides Rk1 and Rg5 in rats by UFLC-MS/MS

A rapid ultra-fast liquid chromatography tandem mass spectrometry method was developed and validated to determine ginsenosides Rk1 and Rg5, a pair of isomers, in rat plasma, which was successfully applied to their pharmacokinetic studies. Two ginsenosides were given to male Sprague-Dawley rats via intragastrical and intravenous routes, respectively, and the impact of double bond position on the pharmacokinetic features of the two ginsenosides was elucidated in rats. Ginsenoside Rg3 was used as internal standard and ethyl acetate was applied to extract analytes and internal standard. Chromatographic separation was carried out on a reverse-phase UPLC HSS T3 column (100 × 2.1 mm, 1.8 μm). The flow rate was set to 0.4 ml/min. The fragmentation transition was m/z 765.4 → m/z 101.1 for two ginsenosides. The mobile phases were composed of 0.1% formic acid aqueous solution and acetonitrile. The linear range was 2-1,000 ng/ml for the two ginsenosides. Intra- and inter-day precisions were <11.67%, and accuracy fluctuated from -7.44 to 6.78%. The extraction recovery, matrix effect and stability were within acceptable levels. After treatment with ginsenosides Rk1 and Rg5, some differences were found in their pharmacokinetic profiles in rats. The maximum plasma drug concentration and the area under the plasma drug concentration-time curve of ginsenoside Rg5 were about 5 times bigger than those of ginsenoside Rk1 after oral administration, and 3 times higher after intravenous administration. The oral bioavailabilities of ginsenosides Rk1 and Rg5 were 0.67 and 0.97%, respectively. The results indicated that ∆²⁰⁽²²⁾ -ginsenosides showed better pharmacokinetic features than ∆²⁰⁽²¹⁾ -ginsenosides with the same glycosylation.

Pharmacokinetic, bioavailability, and metabolism studies of lusianthridin, a dihydrophenanthrene compound, in rats by liquid chromatography/electrospray ionization tandem mass spectrometry

Lusianthridin was reported to possess many biological properties such as anti-oxidant and anti-cancer activities. However, its metabolic profiles and pharmacokinetics in vivo remain unknown. This study was carried out to investigate the metabolic profiles and pharmacokinetics of lusianthridin in rats. The metabolic profiles were obtained by an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). A total of eighteen metabolites involved three phase I metabolites and fifteen phase II metabolites were detected and identified. The major metabolic pathways of lusianthridin were demethylation, oxidation, sulfation, glucuronidation and glutathione conjugation. In addition, a simple and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for determination of lusianthridin in rat plasma. After extracted by protein precipitation, lusianthridin was quantitated in positive ion mode. The method was linear over the range of 0.5-500 ng/mL (r ≥ 0.995) with the LLOQ of 0.5 ng/mL. The intra- and inter- precision and accuracy, extraction recovery, matrix effect and stability were within the acceptable limits. The validated method was applied to the pre-clinical pharmacokinetic study of lusianthridin in rats. After oral administration, lusianthridin was quickly absorbed into plasma and reached the max concentration of 236.22 ng/mL at 22.00 min. The elimination half life of lusianthridin from plasma was approximately 83.05-104.47 min and the oral absolute bioavailability was calculated as 30.93 %.

A rapid and sensitive ultra-high-pressure liquid chromatography-tandem mass spectrometry method for the determination of notoginsenoside Ft1 in rat plasma with application to pharmacokinetic study

Notoginsenoside Ft1 (NGFt1), a dammarane triterpene glycoside isolated from Panax notoginseng, showed potent effective in stimulating platelet aggregation in our previous assay, yet its pharmacokinetic behavior is still unclear. This study describes a rapid and sensitive ultra-high-pressure LC-tandem mass spectrometry assay for determining of NGFt1 in rat plasma. Methanol-mediated precipitation was used for sample pre-treatment. Chromatographic separation was achieved on a C₁₈ column with gradient elution using water and acetonitrile as mobile phase. Determination was obtained using an electrospray ionization source in negative selected reaction monitoring (SRM) mode at the transitions of m/z 915.9 → m/z 783.8 and m/z 799.8 → m/z 637.8 for NGFt1 and internal standard, respectively. The assay was linear over the concentration range 0.25-2500 ng/mL (r > 0.995) with the lower limit of quantification of 0.25 ng/mL. The intra- and inter-day precisions (relative standard deviation, %) ranged 1.65%-9.84% and 2.46%-13.49%, respectively, whereas accuracy (relative recovery, %) ranged from 96.21% to 99.45%, respectively. The recovery ranged from 95.09% to 102.22% and the matrix effect from 98.29% to 100.13%. The analyte was stable under tested storage conditions. The method has been successfully applied to a preclinical pharmacokinetic study in rats after a single intravenous (2 mg/kg) and oral (50 mg/kg) administration.

UHPLC-MS/MS method for pharmacokinetic and bioavailability determination of five bioactive components in raw and various processed products of Polygala tenuifolia in rat plasma

CONTEXT

Sibiricose A5 (A5), sibiricose A6 (A6), 3,6'-disinapoyl sucrose (DSS), tenuifoliside A (TFSA) and 3,4,5-trimethoxycinnamic acid (TMCA) are the main active components of Polygala tenuifolia Willd. (Polygalaceae) (PT) that are active against Alzheimer's disease.

OBJECTIVE

To compare the pharmacokinetics and bioavailability of five active components in the roots of raw PT (RPT), liquorice-boiled PT (LPT) and honey-stir-baked PT (HPT).

MATERIALS AND METHODS

The median lethal dose (LD₅₀) was evaluated through acute toxicity test. The pharmacokinetics of five components after oral administration of extracts of RPT, LPT, HPT (all equivalent to 1.9 g/kg of RPT extract for one dose) and 0.5% CMC-Na solution (control group) were investigated, respectively, in Sprague-Dawley rats (four groups, n = 6) using UHPLC-MS/MS. In addition, the absolute bioavailability of A5, A6, DSS, TFSA and TMCA after oral administration (7.40, 11.60, 16.00, 50.00 and 3.11 mg/kg, respectively) and intravenous injection (1/10 of the corresponding oral dose) in rats (n = 6) was studied.

RESULTS

The LD₅₀ of RPT, LPT and HPT was 7.79, 14.55 and 15.99 g/kg, respectively. AUC _{0- t} of RPT, LPT and HPT were as follows: A5 (433.18 ± 65.48, 680.40 ± 89.21, 552.02 ± 31.10 ng h/mL), A6 (314.55 ± 62.73, 545.76 ± 123.16, 570.06 ± 178.93 ng h/mL) and DSS (100.30 ± 62.44, 232.00 ± 66.08, 197.58 ± 57.37 ng h/mL). The absolute bioavailability of A5, A6, DSS, TFSA and TMCA was 3.25, 2.95, 2.36, 1.17 and 42.91%, respectively.

DISCUSSION AND CONCLUSIONS

The pharmacokinetic and bioavailability parameters of each compound can facilitate future clinical studies.

In Vivo Metabolic Profiles of Panax notoginseng Saponins Mediated by Gut Microbiota in Rats

Panax notoginseng saponins (PNSs) are the major health-beneficial components of P. notoginseng with very low oral bioavailability, which could be biotransformed by gut microbiota in vitro. However, in vivo biotransformation of PNS mediated by gut microbiota is not well known. This study aimed to characterize the in vivo metabolic profiles of PNS mediated by gut microbiota. The saponins and yielded metabolites in rat feces were identified and relatively quantified by ultra-performance liquid chromatography tandem/quadrupole time-of-flight mass spectrometry. Seventy-three PNS metabolites had been identified in the normal control group, but only 11 PNS metabolites were determined in the pseudo germ-free (GF) group. In addition, the main biotransformation pathway of PNS metabolism was hydrolytic and dehydration reactions. The results indicated that a significant metabolic difference was observed between the normal control group and pseudo GF group, while gut microbiota played a profound role in the biotransformation of PNS in vivo.

Focus on Notoginsenoside R1 in Metabolism and Prevention Against Human Diseases

Notoginsenoside (NG)-R1 is one of the main bioactive compounds from Panax notoginseng (PN) root, which is well known in the prescription for mediating the micro-circulatory hemostasis in human. In this article, we mainly discuss NG-R1 in metabolism and the biological activities, including cardiovascular protection, neuro-protection, anti-diabetes, liver protection, gastrointestinal protection, lung protection, bone metabolism regulation, renal protection, and anti-cancer. The metabolites produced by deglycosylation of NG-R1 exhibit higher permeability and bioavailability. It has been extensively verified that NG-R1 may ameliorate ischemia-reperfusion (IR)-induced injury in cardiovascular and neuronal systems mainly by upregulating the activity of estrogen receptor α-dependent phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and nuclear factor erythroid-2-related factor 2 (NRF2) pathways and downregulating nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. However, no specific targets for NG-R1 have been identified. Expectedly, NG-R1 has been used as a main bioactive compound in many Traditional Chinese Medicines clinically, such as Xuesaitong, Naodesheng, XueShuanTong, ShenMai, and QSYQ. These suggest that NG-R1 exhibits a significant potency in drug development.

Dose-dependent exposure profile and metabolic characterization of notoginsenoside R1 in rat plasma by ultra-fast liquid chromatography-electrospray ionization-tandem mass spectrometry

Notoginsenoside R₁ (NGR₁ ), a diagnostic protopanaxatriol-type (ppt-type) saponin in Panax notoginseng, possesses potent biological activities including antithrombotic, anti-inflammatory, neuron protection and improvement of microcirculation, yet its pharmacokinetics and metabolic characterization as an individual compound remain unclear. The aim of this study was to investigate the exposure profile of NGR₁ in rats after oral and intravenous administration and to explore the metabolic characterization of NGR₁ . A simple and sensitive ultra-fast liquid chromatographic-tandem mass spectrometric method was developed and validated for the quantitative determination of NGR₁ and its major metabolites, and for characterization of its metabolic profile in rat plasma. The blood samples were precipitated with methanol, quantified in a negative multiple reaction monitoring mode and analyzed within 6.0 min. Validation parameters (linearity, precision and accuracy, recovery and matrix effect, stability) were within acceptable ranges. After oral administration, NGR₁ exhibited dose-independent exposure behaviors with t_1/2 over 8.0 h and oral bioavailability of 0.25-0.29%. A total of seven metabolites were characterized, including two pairs of epimers, 20(R)-notoginsenoside R₂ /20(S)-notoginsenoside R₂ and 20(R)-ginsenoside Rh₁ /20(S)-ginsenoside Rh₁ , with the 20(R) form of saponins identified for the first time in rat plasma. Five deglycometabolites were quantitatively determined, among which 20(S)-notoginsenoside R₂ , ginsenoside Rg₁ , ginsenoside F₁ and protopanaxatriol displayed relatively high exploration, which may partly explain the pharmacodynamic diversity of ginsenosides after oral dose.

Identification and quantitative investigation of the effects of intestinal microflora on the metabolism and pharmacokinetics of notoginsenoside Fc assayed by liquid chromatography with electrospray ionization tandem mass spectrometry

Notoginsenoside Fc, which is a protopanaxdiol-type saponin isolated from the leaves of Panax notoginseng, exhibits an exceptional antiplatelet aggregatory effect. To study the modulating effect of gastrointestinal contents on the metabolic profile and pharmacokinetics, pseudo germ-free rats were used to study the influence of the bacterial community structure on the metabolic profile. Glycosidase activities were measured using the spectrophotometric method. Biotransformations of notoginsenoside Fc in normal and pseudo germ-free rat intestinal microflora were systematically investigated using ultra high performance liquid chromatography with tandem quadrupole/time-of-flight mass spectrometry. Moreover, a liquid chromatography with tandem mass spectrometry method was established for simultaneous determination of the notoginsenoside Fc prototype and its degradation products. Through an in vivo pharmacokinetic study, the pharmacokinetic characteristics were compared between normal rats and pseudo germ-free rats. During the in vitro biotransformation, seven deglycosylated products were detected and identified after incubation in the intestinal bacteria of normal rats. In pseudo germ-free rats, glycosidase activities were significantly decreased, and no obvious degradation occurred. In an in vivo study, the systemic exposure was significantly increased 40%, as evidenced by the area under the blood concentration-time curve from time zero to infinity value and half-life value, which were prolonged more in the pseudo germ-free group than in normal rats. The results demonstrate that patients who use intestinal bacteria-metabolized herbs, such as panax notoginseng, should understand the profile of intestinal bacteria to ensure therapeutic efficacy.

Re-evaluation of Quillaia extract (E 999) as a food additive and safety of the proposed extension of use

The EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) provides a scientific opinion on Quillaia extract (E 999) when used as a food additive and the evaluation of the safety of its proposed extension of use as a food additive in flavourings. The Scientific Committee for Food (SCF) in 1978 established an acceptable daily intake (ADI) of 0-5 mg spray-dried extract/kg body weight (bw) per day for E 999. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) established in its latest evaluation a group ADI of 0-1 mg/kg bw per day, expressed as quillaia saponins, for Quillaia extract for Type 1 and Type 2. The Panel considered it likely that intact Quillaia extract saponins are absorbed to a low extent, are hydrolysed in the gastrointestinal (GI) tract and that the aglycone is absorbed only to a limited extent. The Panel considered that the genotoxicity data available did not indicate a concern for genotoxicity. Taking into account the available toxicological database, various no observed adverse effect levels (NOAELs) relevant for the derivation of an ADI were identified. The Panel considered that the 2-year study in rats was the most robust and that the NOAEL of 1,500 mg Quillaia extract/kg bw per day could be used to derive the ADI for E 999. Considering that the adverse effects reported were due to the presence of saponins in the extract, that saponins were present in Quillaia extract Type 1 (around 20%) and using an uncertainty factor of 100, the Panel derived a ADI of 3 mg saponins/kg bw per day for E 999. None of the exposure estimates for the different population groups of the refined brand-loyal scenario exceeded the ADI of 3 mg saponins/kg bw per day. The proposed extension of use also would not result in an exceedance of this ADI for the refined scenario. The Panel proposed some recommendations for the European Commission to consider, in particular revising the EU specifications for E 999 in order to differentiate the extracts of Quillaia according to the saponins content and to include other parameters to better characterise the food additive.

Notoginsenoside Fc Accelerates Reendothelialization following Vascular Injury in Diabetic Rats by Promoting Endothelial Cell Autophagy

Interventional therapies, such as percutaneous transluminal angioplasty and endovascular stent implantation, are used widely for the treatment of diabetic peripheral vascular complications. Reendothelialization is an essential process in vascular injury following interventional therapy, and hyperglycemia in diabetes mellitus (DM) plays an important role in damaging endothelial layer integrity, leading to the retardance of reendothelialization and excessive neointimal formation. Notoginsenoside Fc (Fc), a novel saponin isolated from Panax notoginseng, effectively counteracts platelet aggregation. Nevertheless, the potential effects and molecular mechanisms of Fc on reendothelialization have yet to be explored. In this study, we present novel findings that show the benefit of Fc in accelerating reendothelialization and alleviating excessive neointimal formation following carotid artery injury in diabetic Sprague-Dawley rats in vivo. Simultaneously, the decreased autophagy of the injured carotid artery in diabetic rats was restored by Fc treatment. Our in vitro results also demonstrated that Fc promoted endothelial cell proliferation and migration under high-glucose treatment by increasing autophagy. In summary, this study supported the notion that Fc could accelerate reendothelialization following vascular injury in diabetic rats by promoting autophagy, suggesting that Fc may exert therapeutic benefits for early endothelial injury and restenosis following intervention in diabetes-associated vascular diseases.

Metabolic analysis of Panax notoginseng saponins with gut microbiota-mediated biotransformation by HPLC-DAD-Q-TOF-MS/MS

Saponins such as notoginsenosides and ginsenosides from Panax notoginseng are responsible for the herb's clinical applications. Unfortunately, there is poor oral bioavailability of saponins. However, gut microbiota can transform saponins to yield the metabolites that are potential bioactive substances. In this study, we aimed to characterize the metabolic profiles of P. notoginseng saponins (PNS) by incubating them with human gut microbiota. The notoginsenosides, ginsenosides and related metabolites were separated and identified using a highly sensitive and selective high-performance liquid chromatography coupled with diode array detection/quadrupole tandem time-of-flight mass spectrometry (HPLC-DAD-Q-TOF-MS/MS). The results showed that the most abundant metabolites, ginsenoside F₁, protopanaxatriol (PPT), ginsenoside Rh₂, ginsenoside compound K (GCK) and protopanaxadiol (PPD), were reported to possess stronger related pharmacological activities when compared with parent ginsenosides. These metabolites were identified among a total of 45 other metabolites. Furthermore, it was elucidated that deglycosylation is the main metabolic pathway which saponins are split off from glycosyl moieties by the enzymes secreted from gut microbiota. The gut microbiota may play a significant role in mediating the bioactivities of PNS.

A simple and sensitive UHPLC-MS/MS method for quantification of buddlejasaponin IV in rat plasma and its application to a pharmacokinetic study

Buddlejasaponin IV (BS-IV), a natural triterpene saponin isolated from several herbal plants, has drawn a lot of attention for its anti-inflammatory, antinociceptive, antihyperlipidemia, and antitumor activities. In this study, a simple and sensitive method for determination of BS-IV in rat plasma was developed for the first time, using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Tenacissoside I was used as an internal standard (IS). Separation was achieved on an Agilent Extend-C18 column with gradient elution using methanol-water as mobile phase at a flow rate of 400μL/min. A triple quadrupole mass spectrometer operating in the positive/negative ion-switching electrospray ionization mode with selection reaction monitoring (SRM) was used to determine BS-IV and IS transitions of 941.4→779.5 and 815.5→755.5, respectively. The lower limit of quantification was 3.00ng/mL with a linear range of 3.0-3000ng/mL. The intra- and inter-day precisions were both ≤10.4% for BS-IV, and the average intra- and inter-day accuracies ranged from -7.2% to 6.7%. The validated assay was successfully applied to a pharmacokinetic study of BS-IV following oral administration of 3, 6, 12mg/kg and an intravenous administration of 0.9mg/kg to rats.

Discovery and Current Status of Evaluation System of Bioavailability and Related Pharmaceutical Technologies for Traditional Chinese Medicines--Flos Lonicerae Japonicae--Fructus Forsythiae Herb Couples as an Example

Traditional Chinese medicines (TCMs) have attracted extensive interest throughout the world due to their long history of health protection and disease control, and the internalization of TCM preparations or patented drugs has been considered a wind vane in the process of TCM modernization. However, multi-target effects, caused by multiple components in TCMs, hinder not only the construction of the quality evaluation system (bioavailability), but also the application of pharmaceutical technologies, which results in the poor efficacy in clinical practice. This review describes the methods in the literature as well as in our thoughts about how to identify the marker components, establish the evaluation system of bioavailability, and improve the bioavailability in TCM preparations. We expect that the current study will be positive and informative.