Shen Yuan extract exerts a hypnotic effect via the tryptophan/5-hydroxytryptamine/melatonin pathway in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Sleep plays a critical role in several physiologic processes, and sleep disorders increase the risk of depression, dementia, stroke, cancer, and other diseases. Stress is one of the main causes of sleep disorders. Ginseng Radix et Rhizoma and Polygalae Radix have been reported to have effects of calming the mind and intensifying intelligence in Chinese Pharmacopoeia. Traditional Chinese medicine prescriptions composed of Ginseng Radix et Rhizoma and Polygalae Radix (Shen Yuan, SY) are commonly used to treat insomnia, depression, and other psychiatric disorders in clinical practice. Unfortunately, the underlying mechanisms of the SY extract's effect on sleep are still unknown. AIM OF THE STUDY: This study aimed to investigate the hypnotic effect of the SY extract in normal mice and mice with chronic restraint stress (CRS)-induced sleep disorders and elucidate the underlying mechanisms. MATERIALS AND METHODS: The SY extract (0.5 and 1.0 g/kg) was intragastrically administered to normal mice for 1, 14, and 28 days and to CRS-treated mice for 28 days. The open field test (OFT) and pentobarbital sodium-induced sleep test (PST) were used to evaluate the hypnotic effect of the SY extract. Liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay were utilized to detect the levels of neurotransmitters and hormones. Molecular changes at the mRNA and protein levels were determined using real-time quantitative polymerase chain reaction and Western blot analysis to identify the mechanisms by which SY improves sleep disorders. RESULTS: The SY extract decreased sleep latency and increased sleep duration in normal mice. Similarly, the sleep duration of mice subjected to CRS was increased by administering SY. The SY extract increased the levels of tryptophan (Trp) and 5-hydroxytryptamine (5-HT) and the expression of tryptophan hydroxylase 2 (TPH2) in the cortex of normal mice. The SY extract increased the Trp level, transcription and expression of estrogen receptor beta and TPH2 in the cortex in mice with sleep disorders by decreasing the serum corticosterone level, which promoted the synthesis of 5-HT. Additionally, the SY extract enhanced the expression of arylalkylamine N-acetyltransferase, which increased the melatonin level and upregulated the expressions of melatonin receptor-2 (MT2) and Cryptochrome 1 (Cry1) in the hypothalamus of mice with sleep disorders. CONCLUSIONS: The SY extract exerted a hypnotic effect via the Trp/5-HT/melatonin pathway, which augmented the synthesis of 5-HT and melatonin and further increased the expressions of MT2 and Cry1.

Anti-inflammatory effect and pharmacokinetics of dehydroandrographolide, an active component of Andrographis paniculata, on Poly(I:C)-induced acute lung injury.

Acute lung injury (ALI) is a common and critical respiratory disorder caused by various factors, with viral infection being the leading contributor. Dehydroandrographolide (DAP), a constituent of the Chinese herbal plant Andrographis paniculata, exhibits a range of activities including anti-inflammatory, in vitro antiviral and immune-enhancing effects. This study evaluated the anti-inflammatory effects and pharmacokinetics (PK) profile of DAP in ALI mice induced by intratracheal instillation of Poly(I:C) (PIC). The results showed that oral administration of DAP (10-40 mg/kg) effectively suppressed the increase in lung wet-dry weight ratio, total cells, total protein content, accumulation of immune cells, inflammatory cytokines and neutrophil elastase levels in bronchoalveolar lavage fluid of PIC-treated mice. DAP concentrations, determined by an LC-MS/MS method, in plasma after receiving DAP (20 mg/kg) were unchanged compared to those in normal mice. However, DAP concentrations and relative PK parameters in the lungs were significantly altered in PIC-treated mice, exhibiting a relatively higher maximum concentration, larger AUC, and longer elimination half-life than those in the lungs of normal mice. These results demonstrated that DAP could improve lung edema and inflammation in ALI mice, and suggested that lung injury might influence the PK properties of DAP, leading to increased lung distribution and residence. Our study provides evidence that DAP displays significant anti-inflammatory activity against viral lung injury and is more likely to distribute to damaged lung tissue.

Interferon lambda in respiratory viral infection: immunomodulatory functions and antiviral effects in epithelium.

Type III interferon (IFN-λ), a new member of the IFN family, was initially considered to possess antiviral functions similar to those of type I interferon, both of which are induced via the JAK/STAT pathway. Nevertheless, recent findings demonstrated that IFN-λ exerts a nonredundant antiviral function at the mucosal surface, preferentially produced in epithelial cells in contrast to type I interferon, and its function cannot be replaced by type I interferon. This review summarizes recent studies showing that IFN-λ inhibits the spread of viruses from the cell surface to the body. Further studies have found that the role of IFN-λ is not only limited to the abovementioned functions, but it can also can exert direct and/or indirect effects on immune cells in virus-induced inflammation. This review focuses on the antiviral activity of IFN-λ in the mucosal epithelial cells and its action on immune cells and summarizes the pathways by which IFN-λ exerts its action and differentiates it from other interferons in terms of mechanism. Finally, we conclude that IFN-λ is a potent epidermal antiviral factor that enhances the respiratory mucosal immune response and has excellent therapeutic potential in combating respiratory viral infections.

Melatonin-related dysfunction in chronic restraint stress triggers sleep disorders in mice.

Stress may trigger sleep disorders and are also risk factors for depression. The study explored the melatonin-related mechanisms of stress-associated sleep disorders on a mouse model of chronic stress by exploring the alteration in sleep architecture, melatonin, and related small molecule levels, transcription and expression of melatonin-related genes as well as proteins. Mice undergoing chronic restraint stress modeling for 28 days showed body weight loss and reduced locomotor activity. Sleep fragmentation, circadian rhythm disorders, and insomnia exhibited in CRS-treated mice formed sleep disorders. Tryptophan and 5-hydroxytryptamine levels were increased in the hypothalamus, while melatonin level was decreased. The transcription and expression of melatonin receptors were reduced, and circadian rhythm related genes were altered. Expression of downstream effectors to melatonin receptors was also affected. These results identified sleep disorders in a mice model of chronic stress. The alteration of melatonin-related pathways was shown to trigger sleep disorders.

Effect of dexmedetomidine for prevention of acute kidney injury after cardiac surgery: an updated systematic review and meta-analysis.

BACKGROUND: Acute kidney injury (AKI) is a serious complication related to cardiac surgery. Several studies have been conducted to investigate the effect of dexmedetomidine administration on AKI prevention. OBJECTIVE: To assess if dexmedetomidine is associated with a protective effect of renal function after cardiac surgery. And the aim of conducting this meta-analysis is to summarize the literature and determine the clinical utility of dexmedetomidine administration in patients undergoing cardiac surgery. METHODS: PubMed, Cochrane Library, and EMBASE databases were comprehensively searched for all randomized controlled trials (RCTs) published before 1 December, 2021 that investigated the effect of dexmedetomidine on AKI prevention. RESULTS: Our analysis included 16 studies involving 2148 patients. Compared with the control group, dexmedetomidine administration significantly reduced AKI incidence (OR, 0.47; 95% CI, 0.36-0.61; p < 0.00001; I2 = 26%) and the length of stay in the intensive care unit (ICU) but did not alter mortality rate, length of stay in the hospital, and mechanical ventilation time. Furthermore, the incidence of delirium among patients treated with dexmedetomidine was significantly decreased. CONCLUSION: Dexmedetomidine administration has a positive effect on preventing AKI and postoperative delirium after cardiac surgery and significantly reduces the length of stay in the ICU.

Analysis of pyrrolizidine alkaloids in Eupatorium fortunei Turcz. and their in vitro neurotoxicity.

This study was to analyze the pyrrolizidine alkaloids (PAs) in Eupatorium fortunei herbs and its derived finished products with a view to evaluating their effects on the proliferation and oligodendrogenesis of neural progenitor cells (NPCs). Using a LC-MS/MS method with 32 PAs reference standards, 8 PAs including intermedine, intermedine N-oxide, lycopsamine, lycopsamine N-oxide, retronecine, seneciphylline and senkirkine and 7-acetylintermedine N-oxide were identified with intermedine N-oxide and lycopsamine N-oxide being most abundant. The total PA amounts were found to vary from 0.18 to 61.81 µg/g in 30 batches of herbs and from 0.86 to 36.96 µg/g in 4 commercial finished products, respectively. Risk assessments indicated that the short-term intake seemed unlikely lead to acute toxic effects but the chronic use warranted cautions. Using NPCs derived from mouse induced pluripotent stem cells as an in vitro testing model, intermedine, intermedine N-oxide and lycopsamine N-oxide appeared to decrease cell viability at 30 µM whereas intermedine N-oxide inhibited oligodendrogenesis of NPCs at 10 µM. The present results suggested that the PAs in the majority of E. fortunei herbs and the derived products not only resulted in their exposure far exceeding the acceptable intake limit (i. e. 1.0 µg PA per day for adults) in herbal medicinal products recommended by the European Medicines Agency but also induced neurotoxicity to NPCs in vitro.

Enhancing in vivo oral bioavailability of cajaninstilbene acid using UDP-glucuronosyl transferase inhibitory excipient containing self-microemulsion.

Cajaninstilbene acid (CSA) exerts wide pharmacological activities, such as anti-inflammation, hypoglycaemic activity, analgesic effect and cognition improvement. However, it underwent severe phase II metabolism mediated by UDP-glucuronosyltransferase (UGT) in the gastrointestinal (GI) tract after oral administration, affecting its oral bioavailability. In the present study, we utilize UGT inhibitory excipient containing self-microemulsion (SME) delivery system to reduce the production of glucuronide metabolites and increase its oral bioavailability. The present results showed that although similar properties in physiochemical, cytotoxicity, cellular uptake, absorption and transport across rat everted gut sacs between SME-1 (inhibitory excipient containing SME) and SME-2 (control SME, without inhibitory excipient), an improved absolute bioavailability of 57.3 % was conferred by SME-1, significantly higher than the value of 35.4 % by SME-2 and 34.0 % by free CSA. Noticeably, the significantly lower AUC value of CSA glucuronide was determined in rats treated with SME-1 than those either treated with SME-2 or free CSA. Thus, the ability of SME-1 to enhance oral bioavailability of CSA is mainly attributed to the inhibition of phase II metabolism in the GI tract.

Size-Transformable Hyaluronan Stacked Self-Assembling Peptide Nanoparticles for Improved Transcellular Tumor Penetration and Photo-Chemo Combination Therapy.

Size-transformable nanomedicine has the potential to overcome systemic and local barriers, leading to efficient accumulation and penetration throughout the tumor tissue. However, the design of this type of nanomedicine was seldom based on active targeting and intracellular size transformation. Here, we report an intracellular size-transformable nanosystem, in which small and positively charged nanoparticles (<30 nm) prepared from the self-assembly of an amphiphilic hexadecapeptide derivative was coated by folic acid- and dopamine-decorated hyaluronan (HA) to form large and negatively charged nanoparticles (∼130 nm). This nanosystem has been proven to improve the blood circulation half-life of the drug and prevent premature intravascular drug leakage from the nanocarrier. Once accumulated in the tumor, the nanoparticles were prone to HA- and folic acid-mediated cellular uptake, followed by intracellular size transformation and discharge of transformed small nanoparticles. The size-transformable nanosystem facilitated the transcytosis-mediated tumor penetration and improved the internalization of nanoparticles by cells and the intracellular release of 7-ethyl-10 hydroxycamptothecin. With an indocyanine green derivative as the intrinsic component of the amphiphilic polymer, the nanosystem has exhibited additional theranostic functions: photoacoustic imaging, NIR-laser-induced drug release, and synergistic chemotherapy and phototherapy, leading to a 50% complete cure rate in a subcutaneous B16 melanoma model. This nanosystem with multimodalities and efficient tumor penetration has shown potentials in improving anticancer efficacy.

Antidepressant-like effects of cajaninstilbene acid and its related mechanisms in mice.

Cajaninstilbene acid (CSA), a bioactive constituent isolated from pigeon pea leaves, exhibited neuroprotective activities in previous studies. The present study aims to evaluate the antidepressant effects of CSA by using behavioral despair models of tail suspension test (TST) and forced swimming test (FST), and a chronic unpredictable mild stress (CUMS) model. CSA (30 or 60 mg/kg), intragastrically administrated for 7 days, could significantly reduce the immobility time of mice in TST and FST. CSA treatment (15 or 30 mg/kg) significantly reversed the depressive-like behavioral changes of mice induced by 3 or 6 weeks CUMS that caused the decrease of sucrose preference, the increase of latency to feed in the novelty-suppressed feeding test, and the increase of immobility time in TST of mice. Furthermore, the related mechanisms of the effect were explored by accessing the metabolite levels of kynurenine pathway of tryptophan metabolism and the expression of some related proteins in cerebral cortex of CUMS mice. Our results showed that the kynurenine pathway was upregulated after CUMS, while the alteration could be significantly reversed by CSA. CSA also reversed the CUMS-induced decrease in the levels of BDNF, PSD-95, p-Akt/Akt and p-mTOR/mTOR. Therefore, the antidepressant-like effects of CSA might be achieved through regulating tryptophan metabolism, promoting BDNF and PSD-95 expression, and activating Akt/mTOR pathway in the cerebral cortex.

Cajaninstilbene Acid Ameliorates Cognitive Impairment Induced by Intrahippocampal Injection of Amyloid-ß1-42 Oligomers.

Amyloid-ß1-42 (Aß1-42) oligomers play an important role at the early stage of Alzheimer's disease (AD) and have been a vital target in the development of therapeutic drugs for AD. Cajaninstilbene acid (CSA), a major bioactive stilbene isolated from pigeon pea (Cajanus cajan) leaves, exerted the neuroprotective property in our previous studies. The present study utilized a validated mouse model of early-stage AD induced by bilateral injection of Aß1-42 oligomers into hippocampal CA1 regions (100 pmol/mouse) to investigate the cognitive enhancing effects of CSA and the underlying mechanism, by a combination of animal behavioral tests, immunohistochemistry, liquid chromatography-tandem mass spectrometry analysis, and Western blot methods. Intragastric administration of CSA (7.5, 15, and 30 mg/kg) attenuated the impairment of learning and memory induced by Aß1-42 oligomers. CSA stimulated Aß clearance and prevented microglial activation and astrocyte reactivity in the hippocampus of model mice. It also decreased the high levels of Glu but increased the low levels of GABA. In addition, CSA inhibited excessive expression of GluN2B-containing NMDARs and upregulated the downstream PKA/CREB/BDNF/TrkB signaling pathway. These results suggest that CSA could be a potential therapeutic agent at the early stage of AD.

Fluticasone propionate nanosuspensions for sustained nebulization delivery: An in vitro and in vivo evaluation.

This study intended to investigate the in vivo pulmonary fate of intratracheally dosed nanosuspensions of fluticasone propionate (FP). Three FP suspensions, including a microsuspension and two nanosuspensions with different dissolution profiles, were prepared and they exhibited comparable aerodynamic performances after nebulization via a jet nebulizer. Following intratracheal administration to rats, the microsuspension underwent extensive mucociliary clearance, leading to a limited absorption time whereas the nanosuspensions decreased the mucociliary clearance and allowed dissolution rate-limiting and extended pulmonary absorption, resulting in prolonged pulmonary retention and long-acting anti-inflammatory efficacy in a lipopolysaccharide induced lung injury model. Delaying the FP dissolution of a nanosuspension by phospholipid coating increased AUC value in lung tissues to 1.72-fold of a conventional nanosuspension, but led to a decreased pharmacological efficacy. This study demonstrated that inhalable nanosuspensions were a feasible means for the sustained pulmonary delivery of FP and the local anti-inflammatory efficacy was highly dependent on the dissolution profiles.

LC-MS/MS-based quantification of tryptophan metabolites and neurotransmitters in the serum and brain of mice.

l-Tryptophan (Trp) metabolites and related neurotransmitters play crucial roles in physiological functions, and their imbalances are implicated in the pathology of depression, Alzheimer's disease and other diseases. Measurement of Trp metabolites and related neurotransmitters possesses a great potential to elucidate the disease mechanisms and evaluate the outcomes of therapeutic interventions. A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of Trp, l-kynurenine (Kyn), kynurenic acid (Kyna), 3-hydroxykynurenine (3-HK), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE), l-glutamic acid (Glu), γ-aminobutyric acid (GABA) and acetylcholine (ACh) in mice serum and the brain tissues in a single chromatographic run. Samples were spiked with the internal standard, mixed with trifluoroacetic acid to precipitate protein and analyzed by LC-MS/MS. Chromatographic separation was achieved using a Restek Ultra Aqueous C18 column in combination with a gradient elution within 8 min. Mass spectrometric detection was performed using multiple reaction monitoring with electrospray ionization source in positive mode. The method exhibited good selectivity and correlation coefficient values for the calibration curves of each analyte were >0.99. The limit of detection and quantification ranged from 0.96 to 24.48 nmol/L and 3.42 to 244.82 nmol/L, respectively. The intra- and inter-day precision were ≤13.92%. All analytes were stable in prepared samples at room temperature in the autosampler for 24 h. This method was successfully applied to the analysis of biological samples from control and chronic mild stress (CMS) induced depression mice. It was found that Kyn and 3-HK pathways were enhanced by CMS, while the levels of Trp, Kyna, 5-HIAA, Glu, GABA and ACh were significantly reduced. The changes in 5-HT and NE levels were not uniform in the periphery and the brain. This method can therefore be applied to analyze Trp metabolites and related neurotransmitters levels to monitor disease states, study the mechanisms and outcomes of therapeutic interventions.

Simultaneous Determination and Risk Assessment of Pyrrolizidine Alkaloids in Artemisia capillaris Thunb. by UPLC-MS/MS Together with Chemometrics.

Pyrrolizidine alkaloids (PAs) are natural toxins found in some genera of the family Asteraceae. However, it has not been reported whether PAs are present in the widely used Asteraceae plant Artemisia capillaris Thunb. (A. capillaris). The purpose of this study was to establish a sensitive and rapid UPLC-MS/MS method together with chemometrics analysis for simultaneous determination and risk assessment of PAs in A. capillaris. The developed UPLC-MS/MS method was validated and was confirmed to display desirable high selectivity, precision and accuracy. Risk assessment was conducted according to the European Medicines Agency (EMA) guideline. Chemometrics analysis was performed with hierarchical clustering analysis and principal component analysis to characterize the differences between PAs of A. capillaris. Finally, PAs were found in 29 out of 30 samples and at least two were detected in each sample, besides, more than half of the samples exceeded the EMA baseline. Nevertheless, the chemometrics results suggested that the PAs contents of A. capillaris from different sources varied significantly. The method was successfully applied to the detection and risk evaluation of PAs-containing A. capillaris for the first time. This study should provide a meaningful reference for the rational and safe use of A. capillaris.

Alginate Hydrogel Modified with a Ligand Interacting with α3ß1 Integrin Receptor Promotes the Differentiation of 3D Neural Spheroids toward Oligodendrocytes in Vitro.

In this study, we established a long-term three-dimensional (3D) culture system by using integrin ligand modified alginate hydrogels to encapsulate and differentiate neural progenitor cells (NPCs) toward oligodendrocyte (OL) lineage cells. The porosity of the hydrogel was optimized by varying the alginate concentrations and then characterized by scanning electronic microscopy (SEM). The surface plasmon resonance (SPR) test was used to confirm the ligand-integrin interactions indicating adherence between the NPC surfaces and the hydrogels. Following encapsulation in the hydrogels, both mouse and human NPC sphere cultures could be maintained up to 90 days. Mouse NPC spheres were differentiated into viable neurons, astrocytes and mature OLs by day 60 in all groups whereas human NPC spheres were differentiated into neurons and later into GFAP positive astrocytes and O4 positive pre-OL within 90 days. The species difference in the timeline of OL development between mouse and human was reflected in this system. The ligand LXY30 interacting with the α3ß1 integrin receptor was more effective in promoting the differentiation of hNPCs to OL lineage cells compared with the ligand LXW64 interacting with the αvß3 integrin receptor, hyaluronic acid interacting with CD44 receptor or without any ligand. This study is the first to differentiate O4+ pre-OLs from hNPCs in a LXY30-α3ß1 (integrin-ligand) modified alginate 3D hydrogel culture. This 3D platform could serve as a valuable tool in disease modeling, drug discovery, and NPC transplantation.

Ciclesonide and budesonide suspensions for nebulization delivery: An in vivo inhalation biopharmaceutics investigation.

The pulmonary fate of inhaled poorly water-soluble drugs is not entirely clear. In this study, the main objective was to investigate the in vivo inhalation biopharmaceutics in the aspects of dissolution, mucociliary clearance, absorption and tissue binding using intratracheally administered budesonide and ciclesonide suspensions as model drugs. In doing so, this study first developed a method to differentiate between dissolved and undissolved ciclesonide in the lungs for evaluating in vivo dissolution. Following deposited in rat airways, the drug particles underwent rapid dissolution and mucociliary clearance, leading to the complete removal of drugs from the airways within 2 h and a limited absorption time less than 2 h. Upon dissolution, budesonide and ciclesonide were taken up and retained in the lung tissues for up to 12 h and 24 h, respectively. The in vivo dissolution profiles in the airways exhibited the sameness as the in vitro counterparts in a 0.5% sodium dodecyl sulfate solution as indicated by the similarity factor f2. The efficacy results in a lipopolysaccharide induced lung injury model showed that the duration of local anti-inflammatory was dependent on the drug levels in the lung tissues, but not on the in vitro/in vivo dissolution and plasma pharmacokinetics. The present results demonstrated that ciclesonide suspension has the potential to achieve once-daily dosing for nebulization therapy and the in vitro dissolution profile has limited usefulness in predicting in vitro-in vivo correlation.

[Characteristics of collateral circulation in adult moyamoya disease based on modified Suzuki staging].

OBJECTIVE: To investigate the characteristics of collateral circulation in adult moyamoya disease (MMD). METHODS: The clinical data were collected from all adult patients with MMD undergoing digital subtractive angiography (DSA) in our department from 2006 to 2016. Based on the imaging findings, the patients were divided into ischemia group and bleeding group. A double-blind analysis was conducted of the CT or magnetic resonance imaging findings and the severity of the disease was graded using the modified Suzuki score (mSS). We classified the anastomotic networks in MMD into the superficial meningeal type and deep parenchymal type. The superficial meningeal type was further classified into the leptomeningeal and the durocortical networks, and the deep parenchymal networks into subependymal networks and the inner striatal and inner thalamic networks. RESULTS: No significant difference was found in the distribution of mSS scores between the hemorrhage group and the ischemic group (Χ2=5.812, v=5, P=0.325), but the posterior communicating artery and internal carotid artery diameter ratio (Pcom/ICA ratio) was significantly greater in the hemorrhage group (t=2.119, v=108, P=0.036). The Pcom/ICA ratio differed significantly among the groups with different mSS scores (f=8.924, P=0.00), higher in groups with mSS scores of 3, 4 and 5. The incidence of anterior choroidal artery dilation differed significantly between hemorrhage and ischemic groups (Χ2=11.79, P=0.001). The incidences of durocortical networks (Χ2=0.327, P=0.567) and subependymal networks (Χ2=0.011, P=0.917) were comparable between hemorrhage group and ischemic groups, but the incidence of leptomeningeal networks (P=0.018) and inner striatal and inner thalamic networks (Χ2=7.551, P=0.006) differed significantly between the two groups. CONCLUSION: The collateral circulation vascular system is an important component of cerebral blood flow in MMD patients and varies from patient to patient. Patients with MMD exhibit increased Pcom/ICA ratio with abnormal expansion of the anterior choroidal artery, and the leptomeningeal networks and the inner striatal and inner thalamic networks are independent risk factors for cerebral hemorrhage.

Improving oral bioavailability of resveratrol by a UDP-glucuronosyltransferase inhibitory excipient-based self-microemulsion.

Self-microemulsifying (SME) drug delivery system has been developed to increase oral bioavailabilities, and inhibitory excipients are capable of improving oral bioavailability by inhibiting enzyme mediated intestinal metabolism. However, the potential of enzyme inhibitory excipients containing SME in boosting resveratrol bioavailability remains largely uninvestigated. In this study, we set out to prepare SME-1 with UGT inhibitory excipients (excipients without inhibitory activities named SME-2 as control) to increase the bioavailability of RES by inhibiting intestinal metabolism. Results demonstrated that similar physicochemical properties such as size, polydistribution index and in vitro release, cellular uptake and permeability in Caco-2 cells as well as in vivo lymphatic distribution between inhibitory SME-1 and non-inhibitory SME-2 were observed. In vivo study demonstrated that the molar ratios of RES-G/RES were 7.25±0.48 and 5.06±2.42 for free drug and SME-2, respectively, and the molar ratio decreased to 0.36±0.10 in SME-1 group. Pharmacokinetic study confirmed that the inhibitory excipients containing SME demonstrated potential in increasing bioavailability of RES from 6.5% for the free RES and 12.9% for SME-2 to 76.1% in SME-1 through modulating the glucuronidation by UGT inhibitory excipients.

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.

Effects of phenolic constituents of daylily flowers on corticosterone- and glutamate-treated PC12 cells.

BACKGROUND: Daylily flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-You-Cao in Chinese, meaning forget-one's sadness plant. However, the major types of active constituents responsible for the neurological effects remain unclear. This study was to examine the protective effects of hydroalcoholic extract and fractions and to identify the active fractions. METHODS: The extract of daylily flowers was separated with AB-8 resin into different fractions containing non-phenolic compounds, phenolic acid derivatives and flavonoids as determined using UPLC-DAD chromatograms. The neuroprotective activity was measured by evaluating the cell viability and lactate dehydrogenase release using PC12 cell damage models induced by corticosterone and glutamate. The neurological mechanisms were explored by determining their effect on the levels of dopamine (DA), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), noradrenaline (NE) and acetylcholine (ACh) in the cell culture medium measured using an LC-MS/MS method. RESULTS: Pretreatment of PC12 cells with the extract and phenolic fractions of daylily flowers at concentrations ranging from 0.63 to 5 mg raw material/mL significantly reversed corticosterone- and glutamate-induced neurotoxicity in a dose-dependent manner. The fractions containing phenolic acid derivatives (0.59% w/w in the flowers) and/or flavonoids (0.60% w/w) exerted similar dose-dependent neuroprotective effect whereas the fractions with non-phenolic compounds exhibited no activity. The presence of phenolic acid derivatives in the corticosterone- and glutamate-treated PC12 cells elevated the DA level in the cell culture medium whereas flavonoids resulted in increased ACH and 5-HT levels. CONCLUSION: Phenolic acid derivatives and flavonoids were likely the active constituents of daylily flowers and they conferred a similar extent of neuroprotection, but affected the release of neurotransmitters in a different manner.