Bioorthogonal PEGylation Prolongs the Elimination Half-Life of N-TIMP2 While Retaining MMP Inhibition.

Tissue inhibitors of metalloproteinases (TIMPs) are natural inhibitors of the matrix metalloproteinase (MMP) family of proteins, whose members are key regulators of the proteolysis of extracellular matrix components and hence of multiple biological processes. In particular, imbalanced activity of matrix metalloproteinase-14 (MMP-14) may lead to the development of cancer and cardiovascular and other diseases. This study aimed to engineer TIMP2, one of the four homologous TIMPs, as a potential therapeutic by virtue of its ability to bind to the active-site Zn2+ of MMP-14. However, the susceptibility to degradation of TIMP2 and its small size, which results in a short circulation half-life, limit its use as a therapeutic. PEGylation was thus used to improve the pharmacokinetic profile of TIMP2. PEGylation of the MMP-targeting N-terminal domain of TIMP2 (N-TIMP2), via either cysteine or lysine residues, resulted in a significant decrease in N-TIMP2 affinity toward MMP-14 or multisite conjugation and conjugate heterogeneity, respectively. Our strategy designed to address this problem was based on incorporating a noncanonical amino acid (NCAA) into N-TIMP2 to enable site-specific mono-PEGylation. The first step was to incorporate the NCAA propargyl lysine (PrK) at position S31 in N-TIMP2, which does not interfere with the N-TIMP2-MMP-14 binding interface. Thereafter, site-specific PEGylation was achieved via a click chemistry reaction between N-TIMP2-S31PrK and PEG-azide-20K. Inhibition studies showed that PEGylated N-TIMP2-S31PrK did indeed retain its inhibitory activity toward MMP-14. The modified protein also showed improved serum stability vs non-PEGylated N-TIMP2. In vivo pharmacokinetic studies in mice revealed a significant 8-fold increase in the elimination half-life of PEGylated N-TIMP2 vs the non-PEGylated protein. This study shows that site-specific bioorthogonal mono-PEGylation extends the half-life of N-TIMP2 without impairing its biological activity, thereby highlighting the advantage of this strategy for generating potent PEGylated proteins.

Levetiracetam in lactation: How much is excreted into human breast milk?

AIMS: In breastfeeding women, anti-epileptic therapy can lead to infant toxicities, even with newer anti-epileptic drugs such as levetiracetam. This study assessed levetiracetam breastmilk excretion and its correlation with the maternal oral dose and serum concentrations. METHODS: Women with epilepsy treated with levetiracetam were recruited to this study and completed a questionnaire. Levetiracetam concentrations were determined in serial breastmilk samples (pre-dose to 12 h post-dose period) and in a single pre-dose maternal serum sample. RESULTS: Twenty breastfeeding women and 21 infants (one woman with twins; 16 fully and five partially breastfed infants) participated in this study. The trough breastmilk/serum ratio of levetiracetam was 0.98 ± 0.20. The infant levetiracetam daily dose was 5.39 ± 1.96 and 2.70 ± 0.98 mg. kg-1. d-1 , and the relative infant dose (RID) was 13.8 ± 3.1% and 6.9 ± 1.6% in the fully and partially breastfed infants, respectively. Substantial correlations between the levetiracetam dose, maternal serum and breastmilk trough concentrations, and breastmilk AUC values were found. Three women reported somnolence in their fully breastfed infants, which resolved shortly after switching to partial breastfeeding. All the infants gained weight according to their age. CONCLUSIONS: Infant levetiracetam exposure via the breastmilk was close to the safety thresholds (trough breastmilk/serum ratio slightly below 1, RID > 10% in fully breastfed infants), and infant somnolescence reports could be related to exposure of the infants to levetiracetam via breastmilk. Further studies are warranted to reveal the short- and long-term safety of levetiracetam in breastfeeding.

Combined Effects of Carotenoids and Polyphenols in Balancing the Response of Skin Cells to UV Irradiation.

Oral carotenoids and polyphenols have been suggested to induce photo-protective effects. The aim of the study was to test whether the combination of carotenoids and polyphenols produce greater protective effects from UV-induced damage to skin cells. Such damage is characterized by inflammation and oxidative stress; thus, the photo-protective effect can be partially explained by modulating the nuclear factor kappa B (NFκB) and antioxidant response element/Nrf2 (ARE/Nrf2) transcription systems, known as important regulators of these two processes. Indeed, it was found in keratinocytes that carotenoids and polyphenols inhibit UVB-induced NFκB activity and release of cytokine IL-6. A combination of tomato extract with rosemary extract inhibited UVB-induced release of IL-6 more than each of the compounds alone. Moreover, this combination synergistically activated ARE/Nrf2 transcription systems. Inflammatory cytokines such as IL-6 and TNFα induce the expression of matrix metalloproteinases (MMPs), which leads to collagen breakdown; thus, it is important to note that carnosic acid reduced TNFα-induced MMP-1 secretion from human dermal fibroblasts. The in vitro results suggest beneficial effects of phytonutrient combinations on skin health. To assure that clinical experiments to prove such effects in humans are feasible, the human bioavailability of carotenoids from tomato extract was tested, and nearly a twofold increase in their plasma concentrations was detected. This study demonstrates that carotenoids and polyphenols cooperate in balancing UV-induced skin cell damage, and suggests that NFκB and ARE/Nrf2 are involved in these effects.

Imaging Cancer Cells Expressing the Folate Receptor with Carbon Dots Produced from Folic Acid.

Development of new imaging tools for cancer cells in vitro and in vitro is important for advancing cancer research, elucidating drug effects upon cancer cells, and studying cellular processes. We showed that fluorescent carbon dots (C-dots) synthesized from folic acid can serve as an effective vehicle for imaging cancer cells expressing the folate receptor on their surface. The C-dots, synthesized through a simple one-step process from folic acid as the carbon source, exhibited selectivity towards cancer cells displaying the folate receptor, making such cells easily distinguishable in fluorescence microscopy imaging. Biophysical measurements and competition experiments both confirmed the specific targeting and enhanced uptake of C-dots by the folate receptor-expressing cells. The folic acid-derived C-dots were not cytotoxic, and their use in bioimaging applications could aid biological studies of cancer cells, identification of agonists/antagonists, and cancer diagnostics.

Limited Efficiency of Drug Delivery to Specific Intracellular Organelles Using Subcellularly "Targeted" Drug Delivery Systems.

Many drugs have been designed to act on intracellular targets and to affect intracellular processes inside target cells. For the desired effects to be exerted, these drugs should permeate target cells and reach specific intracellular organelles. This subcellular drug targeting approach has been proposed for enhancement of accumulation of these drugs in target organelles and improved efficiency. This approach is based on drug encapsulation in drug delivery systems (DDSs) and/or their decoration with specific targeting moieties that are intended to enhance the drug/DDS accumulation in the intracellular organelle of interest. During recent years, there has been a constant increase in interest in DDSs targeted to specific intracellular organelles, and many different approaches have been proposed for attaining efficient drug delivery to specific organelles of interest. However, it appears that in many studies insufficient efforts have been devoted to quantitative analysis of the major formulation parameters of the DDSs disposition (efficiency of DDS endocytosis and endosomal escape, intracellular trafficking, and efficiency of DDS delivery to the target organelle) and of the resulting pharmacological effects. Thus, in many cases, claims regarding efficient delivery of drug/DDS to a specific organelle and efficient subcellular targeting appear to be exaggerated. On the basis of the available experimental data, it appears that drugs/DDS decoration with specific targeting residues can affect their intracellular fate and result in preferential drug accumulation within an organelle of interest. However, it is not clear whether these approaches will be efficient in in vivo settings and be translated into preclinical and clinical applications. Studies that quantitatively assess the mechanisms, barriers, and efficiencies of subcellular drug delivery and of the associated toxic effects are required to determine the therapeutic potential of subcellular DDS targeting.

Celecoxib interferes to a limited extent with aspirin-mediated inhibition of platelets aggregation.

AIMS: The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects. METHODS: We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib. RESULTS: The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs. CONCLUSIONS: At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.

Efficient decoration of nanoparticles intended for intracellular drug targeting with targeting residues, as revealed by a new indirect analytical approach.

In our previous studies, we developed a nanodrug delivery system (nano-DDS) based on poly(lactic-co-glycolic acid) PLGA nanoparticles encapsulating antigenic peptide and fluorescent marker and 3-stage approach for its decoration with peptide targeting residues. The objectives of this study were (a) to develop methods for quantitative analysis of efficiency of individual conjugation steps and (b) to determine, based on these methods, the efficiency of our 3-stage approach of nano-DDS decoration. We prepared antigenic peptide-loaded PLGA-based nano-DDSs and sequentially decorated them with specific residues using carbodiimide and Click (azide-alkyne Huisgen cycloaddition using copper(I) catalysis) reactions. The extent of cargo encapsulation and release kinetics were analyzed using HPLC-based and colorimetric analytical methods. The efficiency of residue conjugation to the nano-DDSs was analyzed using FTIR spectroscopy and by quantifying the unreacted residues in the reaction mixture (i.e., by indirect analysis of reaction efficiencies). We revealed that copper, the catalyst of the Click reactions, formed complexes with unreacted targeting residues and interfered with the analysis of their conjugation efficiency. We used penicillamine (a chelator) to disrupt these complexes, and to recover the unreacted residues. Quantitative analysis revealed that 28,800-34,000 targeting residues (corresponding to 11-13 nm(2) surface area per residue) had been conjugated to a single nano-DDS using our 3-stage decoration approach, which is much higher than previously reported conjugation efficiencies. We conclude that the applied analytical tools allow quantitative analysis of nano-DDSs and the efficiency of their conjugation with targeting residues. The 3-stage decoration approach resulted in dense conjugation of nano-DDSs with targeting residues. The present decoration and analytical approaches can be effectively applied to other types of delivery systems and other targeting residues.

Comparative Pharmacokinetic Assessment of Innovative Sublingual, Rectal and Vaporizer Cannabis Products Versus Approved Cannabis Products in Healthy Volunteers.

Background: Over the last years, there is a dramatic increase in the use of medical cannabis products for an expanding range of clinical indications. The type of the drug product and its administration route affect substantially the rate and the extent of absorption of cannabinoids and the effects induced by them in the patients. The current challenge for the cannabis pharmaceutical industry is to develop formulations that allow predictable and stable absorption of cannabinoids. This article reports the results of the clinical trial that investigated the pharmacokinetics (PKs) of innovative cannabis products in healthy volunteers. Materials and Methods: This was a single-center study with a single-dose, randomized, crossover, partially blinded controlled design. Each of the 12 healthy volunteers received 8 different products, of the 10 products that were assessed in this trial: novel sublingual (SL) tablet, vaporizer, and rectal products, comparator products (Sativex® and oil-based oromucosal products), and placebo products. Serial blood samples were collected, plasma concentrations of the THC, 11-OH-THC, and CBD were quantified and subjected to noncompartmental PK analysis. Results: Novel medical cannabis products that were investigated in the study induced substantial exposure of the volunteers to the active ingredients, had more rapid absorption, and in some cases also less variable absorption of THC and CBD, in comparison with the approved comparison products. The bioavailability of the novel SL tablet-based and suppositories products was somewhat lower than that of the oromucosal products. The vaporizer provided immediate systemic absorption with highest maximal concentration. The safety profile of the novel cannabis products, namely vaporizer, SL tablets, and suppositories, was not inferior to the Sativex and oil-based oromucosal formulations. Conclusions: The novel cannabis products that were assessed in this study have PK properties that may be advantageous for management of specific medical conditions or in specific subgroups of patients that are prescribed medical cannabis.

Serine protease inhibitors decrease metastasis in prostate, breast, and ovarian cancers.

Targeted therapies for prostate, breast, and ovarian cancers are based on their activity against primary tumors rather than their anti-metastatic activity. Consequently, there is an urgent need for new agents targeting the metastatic process. Emerging evidence correlates in vitro and in vivo cancer invasion and metastasis with increased activity of the proteases mesotrypsin (prostate and breast cancer) and kallikrein 6 (KLK6; ovarian cancer). Thus, mesotrypsin and KLK6 are attractive putative targets for therapeutic intervention. As potential therapeutics for advanced metastatic prostate, breast, and ovarian cancers, we report novel mesotrypsin- and KLK6-based therapies, based on our previously developed mutants of the human amyloid ß-protein precursor Kunitz protease inhibitor domain (APPI). These mutants, designated APPI-3M (prostate and breast cancer) and APPI-4M (ovarian cancer), demonstrated significant accumulation in tumors and therapeutic efficacy in orthotopic preclinical models, with the advantages of long retention times in vivo, high affinity and favorable pharmacokinetic properties. The applicability of the APPIs, as a novel therapy and for imaging purposes, is supported by their good safety profile and their controlled and scalable manufacturability in bioreactors.

Pharmacokinetics of glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase and their blood glutamate-lowering activity in naïve rats.

Traumatic brain injury (TBI) and stroke lead to elevated levels of glutamate in the brain that negatively affect the neurological outcomes in both animals and humans. Intravenous administration of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) enzymes can be used to lower the blood glutamate levels and to improve the neurological outcome following TBI and stroke. The objective of this study was to analyze the pharmacokinetics and to determine the glutamate-lowering effects of GOT and GPT enzymes in naïve rats. We determined the time course of serum GOT, GPT, and glutamate levels following a single intravenous administration of two different doses of each one of the studied enzymes. Forty-six male rats were randomly assigned into one of 5 treatment groups: saline (control), human GOT at dose 0.03 and 0.06 mg/kg and porcine GPT at dose 0.6 and 1.2 mg/kg. Blood samples were collected at baseline, 5 min, and 2, 4, 8, 12, and 24 h after the drug injection and GOT, GPT and glutamate levels were determined. The pharmacokinetics of both GOT and GPT followed one-compartment model, and both enzymes exhibited substantial glutamate-lowering effects following intravenous administration. Analysis of the pharmacokinetic data indicated that both enzymes were distributed predominantly in the blood (central circulation) and did not permeate to the peripheral organs and tissues. Several-hour delay was present between the time course of the enzyme levels and the glutamate-lowering effects (leading to clock-wise hysteresis on concentration-effect curves), apparently due to the time that is required to affect the pool of serum glutamate. We conclude that the interaction between the systemically-administered enzymes (GOT and GPT) and the glutamate takes place in the central circulation. Thus, glutamate-lowering effects of GOT and GPT apparently lead to redistribution of the excess glutamate from the brain's extracellular fluid into the blood and can reduce secondary brain injury due to glutamate neurotoxicity. The outcomes of this study regarding the pharmacokinetic and pharmacodynamic properties of the GOT and GPT enzymes will be subsequently verified in clinical studies that can lead to design of effective neuroprotective treatment strategies in patients with traumatic brain diseases and stroke.

Magnitude of Lamotrigine Exposure Through Breastfeeding.

Importance: Lamotrigine use during breastfeeding has significantly increased in the recent years, whereas breast milk lamotrigine pharmacokinetics data are still sparse. Objectives: To assess lamotrigine exposure in breastfed infants by monitoring maternal serum and breast milk concentrations. Methods: Breastfeeding women treated with lamotrigine were recruited to this study. Maternal trough breast milk and serum samples were collected, and additional breast milk samples were collected 1, 3, 6, 9, 12 hours after lamotrigine consumption. Trough breast milk/serum ratios (M/S ratio) and breast milk area under the curve (AUC) values were calculated. Results: Twenty-one breastfeeding women were recruited to this study, and the final dataset was based on the samples collected from 17 women. Lamotrigine trough serum and mother's milk concentrations were 5.1 ± 3.3 mg/L and 3.1 ± 1.9 mg/L, respectively (mean ± standard deviation). The trough M/S ratio of lamotrigine was 0.66 ± 0.22. The lamotrigine breast milk average AUC was 41.7 ± 24.6 mg·h/L. The estimated infant dose of lamotrigine was 0.52 ± 0.31 mg/kg/day and 0.26 ± 0.15 mg/kg/day for fully and partially breastfed infants, respectively. Significant correlation was found between the maternal lamotrigine serum trough concentrations and the breast milk parameters: trough breast milk concentrations (Spearman's rho = 0.986, p < 0.0001) and breast milk AUC values (Spearman's rho = 0.941, p < 0.0001). No significant correlation was found between the maternal lamotrigine daily dose and serum trough concentrations, breast milk trough concentrations, and breast milk AUC values (Spearman's rho = 0.294, 0.285, and 0.438, p = 0.252, 0.396, and 0.078, respectively). Conclusion and Relevance: High correlation between the maternal lamotrigine trough serum concentrations and the breast milk AUC values was found, implying that monitoring the maternal lamotrigine serum concentrations can be useful for prediction of exposure of infants to lamotrigine through the breast milk. The trial was registered in the Israeli trials registry MOH_2021-09-05_010243 at September 5, 2021 Retrospectively registered https://my.health.gov.il/CliniTrials.

'IntraCell' plugin for assessment of intracellular localization of nano-delivery systems and their targeting to the individual organelles.

Efficient intracellular targeting of drugs and drug delivery systems (DDSs) is a major challenge that should be overcome to enhance the therapeutic efficiency of biopharmaceuticals and other intracellularly-acting drugs. Studies that quantitatively assess the mechanisms, barriers, and efficiency of intracellular drug delivery are required to determine the therapeutic potential of intracellular targeting of nano-delivery systems. In this study we report development and application of a novel 'IntraCell' plugin for ImageJ that is useful for quantitative assessment of uptake and intracellular localization of the drug/DDS and estimation of targeting efficiency. The developed plugin is based on threshold-based identification of borders of cell and of the individual organelles on confocal images and pixel-by-pixel analysis of fluorescence intensities. We applied the developed 'IntraCell' plugin to investigate uptake and intracellular targeting of novel endoplasmic reticulum (ER)-targeted delivery system based on PLGA nanoparticles decorated with ER-targeting or control peptides and encapsulating antigenic peptide and fluorescent marker. Decoration of the nanoparticles with peptidic residues affected their uptake and intracellular trafficking in HeLa cells, indicating that the targeting peptide was identified as ER-targeting signal by the intracellular trafficking mechanisms in HeLa cells and that these mechanisms can handle nano-DDS of the size comparable to some intracellular vesicles (hundreds of nanometers in diameter). We conclude that decoration of nanoparticles with peptidic residues affects their intracellular localization and trafficking and can be potentially used for intracellularly-targeted drug delivery. 'IntraCell' plugin is an useful tool for quantitative assessment of efficiency of uptake and intracellular drug targeting. In combination with other experimental approaches, it will be useful for the development of intracellularly-targeted formulations with enhanced and controlled drug pharmacological activities, such as delivery of antigenic peptides for anticancer vaccination and for other applications.

Intracellular targeting of PLGA nanoparticles encapsulating antigenic peptide to the endoplasmic reticulum of dendritic cells and its effect on antigen cross-presentation in vitro.

Intracellularly targeted delivery system based on PLGA nanoparticles decorated with endoplasmic reticulum (ER)-targeting or control peptides and encapsulating antigenic peptide and fluorescent marker, was developed and characterized. The cellular uptake by dendritic cells (murine DC2.4 cells), intracellular trafficking, and cross-presentation efficiency of this delivery system were studied in vitro. The prepared nanoparticles (an average diameter of ~350 nm) efficiently encapsulated antigenic peptide and fluorescent marker and gradually released them over several days. Yet, the nanoparticles' size was small enough to allow their efficient endocytosis by the antigen-presenting cells in vitro. Surface conjugation of the targeting or control peptides enhanced the endocytosis of the nanoparticles, affected their intracellular trafficking, and induced prolonged low-magnitude cross-presentation of the antigenic peptide. We demonstrated in vitro that the intracellular fate of nanoparticulate drug delivery systems can be altered by their surface decoration with peptidic targeting residues. More detailed investigation is required to determine the mechanisms and therapeutic potential of intracellular targeting of nanodelivery systems in vivo for the goal of an anticancer vaccine.

Doxorubicin liposomes cell penetration enhancement and its potential drawbacks for the tumor targeting efficiency.

The clinical efficacy of the PEGylated doxorubicin liposomes (PLD) is limited by low tumor accumulation and limited intra-tumoral disposition. Decoration with the cell penetration enhancers (CPEs) can increase the PLD permeability via the biological barriers, however at the expense of enhanced distribution to the non-target organs and tissues, and may interfere with their tumor accumulation and with the resulting anti-cancer effects. We investigated the effect of the surface CPE agent tetraArg-[G-1]-distearoyl glycerol (DAG-Arg4) on the systemic and intra-tumoral accumulation of PLD, using a 4 T1-Luc murine orthotopic model of breast cancer, using several analytical approaches. CPE-decorated liposomes undergo efficient in vitro endocytosis, and delivered doxorubicin to the cell nuclei. In vivo, they had lower tumor and spleen accumulation, similar liver accumulation, and higher lung accumulation, as compared to those of the PLD. Despite the lower tumor accumulation, CPE-decorated liposomes induced more prominent in vivo anti-cancer effects, as compared to the PLD, apparently ascribable to the higher intra-tumoral permeability mediated by the CPE surface residues. Overall, liposomes decoration with the CPE residues had mostly beneficial effects on their systemic and intra-tumoral disposition. The mechanisms of the CPE-mediated effects on the liposome disposition should be further assessed with additional experimental models using robust analytical methods with high spatial resolution.

Life-extended glycosylated IL-2 promotes Treg induction and suppression of autoimmunity.

IL-2 is the master-regulator cytokine for T cell dependent responses and is crucial for proliferation and survival of T cells. However, IL-2-based treatments remained marginal, in part due to short half-life. Thus, we aimed to extend IL-2 half-life by flanking the IL-2 core with sequences derived from the extensively glycosylated hinge region of the NCR2 receptor. We termed this modified IL-2: "S2A". Importantly, S2A blood half-life was extended 14-fold compared to the clinical grade IL-2, Proleukin. Low doses inoculation of S2A significantly enhanced induction of Tregs (CD4+ Regulatory T cells) in vivo, as compared to Proleukin, while both S2A and Proleukin induced low levels of CD8+ T cells. In a B16 metastatic melanoma model, S2A treatment was unable to reduce the metastatic capacity of B16 melanoma, while enhancing induction and recruitment of Tregs, compared to Proleukin. Conversely, in two autoimmune models, rheumatoid arthritis and DSS-induced colitis, S2A treatment significantly reduced the progression of disease compared to Proleukin. Our results suggest new avenues for generating long-acting IL-2 for long-standing treatment and a new technique for manipulating short-life proteins for clinical and research uses.

Effect of Tomato Nutrient Complex on Blood Pressure: A Double Blind, Randomized Dose⁻Response Study.

Oxidative stress is implicated in the pathogenesis of essential hypertension, a risk factor for cardiovascular morbidity and mortality. Tomato carotenoids such as lycopene and the colorless carotenoids phytoene and phytofluene induce the antioxidant defense mechanism. This double-blind, randomized, placebo-controlled study aimed to find effective doses of Tomato Nutrient Complex (TNC) to maintain normal blood pressure in untreated hypertensive individuals. The effect of TNC treatment (5, 15 and 30 mg lycopene) was compared with 15 mg of synthetic lycopene and a placebo over eight weeks. Results indicate that only TNC treatment standardized for 15 or 30 mg of lycopene was associated with significant reductions in mean systolic blood pressure (SBP). Treatment with the lower dose standardized for 5 mg of lycopene or treatment with 15 mg of synthetic lycopene as a standalone had no significant effect. To test carotenoid bioavailability, volunteers were treated for four weeks with TNC providing 2, 5 or 15 mg lycopene. The increase in blood levels of lycopene, phytoene, and phytofluene was dose dependent. Results suggest that only carotenoid levels achieved by the TNC dose of 15 mg lycopene or higher correlate to a beneficial effect on SBP in hypertensive subjects while lower doses and lycopene alone do not.

Therapeutic levetiracetam monitoring during pregnancy: "mind the gap".

BACKGROUND: Epilepsy is one of the most common chronic neurological conditions and its treatment during pregnancy is challenging. Levetiracetam (LEV) is an antiepileptic medication frequently used during pregnancy. Only a few small studies have been published on LEV monitoring during pregnancy, demonstrating decreased serum LEV levels during the first and second trimester; however, the most significant decrease was observed during the third trimester of pregnancy. In this study we aimed to evaluate LEV pharmacokinetics during different stages of pregnancy. METHODS: We followed up and monitored serum levels of pregnant women treated with LEV for epilepsy. RESULTS: Fifty-nine women with 66 pregnancies during the study period were included. The lowest raw LEV serum concentrations were observed during the first trimester. Compared with the pre-pregnancy period, raw serum concentration was lower by 5.76 mg/L [95% confidence interval (CI) (2.78, 8.75), p = 0.039] during the first trimester. Comparing the decrease in the first trimester with either the second or the third, no significant changes were observed (p = 0.945, p = 0.866). Compared with pre-pregnancy measurements, apparent clearance was increased by 71.08 L/day [95%CI (16.34, 125.83), p = 0.011] during the first trimester. About 30% of LEV serum levels during pregnancy were below the laboratory quoted reference range. CONCLUSIONS: Raw LEV serum levels tend to decrease during pregnancy, mainly during the first trimester contrary to previous reports. Monitoring of LEV serum levels is essential upon planning pregnancy and thereafter if pre-pregnancy LEV levels are to be maintained. However, more studies are needed to assess the correlation with clinical outcome.

Pharmacokinetics of Toxin-Derived Peptide Drugs.

Toxins and venoms produced by different organisms contain peptides that have evolved to have highly selective and potent pharmacological effects on specific targets for protection and predation. Several toxin-derived peptides have become drugs and are used for the management of diabetes, hypertension, chronic pain, and other medical conditions. Despite the similarity in their composition (amino acids as the building blocks), toxin-derived peptide drugs have very profound differences in their structure and conformation, in their physicochemical properties (that affect solubility, stability, etc.), and subsequently in their pharmacokinetics (the processes of absorption, distribution, metabolism, and elimination following their administration to patients). This review summarizes and critically analyzes the pharmacokinetic properties of toxin-derived peptide drugs: (1) the relationship between the chemical structure, physicochemical properties, and the pharmacokinetics of the specific drugs, (2) the major pharmacokinetic properties and parameters of these drugs, and (3) the major pharmacokinetic variability factors of the individual drugs. The structural properties of toxin-derived peptides affect their pharmacokinetics and pose some limitations on their clinical use. These properties should be taken into account during the development of new toxin-derived peptide drugs, and for the efficient and safe use of the clinically approved drugs from this group in the individual patients.

Efficacy of paclitaxel/dexamethasone intra-tumoral delivery in treating orthotopic mouse breast cancer.

The effect of topical co-administration of promoter drugs with paclitaxel to increase anti-tumor effects of paclitaxel was investigated. Mice with orthotopic 4T1-Luc breast cancer received single intra-tumoral injection of a polymeric formulation with paclitaxel and a specific promoter drug. Several promoter drugs were evaluated, including: dexamethasone, losartan, nicotinamide, Azone, and oleic acid. Dexamethasone exhibited the highest effect on paclitaxel anti-tumor activity, in a dose-dependent fashion. However, this effect was accompanied by systemic effects of dexamethasone, and inability to prevent tumor metastasis to the lungs. Topical co-administration of promoter drugs with anti-cancer agents can enhance their anti-tumor effects. Further investigations are needed to identify the most efficient combinations of promoter and anti-cancer drugs, and their suitability for the clinical management of the breast cancer disease.