Publications by authors named "WonKu Kang"

Propolis is a natural resinous substance made by bees through mixing various plant sources. Propolis has been widely recognized as a functional food due to its diverse range of beneficial bioactivities. However, the therapeutic effects of consuming propolis against atopic dermatitis (AD) remain largely unknown.

View Article and Find Full Text PDF

Dexamethasone eye implant has been used to treat macular edema and non-infectious uveitis. To date, its ocular pharmacokinetics are not fully characterized, and the development of generic preparations is in progress, as the patent of the original brand expires soon. Therefore, this work was designed to 1) determine the time course of vitreous dexamethasone concentrations following intravitreal implantation in rabbits and 2) explore the alternative use of NDF-SI01 from a pharmacokinetic point of view compared to Ozurdex, which is currentlyused in the market.

View Article and Find Full Text PDF

Although systemic exposure to peptides, such as Gly-Pro-Hyp, Pro-Hyp, and Gly-Pro, has been reported following administration of collagen hydrolysates from fish scale and porcine skin in vivo, the individual peptide pharmacokinetics remain unknown. We administered the three peptides individually to rats via the intravenous (5 mg/kg) and intragastric (100 mg/kg) routes and then monitored systemic exposure and urinary excretion. The peptides in biological samples were analyzed via liquid chromatography/tandem mass spectrometry.

View Article and Find Full Text PDF

Kinetin riboside is a naturally produced cytokinin that displays strong antiproliferative activity in various human cancer cells. However, the mechanism of chemoprevention in colorectal cancer cells has not been elucidated. We used a cell-based reporter system to identify kinetin riboside as an antagonist of the Wnt/β-catenin pathway, which is aberrantly upregulated in colorectal cancer.

View Article and Find Full Text PDF

Although xanthorrhizol, a sesquiterpenoid oil obtained from the rhizome of Roxb., known as Java turmeric, has many pharmacological effects, its pharmacokinetics remain unclear. Therefore, we investigated the pharmacokinetics of xanthorrhizol in mice and rats.

View Article and Find Full Text PDF

Although ICG-001, chemically synthesised from a bicyclic β-turn peptidomimetic template, represents various pharmacological activities, no validated determination methods in biological samples have been reported. This study was designed to establish a quantitative determination method for ICG-001 in rat plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) to validate the analytical method, including stability, and to characterise its pharmacokinetic behaviour in rats. After simple protein precipitation with acetonitrile, ICG-001 was eluted on a reversed-phase column using a mobile phase of water and acetonitrile (3:7 v/v, including 0.

View Article and Find Full Text PDF

Boesenbergia pandurata and its major active ingredient, panduratin A (PAN), exhibit antibacterial, anti-oxidant, anti-inflammatory, and anti-obesity effects. We explored the time course of the plasma and tissue (in the major organs, gums and skin) concentrations of PAN after oral administration of a B. pandurata extract to rats.

View Article and Find Full Text PDF

Lung cancer has the highest incidence and mortality rates among all types of cancer worldwide, and 80%-85% of patients with lung cancer are diagnosed with non-small cell lung cancer (NSCLC), which has 5-year survival rate of only 5% at advanced stages. Development of new therapeutic agents and strategies is required to enhance the treatment efficiency in patients with NSCLC. Metabolic alterations and anticancer effects of plant hormones and their derivatives have not been investigated in NSCLC in vitro and in vivo.

View Article and Find Full Text PDF

Among essential phytohormones playing a pivotal role in regulating growth and development, ortho-topolin riboside (oTR) exerts the most substantial anti-tumor potency in various cancer cell lines. This study was designed to establish a quantitative determination method for oTR in mouse plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), to validate the analytical method including stability, and to characterise its pharmacokinetic behaviour in mice. After simple protein precipitation with acetonitrile including kinetin riboside (internal standard), oTR was eluted on a reversed-phase column using a mobile phase of water and acetonitrile (3:7 v/v, including 0.

View Article and Find Full Text PDF

A protein precipitation technique was optimized to produce biophysically stable 'protein microbeads', applicable to highly concentrated protein formulation. Initially, production of BSA microbeads was performed using rapid dehydration by vortexing in organic solvents followed by cold ethanol treatment and a vacuum drying. Out of four solvents, n-octanol produced the most reversible microbeads upon reconstitution.

View Article and Find Full Text PDF

Fluoxetine is a selective serotonin reuptake inhibitor that is metabolized to norfluoxetine by cytochrome P450 (CYP) 2D6, CYP2C19, and CYP3A4. A physiologically based pharmacokinetic model for fluoxetine and norfluoxetine metabolism was developed to predict and investigate changes in concentration-time profiles according to fluoxetine dosage in the Korean population. The model was developed based on the Certara repository model and information gleaned from the literature.

View Article and Find Full Text PDF

SG-SP1, a newly synthesised gallic acid derivative, blocks histamine release by reducing calcium influx in mast cells and inhibits inflammatory cytokine expression. This derivative has promising anti-allergic potential. Our research was designed to establish a quantitative determination method for SG-SP1 in rat plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), to validate the analytical method including stability and to characterise its pharmacokinetic behaviour in rats.

View Article and Find Full Text PDF

Shikimic acid, a critical starting material for the semi-total synthesis of oseltamivir to treat and prevent influenza, exerts many pharmacological effects. However, the optimal bioanalytical method has not been adequately defined. We used liquid chromatography-tandem mass spectrometry to quantitate shikimic acid in rat plasma and studied its pharmacokinetics after intragastric and intravenous administration.

View Article and Find Full Text PDF

Neovascular age-related macular degeneration (nAMD) is a common cause of irreversible vision loss in the elderly. Anti-vascular endothelial growth factor has been effective in treating pathological ocular neovascularization, but it has limitations including the need for repeated intraocular injections for the maintenance of therapeutic effects in most patients and poor or non-response to this agent in some patients. in vitro cellular studies were conducted using retinal pigment epithelial cell lines (ARPE-19 and hTERT-RPE1), human umbilical vein endothelial cells (HUVECs), and human umbilical vein smooth muscle cells (HUVSMCs).

View Article and Find Full Text PDF

CGK012 is a newly synthesized pyranocoumarin substance suppressing the activation and transcription of β-catenin related to Wnt3a-CM. A bioanalytical method for CGK012 was developed and validated in rat plasma, and the method was applied to determine the plasma concentrations after intravenous administration. Plasma was cleaned-up by protein precipitation by acetonitrile including an internal standard.

View Article and Find Full Text PDF

Glial cells are the resident immune cells of the central nervous system. Reactive glial cells release inflammatory mediators that induce neurotoxicity or aggravate neurodegeneration. Regulation of glial activation is crucial for the initiation and progression of neuropathological conditions.

View Article and Find Full Text PDF

Duloxetine (DLX) is a potent drug investigated for the treatment of depression and urinary incontinence. DLX is extensively metabolized in the liver by two P450 isozymes, CYP2D6 and CYP1A2. Propolis (PPL) is one of the popular functional foods known to have effects on activities of CYPs, including CYP1A2.

View Article and Find Full Text PDF

It can be difficult to identify health/functional foods that exert therapeutic benefits for alleviating gingivitis and periodontitis. Recently, extracts of (Roxb.), which is a tropical plant, have shown promising inhibitory activity against lipopolysaccharide-induced periodontitis.

View Article and Find Full Text PDF

As the number of allergic disease increases, studies to identify new treatments take on new urgency. Epigallocatechin gallate (EGCG), a major component of green tea, has been shown to possess a wide range of pharmacological properties, including anti-inflammation and anti-viral infection. In previous study, gallic acid (GA), a part of EGCG, has shown anti-allergic inflammatory effect.

View Article and Find Full Text PDF

Although bilobetin, a biflavone isolated from the leaves of Ginkgo biloba, represents a variety of pharmacological activities, to date there have been no validated determination methods for bilobetin in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of bilobetin in rat plasma. After protein precipitation with acetonitrile including diclofenac (internal standard), the analytes were chromatographed on a reversed-phased column with a mobile phase of purified water and acetonitrile (3:7, v/v, including 0.

View Article and Find Full Text PDF

Owing to the development of information technology and the electronics industry, and the increase in the use of electronic products, an increasing number of people are exposed to electromagnetic fields (EMFs) in daily life. There has been concern about the effects of EMFs on the human body. Th9 cells, which are characterized by the generation of interleukin-(IL-9), are a recently defined subset of T helper (Th) cells.

View Article and Find Full Text PDF

Aberrant activation of β-catenin-response transcription (CRT) is a well-recognized characteristic of colorectal and liver cancers and thus a potential therapeutic target for these malignancies. Broussonetia papyrifera (paper mulberry) has been used as a herbal medicine to treat various diseases. Using a sensitive cell-based screening system, we identified broussochalcone A (BCA), a prenylated chalcone isolated from Broussonetia papyrifera, as an antagonist of CRT.

View Article and Find Full Text PDF

Inhibitors of the secretion of cancer exosomes, which promote cancer progression and metastasis, may not only accelerate exosome biology research but also offer therapeutic benefits for cancer patients. Here we identify sulfisoxazole (SFX) as an inhibitor of small extracellular vesicles (sEV) secretion from breast cancer cells through interference with endothelin receptor A (ETA). SFX, an FDA-approved oral antibiotic, showed significant anti-tumor and anti-metastatic effects in mouse models of breast cancer xenografts, the reduced expression of proteins involved in biogenesis and secretion of sEV, and triggered co-localization of multivesicular endosomes with lysosomes for degradation.

View Article and Find Full Text PDF

Concomitant use of rivaroxaban with non-dihydropyridine calcium channel blockers (non-DHPs) might lead to an increase of systemic rivaroxaban exposure and anticoagulant effects in relation to the inhibition of metabolic enzymes and/or transporters by non-DHPs. This study was designed to evaluate the effects of verapamil and diltiazem on the pharmacokinetics and the prolongation of prothrombin time of rivaroxaban in rats. The data were analyzed using a pharmacokinetic/pharmacodynamics (PK/PD) modeling approach to quantify the influence of verapamil.

View Article and Find Full Text PDF

An ilimquinone (IQ) mixture isolated from , consisting of IQ and epi-ilimaquinone (epi-IQ), exerts anti-HIV, anti-microbial, anti-inflammatory, and anti-cancer effects. An HPLC-MS/MS method was developed for simultaneous determination of the two epimers in rat plasma, separating them using a biphenyl column. Ascorbic acid is added during the sample preparation to ensure the stability of both isomers.

View Article and Find Full Text PDF