A positron emission tomography imaging study to confirm target engagement in the lungs of patients with idiopathic pulmonary fibrosis following a single dose of a novel inhaled αvß6 integrin inhibitor.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease with poor prognosis and a significant unmet medical need. This study evaluated the safety, pharmacokinetics (PK) and target engagement in the lungs, of GSK3008348, a novel inhaled alpha-v beta-6 (αvß6) integrin inhibitor, in participants with IPF. METHODS: This was a phase 1b, randomised, double-blind (sponsor unblind) study, conducted in the UK (two clinical sites, one imaging unit) between June 2017 and July 2018 (NCT03069989). Participants with a definite or probable diagnosis of IPF received a single nebulised dose of 1000 mcg GSK3008348 or placebo (ratio 5:2) in two dosing periods. In period 1, safety and PK assessments were performed up to 24 h post-dose; in period 2, after a 7-day to 28-day washout, participants underwent a total of three positron emission tomography (PET) scans: baseline, Day 1 (~ 30 min post-dosing) and Day 2 (~ 24 h post-dosing), using a radiolabelled αvß6-specific ligand, [18F]FB-A20FMDV2. The primary endpoint was whole lung volume of distribution (VT), not corrected for air volume, at ~ 30 min post-dose compared with pre-dose. The study success criterion, determined using Bayesian analysis, was a posterior probability (true % reduction in VT > 0%) of ≥80%. RESULTS: Eight participants with IPF were enrolled and seven completed the study. Adjusted posterior median reduction in uncorrected VT at ~ 30 min after GSK3008348 inhalation was 20% (95% CrI: - 9 to 42%). The posterior probability that the true % reduction in VT > 0% was 93%. GSK3008348 was well tolerated with no reports of serious adverse events or clinically significant abnormalities that were attributable to study treatment. PK was successfully characterised showing rapid absorption followed by a multiphasic elimination. CONCLUSIONS: This study demonstrated engagement of the αvß6 integrin target in the lung following nebulised dosing with GSK3008348 to participants with IPF. To the best of our knowledge this is the first time a target-specific PET radioligand has been used to assess target engagement in the lung, not least for an inhaled drug. TRIAL REGISTRATION: clinicaltrials.gov: NCT03069989; date of registration: 3 March 2017.

Pemafibrate, a New Selective PPARα Modulator: Drug Concept and Its Clinical Applications for Dyslipidemia and Metabolic Diseases.

PURPOSE OF REVIEW: Reduction of serum low-density lipoprotein cholesterol (LDL-C) levels by statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has been shown to significantly reduce cardiovascular events risk. However, fasting and postprandial hypertriglyceridemia as well as reduced high-density lipoprotein cholesterol (HDL-C) remain as residual risk factors of atherosclerotic cardiovascular diseases (ASCVD). To treat patients with hypertriglyceridemia and/or low HDL-C, drugs such as fibrates, nicotinic acids, and n-3 polyunsaturated fatty acids have been used. However, fibrates were demonstrated to cause side effects such as liver dysfunction and increase in creatinine levels, and thus large-scale clinical trials of fibrates have shown negative results for prevention of ASCVD. The failure could be attributed to their low selectivity and potency for binding to peroxisome proliferator-activated receptor (PPAR) α. To resolve these issues, the concept of selective PPARα modulator (SPPARMα) with a superior balance of efficacy and safety has been proposed and pemafibrate (K-877) has been developed. RECENT FINDINGS: Pemafibrate, one of SPPARMsα, was synthesized by Kowa Company, Ltd. for better efficiency and safety. Clinical trials in Japan have established the superiority of pemafibrate on effects on serum triglycerides (TG) reduction and HDL-C elevation as well safety. Although available fibrates showed worsening of liver and kidney function test values, pemafibrate indicated improved liver function test values and was less likely to increase serum creatinine or decrease estimated glomerular filtration rate (eGFR). Very few drug-drug interactions were observed even when used concomitantly with statins. Furthermore, pemafibrate is metabolized in the liver and excreted into the bile, while many of available fibrates are mainly excreted from the kidney. Therefore, pemafibrate can be used safely even in patients with impaired renal function since there is no significant increase in its blood concentration. A large-scale trial of pemafibrate, PROMINENT, for dyslipidemic patients with type 2 diabetes is ongoing. Pemafibrate is one of novel SPPARMsα and has superior benefit-risk balance compared to conventional fibrates and can be applicable for patients for whom the usage of existing fibrates is difficult such as those who are taking statins or patients with renal dysfunction. In the current review, all the recent data on pemafibrate will be summarized.

Modelled plasma concentrations of pemafibrate with co-administered typical cytochrome P450 inhibitors clopidogrel, fluconazole or clarithromycin predicted by physiologically based pharmacokinetic modelling in virtual populations.

Oral antidyslipidaemic drug pemafibrate is cleared from human plasma via hepatic uptake by organic anion transporting polypeptide (OATP) 1B1 and oxidation by cytochromes P450 (P450) 2C8, 2C9 and 3A4. The pharmacokinetic profiles of pemafibrate with virtual administrations of P450 inhibitors and/or disease interactions were generated using a physiologically based pharmacokinetic (PBPK) model previously established for co-administration of pemafibrate with OATP1B1 inhibitors. This PBPK model was validated in the current study using reported maximum pemafibrate plasma concentrations and areas under the curve from interaction studies in healthy subjects co-administered with clopidogrel (P450 2C8 inhibitor), fluconazole (P450 2C9/3A4 inhibitor) or clarithromycin (P450 3A4 inhibitor). Virtual co-administrations of pemafibrate with clopidogrel, fluconazole or clarithromycin increased the predicted plasma exposures of pemafibrate 1.4-1.7-fold, 1.2-1.4-fold and 2.9-11-fold, respectively, in subjects with or without moderate or severe renal impairment or Child-Pugh A or B liver cirrhosis. Some of the exposure-enhancing effects of clarithromycin may originate from its inhibitory potential toward OATP1B1, because the estimated effects of itraconazole (a P450 3A4 inhibitor) were only minor. Simulations using the current PBPK model in groups of virtual subjects with or without renal or hepatic impairment revealed modified pharmacokinetic profiles for pemafibrate following co-administration of typical P450 inhibitors.

Pharmacokinetics and metabolism of pemafibrate, a novel selective peroxisome proliferator-activated receptor-alpha modulator, in rats and monkeys.

The metabolic profiles and pharmacokinetics of pemafibrate, a novel selective peroxisome proliferator activated receptor-alpha modulator currently launched as an antidyslipidemic drug, were investigated in vitro using hepatocytes from rats, monkeys and humans and in vivo in rats and monkeys. Hepatocytes from rats, monkeys and humans all biotransformed pemafibrate to its demethylated form (M1). The bioavailabilities of pemafibrate in Sprague-Dawley rats and cynomolgus monkeys were 15% and 87%, respectively, after a single oral administration of pemafibrate (1 mg/kg). In rat plasma, unmetabolized pemafibrate was the major form, accounting for 29% of the area under the curve (AUC) of total radioactivity. In monkey plasma, in contrast, the major circulating metabolites were M2/3 (dearylated/dicarboxylic acid forms, 15%), M4 (N-dealkylated form, 21%) and M5 (benzylic oxidative form, 9%), but pemafibrate was the notable minor form (3%). These results, in combination with the reported findings in humans, suggest that the metabolite profile of pemafibrate in plasma was different for rats and monkeys, and that monkeys could be a suitable animal model for further pharmacokinetic studies of pemafibrate in humans.

Safety, tolerability and pharmacokinetics of GSK3008348, a novel integrin αvß6 inhibitor, in healthy participants.

PURPOSE: Inhaled drug delivery is an attractive route by which to deliver drugs to lungs of patients with idiopathic pulmonary fibrosis (IPF). GSK3008348 is a potent and selective small molecule being developed as the first inhaled inhibitor of the αvß6 integrin for the treatment of IPF. The phase 1 first-time-in-human clinical trial (NCT02612051) presented here was designed to investigate the safety, tolerability and pharmacokinetic (PK) profile of single doses of GSK3008348 in healthy participants. METHODS: Single ascending doses of GSK3008348 were administered to three cohorts of eight healthy participants in a randomised, double-blind, placebo-controlled, 4-period crossover design. Safety, tolerability and PK were assessed after single doses of 1-3000 mcg given by nebulisation. RESULTS: A total of 29 participants were enrolled and received at least one dose of study treatment. There were no serious adverse events (AE) reported in any participant. No trends or clinically important differences were noted in the incidence or intensity of AEs or other safety assessments. Maximum plasma concentrations of GSK3008348 were generally attained within approximately 30 min after start of nebulisation, with geometric mean terminal elimination half-lives ranging from 7.95 to 10.2 h. Exposures, as measured by area under the plasma concentration-time curve (AUC), were dose proportional across all doses where estimates were possible (100-3000 mcg). Dose normalised geometric mean Cmax increased with dose up to 3000 mcg. This supra proportionality was relatively modest, with a less than 3-fold increase over the range from 30 to 3000 mcg. The reason(s) for this observation are currently not known but may be due to slower absorption at the lowest doses. All exposures were within the exposure margins set by the non-clinical toxicity studies and so this is not expected to have any impact on safety. CONCLUSIONS: In summary, GSK3008348 was well tolerated at single doses up to 3000 mcg in healthy participants, and its PK profile was dose proportional at potentially clinically relevant doses (300-3000 mcg). These findings support further development of GSK3008348 as a novel inhaled treatment option for IPF.

Natural Korean Medicine Dang-Gui: Biosynthesis, Effective Extraction and Formulations of Major Active Pyranocoumarins, Their Molecular Action Mechanism in Cancer, and Other Biological Activities.

Angelica gigas Nakai (AGN) is a crucial oriental medicinal herb that grows especially in Korea and the Far-East countries. It contains chemically active compounds like pyranocoumarins, polyacetylenes and essential oils, which might be useful for treatment of several chronic diseases. It has been used for centuries as a traditional medicine in Southeast Asia, but in Western countries is used as a functional food and a major ingredient of several herbal products. The genus Angelica is also known as 'female ginseng' due to its critical therapeutic role in female afflictions, such as gynecological problems. However, it is well-documented that the AGN pyranocoumarins may play vital beneficial roles against cancer, neurodisorders, inflammation, osteoporosis, amnesia, allergies, depression, fungi, diabetes, ischemia, dermatitis, reactive oxygen species (ROS) and androgen. Though numerous studies revealed the role of AGN pyranocoumarins as therapeutic agents, none of the reviews have published their molecular mechanism of action. To the best of our knowledge, this would be the first review that aims to appraise the biosynthesis of AGN's major active pyranocoumarins, discuss effective extraction and formulation methods, and detail the molecular action mechanism of decursin (D), decursinol angelate (DA) and decursinol (DOH) in chronic diseases, which would further help extension of research in this area.

Safety, pharmacokinetics and pharmacodynamics of GLPG0974, a potent and selective FFA2 antagonist, in healthy male subjects.

AIMS: Free fatty acids (FFA) can act as direct signalling molecules through activation of several membrane-bound G-protein coupled receptors. The FFA2 receptor (known as GPR43) is activated by short chain fatty acids (SCFA) such as acetate and has been shown to play a major role in SCFA-induced neutrophil activation and migration and to contribute in the development and control of inflammation. GLPG0974 is a potent and selective antagonist of the human FFA2. The main objectives of the two phase 1 trials were to characterize the safety, tolerability, pharmacokinetics and pharmacodynamics of GLPG0974. METHODS: Two consecutive randomized, double-blind, placebo-controlled, single centre trials in healthy subjects were performed. In the first, GLPG0974 was administered as single doses up to 250 mg and in the second, multiple daily doses up to 400 mg for 14 days were evaluated. Non-compartmental analysis was used to determine GLPG0974 pharmacokinetics while target engagement was investigated through the inhibition of neutrophils in acetate-simulated whole blood samples using surface expression of CD11b activated epitope as a marker of neutrophil activation. RESULTS: The investigation of safety/tolerability and pharmacokinetics in the early development phase showed that GLPG0974 was safe and well tolerated up to a daily dose of 400 mg. GLPG0974 showed good and dose proportional exposure up to 400 mg daily as well as a substantial and sustained inhibition of acetate-stimulated neutrophil activation. CONCLUSION: Based on these results, a proof-of-concept study was initiated to evaluate the safety, tolerability and efficacy of GLPG0974 in patients with mild to moderate ulcerative colitis.

[Simultaneous determination of clevidipine butyrate and its metabolite clevidipine acid in dog blood by liquid chromatography-tandem mass spectrometry].

A rapid, sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of clevidipine butyrate and its primary metabolite clevidipine acid in dog blood. After one-step protein precipitation with methanol, the chromatographic separation was carried out on an Ecosil C18 column (150 mm x 4.6 mm, 5 µm) with a gradient mobile phase consisting of methanol and 5 mmol · L(-1) ammonium formate. A chromatographic total run time of 13.0 min was achieved. The quantitation analysis was performed using multiple reaction monitoring (MRM) at the specific ion transitions of m/z 454.1 [M-H]- --> m/z 234.1 for clevidipine butyrate, m/z 354.0 [M-H]- --> m/z 208.0 for clevidipine acid and m/z 256.1 [M-H]- --> m/z 227.1 for elofesalamide (internal standard, IS) in the negative ion mode with electrospray ionization (ESI) source. The linear calibration curves for clevidipine butyrate and clevidipine acid were obtained in the concentration ranges of 0.5-100 ng · mL and 1-200 ng · mL(-1), separately. The lower limit of quantification of clevidipine butyrate and clevidipine acid were 0.5 ng · mL(-1) and 1 ng · mL(-1). The intra and inter-assay precisions were all below 12.9%, the accuracies were all in standard ranges. Stability testing indicated that clevidipine butyrate and clevidipine acid in dog blood with the addition of denaturant methanol was stable under various processing and/or handling conditions. The validated method has been successfully applied to a pharmacokinetic study of clevidipine butyrate injection to 8 healthy Beagle dogs following intravenous infusion at a flow rate of 5 mg · h(-1) for 0.5 h.

Hyperpolarized butyrate: a metabolic probe of short chain fatty acid metabolism in the heart.

PURPOSE: Butyrate, a short chain fatty acid, was studied as a novel hyperpolarized substrate for use in dynamic nuclear polarization enhanced magnetic resonance spectroscopy experiments, to define the pathways of short chain fatty acid and ketone body metabolism in real time. METHODS: Butyrate was polarized via the dynamic nuclear polarization process and subsequently dissolved to generate an injectable metabolic substrate. Metabolism was initially assessed in the isolated perfused rat heart, followed by evaluation in the in vivo rat heart. RESULTS: Hyperpolarized butyrate was generated with a polarization level of 7% and was shown to have a T1 relaxation time of 20 s. These physical characteristics were sufficient to enable assessment of multiple steps in its metabolism, with the ketone body acetoacetate and several tricarboxylic acid cycle intermediates observed both in vitro and in vivo. Metabolite to butyrate ratios of 0.1-0.4% and 0.5-2% were observed in vitro and in vivo respectively, similar to levels previously observed with hyperpolarized [2-(13) C]pyruvate. CONCLUSIONS: In this study, butyrate has been demonstrated to be a suitable hyperpolarized substrate capable of revealing multi-step metabolism in dynamic nuclear polarization experiments and providing information on the metabolism of fatty acids not currently achievable with other hyperpolarized substrates.

Characterization of butyrate transport across the luminal membranes of equine large intestine.

The diet of the horse, pasture forage (grass), is fermented by the equine colonic microbiota to short-chain fatty acids, notably acetate, propionate and butyrate. Short-chain fatty acids provide a major source of energy for the horse and contribute to many vital physiological processes. We aimed to determine both the mechanism of butyrate uptake across the luminal membrane of equine colon and the nature of the protein involved. To this end, we isolated equine colonic luminal membrane vesicles. The abundance and activity of cysteine-sensitive alkaline phosphatase and villin, intestinal luminal membrane markers, were significantly enriched in membrane vesicles compared with the original homogenates. In contrast, the abundance of GLUT2 protein and the activity of Na(+)-K(+)-ATPase, known markers of the intestinal basolateral membrane, were hardly detectable. We demonstrated, by immunohistochemistry, that monocarboxylate transporter 1 (MCT1) protein is expressed on the luminal membrane of equine colonocytes. We showed that butyrate transport into luminal membrane vesicles is energized by a pH gradient (out < in) and is not Na(+) dependent. Moreover, butyrate uptake is time and concentration dependent, with a Michaelis-Menten constant of 5.6 ± 0.45 mm and maximal velocity of 614 ± 55 pmol s(-1) (mg protein)(-1). Butyrate transport is significantly inhibited by p-chloromercuribenzoate, phloretin and α-cyano-4-hydroxycinnamic acid, all potent inhibitors of MCT1. Moreover, acetate and propionate, as well as the monocarboxylates pyruvate and lactate, also inhibit butyrate uptake. Data presented here support the conclusion that transport of butyrate across the equine colonic luminal membrane is predominantly accomplished by MCT1.

Development of a pharmacokinetic/pharmacodynamic/disease progression model in NC/Nga mice for development of novel anti-atopic dermatitis drugs.

1. JHL45, a novel immune modulator against atopic dermatitis (AD), was synthesized from decursin isolated from Angelica gigas. The goal is to evaluate the lead compound using quantitative modeling approaches to novel anti-AD drug development. 2. We tested the anti-inflammatory effect of JHL45 by in vitro screening, characterized its in vitro pharmacokinetic (PK) properties. The dose-dependent efficacy of JHL45 was developed using a pharmacokinetics/pharmacodynamics/disease progression (PK/PD/DIS) model in NC/Nga mice. 3. JHL45 has drug-like properties and pharmacological effects when administered orally to treat atopic dermatitis. The developed PK/PD/DIS model described well the rapid metabolism of JHL45, double-peak phenomenon in the PK of decursinol and inhibition of IgE generation by compounds in NC/Nga mice. Also, a quantitative model was developed and used to elucidate the complex interactions between serum IgE concentration and atopic dermatitis symptoms. 4. Our findings indicate that JHL45 has good physicochemical properties and powerful pharmacological effects when administered orally for treatment of AD in rodents.

Enhanced oral and pulmonary delivery of biomacromolecules via amplified transporter targeting.

Ligand-modified nanocarriers can promote oral or inhalative administration of macromolecular drugs across the intestinal or pulmonary mucosa. However, enhancing the unidirectional transport of the nanocarriers through "apical uptake→intracellular transport→basolateral exocytosis" route remains a hot topic and challenge in current research. Forskolin is a naturally occurring diterpenoid compound extracted from the roots of C. forskohlii. In our studies, we found that forskolin could increase the transcellular transport of butyrate-modified nanoparticles by 1.67-fold and 1.20-fold in Caco-2 intestinal epithelial cell models and Calu-3 lung epithelial cell models, respectively. Further mechanistic studies revealed that forskolin, on the one hand, promoted the cellular uptake of butyrate-modified nanoparticles by upregulating the expression of monocarboxylic acid transporter-1 (MCT-1) on the apical membrane. On the other hand, forskolin facilitated the binding of MCT-1 to caveolae, thereby mediating butyrate-modified nanoparticles hijacking caveolae to promote the basolateral exocytosis of butyrate-modified nanoparticles. Studies in normal mice model showed that forskolin could promote the transmucosal absorption of butyrate-modified nanoparticles by >2-fold, regardless of oral or inhalative administration. Using semaglutide as the model drug, both oral and inhalation delivery approaches demonstrated significant hypoglycemic effects in type 2 diabetes mice model, in which inhalative administration was more effective than oral administration. This study optimized the strategies aimed at enhancing the transmucosal absorption of ligand-modified nanocarriers in the intestinal or pulmonary mucosa.

A dose-escalation phase IIa study of 2,2-dimethylbutyrate (HQK-1001), an oral fetal globin inducer, in sickle cell disease.

2,2-Dimethylbutyrate (HQK-1001), an orally-bioavailable promoter-targeted fetal globin gene-inducing agent, was evaluated in an open-label, randomized dose-escalation study in 52 subjects with hemoglobin SS or S/ß(0) thalassemia. HQK-1001 was administered daily for 26 weeks at 30 mg/kg (n = 15), 40 mg/kg (n = 18) and 50 mg/kg (n = 19), either alone (n = 21) or with hydroxyurea (n = 31). The most common drug-related adverse events were usually mild or moderate and reversible. Gastritis was graded as severe in three subjects at 40 mg/kg and was considered the dose-limiting toxicity. Subsequently all subjects were switched to the maximum tolerated dose of 30 mg/kg. Due to early discontinuations for blood transfusions, adverse events or non-compliance, only 25 subjects (48%) completed the study. Drug plasma concentrations were sustained above targeted levels at 30 mg/kg. Increases in fetal hemoglobin (Hb F) were observed in 42 subjects (80%), and 12 (23%) had increases ≥4%. The mean increase in Hb F was 2% [95% confidence interval (CI), 0.8-3.2%] in 21 subjects receiving HQK-1001 alone and 2.7% (95% CI, 1.7-3.8%) in 31 subjects receiving HQK-1001 plus hydroxyurea. Total hemoglobin increased by a mean of 0.65 g/dL (95% CI, 0.5-1.0 g/dL), and 13 subjects (25%) had increases ≥1 g/dL. Future studies are warranted to evaluate the therapeutic potential of HQK-1001 in sickle cell disease. .

Comparative study of a new organic selenium source v. seleno-yeast and mineral selenium sources on muscle selenium enrichment and selenium digestibility in broiler chickens.

Two experiments were conducted on broiler chickens to compare the effect of a new organic Se source, 2-hydroxy-4-methylselenobutanoic acid (HMSeBA; SO), with two practical Se additives, sodium selenite (SS) and Se yeast (SY). The relative bioavailability of the different Se sources was compared on muscle (pectoralis major) total Se, selenomethionine (SeMet) and selenocysteine (SeCys) concentrations and apparent digestibility of total Se (ADSe). In the first experiment, from day (d) 0 to d21, Se sources were tested at different supplied levels and compared with an unsupplemented diet (NC). No significant effects were observed on growth performance during the experimental period. However, the different Se sources and levels improved muscle Se concentration compared with the NC, with a significant source effect in the following order: SS < SY < SO (P<0·05). Seleno-amino acids speciation results for NC, SY and SO at 0·3 mg Se/kg feed indicated that muscle Se was only present as SeMet or SeCys, showing a full conversion of Se by the bird. The second experiment (d0-d24) compared SS, SY or SO at 0·3 mg Se/kg feed. The ADSe measurements carried out between d20 and d23 were 24, 46 and 49% for SS, SY and SO, respectively, with significant differences between the organic and mineral Se sources (P<0·05). These results confirmed the higher bioavailability of organic Se sources compared with the mineral source and demonstrated a significantly better efficiency of HMSeBA compared with SY for muscle Se enrichment.

Calcium bioavailability of calcium L-threonate in healthy Chinese subjects measured with stable isotopes (44Ca and 4²Ca).

PURPOSE: Calcium L-threonate is a novel drug that was developed for the treatment of osteoporosis and as a calcium supplement. However, calcium bioavailability of this drug is unknown due to lack of effective evaluation methods. In this study, we sought to measure the bioavailability of calcium L-threonate with a double-label stable isotope method. METHODS: Fourteen healthy Chinese subjects were enrolled in the clinical study and were given 300 mg calcium L-threonate tablets containing 40 mg (44)Ca after an intravenous injection of 4 mg (42)Ca solution (as calcium chloride). Fractional urine samples were collected at the following time intervals: 0-3, 3-6, 6-9, 9-13, 13-24, 24-36 and 36-48 h. The abundance ratios of (44)Ca/(40)Ca and (42)Ca/(40)Ca in the urine were determined with thermal-ionization mass spectrometry (TI-MS). The calcium bioavailability was estimated by calculating the true fractional calcium absorption (TFCA) using the abundance ratios of (44)Ca/(40)Ca and (42)Ca/(40)Ca. RESULTS: The bioavailability of calcium L-threonate in 14 healthy Chinese subjects was 26.49 ± 9.39 %. There was good agreement between TFCA from the 24 to 36 h and the 36 to 48 h urine pool, indicating that calcium balance was achieved at 24 h after dosing. The TFCA of the subjects did not statistically correlate with total urinary calcium excretion (0-48 h). There were no serious adverse events in this study. CONCLUSIONS: The bioavailability of calcium L-threonate in humans was successfully determined by estimating TFCA with the double-label stable isotope method, thus providing a useful approach for the evaluation of bioavailability of calcium formulations.

Single oral dose pharmacokinetics of decursin, decursinol angelate, and decursinol in rats.

Decursin and decursinol angelate are the major components in the alcoholic extract of the root of Angelica gigas Nakai. Our previous work convincingly demonstrated that both decursin and decursinol angelate were rapidly converted to decursinol in mice after administration by either oral gavage or i. p. injection. In the current study, we compared for the first time the plasma profiles of decursinol, when equal moles of decursin/decursinol angelate or decursinol were given to rats by oral gavage, and investigated the effect of different formulas and other chemicals in Angelica gigas extract on the bioavailability of decursinol. Our results show that gavage of decursinol led to a faster attainment of plasma decursinol peak (Tmax ~ 0.7 h) and much higher peak levels than an equal molar amount administered as decursin/decursinol angelate mixture or as Angelica gigas ethanol extract, resulting in 2-3 fold higher bioavailability as estimated by the area under the curve of the respective regimens (65 012 vs. 27 033 h · ng/mL for decursinol and decursin/decursinol angelate treatment groups, respectively). Compared to a formula based on ethanol-PEG400-Tween80, carboxyl methyl cellulose was a less optimized vehicle. In addition, we detected peak levels of decursin and decursinol angelate in the plasma of rats administered with decursin/decursinol angelate or Angelica gigas extract in the nM range (Tmax ~ 0.5 h) with a newly established sensitive UHPLC-MS/MS method. Furthermore, our data support the liver, instead of intestine, as a major organ site where decursin and decursinol angelate were hydrolyzed to decursinol with a S9 microsomal in vitro metabolism assay. Taken together, our study provided important PK, LC-MS/MS methodology, formulation and metabolism insights in a rodent model for the rational design of in vivo efficacy studies of the corresponding chemicals in the future.

Biopharmaceutical characterization of decursin and their derivatives for drug discovery.

Angelica gigas Nakai and its components are known to have neuroprotective, antiplatelet, and anticancer activities. The present study evaluated the in vitro and in vivo biopharmaceutical characterization of Angelica gigas component substances, including decursin (the main substance), decursinol angelate (decursin isomer), JH714 (ether form of decursin) and epoxide decursin (epoxide form of decursin). Decursin, decursinol angelate and JH714 exhibited acceptable metabolic stability (>50%) in liver microsomes from human and higher bound fraction (>90%) in human plasma operating ultrafiltration. Decursin and decursinol angelate in CYP1A2 and CYP2C19 indicated less than 50% CYP activity, suggesting inhibition of the CYP isoforms using Vivid® CYP screening kit. JH714 only showed an apparent permeability coefficient of <10 × 10⁻6 cm/s in MDCK cells, suggesting that it is poorly absorbed. Blood brain barrier permeability was examined after oral administration to male Sprague-Dawley (SD) rats, and pharmacokinetic studies were performed after oral and intravenous administration of 10 mg/kg compounds. Decursin, decursinol angelate and JH714 showed ratios of compound concentration in brain with respect to plasma (Cbrain/Cplasma) of >1.5, suggesting good brain/plasma ratio at 0.5, 1, 3, and 5 h. In contrast, Cbrain/Cplasma was <0.5 for epoxide decursin. For all test compounds, >1.5% of the dose remained in GI tract after 8 h, and the excretion rate in urine was <0.5% which suggests that gastro intestinal tract may be major site of disposition following oral administration. Finally, these results may be useful for the design of dosage regimens of decursin and its derivatives.

A phase 1/2 trial of HQK-1001, an oral fetal globin inducer, in sickle cell disease.

Therapeutics which reduce the pathology in sickle cell syndromes are needed, particularly noncytotoxic therapeutics. Fetal hemoglobin (HbF, α(2) γ(2) ) is established as a major regulator of disease severity; increased HbF levels correlate with milder clinical courses and improved survival. Accordingly, sodium dimethylbutyrate (HQK-1001), an orally-bioavailable, promoter-targeted fetal globin gene-inducing agent, was evaluated in a randomized, blinded, dose-ranging Phase I/II trial in 24 adult patients with HbSS or S/ß thalassemia, to determine safety and tolerability of three escalating dose levels. The study therapeutic was administered once daily for two 6-week cycles, with a two-week interim dose holiday. Twenty-one patients completed the study. Five patients received study drug at 10 or 20 mg/kg doses, seven patients received study drug at 30 mg/kg/dose, and 4 patients received placebo. HQK-1001 was well-tolerated with no unexpected drug-related adverse events; a dose-limiting toxicity was not identified. Plasma drug levels were sustained above targeted levels for 24 hr. Increases in HbF above baseline were observed particularly with 30 mg/kg/day doses; in five of seven treated patients, a mean absolute increase in HbF of 0.2 g/dl and a mean increase in total hemoglobin (Hgb) of 0.83 g/dl above baseline were observed, whereas no increases occurred in placebo-treated controls. These findings of favorable PK profiles, tolerability, early rises in HbF, and total Hgb indicate that trials of longer duration appear warranted to more definitively evaluate the therapeutic potential of HQK-1001 in sickle cell disease.

First-pass metabolism of decursin, a bioactive compound of Angelica gigas, in rats.

Decursin is considered the major bioactive compound of Angelica gigas roots, a popular Oriental herb and dietary supplement. In this study, the pharmacokinetics of decursin and its active metabolite, decursinol, were evaluated after the administration of decursin in rats. The plasma concentration of decursin decreased rapidly, with an initial half-life of 0.05 h. It was not detectable at 1 h after intravenous administration at an area under the plasma concentration-time curve of 1.20 µg · mL-1·h, whereas the concentration of decursinol increased rapidly reaching a maximum concentration of 2.48 µg · mL-1 at the time to maximum plasma concentration of 0.25 h and an area under the plasma concentration-time curve of 5.23 µg · mL-1·h. Interestingly, after oral administration of decursin, only decursinol was present in plasma, suggesting an extensive hepatic first-pass metabolism of decursin. The extremely low bioavailability of decursin after its administration via the hepatic portal vein (the fraction of dose escaping first-pass elimination in the liver, FH = 0.11) is indicative of extensive hepatic first-pass metabolism of decursin, which was confirmed by a tissue distribution study. These findings suggest that decursin is not directly associated with the bioactivity of A. gigas and that it may work as a type of natural prodrug of decursinol.

Quantitative determination of decursin, decursinol angelate, and decursinol in mouse plasma and tumor tissue using liquid-liquid extraction and HPLC.

The pyranocoumarin compound decursin and its isomer decursinol angelate (DA) are the major hydrophobic phytochemicals in the root of Angelica gigas Nakai (AGN, Korean Angelica), a major traditional medicinal herb. The ethanol extract of AGN and especially the purified decursin and DA have been shown to exhibit antitumor activities by our collaborative team and others. Although decursinol has been identified as a major hydrolysis metabolite of decursin and DA in vivo in previous pharmacokinetic studies with mouse and rat, other recently published results sharply disputed this conclusion. In this study, we set up a practical method for the concurrent analysis of decursin, DA, and decursinol in mouse plasma and tumor tissues by liquid-liquid extraction and HPLC-UV and applied the method to several animal experiments. Plasma or tumor homogenate was extracted directly with ethyl acetate. The extraction efficiency for decursin/DA (quantitated together) and decursinol was between 82-95 % in both mouse plasma and tumor homogenate. The lower limit of quantitation (LLOQ) was approximately 0.25 µg/mL for decursin/DA and 0.2 µg/mL for decursinol in mouse plasma. In a pilot pharmacokinetic study, male C57BL/6 mice were given a single dose of 4.8 mg decursin/DA mixture (~240 mg/kg) per mouse either by oral gavage or intraperitoneal injection. Maximum plasma concentrations for decursin/DA and decursinol were 11.2 and 79.7 µg/mL, respectively, when decursin/DA was administered via intraperitoneal injection, and 0.54 and 14.9 µg/mL via oral gavage. Decursin/DA and decursinol contents in the tumor tissues from nude mouse xenografts correlated very well with those in plasma. Overall, our results confirm the conclusion that the majority of decursin/DA hydrolyze to decursinol in rodent models with a tiny fraction remaining as the intact compounds administered.