A model-informed approach to accelerate the clinical development of cofrogliptin (HSK7653), a novel ultralong-acting dipeptidyl peptidase-4 inhibitor.

AIM: To employ a model-informed drug development approach in facilitating decision making and expediting the clinical progress of cofrogliptin (HSK7653), a novel ultralong-acting dipeptidyl peptidase-4 (DPP-4) inhibitor, for the treatment of type 2 diabetes (T2D) via a biweekly dosing regimen. METHODS: Firstly, a population pharmacokinetics and pharmacodynamics (PopPKPD) model was developed using PK and PD data from a single ascending dose study to simulate the PK and PD time profiles of HSK7653 after multiple doses. Secondly, model-based meta-analysis (MBMA) was performed on published clinical studies of Eastern Asian subjects for all DPP-4 inhibitors. We hypothesized a consistent relationship between PK and DPP-4 inhibition in both healthy individuals and in those with T2D, establishing a quantitative correlation between DPP-4 inhibition and HbA1c. Finally, the predicted PK/DPP-4 inhibition/HbA1c profiles were validated by T2D patients in late clinical trials. RESULTS: The PK/DPP-4 inhibition/HbA1c profiles of T2D patients treated with HSK7653 matched the modelled data. Our PopPKPD and MBMA models predict multiple ascending dosing PK and PD characteristics from single ascending dosing data, as well as the long-term efficacy in T2D patients, based on healthy subjects. CONCLUSIONS: Successful waiver approval for the phase 2b dose-finding study was achieved through model-informed recommendations, facilitating the clinical development of HSK7653 and other DPP-4 inhibitors.

Population Pharmacokinetic/Pharmacodynamic Analysis of the Glucokinase Activator PB201 in Healthy Volunteers and Patients with Type 2 Diabetes Mellitus: Facilitating the Clinical Development of PB201 in China.

PB201 is an orally active, partial glucokinase activator targeting both pancreatic and hepatic glucokinase. As the second glucokinase activator studied beyond phase I, PB201 has demonstrated promising glycemic effects as well as favorable pharmacokinetic (PK) and safety profiles in patients with type 2 diabetes mellitus (T2DM). This study aims to develop a population PK/pharmacodynamic (PD) model for PB201 using the pooled data from nine phase I/II clinical trials conducted in non-Chinese healthy volunteers and a T2DM population and to predict the PK/PD profile of PB201 in a Chinese T2DM population. We developed the PK/PD model using the non-linear mixed-effects modeling approach. All runs were performed using the first-order conditional estimation method with interaction. The pharmacokinetics of PB201 were well fitted by a one-compartment model with saturable absorption and linear elimination. The PD effects of PB201 on reducing the fasting plasma glucose and glycosylated hemoglobin levels in the T2DM population were described by indirect response models as stimulating the elimination of fasting plasma glucose, where the production of glycosylated hemoglobin was assumed to be stimulated by fasting plasma glucose. Covariate analyses revealed enhanced absorption of PB201 by food and decreased systemic clearance with ketoconazole co-administration, while no significant covariate was identified for the pharmacodynamics. The population PK model established for non-Chinese populations was shown to be applicable to the Chinese T2DM population as verified by the PK data from the Chinese phase I study. The final population PK/PD model predicted persistent and dose-dependent reductions in fasting plasma glucose and glycosylated hemoglobin levels in the Chinese T2DM population receiving 50/50 mg, 100/50 mg, and 100/100 mg PB201 twice daily for 24 weeks independent of co-administration of metformin. Overall, the proposed population PK/PD model quantitatively characterized the PK/PD properties of PB201 and the impact of covariates on its target populations, which allows the leveraging of extensive data in non-Chinese populations with the limited data in the Chinese T2DM population to successfully supported the waiver of the clinical phase II trial and facilitate the optimal dose regimen design of a pivotal phase III study of PB201 in China.

Absorption, Metabolism, and Excretion of Cajaninstilbene Acid.

Cajaninstilbene acid (CSA), an active stilbene isolated from the leaves of pigeon pea (Cajanus cajan), exhibits several bioactivities. To develop CSA as a potential nutraceutical and provide pharmacokinetic foundations for its further in vivo bioactivity studies, this study aims to explore its absorption, metabolism, and excretion systematically. Human colon adenocarcinoma (Caco-2) cell monolayers were utilized to investigate the CSA transport mechanism. CSA metabolites were identified in rat biological samples and quantified to explore their excretion routes. CSA exhibited a high permeability and was transported across Caco-2 monolayers mainly by passive transport via the transcellular process. Four new CSA metabolites were found in vivo, namely, CSA-2-COO-glucuronide, 6,12-dihydroxy CSA, 3-hydroxy-5-methoxystilbene-3-O-glucuronide, and 6-hydroxy CSA-3-O-glucuronide, in addition to our previously reported metabolite CSA-3-O-glucuronide. These metabolites were mainly excreted in bile. Our results indicate that metabolism but not absorption is the major barrier limiting the oral bioavailability of CSA.

Brain Pharmacokinetics and the Pharmacological Effects on Striatal Neurotransmitter Levels of Pueraria lobata Isoflavonoids in Rat.

Isoflavonoids are putatively active components of Pueraria lobata and has been demonstrated prominent neuro-protection effect against cerebrovascular disorders, hypertension or Parkinson's disease (PD). However, the molecular basis for the beneficial effect of Pueraria lobata on nervous systems has not been well revealed. The present study aims to assess striatum exposure to main active isoflavonoids and changes of striatal extracellular neurotransmitters levels in rat brain after intravenous administration of Pueraria lobata isoflavonoids extracts (PLF), to further elucidate its' substantial bases for neuro activities. Fifteen rats were divided into 3 groups (five rats in each group) to receive a dose of PLF at 80 or 160 mg/kg or normal saline (vehicle), respectively. An LC-MS/MS method was employed to determine the concentrations of five main isoflavonoids and multiple neurotransmitters in microdialysate from striatal extracellular fluid (ECF) of the rats. The exposed quantities of puerarin (PU), 3'-methoxypuerarin (MPU), daidzein-8-C-apiosyl-(1-6)-glucoside (DAC), and 3'-hydroxypuerarin (HPU) in striatum were dose-dependent. The content of daidzein (DAZ) was too low to be detected in all dialysate samples through the experiment. Optimal dose PLF (80 mg/kg) promoted DA metabolism and inhibited 5-HT metabolism. No obvious change in the level of GLu was determined. The concentration of GABA presented a temporary decline firstly and then a gradual uptrend followed by a further downtrend. Higher dose (160 mg/kg) PLF could enhance the metabolism of both DA and 5-HT, and lower the extracellular level of GLu, without changing GABA concentrations, which might result in alleviation on excitatory toxicity under conditions, such as ischemia. The results infer that different dose of PLF should be chosen to achieve appropriate neurochemical modulation effects under conditions, such as hypertension or ischemia/stroke. These findings may significantly contribute to a better understanding of the neuroprotective effect of Pueraria lobata and provide new insights into its application toward neuro-degenerative diseases in the future.

Ganoderic Acid A Metabolites and Their Metabolic Kinetics.

Ganoderic acid A (GAA), a representative active triterpenoid from Ganoderma lucidum, has been reported to exhibit antinociceptive, antioxidative, cytotoxic, hepatoprotective and anticancer activities. The present study aims (1) to identify GAA metabolites, in vivo by analyzing the bile, plasma and urine after intravenous administration to rats (20 mg/kg), and in vitro by incubating with rat liver microsomes (RLMs) and human liver microsomes (HLMs); (2) to investigate the metabolic kinetics of main GAA metabolites. Using HPLC-DAD-MS/MS techniques, a total of 37 metabolites were tentatively characterized from in vivo samples based on their fragmentation behaviors. The metabolites detected in in vitro samples were similar to those found in vivo. GAA underwent extensive phase I and II metabolism. The main metabolic soft spots of GAA were 3, 7, 11, 15, 23-carbonyl groups (or hydroxyl groups) and 12, 20, 28 (29)-carbon atoms. Ganoderic acid C2 (GAC2) and 7ß,15-dihydroxy-3,11,23-trioxo-lanost-26-oic acid were two main reduction metabolites of GAA, and their kinetics followed classical hyperbolic kinetics. The specific isoenzyme responsible for the biotransformation of the two metabolites in RLMs and HLMs was CYP3A. This is the first report on the comprehensive metabolism of GAA, as well as the metabolic kinetics of its main metabolites.

Pharmacokinetics of Cajaninstilbene Acid and Its Main Glucuronide Metabolite in Rats.

As a major active stilbene from the leaves of pigeon pea (Cajanus cajan), cajaninstilbene acid (CSA) exerts various pharmacological activities. The present study aimed to investigate the pharmacokinetics of CSA and one of its main metabolites (M1) to explore their fate in the body and provide a pharmacokinetic foundation for their in vivo biological activities and functional food or complementary medicine application. M1 was characterized as CSA-3-O-glucuronide using the multiple reaction monitoring-information-dependent acquisition-enhanced product ion technique. After oral and intravenous administration, plasma, urine, and bile were collected and analyzed to estimate pharmacokinetic properties of CSA and M1 and to explore the main excretion route. The oral bioavailability of CSA was estimated to be 44.36%. This study first reported that CSA is mainly metabolized to CSA-3-O-glucuronide via the first-pass effect to limit its oral bioavailability and excreted predominantly through the biliary route, while the enterohepatic circulation, extravascular distribution, and renal reabsorption characteristics of CSA might delay its elimination.

Plasma and brain pharmacokinetics of ganoderic acid A in rats determined by a developed UFLC-MS/MS method.

Ganoderic acid A (GAA), an active triterpenoid of the traditional Chinese herbal medicine Lingzhi, has been reported to exhibit antinociceptive, antioxidative, and anti-cancer activities. The present study aims to establish a sensitive and rapid UPLC-MS/MS method for studying the plasma and brain pharmacokinetics of GAA in rats. The analytes were separated on a C18 column eluted with a gradient mobile phase consisting of acetonitrile and 0.1% aqueous formic acid at 0.3mL/min. The eluate was monitored by a mass detector using an MRM (m/z, 515.3-285.1) model in negative electrospray ionization. The calibration curve showed good linearity (r2>0.99), with limits of detection and quantification of 0.25 and 2.00 nmol/L, respectively. The intra- and inter-day precision and accuracy were less than 9.99% and ranged from 97.45% to 114.62%, respectively. The extraction recovery from plasma was between 92.89% and 98.87%. GAA was found to be stable in treated samples at room temperature (22°C) for 12h and in plasma at -20°C for 7d. The developed method was successfully applied to a pharmacokinetic study of GAA in rats. GAA could be rapidly absorbed into the circulation (Tmax, 0.15h) and eliminated relatively slowly (t1/2, 2.46h) after orally dosing, and could also be detected in the brain lateral ventricle (Tmax, 0.25h and t1/2, 1.40h) after intravenously dosing. The absolute oral bioavailability and brain permeability of GAA were estimated to be 8.68% and 2.96%, respectively.

Formulation of 20(S)-protopanaxadiol nanocrystals to improve oral bioavailability and brain delivery.

The aim of this study was to fabricate 20(S)-protopanaxadiol (PPD) nanocrystals to improve PPD's oral bioavailability and brain delivery. PPD nanocrystals were fabricated using an anti-solvent precipitation approach where d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was optimized as the stabilizer. The fabricated nanocrystals were nearly spherical with a particle size and drug loading of 90.44 ± 1.45 nm and 76.92%, respectively. They are in the crystalline state and stable at 4°C for at least 1 month. More than 90% of the PPD could be rapidly released from the nanocrystals, which was much faster than the physical mixture and PPD powder. PPD nanocrystals demonstrated comparable permeability to solution at 2.52 ± 0.44×10(-5)cm/s on MDCK monolayers. After oral administration of PPD nanocrystals to rats, PPD was absorbed quickly into the plasma and brain with significantly higher Cmax and AUC0-t compared to those of the physical mixture. However, no brain targeting was observed, as the ratios of the plasma AUC0-t to brain AUC0-t for the two groups were similar. In summary, PPD nanocrystals are a potential oral delivery system to improve PPD's poor bioavailability and its delivery into the brain for neurodegenerative disease and intracranial tumor therapies in the future.

Pharmacokinetic profiles of the five isoflavonoids from Pueraria lobata roots in the CSF and plasma of rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese medicine Radix Puerariae, the roots of Pueraria lobata (Wild.) Ohwi., has been widely used for the treatment of cardiovascular and cerebrovascular diseases in China for centuries. Isoflavonoids are believed the active components of this herb. AIM OF THIS STUDY: The present study aims to investigate the brain penetration and pharmacokinetics of five active isoflavonoids in the ventricular CSF and plasma of rats after intravenous administration of a Pueraria isoflavonoids (PIF) extract, to better understand the active components of this herb for neuro-activities. MATERIAL AND METHODS: Under anesthesia condition, SD rats (n=6) were successively suffered two surgeries for implanting cannulas at lateral ventricle and right jugular vein for brain microdialysis and blood collection, respectively. After recovery, the rats received intravenous dose of PIF at 80mg/kg and the concentrations of puerarin (PU), 3'-methoxypuerarin (MPU), 3'-hydroxypuerarin (HPU), daidzein (DA) and daidzein-8-C-apiosyl-(1-6)-glycoside (DAC) in the ventricular dialysate and plasma samples were determined using a ultra-fast liquid chromatography tandem mass spectrometry method. RESULTS: Complete concentration versus time profiles of the five components in plasma and four components except for HPU in ventricular CSF were obtained. After dosing, the average C0 values of PU, MPU, DA, DAC and HPU in plasma were estimated 6.53, 13.72, 1.54, 15.84 and 86.07µg/mL, and PU, MPU, DA and DAC were rapidly penetrated to the brain and reached to their Cmax of 521.52, 415.00, 74.34 and 380.03ng/mL in CSF at about 0.5-0.8h, respectively. The elimination t1/2 of PU, DA and DAC in CSF and plasma were no significant difference, while the t1/2 of MPU in ventricular CSF was longer than that in plasma which may attributable to the different physiological environment of central and peripheral compartments. The brain penetration index (AUCCSF/AUCplasma) was found to be about 9.29, 7.25, 11.96, and 4.21% for PU, MPU, DA, and DAC respectively. CONCLUSION: PU, MPU, DA, DAC can quickly penetrate to the brain through the blood brain barrier (BBB) and might be responsible for the neuro-pharmacological activities of P. lobata.

Anti-stress effects of ginseng total saponins on hindlimb-unloaded rats assessed by a metabolomics study.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng, the roots and rhizomes of Panax ginseng C.A. Mey. (Araliaceae), is used as a tonic herb for thousands of years in Asian countries. Saponins are recognized as its major active ingredients and reportedly can ease disorders caused by various adverse stimuli. Nevertheless, it is unclear whether ginseng saponins have beneficial effects on stress caused by microgravity. AIM OF THE STUDY: This study aimed to assess the anti-stress effects and corresponding mechanisms of ginseng total saponins (GTSs) on simulated microgravity (SM) hindlimb-unloaded rats using a metabolomics method. MATERIALS AND METHODS: The stressed rats were induced by hindlimb unloading for 7 continuous days. Levels of plasma corticosterone (CORT) and weights of immune organs including the thymuses, spleens, and adrenal glands were determined. Urinary metabolic profiles of the rats under the simulated microgravity condition with and without GTSs intervention were compared using an ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS) based metabolomics method. Multivariate statistical analysis including Principal Component Analysis (PCA) and Partial Least Squares project to latent structures-Discriminant Analysis (PLS-DA) were performed. RESULTS: Compared with control (66.22±10.40ng/mL), the plasma CORT level of the SM rats (82.67±13.64ng/mL) were significantly (p<0.05) elevated, and GTSs could restore this elevation to a lower level (77.75±14.35ng/mL). GTSs could also significantly alleviate the atrophy of the thymuses and the spleens, as well as the hypertrophy of the adrenal glands of the SM rats. Urinary metabolic profiling showed comprehensive metabolic variation among the three groups. A series of metabolic pathways including taurine and hypotaurine, purine and pyridine, and amino acid were affected. Eleven potential biomarkers such as taurine, adenine, and valine were identified. GTSs could correct the disturbed metabolic pathways and restore the variation of these potential markers. CONCLUSION: GTSs can exert anti-stress effects by reducing the secretion of plasma CORT, enhancing the immune function, and restoring an array of disturbed metabolic pathways and metabolites. The findings of this study provide crucial evidence of a link between metabolic imbalance and microgravity, and reveal a molecular basis for the anti-stress benefits of GTSs in the management of microgravity-related disorders.

LC/MS-based metabolomics strategy to assess the amelioration effects of ginseng total saponins on memory deficiency induced by simulated microgravity.

Microgravity-induced memory deficiency seriously affects learning and memory ability of the astronaut during spaceflight, with few effective countermeasures. Panax ginseng C. A. Mey. has been used as a nootropic herb for thousands of years in Asian countries. Saponins are recognized as its major active components. Previous studies have shown that ginseng saponins offer protection against memory deficits caused by various factors. Nevertheless, the underlying mechanisms of their nootropic effects are still largely unknown. In this study, we evaluated the memory-improving effects of ginseng total saponins (GTS) on simulated microgravity hindlimb-unloaded rats using a metabolomics approach. After being exposed to a 7-days hindlimb unloading (HU), variations of plasmatic and hippocampal metabolic profiles of rats with and without GTS intervention were examined by a liquid chromatography-mass spectrometry (LC-MS) based untargeted metabolomics method. Subsequently, 8 hippocampal neurotransmitters were determined using a LC-MS/MS method. Finally, a LC-MS/MS based targeted metabolomics was performed to validate biomarkers found in the untargeted analysis. Besides, to support the metabolomics results, passive avoidance (PA) test, Nissl staining, and plasmatic corticosterone (CORT) levels determination were performed. The results showed that HU could lead to variations of 7 neurotransmitters and significantly different plasmatic and hippocampal metabolic profiles. GTS could restore most of the imbalanced neurotransmitters, especially glutamic acid and acetylcholine, and correct the levels of various disturbed learning and memory relevant biomarkers such as asparagine, phenylalanine, tyrosine, tryptophan, and choline. In addition, GTS could markedly ameliorate HU-induced memory deficiency, protect hippocampal neurons from damage, and down-regulate elevated CORT levels. In conclusion, GTS exhibits memory-improving effects mainly through regulating the metabolism of amino acids, neurotransmitters, choline, kynurenine, and sphingolipids. The findings of this study not only can deepen our understanding of the underlying molecular mechanisms of MG-induced memory disorders, but also provide scientific evidence for choosing ginseng as a countermeasure against MG-induced memory deficiency.

Lotus leaf alkaloid fraction can strongly inhibit CYP2D6 isoenzyme activity.

ETHNOPHARMACOLOGICAL RELEVANCE: The Chinese herbal medicine He-Ye, the leaves of the lotus (Nelumbo nucifera) plant, is traditionally used in China for the treatment of sunstroke, thirst, diarrhea, and fever. Currently, the leaf is used not only as an herbal tea to reduce lipid level and control body weight, but also as a major ingredient in some lipid-lowering Chinese patented medicines. Our previous study demonstrated that the alkaloid fraction (AF) of the herb has a strong inhibitory effect on CYP2D6 isoenzyme activity in vitro. The present study aims to further verify this activity using the in vivo rat model and to explore the inhibitory mechanism on CYP2D6 using human liver microsomes (HLMs). MATERIALS AND METHODS: After a continuous 7-d oral dose of AF (50mg/kg) or a vehicle, Sprague Dawley rats received a single intravenous dose of dextromethorphan or metoprolol. Blood samples were collected at various time points, and the plasma concentrations of the relevant metabolites dextrorphan and hydroxymetoprolol were assayed by LC-MS/MS for evaluating the effect of AF on their pharmacokinetics and CYP2D6 activity. Dextromethorphan as a probe at different concentrations was incubated with HLMs in an incubation buffer system, in the presence or absence of AF at different concentrations. After incubation, the produced metabolite was assayed. RESULTS: After being pretreated with AF in rats, the plasma concentrations of dextrorphan and hydroxymetoprolol significantly decreased, with Cmax going from 79.44 to 29.96 and 151.18 to 83.39hng/mL (P<0.05), AUCall from 167.27 to 62.25 and 347.68 to 223.24hng/mL (P<0.05), and AUCinf from 183.39 to 84.76 and 350.59 to 234.57hng/mL (P<0.05), respectively, in comparison with those of untreated rats. The t1/2 of hydroxymetoprolol significantly increased from 1.14 to 1.99h (P<0.05). The in vitro incubation test showed that AF competitively inhibited the CYP2D6, with apparent Ki value of 0.64µg/mL. CONCLUSIONS: AF can strongly inhibit the activity of CYP2D6 enzyme, as confirmed by in vivo and in vitro models. Possible drug interactions may occur between AF and other medications metabolized by CYP2D6. Thus, caution should be paid when the lotus leaf and its preparations are concurrently administered with conventional medicines.

De novo assembly and comparative analysis of root transcriptomes from different varieties of Panax ginseng C. A. Meyer grown in different environments.

Panax ginseng C. A. Meyer is an important traditional herb in eastern Asia. It contains ginsenosides, which are primary bioactive compounds with medicinal properties. Although ginseng has been cultivated since at least the Ming dynasty to increase production, cultivated ginseng has lower quantities of ginsenosides and lower disease resistance than ginseng grown under natural conditions. We extracted root RNA from six varieties of fifth-year P. ginseng cultivars representing four different growth conditions, and performed Illumina paired-end sequencing. In total, 163,165,706 raw reads were obtained and used to generate a de novo transcriptome that consisted of 151,763 contigs (76,336 unigenes), of which 100,648 contigs (66.3%) were successfully annotated. Differential expression analysis revealed that most differentially expressed genes (DEGs) were upregulated (246 out of 258, 95.3%) in ginseng grown under natural conditions compared with that grown under artificial conditions. These DEGs were enriched in gene ontology (GO) terms including response to stimuli and localization. In particular, some key ginsenoside biosynthesis-related genes, including HMG-CoA synthase (HMGS), mevalonate kinase (MVK), and squalene epoxidase (SE), were upregulated in wild-grown ginseng. Moreover, a high proportion of disease resistance-related genes were upregulated in wild-grown ginseng. This study is the first transcriptome analysis to compare wild-grown and cultivated ginseng, and identifies genes that may produce higher ginsenoside content and better disease resistance in the wild; these genes may have the potential to improve cultivated ginseng grown in artificial environments.

An LC-MS/MS method for simultaneous determination of three Polygala saponin hydrolysates in rat plasma and its application to a pharmacokinetic study.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Polygala has a long history of use as a sedative in traditional Chinese medicine and its major ingredients are saponins, which are recognized effective in memory improvement but highly toxic to gastricintestinal mucosa. Polygala saponin hydrolysates (PSH), an alkaline hydrolysis product and also the intestinal metabolites of the saponins, exhibited stronger effects in improving memory of mice and had less toxicity than its original saponins. The present study aims to develop a sensitive LC-MS/MS method for simultaneously determining PSH three major active components, 3,4,5-trimethoxycinnamylic acid (TMCA), p-methoxycinnamylic acid (PMCA) and tenuifolin (TF), in rat plasma and apply the method to a pharmacokinetic study. MATERIALS AND METHODS: The acidic plasma (100µl) was treated by liquid-liquid extraction with ethyl acetate and reconstituted sample was analyzed on a C18 column eluted with acetonitrile-water (50:50) containing 0.2% formic acid at 0.4ml/min. The mass detection in negative electrospray ionization was used. The ion pairs for multiple reaction monitoring were set at m/z 237.0/103.0, 177.0/116.6 and 679.5/425.3 for TMCA, PMCA and TF, respectively. Their pharmacokinetic profiles were studied in rats after intravenous and oral dose of PSH at 20 and 100mg/kg, respectively. RESULTS: The calibration curves had good linearity (r(2)>0.99) for TMCA, PMCA and TF within the tested concentration ranges. The limits of detection and quantification were 1, 10, 0.5ng/ml and 10.0, 20.0, 1.0ng/ml, respectively. The intra-day and inter-day precisions were less than 18.9% and accuracies between 93.2% and 113.3%, and the extraction recovery ranged from 91.2% to 112.1% for all analytes. The pharmacokinetic study showed that TMCA, PMCA and TF could be rapidly absorbed into the circulation and reached their peak concentrations at about 9.1, 9.0 and 24.0min, respectively. TF had a lower oral bioavailability (2.0%) than TMCA (90.1%) and PMCA (96.5%), but it remained in the body much longer (t1/2, λz, 4.8h, oral dose) than TMCA (0.6h) and PMCA (0.9h). CONCLUSIONS: A sensitive LC-MS/MS method was developed and applied to a pharmacokinetic study of TMCA, PMCA and TF of PSH in rats. The three components are proved to be bio-available active components of PSH and might display their in vivo pharmacological activities at different levels and different time periods after oral administration.

Lotus Leaf Alkaloid Extract Displays Sedative-Hypnotic and Anxiolytic Effects through GABAA Receptor.

Lotus leaves have been used traditionally as both food and herbal medicine in Asia. Open-field, sodium pentobarbital-induced sleeping and light/dark box tests were used to evaluate sedative-hypnotic and anxiolytic effects of the total alkaloids (TA) extracted from the herb, and the neurotransmitter levels in the brain were determined by ultrafast liquid chromatography-tandem mass spectrometry. The effects of picrotoxin, flumazenil, and bicuculline on the hypnotic activity of TA, as well as the influence of TA on Cl(-) influx in cerebellar granule cells, were also investigated. TA showed a sedative-hypnotic effect by increasing the brain level of γ-aminobutyric acid (GABA), and the hypnotic effect could be blocked by picrotoxin and bicuculline, but could not be antagonized by flumazenil. Additionally, TA could increase Cl(-) influx in cerebellar granule cells. TA at 20 mg/kg induced anxiolytic-like effects and significantly increased the concentrations of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and dopamine (DA). These data demonstrated that TA exerts sedative-hypnotic and anxiolytic effects via binding to the GABAA receptor and activating the monoaminergic system.

Nanosuspension development of scutellarein as an active and rapid orally absorbed precursor of its BCS class IV glycoside scutellarin.

This work addressed solubility and membrane permeability problems of Biopharmaceutics Classification System (BCS) Class IV glycoside scutellarin (SG) by developing a nanosuspension of its aglycone scutellarein (S) as a precursor. An S nanosuspension containing poloxamer 188 was prepared using antisolvent precipitation where hydroxypropyl-ß-cyclodextrin was utilized as a lyophilizing protectant. Particle size and polydispersity index after redispersion were 342.6 ± 18.2 and 0.32 ± 0.06 nm, respectively. The dissolution rate of the S nanosuspension was superior compared with the physical mixture. No free S, but SG and SG's isomer were detected in plasma following oral delivery of SG or S, S nanosuspension or physical mixture of S. The Cmax values of SG after dosing with the S nanosuspension were 12.0, 8.0, and 4.5-fold higher than the SG, S, or physical mixture, respectively. The Tmax and mean residence time (MRTlast ) of SG after dosing with the S nanosuspension were significantly shorter than S and SG. Treatments with SG, S, or S nanosuspensions reduced the hemorrhage rate in a zebrafish model, but the S nanosuspension exhibited the strongest rescue effect. This study highlights a new strategy to circumvent BCS Class IV flavonoid glycosides using a formulation of their aglycone as a precursor to accelerate oral absorption and improve bioactivity.