Pharmacokinetics and Tolerability of Intraperitoneal Chloroprocaine After Fetal Extraction in Women Undergoing Cesarean Delivery.

BACKGROUND: Intraperitoneal chloroprocaine has been used during cesarean delivery to supplement suboptimal neuraxial anesthesia for decades. The short in vitro half-life of chloroprocaine (11-21 seconds) has been cited to support the safety of this approach. However, there are no data regarding the rate of absorption, representing patient drug exposure, through this route of administration. Accordingly, we designed a study to determine the in vivo half-life of intraperitoneal chloroprocaine and assess clinical tolerability. METHODS: We designed a single-center, prospective, cohort, multiple-dose escalation study of women 18 to 50 years of age undergoing cesarean delivery with spinal anesthesia. Chloroprocaine (40 mL) was administered after delivery of the newborn and before uterine closure. The first cohort (n = 5) received 1%, the second cohort (n = 5) received 2%, and the third cohort (n = 5) received 3% chloroprocaine solution. Maternal blood samples were obtained before administration and 1, 5, 10, 20, and 30 minutes after dosing. The primary objective was to define the pharmacokinetic profile of intraperitoneal chloroprocaine, including in vivo half-life. The secondary objective was to evaluate tolerability through determination of peak plasma concentration and prospective assessment for local anesthetic systemic toxicity. RESULTS: The peak plasma concentration occurred 5 minutes after intraperitoneal administration in all 3 cohorts: 64.8 ng/mL (6.5 µg/kg), 28.7 ng/mL (2.9 µg/kg), and 799.2 ng/mL (79.9 µg/kg) for 1%, 2%, and 3% chloroprocaine, respectively. The in vivo half-life of chloroprocaine after intraperitoneal administration was estimated to be 5.3 minutes (95% confidence interval, 4.0-6.6). We did not detect clinical signs of local anesthetic systemic toxicity in any of the 3 cohorts. CONCLUSIONS: The in vivo half-life of intraperitoneal chloroprocaine (5.3 minutes) is more than an order of magnitude greater than the in vitro half-life (11-21 seconds). However, maximum plasma concentrations of chloroprocaine (C max range, 0.05-79.9 µg/kg) were not associated with local anesthetic systemic toxicity and remain well below our predefined safe level of exposure (970 µg/kg) and levels associated with clinical symptoms (2.6-2.9 mg/kg). Therefore, our study suggests that intraperitoneal chloroprocaine, in a dosage ≤1200 mg, administered after fetal extraction, is well tolerated during cesarean delivery.

Cannabis use and measurement of cannabinoids in plasma and breast milk of breastfeeding mothers.

BACKGROUND: Information on cannabinoids in breast milk and maternal cannabis use is limited. We quantified cannabinoids in plasma and breast milk of breastfeeding mothers and assessed cannabis use patterns. METHODS: This is a prospective study at a university hospital in a state with legal medical and recreational cannabis. Breast milk and plasma samples along with survey data were collected from volunteers using cannabis in the last 48 h at 2 weeks and 2 months postpartum. RESULTS: Twenty subjects were enrolled. Median age (IQR) was 27 (24-34) years. Median (IQR) instances of cannabis use in the last 7 days were visit 1: 17 (6-29) and visit 2: 23 (15-45). Median (IQR) tetrahydrocannabinol (THC) concentrations were: plasma 3.7 ng/ml (0.8-56.8) and breast milk 27.5 ng/ml (0.8-190.5). Median (IQR) cannabidiol (CBD) concentrations were: plasma 0.6 ng/ml (0.5-6.4) and breast milk 1.2 ng/ml (0.5-17.0). Median (IQR) THC M/P: 7.0 (1.8-34.6) and CBD M/P: 2.6. Median breast milk THC concentration increased from visit 1 to visit 2 by 30.2 ng/ml (95% CI 3.05-69.3 ng/ml). CONCLUSIONS: THC and CBD accumulate in breast milk. Breastfeeding mothers used cannabis frequently and increased use in the early postpartum period. Research on the effects of infant exposure to cannabinoids in breast milk is urgently needed. IMPACT: Cannabis use is increasing in the general population and many nursing mothers use cannabis. THC has been previously detected in breast milk but little is known on how it concentrates relative to plasma. Data on cannabinoids other than THC, reasons for cannabis use, and patterns of use in breastfeeding women are also limited. We detected THC and CBD in breast milk. Both concentrate in breast milk relative to plasma. We showed that breastfeeding mothers increased cannabis use in the weeks after childbirth. Further research is needed to evaluate infant exposure to cannabinoids via breast milk and effects on infant health.

ELQ-331 as a prototype for extremely durable chemoprotection against malaria.

BACKGROUND: The potential benefits of long-acting injectable chemoprotection (LAI-C) against malaria have been recently recognized, prompting a call for suitable candidate drugs to help meet this need. On the basis of its known pharmacodynamic and pharmacokinetic profiles after oral dosing, ELQ-331, a prodrug of the parasite mitochondrial electron transport inhibitor ELQ-300, was selected for study of pharmacokinetics and efficacy as LAI-C in mice. METHODS: Four trials were conducted in which mice were injected with a single intramuscular dose of ELQ-331 or other ELQ-300 prodrugs in sesame oil with 1.2% benzyl alcohol; the ELQ-300 content of the doses ranged from 2.5 to 30 mg/kg. Initial blood stage challenges with Plasmodium yoelii were used to establish the model, but the definitive study measure of efficacy was outcome after sporozoite challenge with a luciferase-expressing P. yoelii, assessed by whole-body live animal imaging. Snapshot determinations of plasma ELQ-300 concentration ([ELQ-300]) were made after all prodrug injections; after the highest dose of ELQ-331 (equivalent to 30 mg/kg ELQ-300), both [ELQ-331] and [ELQ-300] were measured at a series of timepoints from 6 h to 5½ months after injection. RESULTS: A single intramuscular injection of ELQ-331 outperformed four other ELQ-300 prodrugs and, at a dose equivalent to 30 mg/kg ELQ-300, protected mice against challenge with P. yoelii sporozoites for at least 4½ months. Pharmacokinetic evaluation revealed rapid and essentially complete conversion of ELQ-331 to ELQ-300, a rapidly achieved (< 6 h) and sustained (4-5 months) effective plasma ELQ-300 concentration, maximum ELQ-300 concentrations far below the estimated threshold for toxicity, and a distinctive ELQ-300 concentration versus time profile. Pharmacokinetic modeling indicates a high-capacity, slow-exchange tissue compartment which serves to accumulate and then slowly redistribute ELQ-300 into blood, and this property facilitates an extremely long period during which ELQ-300 concentration is sustained above a minimum fully-protective threshold (60-80 nM). CONCLUSIONS: Extrapolation of these results to humans predicts that ELQ-331 should be capable of meeting and far-exceeding currently published duration-of-effect goals for anti-malarial LAI-C. Furthermore, the distinctive pharmacokinetic profile of ELQ-300 after treatment with ELQ-331 may facilitate durable protection and enable protection for far longer than 3 months. These findings suggest that ELQ-331 warrants consideration as a leading prototype for LAI-C.

A role for adenine nucleotides in the sensing mechanism to purine starvation in Leishmania donovani.

Purine salvage by Leishmania is an obligatory nutritional process that impacts both cell viability and growth. Previously, we have demonstrated that the removal of purines in culture provokes significant metabolic changes that enable Leishmania to survive prolonged periods of purine starvation. In order to understand how Leishmania sense and respond to changes in their purine environment, we have exploited several purine pathway mutants, some in which adenine and guanine nucleotide metabolism is uncoupled. While wild type parasites grow in any one of a variety of naturally occurring purines, the proliferation of these purine pathway mutants requires specific types or combinations of exogenous purines. By culturing purine pathway mutants in high levels of extracellular purines that are either permissive or non-permissive for growth and monitoring for previously defined markers of the adaptive response to purine starvation, we determined that adaptation arises from a surveillance of intracellular purine nucleotide pools rather than from a direct sensing of the extracellular purine content of the environment. Specifically, our data suggest that perturbation of intracellular adenine-containing nucleotide pools provides a crucial signal for inducing the metabolic changes necessary for the long-term survival of Leishmania in a purine-scarce environment.

A phase II study of sulforaphane-rich broccoli sprout extracts in men with recurrent prostate cancer.

INTRODUCTION: Diets high in cruciferous vegetables are associated with lower risk of incidence of prostate cancer, including aggressive forms of this disease. Human intervention studies with cruciferous vegetable-rich diets also demonstrate modulation of gene expression in important pathways in prostate cells. PURPOSE: Sulforaphane is a constituent of these foods postulated to harbor the anti-neoplastic activity based on multiple tumor models. Our own work demonstrates that sulforaphane inhibits AR signaling in prostate cancer cells. Here, we report results from the first clinical trial of sulforaphane-rich extracts in men with prostate cancer. METHODS: We treated 20 patients who had recurrent prostate cancer with 200 µmoles/day of sulforaphane-rich extracts for a maximum period of 20 weeks and determined the proportion of patients with ≥50% PSA declines, the primary endpoint. Only one subject experienced a ≥50% PSA decline. Thus, the primary endpoint was not achieved. Seven patients experienced smaller PSA declines (<50%). There was also a significant lengthening of the on-treatment PSA doubling time (PSADT) compared with the pre-treatment PSADT [6.1 months pre-treatment vs. 9.6 months on-treatment (p = 0.044)]. Finally, treatment with sulforaphane-rich extracts was safe with no Grade 3 adverse events. CONCLUSIONS: Treatment with 200 µmoles/day of sulforaphane-rich extracts did not lead to ≥50% PSA declines in the majority of patients. However, because of the safety of treatment and the effects on PSADT modulation, further studies, including those with higher doses, may be warranted to clarify the role of sulforaphane as a prevention agent or treatment agent.

Ubiquitin-dependent proteasomal degradation of human liver cytochrome P450 2E1: identification of sites targeted for phosphorylation and ubiquitination.

Human liver CYP2E1 is a monotopic, endoplasmic reticulum-anchored cytochrome P450 responsible for the biotransformation of clinically relevant drugs, low molecular weight xenobiotics, carcinogens, and endogenous ketones. CYP2E1 substrate complexation converts it into a stable slow-turnover species degraded largely via autophagic lysosomal degradation. Substrate decomplexation/withdrawal results in a fast turnover CYP2E1 species, putatively generated through its futile oxidative cycling, that incurs endoplasmic reticulum-associated ubiquitin-dependent proteasomal degradation (UPD). CYP2E1 thus exhibits biphasic turnover in the mammalian liver. We now show upon heterologous expression of human CYP2E1 in Saccharomyces cerevisiae that its autophagic lysosomal degradation and UPD pathways are evolutionarily conserved, even though its potential for futile catalytic cycling is low due to its sluggish catalytic activity in yeast. This suggested that other factors (i.e. post-translational modifications or "degrons") contribute to its UPD. Indeed, in cultured human hepatocytes, CYP2E1 is detectably ubiquitinated, and this is enhanced on its mechanism-based inactivation. Studies in Ubc7p and Ubc5p genetically deficient yeast strains versus corresponding isogenic wild types identified these ubiquitin-conjugating E2 enzymes as relevant to CYP2E1 UPD. Consistent with this, in vitro functional reconstitution analyses revealed that mammalian UBC7/gp78 and UbcH5a/CHIP E2-E3 ubiquitin ligases were capable of ubiquitinating CYP2E1, a process enhanced by protein kinase (PK) A and/or PKC inclusion. Inhibition of PKA or PKC blocked intracellular CYP2E1 ubiquitination and turnover. Here, through mass spectrometric analyses, we identify some CYP2E1 phosphorylation/ubiquitination sites in spatially associated clusters. We propose that these CYP2E1 phosphorylation clusters may serve to engage each E2-E3 ubiquitination complex in vitro and intracellularly.

Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women.

AIM(S): While it is known that CYP3A4/5 activity is decreased with combined oral contraceptive (COC) use and obesity suppresses CYP expression, the combined effects of obesity and COC use on CYP3A4/5 activity are unclear. Therefore, our aim was to examine the effect of COC usage on CYP3A4/5 activity in obese women. METHODS: Thirty-four, obese (body mass index, BMI > 30 kg m(-2)) women of reproductive age (18-35 years old) were placed on a COC pill containing 20 µg ethinylestradiol/100 µg levonorgestrel for 21 days starting at the onset of menses. A midazolam pharmacokinetic study was conducted prior to initiation and after 21 days of COC treatment. Serial blood samples were collected and plasma concentrations of midazolam were measured using liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were estimated using a non-compartmental method. RESULTS: Midazolam clearance, a surrogate measure of CYP3A4/5 activity, was significantly decreased upon COC use (63.3 l h(-1) vs. 53.9 l h(-1), P < 0.05). A median decrease of 5.6 l h(-1) (95% CI -4.1, 13.3 l h(-1)) was observed. However, the magnitude of change was similar to that reported in women with normal BMI. CONCLUSIONS: Although we hypothesized that obesity might amplify the impact on CYP3A4/5 activity in COC users, we found that this was not the case. This finding is reassuring regarding potential additional drug-drug interactions in obese COC users as CYP3A4/5 is a major enzyme in the metabolism of many marketed drugs.

Optimization of endochin-like quinolones for antimalarial activity.

Our prior work on tricyclic acridones combined with a desire to minimize the tricyclic system led to an interest in antimalarial quinolones and a reexamination of endochin, an experimental antimalarial from the 1940's. In the present article, we show that endochin is unstable in the presence of murine, rat, and human microsomes which may explain its relatively poor antimalarial activity in mammalian systems. We also profile the structure-activity relationships of ≈ 30 endochin-like quinolone (ELQ) analogs and highlight features that are associated with enhanced metabolic stability, potent antiplasmodial activity against multidrug resistant strains of Plasmodium falciparum, and equal activity against an atovaquone-resistant clinical isolate. Our work also features an ELQ construct containing a polyethylene glycol carbonate pro-moiety that is highly efficacious by oral administration in a murine malaria model. These findings provide compelling evidence that development of ELQ therapeutics is feasible.

Pharmacokinetic study of lipoic acid in multiple sclerosis: comparing mice and human pharmacokinetic parameters.

Lipoic acid is a natural antioxidant available as an oral supplement from a number of different manufacturers. Lipoic acid administered subcutaneously is an effective therapy for murine experimental autoimmune encephalomyelitis, a model of multiple sclerosis. The aim of this study was to compare serum lipoic acid levels with oral dosing in patients with multiple sclerosis with serum levels in mice receiving subcutaneous doses of lipoic acid. We performed serum pharmacokinetic studies in patients with multiple sclerosis after a single oral dose of 1200 mg lipoic acid. Patients received one of the three different racemic formulations randomly: tablet (Formulation A) and capsules (Formulations B and C). Mice pharmacokinetic studies were performed with three different subcutaneous doses (20, 50 and 100 mg/kg racemic lipoic acid). The pharmacokinetic parameters included Maximum Serum Concentrations (C(max) in microg/ml) and area under the curve (0-infinity) (AUC ( 0-infinity) in microg*min/ml). We found mean C(max) and AUC (0-infinity) in patients with multiple sclerosis as follows: group A (N = 7) 3.8 +/- 2.6 and 443.1 +/- 283.9; group B (N = 8) 9.9 +/- 4.5 and 745.2 +/- 308.7 and group C (N = 8) 10.3 +/- 3.8 and 848.8 +/- 360.5, respectively. Mean C(max) and AUC (0-infinity) in the mice were: 100 mg/kg lipoic acid: 30.9 +/- 2.9 and 998 +/- 245; 50 mg/kg lipoic acid: 7.6 +/- 1.4 and 223 +/- 20; 20 mg/kg lipoic acid: 2.7 +/- 0.7 and 119 +/- 33. We conclude that patients taking 1200 mg of lipoic acid from two of the three oral formulations achieved serum C(max) and AUC levels comparable to that observed in mice receiving 50 mg/kg subcutaneous dose of lipoic acid, which is a highly therapeutic dose in experimental autoimmune encephalomyelitis. A dose of 1200 mg oral lipoic acid can achieve therapeutic serum levels in patients with multiple sclerosis.

Gastrointestinal Tolerability and Absorption of R- Versus R,S-Lipoic Acid in Progressive Multiple Sclerosis: A Randomized Crossover Trial.

We compared the gastrointestinal (GI) tolerability and assessed for bioequivalent absorption of R-lipoic acid (LA) in people with progressive multiple sclerosis (MS) in a single-center, double-blind, randomized crossover trial. Participants randomly assigned to formulation sequence took 600 mg of R-LA or 1200 mg of a 1:1 racemic R,S-LA mixture in single daily doses for 7 to 10 days, underwent a washout of at least 7 days, and then took the other form of LA for 7 to 10 days. At the end of each period on LA, GI symptoms were assessed with GI questions from the Monitoring of Side Effects Scale. Serum LA concentrations were measured before and 60, 90, 120, 180, and 240 minutes after the first and last day's dose of each form of LA to derive an area under the plasma concentration-time curve (AUC) and maximum serum concentration (Cmax ). Twenty participants enrolled (12 women; 15 secondary progressive MS, 5 primary progressive MS; mean age, 59.6 years). Two withdrew early due to symptoms while taking R,S-LA, and one withdrew early while taking R-LA. The mean GI Monitoring of Side Effects Scale score was 1.7 points lower on R-LA than on R,S-LA (P = .069), and there were fewer reports of each GI side effect when taking the R-LA than the R,S-LA (31 vs 60; P = .025). The AUC and Cmax for R-LA were bioequivalent for the 2 formulations (90% confidence intervals 97.4% to 99.3% for AUC and 93.4% to 98.2% for Cmax ). This study supports that in people with progressive MS, there is better GI tolerability and bioequivalent serum absorption of R-LA when 600 mg of R-LA is taken as R-LA alone than when taken in a 1:1 racemic R,S-LA mixture.

Polymorphisms in the human soluble epoxide hydrolase gene EPHX2 linked to neuronal survival after ischemic injury.

Single nucleotide polymorphisms (SNPs) in the human EPHX2 gene have recently been implicated in susceptibility to cardiovascular disease, including stroke. EPHX2 encodes for soluble epoxide hydrolase (sEH), an important enzyme in the metabolic breakdown of arachidonic acid-derived eicosanoids referred to as epoxyeicosatrienoic acids (EETs). We previously demonstrated that EETs are protective against ischemic cell death in culture. Therefore, we tested the hypothesis that polymorphisms in the human EPHX2 gene alter sEH enzyme activity and affect neuronal survival after ischemic injury in vitro. Human EPHX2 mutants were recreated by site-directed mutagenesis and fused downstream of TAT protein transduction domain. Western blot analysis and immunocytochemistry staining revealed high-transduction efficiency of human TAT-sEH variants in rat primary cultured cortical neurons, associated with increased metabolism of 14,15-EET to corresponding 14,15-dihydroxyeicosatrienoic acid. A human variant of sEH with Arg103Cys amino acid substitution, previously demonstrated to increase sEH enzymatic activity, was associated with increased cell death induced in cortical neurons by oxygen-glucose deprivation (OGD) and reoxygenation. In contrast, the Arg287Gln mutation was associated with reduced sEH activity and protection from OGD-induced neuronal cell death. We conclude that sequence variations in the human EPHX2 gene alter susceptibility to ischemic injury and neuronal survival in a manner linked to changes in the hydrolase activity of the enzyme. The findings suggest that human EPHX2 mutations may in part explain the genetic variability in sensitivity to ischemic brain injury and stroke outcome.

Soluble epoxide hydrolase gene deletion is protective against experimental cerebral ischemia.

BACKGROUND AND PURPOSE: Cytochrome P450 epoxygenase metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs). EETs are produced in the brain and perform important biological functions, including vasodilation and neuroprotection. However, EETs are rapidly metabolized via soluble epoxide hydrolase (sEH) to dihydroxyeicosatrienoic acids (DHETs). We tested the hypothesis that sEH gene deletion is protective against focal cerebral ischemia through enhanced collateral blood flow. METHODS: sEH knockout (sEHKO) mice with and without EETs antagonist 14, 15 epoxyeicosa-5(Z)-enoic acid (EEZE) were subjected to 2-hour middle cerebral artery occlusion (MCAO), and infarct size was measured at 24 hours of reperfusion and compared to wild-type (WT) mice. Local CBF rates were measured at the end of MCAO using iodoantipyrine (IAP) autoradiography, sEH protein was analyzed by Western blot and immunohistochemistry, and hydrolase activity and levels of EETs/DHETs were measured in brain and plasma using LC-MS/MS and ELISA, respectively. RESULTS: sEH immunoreactivity was detected in WT, but not sEHKO mouse brain, and was localized to vascular and nonvascular cells. 14,15-DHET was abundantly present in WT, but virtually absent in sEHKO mouse plasma. However, hydrolase activity and free 14,15-EET in brain tissue were not different between WT and sEHKO mice. Infarct size was significantly smaller, whereas regional cerebral blood flow rates were significantly higher in sEHKO compared to WT mice. Infarct size reduction was recapitulated by 14,15-EET infusion. However, 14,15-EEZE did not alter infarct size in sEHKO mice. CONCLUSIONS: sEH gene deletion is protective against ischemic stroke by a vascular mechanism linked to reduced hydration of circulating EETs.

Isoflurane differentially modulates inhibitory and excitatory synaptic transmission to the solitary tract nucleus.

BACKGROUND: Isoflurane anesthesia produces cardiovascular and respiratory depression, although the specific mechanisms are not fully understood. Cranial visceral afferents, which innervate the heart and lungs, synapse centrally onto neurons within the medial portion of the nucleus tractus solitarius (NTS). Isoflurane modulation of afferent to NTS synaptic communication may underlie compromised cardiorespiratory reflex function. METHODS: Adult rat hindbrain slice preparations containing the solitary tract (ST) and NTS were used. Shocks to ST afferents evoked excitatory postsynaptic currents with low-variability (SEM <200 mus) latencies identifying neurons as second order. ST-evoked and miniature excitatory postsynaptic currents as well as miniature inhibitory postsynaptic currents were measured during isoflurane exposure. Perfusion bath samples were taken in each experiment to measure isoflurane concentrations by gas chromatography-mass spectrometry. RESULTS: Isoflurane dose-dependently increased the decay-time constant of miniature inhibitory postsynaptic currents. At greater than 300 mum isoflurane, the amplitude of miniature inhibitory postsynaptic currents was decreased, but the frequency of events remained unaffected, whereas at equivalent isoflurane concentrations, the frequency of miniature excitatory postsynaptic currents was decreased. ST-evoked excitatory postsynaptic current amplitudes decreased without altering event kinetics. Isoflurane at greater than 300 mum increased the latency to onset and rate of synaptic failures of ST-evoked excitatory postsynaptic currents. CONCLUSIONS: In second-order NTS neurons, isoflurane enhances phasic inhibitory transmission via postsynaptic gamma-aminobutyric acid type A receptors while suppressing excitatory transmission through presynaptic mechanisms. These results suggest that isoflurane acts through multiple distinct mechanisms to inhibit neurotransmission within the NTS, which would underlie suppression of homeostatic reflexes.

Intestinal Metabolites Are Profoundly Altered in the Context of HLA-B27 Expression and Functionally Modulate Disease in a Rat Model of Spondyloarthritis.

OBJECTIVE: HLA-B27-associated spondyloarthritides are associated with an altered intestinal microbiota and bowel inflammation. We undertook this study to identify HLA-B27-dependent changes in both host and microbial metabolites in the HLA-B27/ß2 -microglobulin (ß2 m)-transgenic rat and to determine whether microbiota-derived metabolites could impact disease in this major model of spondyloarthritis. METHODS: Cecal contents were collected from Fischer 344 33-3 HLA-B27/ß2 m-transgenic rats and wild-type controls at 6 weeks (before disease) and 16 weeks (with active bowel inflammation). Metabolomic profiling was performed by high-throughput gas and liquid chromatography-based mass spectrometry. HLA-B27/ß2 m-transgenic rats were treated with the microbial metabolites propionate or butyrate in drinking water for 10 weeks, and disease activity was subsequently assessed. RESULTS: Our screen identified 582 metabolites, of which more than half were significantly altered by HLA-B27 expression at 16 weeks. Both microbial and host metabolites were altered, with multiple pathways affected, including those for amino acid, carbohydrate, xenobiotic, and medium-chain fatty acid metabolism. Differences were even observed at 6 weeks, with up-regulation of histidine, tyrosine, spermidine, N-acetylmuramate, and glycerate in HLA-B27/ß2 m-transgenic rats. Administration of the short-chain fatty acid propionate significantly attenuated HLA-B27-associated inflammatory disease, although this was not associated with increased FoxP3+ T cell induction or with altered expression of the immunomodulatory cytokines interleukin-10 (IL-10) or IL-33 or of the tight junction protein zonula occludens 1. HLA-B27 expression was also associated with altered host expression of messenger RNA for the microbial metabolite receptors free fatty acid receptor 2 (FFAR2), FFAR3, and niacin receptor 1. CONCLUSION: HLA-B27 expression profoundly impacts the intestinal metabolome, with changes evident in rats even at age 6 weeks. Critically, we demonstrate that a microbial metabolite, propionate, attenuates development of HLA-B27-associated inflammatory disease. These and other microbiota-derived bioactive mediators may provide novel treatment modalities in HLA-B27-associated spondyloarthritides.

Alkoxycarbonate Ester Prodrugs of Preclinical Drug Candidate ELQ-300 for Prophylaxis and Treatment of Malaria.

ELQ-300 is a preclinical antimalarial drug candidate that is active against liver, blood, and transmission stages of Plasmodium falciparum. While ELQ-300 is highly effective when administered in a low multidose regimen, poor aqueous solubility and high crystallinity have hindered its clinical development. To overcome its challenging physiochemical properties, a number of bioreversible alkoxycarbonate ester prodrugs of ELQ-300 were synthesized. These bioreversible prodrugs are converted to ELQ-300 by host and parasite esterase action in the liver and bloodstream of the host. One such alkoxycarbonate prodrug, ELQ-331, is curative against Plasmodium yoelii with a single low dose of 3 mg/kg in a murine model of patent malaria infection. ELQ-331 is at least as fully protective as ELQ-300 in a murine malaria prophylaxis model when delivered 24 h before sporozoite inoculation at an oral dose of 1 mg/kg. Here, we show that ELQ-331 is a promising prodrug of ELQ-300 with improved physiochemical and metabolic properties and excellent potential for clinical formulation.

Effect of pregnancy on the pharmacokinetics of paclitaxel: a case report.

Breast cancer during pregnancy is increasingly common as women delay childbearing until later in life. Safe administration of adjuvant chemotherapy during pregnancy has been reported. Physiologic and metabolic changes during pregnancy could alter the pharmacokinetics of these agents. This is a pilot study to prospectively study the pharmacokinetics of chemotherapeutic agents during pregnancy. Herein, we report the initial results with paclitaxel in the first patient.

A comparison of salivary testosterone measurement using immunoassays and tandem mass spectrometry.

Enzyme immunoassays (EIAs) are widely used to measure salivary testosterone. However, little is known about how accurately different EIAs assess testosterone, partially because estimates across various EIAs differ considerably. We compared testosterone concentrations across EIAs of three commonly used manufacturers (DRG International, Salimetrics, and IBL International) to liquid chromatography tandem mass spectrometry (LC-MS/MS). Relative to EIAs from Salimetrics and IBL International, EIAs supplied by DRG International provided the closest approximation to LC-MS/MS testosterone concentrations, followed closely by EIAs from Salimetrics, and then IBL. Additionally, EIAs tended to inflate estimates of lower testosterone concentrations in women. Examining our results and comparing them to existing data revealed that testosterone EIAs had decreased linear correspondence with LC-MS/MS in comparison to cortisol EIAs. Overall, this paper provides researchers with information to better measure testosterone in their research and more accurately compare testosterone measurements across different methods.

Diphenylether-Modified 1,2-Diamines with Improved Drug Properties for Development against Mycobacterium tuberculosis.

New treatments for tuberculosis infection are critical to combat the emergence of multidrug- and extensively drug-resistant Mycobacterium tuberculosis (Mtb). We report the characterization of a diphenylether-modified adamantyl 1,2-diamine that we refer to as TBL-140, which has a minimal inhibitory concentration (MIC99) of 1.2 µg/mL. TBL-140 is effective against drug-resistant Mtb and nonreplicating bacteria. In addition, TBL-140 eliminates expansion of Mtb in cell culture infection assays at its MIC. To define the mechanism of action of this compound, we performed a spontaneous mutant screen and biochemical assays. We determined that TBL-140 treatment affects the proton motive force (PMF) by perturbing the transmembrane potential (ΔΨ), consistent with a target in the electron transport chain (ETC). As a result, treated bacteria have reduced intracellular ATP levels. We show that TBL-140 exhibits greater metabolic stability than SQ109, a structurally similar compound in clinical trials for treatment of MDR-TB infections. Combined, these results suggest that TBL-140 should be investigated further to assess its potential as an improved therapeutic lead against Mtb.

Omega-hydroxylation of farnesol by mammalian cytochromes p450.

Studies have shown that mammalian cytochromes p450 participate in the metabolism of terpenes, yet their role in the biotransformation of farnesol, an endogenous 15-carbon isoprenol, is unknown. In this report, [(14)C]-farnesol was transformed to more polar metabolites by NADPH-supplemented mammalian microsomes. In experiments with microsomes isolated from acetone-treated animals, the production of one polar metabolite was induced, suggesting catalysis by CYP2E1. The metabolite was identified as (2E, 6E, 10E)-12-hydroxyfarnesol. In studies with purified CYP2E1, 12-hydroxyfarnesol was obtained as the major product of farnesol metabolism. Among a series of available human p450 enzymes, only CYP2C19 also produced 12-hydroxyfarnesol. However, in individual human microsomes, CYP2E1 was calculated to contribute up to 62% toward total 12-hydroxyfarnesol production, suggesting CYP2E1 as the major catalyst. Mammalian cells expressing CYP2E1 demonstrated further farnesol metabolism to alpha,omega-prenyl dicarboxylic acids. Since such acids were identified in animal urine, the data suggest that CYP2E1 could be an important regulator of farnesol homeostasis in vivo. In addition, CYP2E1-dependent 12-hydroxyfarnesol formation was inhibited by pharmacological alcohol levels. Given that farnesol is a signaling molecule implicated in the regulation of tissue and cell processes, the biological activity of ethanol may be mediated in part by interaction with CYP2E1-dependent farnesol metabolism.

A phase I study of 5-fluorouracil, leucovorin, and celecoxib in patients with incurable colorectal cancer.

A phase I study of fixed-dose 5-fluorouracil (FU) and leucovorin (LCV), with excalating doses of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib, was conducted in 16 patients with advanced colorectal adenocarcinoma. At doses typically used to treat arthritis patients (100-200 mg po BID), celecoxib did not increase toxicities expected from the chemotherapy alone. 5-FU and leucovorin did not affect COX-2 inhibition by celecoxib. Preliminary data suggest it is safe to combine celecoxib with standard chemotherapeutic agents, in treatment of patients with colorectal cancer.