[Determination of plasma protein binding rate of Shuganning Injection using equilibrium dialysis and UPLC-MS/MS].

Traditional Chinese medicine(TCM) compound preparations have complex compositions. As a widely used TCM injection, Shuganning Injection, its in vivo processes are not yet fully understood. Determining the plasma protein binding rate is of great significance for pharmacokinetic and pharmacodynamic studies. In this experiment, the equilibrium dialysis method combined with UPLC-MS/MS technology was used to determine the plasma protein binding rates of 10 components, including p-hydroxyacetophenone, caffeic acid, baicalein, oroxylin A, geniposide, baicalin, cynaroside, oroxylin A-7-O-ß-D-glucuronide, scutellarin, and hyperoside, in Shuganning Injection in rat and human plasma to provide a theoretical basis for further elucidating the in vivo processes of Shuganning Injection and guiding clinical medication. The results showed that, except for baicalein and geniposide, the plasma protein binding rates of the other eight components were higher in human plasma than in rat plasma, and there were interspecies differences. In human plasma, except for geniposide, caffeic acid, and baicalin, the plasma protein binding rates of the remaining seven components were above 80%, with baicalein and oroxylin A exceeding 90%. All components exhibit a high level of binding to plasma proteins, with the exception of geniposide.

Characterization of Uranyl (UO22+) Ion Binding to Amyloid Beta (Aß) Peptides: Effects on Aß Structure and Aggregation.

Uranium (U) is naturally present in ambient air, water, and soil, and depleted uranium (DU) is released into the environment via industrial and military activities. While the radiological damage from U is rather well understood, less is known about the chemical damage mechanisms, which dominate in DU. Heavy metal exposure is associated with numerous health conditions, including Alzheimer's disease (AD), the most prevalent age-related cause of dementia. The pathological hallmark of AD is the deposition of amyloid plaques, consisting mainly of amyloid-ß (Aß) peptides aggregated into amyloid fibrils in the brain. However, the toxic species in AD are likely oligomeric Aß aggregates. Exposure to heavy metals such as Cd, Hg, Mn, and Pb is known to increase Aß production, and these metals bind to Aß peptides and modulate their aggregation. The possible effects of U in AD pathology have been sparsely studied. Here, we use biophysical techniques to study in vitro interactions between Aß peptides and uranyl ions, UO22+, of DU. We show for the first time that uranyl ions bind to Aß peptides with affinities in the micromolar range, induce structural changes in Aß monomers and oligomers, and inhibit Aß fibrillization. This suggests a possible link between AD and U exposure, which could be further explored by cell, animal, and epidemiological studies. General toxic mechanisms of uranyl ions could be modulation of protein folding, misfolding, and aggregation.

Drug screening of α-amylase inhibitors as candidates for treating diabetes.

In the present study, the identification of potential α-amylase inhibitors is explored as a potential strategy for treating type-2 diabetes mellitus. A computationally driven approach using molecular docking was employed to search for new α-amylase inhibitors. The interactions of potential drugs with the enzyme's active site were investigated and compared with the contacts established by acarbose (a reference drug for α-amylase inhibition) in the crystallographic structure 1B2Y. For this active site characterization, both molecular docking and molecular dynamics simulations were performed, and the residues involved in the α-amylase-acarbose complex were considered to analyse the potential drug's interaction with the enzyme. Two potential α-amylase inhibitors (AN-153I105594 and AN-153I104845) have been selected following this computational strategy. Both compounds established a large number of interactions with key binding site α-amylase amino acids and obtained a comparable docking score concerning the reference drug (acarbose). Aiming to further analyse candidates' properties, their ADME (absorption, distribution, metabolism, excretion) parameters, druglikeness, organ toxicity, toxicological endpoints and median lethal dose (LD50 ) were estimated. Overall estimations are promising for both candidates, and in silico toxicity predictions suggest that a low toxicity should be expected.

Impact of Protein Binding Capacity and Daily Dosage of a Drug on Total Serum Bilirubin Levels in Susceptible Infants.

Hyperbilirubinemia is a common pathological condition in neonates. Free bilirubin can penetrate the blood-brain barrier (BBB), which can lead to bilirubin neurotoxicity. In the context of predicting the risk of bilirubin neurotoxicity, although the specificity and sensitivity of free bilirubin levels are higher than those of total serum bilirubin (TSB), free bilirubin is not widely monitored in clinical practice. The threshold TSB levels at which phototherapy must be administered have been established previously. However, TSB levels are not well correlated with neurodevelopmental outcomes. Currently, TSB levels are commonly used to guide phototherapy for neonatal hyperbilirubinemia. Some clinical drugs can displace bilirubin from its albumin-binding sites, and consequently upregulate plasma bilirubin. Daily dosages play a vital role in regulating bilirubin levels. A drug with both a high protein binding capacity and high daily dosage significantly increases bilirubin levels in infants. Premature or very low birth weight (VLBW) infants are vulnerable to the upregulation of bilirubin levels as they exhibit the lowest reserve albumin levels and consequently the highest bilirubin toxicity index. Because bilirubin is involved in maintaining the balance between pro-oxidant and antioxidant agents, the downregulation of bilirubin levels is not always desirable. This review provides insights into the impact of protein binding capacity and daily dosage of drugs on the bilirubin levels in susceptible infants.

Danggui Buxue Decoction: Comparative pharmacokinetic research on six bio-active components in different states by ultra-performance liquid chromatography-tandem mass spectrometry after oral administration.

Danggui Buxue Decoction is a classic formula containing Astragali Radix and Angelicae Sinensis Radix in a 5:1 ratio and has been extensively used to treat blood deficiency for thousands of years. The aim of the study was to investigate the differences in plasma protein binding, pharmacokinetics, and tissue distribution of Danggui Buxue Decoction in normal and blood-deficient rats by ultra-performance liquid chromatography-tandem mass spectrometry. The effects on peripheral blood routine were verified. The compounds exhibited higher plasma protein binding and absorption in the model group compared to the control group, except formononetin. The six ingredients were distributed widely, and the highest concentrations were detected in the heart and uterus. As has been demonstrated in the previous study of the effect of Danggui Buxue Decoction, its potential is to serve as an effective traditional Chinese medicine formula for treating cardiovascular diseases and impacting estrogenic properties, which reveals the potential target organs of Danggui Buxue Decoction the heart and uterus. Our findings suggested that the absorption and distribution of different components in Danggui Buxue Decoction varies depending on the pathological state, molecular weight, lipid solubility, transporter-mediated efflux, and other factors.

Effects of Munc13-1 and Munc18-1 on dopamine secretion dysfunction in manganese-exposed SH-SY5Y cells / 环境与职业医学

Background Neurotransmitter secretion disorder induced by chronic manganese poisoning has always been one of the important causes of body injury, but the mechanism of neurotransmitter secretion disorder caused by manganese is not clear at present. Objective To investigate the effects of presynaptic membrane intracellular protein 13-1 (Munc13-1) and synapse fusion protein binding protein 18-1 (Munc18-1) on dopamine secretion dysfunction induced by manganese chloride (MnCl2) in human neuroblastoma (SH-SY5Y) cells. Methods A SH-SY5Y cell model induced by MnCl2 was established. Cell viability was measured by MTT assay. Four experimental groups were set up: control group and low-, medium-, and high-dose manganese groups (0, 100, 200, and 400 μmol·L−1 MnCl2). They were treated with corresponding doses of MnCl2 for 24 h. The secretion of dopamine was measured by enzyme-linked immunosorbent assay. The mRNA expression of Syntaxin-1 was detected by real-time quantitaive PCR. Total cell proteins were extracted, and the protein expression levels of Munc13-1, Munc18-1, and Syntaxin-1 were detected by Western blotting. The correlations of MnCl2 exposure and dopamine secretion with the protein expressions of Munc13-1 and Munc18-1 were also analyzed by Pearson correlation. Results Compared with the control group, the cell viability rate decreased gradually with the increase of manganese exposure concentration, and the difference between the medium- and the high-dose manganese groups was statistically significant (P<0.05). The concentration of dopamine in cell culture medium of all manganese exposure groups decreased with the increase of manganese concentration, and compared with the control group and the low-dose manganese group, the medium- and the high-dose manganese groups were statistically significant (P<0.05). The expression of Syntaxin-1 at mRNA or protein level did not change significantly among groups (P>0.05). Compared with the control group, the protein expression of Munc13-1 decreased and that of Munc18-1 increased with the increase of manganese concentration (P<0.05). Compared with the low-dose manganese group, the changes of Munc13-1 protein in the high-dose manganese group and Munc18-1 protein in the medium- and high-dose manganese groups had statistical significance (P<0.05). Compared with the medium-dose manganese group, the protein changes of Munc18-1 in the high-dose manganese group were statistically significant (P<0.05). The correlation analysis showed that MnCl2 dose was negatively correlated with Munc13-1 protein expression (r=−0.898, P<0.05), and positively correlated with Munc18-1 protein expression (r=0.678, P<0.05). Dopamine secretion was positively correlated with Munc13-1 protein expression (r=0.932, P<0.05), and negatively correlated with Munc18-1 protein expression (r=−0.817, P<0.05). Conclusion The inhibition of dopamine secretion in SH-SY5Y cells induced by manganese exposure is related to up-regulation of Munc18-1 and down-regulation of Munc13-1 expression levels, which may be one of the reasons for nerve injury caused by manganese.

Pharmacokinetics, tissue distribution, and plasma protein binding rate of curcumol in rats using liquid chromatography tandem mass spectrometry.

Objective: Curcumol is one of the major active ingredients isolated from the traditional Chinese medicine Curcumae Rhizoma and is reported to exhibit various bioactivities, such as anti-tumor and anti-liver fibrosis effects. However, studies of curcumol pharmacokinetics and tissue distribution are currently lacking. This study aims to characterize the pharmacokinetics, tissue distribution, and protein binding rate of curcumol. Methods: Pharmacokinetics properties of curcumol were investigated afte doses of 10, 40, and 80 mg/kg of curcumol for rats and a single dose of 2.0 mg/kg curcumol was given to rats via intravenous administration to investigate bioavailability. Tissue distribution was investigated after a single dose of 40 mg/kg of orally administered curcumol. Plasma protein binding of curcumol was studied in vitro via the rapid equilibrium dialysis system. Bound and unbound curcumol in rat plasma were analyzed to calculate the plasma protein binding rate. A UHPLC-MS/MS method was developed and validated to determine curcumol in rat plasma and tissues and applied to study the pharmacokinetics, tissue distribution, and plasma protein binding in rats. Results: After oral administration of 10, 40, and 80 mg/kg curcumol, results indicated a rapid absorption and quick elimination of curcumol in rats. The bioavailability ranging from 9.2% to 13.1% was calculated based on the area under the curves (AUC) of oral and intravenous administration of curcumol. During tissue distribution, most organs observed a maximum concentration of curcumol within 0.5-1.0 h. A high accumulation of curcumol was found in the small intestine, colon, liver, and kidney. Moreover, high protein binding rates ranging from 85.6% to 93.4% of curcumol were observed in rat plasma. Conclusion: This study characterized the pharmacokinetics, tissue distribution, and protein binding rates of curcumol in rats for the first time, which can provide a solid foundation for research into the mechanisms of curcumol's biological function and clinical application.

Protein Binding Nanoparticles as an Integrated Platform for Cancer Diagnosis and Treatment.

Smart nanomaterials constitute a new approach toward safer and more effective combined anti-cancer immunotherapy. In this study, polydopamine-multiprotein conjugates (DmPCs) that can be used for targeted delivery of multiple proteins to cells, realize imaging and combine the advantages of multiple treatment methods (photothermal therapy, chemodynamic therapy, and immunotherapy) can be synthesized and characterized. Proteins, as biological agents, are frequently used in this context, given their low toxicity in vivo. To overcome protein instability and short half-life in vivo, the use of several proteins in combination with selected nanomaterials to treat patients with melanoma is proposed. In addition to the synthesis and characterization of protein-bound nanoparticles, it is further demonstrated that several proteins can be efficiently delivered to tumor sites. DmPCs have a wide range of potential adaptability, which provides new opportunities for proteins in the field of treatment and imaging.

Scopolin obtained from Smilax china L. against hepatocellular carcinoma by inhibiting glycolysis: A network pharmacology and experimental study.

ETHNOPHARMACOLOGICAL RELEVANCE: Smilax china L. is a well-known traditional medicinal plant. In China, it is a common anti-cancer drug that has been inherited for thousands of years. Some in vitro and in vivo studies have confirmed its potential lipid-lowering, anti-inflammatory and anti-ovarian cancer effects. However, there is no research on the material basis and mechanism of the rhizome of Smilax china L. against hepatocellular carcinoma. AIM OF THE STUDY: To explore the material basis and mechanism of scopolin from Smilax china L. against hepatocellular carcinoma. METHODS: The potential targets and active components of Smilax china L. against hepatocellular carcinoma were screened by transcriptomics, network pharmacology and molecular docking. Microscale Thermophoresis (MST) detection was used to verify the affinity of small molecule compounds with potential proteins and protein-protein interaction. The Extract from HepG2 cells was used to measure the expression of glycolysis-related proteins, glucose consumption and lactate production. The expression of apoptosis-related factors and glycolysis-related proteins in vivo was detected by immunohistochemistry. RESULTS: The glycolysis-related proteins glucose-6-phosphate isomerase (GPI), glycerol-3-phosphate dehydrogenase, mitochondrial (GPD2) and phosphoglycerate kinase 2 (PGK2) screened by transcriptomics, network pharmacology showed strongly binding with scopolin by molecular docking. MST detection has also verified the affinity of scopolin with GPI and GPD2. It was the first time found that Heat shock protein HSP 90-alpha (Hsp90α) bound strongly to GPI and GPD2 in the worldwide, while scopolin was able to affect the interaction between Hsp90α and GPD2. In vitro and in vivo experiments further demonstrated that scopolin may play an anti-cancer role by affecting the stability of tumor-associated proteins. The results showed that scopolin obtained from Smilax china L. could regulate the expression of GPI, GPD2 and PGK2 and inhibit the interaction of protein-protein, reduce the energy metabolism of tumor tissue, thereby inhibit tumor growth. CONCLUSION: Scopolin obtained from Smilax china L. plays the role of anti-hepatocellular carcinoma by regulating the expression of glycolysis proteins GPI, GPD2 and PGK2. Scopolin could affect the interaction between Hsp90α and GPD2 may provide a novel potential treatment direction for hepatocellular carcinoma.

Pharmacokinetics, tissue distribution, plasma protein binding rate and excretion of sinoacutine following intravenous administration in female and male Sprague-Dawley rats.

Sinoacutine is a natural isoquinoline alkaloid isolated from traditional Chinese medicine Stephanina yunnanensis H. S. Lo. Our aim was to study the pharmacokinetic characteristics of sinoacutine, which is essential during the development of new drugs.In this study, an accurate, sensitive, and efficient liquid chromatography (HPLC) method was developed and applied to evaluate the pharmacokinetics, tissue distribution, plasma protein binding rate, and excretion after intravenous injection of sinoacutine in rats.The pharmacokinetic parameters of sinoacutine were accorded with a two-compartment model in rats, and the AUC0-t in female was greater than that in male. Sinoacutine could be detected in heart, liver, spleen, lung, kidney, and brain, and the content in liver and kidney was relatively high. Meanwhile, it had a high plasma protein binding rate of 79.16%. Excretion of sinoacutine through faeces and urine was low, and the average excretion rate was 9.96%. There were gender differences in blood drug concentration, tissue distribution, and excretion significantly (p < 0.05).In summary, this study lays a foundation for elucidating the pharmacokinetic rule of sinoacutine and the data can provide a reliable scientific resource for further research.

Evaluation of the antiglycating potential of thymoquinone and its interaction with BSA.

Thymoquinone (TQ) is a bioactive component of medicinal plant, Nigella sativa. It has been identified as promising anti-inflammatory and anti-analgesic properties. In the present study, the TQ has been investigated for physiological interaction as well as binding properties with serum albumin and their thermodynamic parameters at different temperatures. Glycation process was checked with the measurement of fructosamine content, carbonyl content and total advanced glycated end products. The aggregation of amyloid ß-structure was measured with Thioflavin-T and the secondary structure of BSA was observed by circular dichroism (CD) in glycated and thermal treated samples. The results indicate that the TQ showed binding interaction (both static and dynamic) with BSA (Kb= 18.31 × 107 M-1 at 293 K) and suppression of glycated products. The glycation-induced and thermal aggregation were prevented and the secondary structure of BSA was maintained. Therefore, these findings suggest that TQ may be used for a therapeutic drug for antiglycation as well as anti-aggregation.Communicated by Ramaswamy H. Sarma.

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-12ß-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.

Interference of Polydatin/Resveratrol in the ACE2:Spike Recognition during COVID-19 Infection. A Focus on Their Potential Mechanism of Action through Computational and Biochemical Assays.

In the search for new therapeutic strategies to contrast SARS-CoV-2, we here studied the interaction of polydatin (PD) and resveratrol (RESV)-two natural stilbene polyphenols with manifold, well known biological activities-with Spike, the viral protein essential for virus entry into host cells, and ACE2, the angiotensin-converting enzyme present on the surface of multiple cell types (including respiratory epithelial cells) which is the main host receptor for Spike binding. Molecular Docking simulations evidenced that both compounds can bind Spike, ACE2 and the ACE2:Spike complex with good affinity, although the interaction of PD appears stronger than that of RESV on all the investigated targets. Preliminary biochemical assays revealed a significant inhibitory activity of the ACE2:Spike recognition with a dose-response effect only in the case of PD.

High-Throughput Analysis of the Cell and DNA Site-Specific Binding of Native NF-κB Dimers Using Nuclear Extract Protein-Binding Microarrays (NextPBMs).

Nuclear factor-kappa B (NF-κB) transcription factors coordinate gene expression in response to a broad array of cellular signals. In vertebrates, there are five NF-κB proteins (c-Rel, RelA/p65, RelB, p50, and p52) that can form various dimeric combinations exhibiting both common and dimer-specific DNA-binding specificity. In this chapter, we describe the use of the nuclear extract protein-binding microarray (nextPBM), a high-throughput method to characterize the DNA binding of transcription factors present in cell nuclear extracts. NextPBMs allow for sensitive analysis of the DNA binding of NF-κB dimers and their interactions with cell-specific cofactors.

Rat plasma protein binding of kaempferol-3-O-rutinoside from Lu'an GuaPian tea and its anti-inflammatory mechanism for cardiovascular protection.

Previous study found a high content of kaempferol-3-O-rutinoside (KR) in Lu'an GuaPian tea, however, the rat plasma protein binding and mechanism of KR for cardiovascular protection are unclear. Thus, we studied plasma protein binding using ultrafiltration followed by UPLC, and screened its inhibition against LPS-induced inflammation injury in vitro as well as the underlying mechanism by molecular docking and western blot. KR showed over 74% plasma protein binding ratio. Furthermore, KR may act on the toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). In vitro experiments showed that KR decreases the overexpression of TLR4, MyD88, and nuclear factor-κB (NF-κB), which further validates the molecular docking results, suggesting that KR could block TLR4/MyD88/NF-κB signaling. These results indicate that KR could be a potential active agent in the protection of myocardial injury. PRACTICAL APPLICATIONS: Health benefits of tea are largely dependent on the intake of flavonoids. Flavonoids are a group of compounds beneficial to cardiovascular disease and an important part of "functional foods." Lu'an GuaPian tea is mainly produced in Lu'an City, Anhui Province and is one of the top 10 famous teas in China. Kaempferol-3-O-rutinoside in Lu'an GuaPian has good hypoglycemic effect, mainly manifested in a strong inhibition of α-glucosidase and α-amylase activities. Present study showed that kaempferol-3-O-rutinoside could block TLR4/MyD88/NF-κB signaling, suggesting that it could be a potential active agent in the protection of myocardial injury.

In vivo and in vitro studies of Banhahoobak-tang tablets using UPLC-ESI-MS/MS with polarity switching.

Banhahoobak-tang is the most prescribed herbal drug in East Asia when individuals experience sudden symptoms such as sore throat or neurological symptoms. The low toxicity and high in-vivo safety of this herbal medicine has made it more attractive to patients, and it has recently been formulated as tablets. In addition, Banhahoobak-tang tablets are registered as health insurance drugs in South Korea, and clinical prescriptions and demand are increasing. However, there are very few clinical trial data as well as very little accurate content analysis and results for Banhahoobak-tang tablets. The purpose of this study was to perform in-vitro and in-vivo studies on Banhahoobak-tang tablets, including content analysis, pharmacokinetics in humans, and plasma protein binding. For this study, a UPLC-ESI-MS/MS method with polarity switching was developed for simultaneous analysis of 18 components of Banhahoobak-tang. To separate the analytes, a C8 reverse-phase column was used as the stationary phase, 0.1 % aqueous formic acid and acetonitrile as the mobile phase, and ionization and multiple reaction monitoring for quantification. The developed method was able to isolate and quantify the 18 components with good sensitivity and selectivity and was fully validated according to international analytical standards. Stability tests were also conducted on the analytes. Finally, the method was applied to in-vitro and in-vivo studies of Banhahoobak-tang tablets, and the tablet components were 52.49 ng/g to 91.00 µg/g on average. The detected components showed rapid oral absorption in humans as well as high plasma protein binding ratio overall. These results and methods can be useful not only for effectiveness and safety evaluation but also for quality control of Banhahoobak-tang tablets.

Elucidation of plasma protein binding, blood partitioning, permeability, CYP phenotyping and CYP inhibition studies of Withanone using validated UPLC method: An active constituent of neuroprotective herb Ashwagandha.

ETHNOPHARMACOLOGICAL RELEVANCE: Withanone (WN), an active constituent of Withania somnifera commonly called Ashwagandha has remarkable pharmacological responses along with neurological activities. However, for a better understanding of the pharmacokinetic and pharmacodynamic behavior of WN, a comprehensive in-vitro ADME (absorption, distribution, metabolism, and excretion) studies are necessary. AIM OF THE STUDY: A precise, accurate, and sensitive reverse-phase ultra-performance liquid chromatographic method of WN was developed and validated in rat plasma for the first time. The developed method was successfully applied to the in-vitro ADME investigation of WN. MATERIAL AND METHODS: The passive permeability of WN was assayed using PAMPA plates and the plasma protein binding (PPB) was performed using the equilibrium dialysis method. Pooled liver microsomes of rat (RLM) and human (HLM) were used for the microsomal stability, CYP phenotyping, and inhibition studies. CYP phenotyping was evaluated using the specific inhibitors. CYP inhibition study was performed using specific probe substrates along with WN or specific inhibitors. RESULTS: WN was found to be stable in the simulated gastric and intestinal environment and has a high passive permeability at pH 4.0 and 7.0 in PAMPA assay. The PPB of WN at 5 and 20 µg/mL concentrations were found to be high i.e. 82.01 ± 1.44 and 88.02 ± 1.15%, respectively. The in vitro half-life of WN in RLM and HLM was found to be 59.63 ± 2.50 and 68.42 ± 2.19 min, respectively. CYP phenotyping results showed that WN was extensively metabolized by CYP 3A4 and1A2 enzymes in RLM and HLM. However, the results of CYP Inhibition studies showed that none of the CYP isoenzymes were potentially inhibited by WN in RLM and HLM. CONCLUSION: The in vitro results of pH-dependent stability, plasma stability, permeability, PPB, blood partitioning, microsomal stability, CYP phenotyping, and CYP inhibition studies demonstrated that WN could be a better phytochemical for neurological disorders.

Early Exposure of Fosphenytoin, Levetiracetam, and Valproic Acid After High-Dose Intravenous Administration in Young Children With Benzodiazepine-Refractory Status Epilepticus.

Fosphenytoin (FOS) and its active form, phenytoin (PHT), levetiracetam (LEV), and valproic acid (VPA) are commonly used second-line treatments of status epilepticus. However, limited information is available regarding LEV and VPA concentrations following high intravenous doses, particularly in young children. The Established Status Epilepticus Treatment Trial, a blinded, comparative effectiveness study of FOS, LEV, and VPA for benzodiazepine-refractory status epilepticus provided an opportunity to investigate early drug concentrations. Patients aged ≥2 years who continued to seizure despite receiving adequate doses of benzodiazepines were randomly assigned to FOS, LEV, or VPA infused over 10 minutes. A sparse blood-sampling approach was used, with up to 2 samples collected per patient within 2 hours following drug administration. The objective of this work was to report early drug exposure of PHT, LEV, and VPA and plasma protein binding of PHT and VPA. Twenty-seven children with median (interquartile range) age of 4 (2.5-6.5) years were enrolled. The total plasma concentrations ranged from 69 to 151.3 µg/mL for LEV, 11.3 to 26.7 µg/mL for PHT and 126 to 223 µg/mL for VPA. Free fraction ranged from 4% to 19% for PHT and 17% to 51% for VPA. This is the first report in young children of LEV concentrations with convulsive status epilepticus as well as VPA concentrations after a 40 mg/kg dose. Several challenges limited patient enrollment and blood sampling. Additional studies with a larger sample size are required to evaluate the exposure-response relationships in this emergent condition.

Serum Albumin Levels: Who Needs Them?

OBJECTIVES: The purpose of this critical narrative review is to discuss common indications for ordering serum albumin levels in adult critically ill patients, evaluate the literature supporting these indications, and provide recommendations for the appropriate ordering of serum albumin levels. DATA SOURCES: PubMed (1966 to August 2020), Cochrane Library, and current clinical practice guidelines were used, and bibliographies of retrieved articles were searched for additional articles. STUDY SELECTION AND DATA EXTRACTION: Current clinical practice guidelines were the preferred source of recommendations regarding serum albumin levels for guiding albumin administration and for nutritional monitoring. When current comprehensive reviews were available, they served as a baseline information with supplementation by subsequent studies. DATA SYNTHESIS: Serum albumin is a general marker of severity of illness, and hypoalbuminemia is associated with poor patient outcome, but albumin is an acute phase protein, so levels vacillate in critically ill patients in conjunction with illness fluctuations. The most common reasons for ordering serum albumin levels in intensive care unit (ICU) settings are to guide albumin administration, to estimate free phenytoin or calcium levels, for nutritional monitoring, and for severity-of-illness assessment. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Because hypoalbuminemia is common in the ICU setting, inappropriate ordering of serum albumin levels may lead to unnecessary albumin administration or excessive macronutrient administration in nutritional regimens, leading to possible adverse effects and added costs. CONCLUSIONS: With the exception of the need to order serum albumin levels as a component of selected severity-of-illness scoring systems, there is little evidence or justification for routinely ordering levels in critically ill patients.

Whole blood or plasma: what is the ideal matrix for pharmacokinetic-driven drug candidate selection?

In the present era of drug development, quantification of drug concentrations following pharmacokinetic studies has preferentially been performed using plasma as a matrix rather than whole blood. However, it is critical to realize the difference between measuring drug concentrations in blood versus plasma and the consequences thereof. Pharmacokinetics using plasma data may be misleading if concentrations differ between plasma and red blood cells (RBCs) because of differential binding in blood. In this review, factors modulating the partitioning of drugs into RBCs are discussed and the importance of determining RBC uptake of drugs for drug candidate selection is explored. In summary, the choice of matrix (plasma vs whole blood) is an important consideration to be factored in during drug discovery.