Jae-Hoon Kang

Effects of Polygonatum sibiricum rhizome ethanol extract in high-fat diet-fed mice

Abstract Context: The rhizome of Polygonatum sibiricum Redoute (Liliaceae) has long been used to treat diabetes-associated complications. However, the pharmacological mechanism of P. sibiricum on metabolic disorders is not clear. Objective: This study investigates the effect of an ethanol extract of P. sibiricum rhizomes (designated ID1216) on obesity conditions including weight loss in high-fat (HF) diet-fed mice and explores the potential underlying mechanisms. Methods: To identify the metabolic impact of the P. sibiricum rhizome extract, HF diet-fed mice were administered ID1216 orally at doses of 250 and 1000 mg/kg/d for 10 weeks, and various factors related to metabolic syndrome were analyzed. We also examined the effects of ID1216 on the expression of genes involved in adipogenesis and lipolysis in 3T3-L1 cells, as well as genes associated with energy homeostasis in C2C12 myocytes. Results: ID1216 administration led to significant decreases in body weight gain (37.5%), lipid accumulation in adipose tissues (52.8%), and the levels of plasma triglycerides (26.4%) and free fatty acids (28.1%) at a dose of 250 mg/kg/d, compared with the vehicle-treated group, as well as improved insulin resistance. In addition, ID1216 was found to regulate the expression of genes related to adipogenesis and fatty acid oxidation in 3T3-L1 cells and enhance the expression of genes that modulate energy homeostasis in C2C12 myocytes. Conclusions: ID1216 may be a promising therapeutic agent for improving obesity conditions through the sirtuin-1 and peroxisome proliferator-activated receptor γ coactivator-1α pathway.

Production of Teicoplanin from Actinoplanes teichomyceticus ID9303 by Adding Proline

We evaluated the influence of amino acids in improving teicoplanin productivity. Arginine, lysine, and proline were selected for better productivity among 20 amino acids in Erlenmeyer flasks. Proline was finally chosen as the additive for maximum teicoplanin productivity in a 5-liter fermenter. We obtained the highest teicoplanin productivity, 3.12 g/l, on the eighth d in a 75-liter pilot fermenter.

Identification of novel aminopiperidine derivatives for antibacterial activity against Gram-positive bacteria.

We have previously reported amidopiperidine derivatives as a novel peptide deformylase (PDF) inhibitor and evaluated its antibacterial activity against Gram-positive bacteria, but poor pharmacokinetic profiles have resulted in low efficacy in in vivo mouse models. In order to overcome these weaknesses, we newly synthesized aminopiperidine derivatives with remarkable antimicrobial properties and oral bioavailability, and also identified their in vivo efficacy against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP).

Anti-amyloidogenic effects of ID1201, the ethanolic extract of the fruits of Melia toosendan, through activation of the phosphatidylinositol 3-kinase/Akt pathway.

Amyloid beta (Aβ) peptides, which are generated from amyloid precursor protein (APP), are thought to play a major role in the pathogenesis of Alzheimers disease (AD). This study investigated the anti-amyloidogenic effects of the ethanolic extract of Meliae Fructus (ID1201) using human embryonic kidney 293 cells with stably expressed human wild-type or Swedish mutant APP695 and β-secretase 1. ID1201 treatment enhanced the non-amyloidogenic metabolism of APP; increases in soluble APPα levels and decreases in soluble APPβ and Aβ levels resulted from the α-secretase activation through the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. In addition, ID1201-treated 5×familial AD (FAD) mice with 5 mutations in APP and presenilin 1 showed reduced levels of Aβ and amyloid plaques in the brain relative to those of 5×FAD mice with vehicle treatments. These results indicate that ID1201 possesses anti-amyloidogenic effects via the activation of the PI3K/Akt pathway, suggesting that it is a potential therapeutic agent for AD.

Abstract 2768: IDH1057, A novel, synthetic, small molecule inhibitor of heat shock protein 90(Hsp90)

Backgroud: The molecular chaperone Heat shock protein 90(Hsp90) governs the stabilization and activity of an array of over 100 ‘client proteins’, many of which are key signaling molecules involved in cell proliferation, survival, and transformation. A significant number of these client proteins are oncogenic in nature, including the protein kinases Her2, C-Raf, B-Raf, and AKT. We report here that IDH1057 is structurally distinct from a geldanamycin derivative, tanespimycin(17-AAG) as a novel and potent small molecule Hsp90 inhibitor that binds to the NH 2 -terminal ATP-binding pocket of Hsp90. Results: IDH1057 exhibited superior binding affinity for the ATPase domain of Hsp90(IDH1057, human Hsp90α FP IC 50 50 =456.3 nM) in vitro. IDH1057 also markedly inhibited proliferation in a broad panel of human tumor cell lines(IC 50 α100 nM) and depleted Her2 in SKBR3 breast cancer cells(IC 50 app =4.7x10 −6 cm/sec). Conclusion: Our results indicate that IDH1057 is a novel and fully synthetic Hsp90 inhibitor with strong anti-tumor activity in vitro and in vivo. IDH1057 is a promising and orally active drug candidate for cancer therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2768. doi:1538-7445.AM2012-2768

Effects of ethanol extract of Polygonatum sibiricum rhizome on obesity-related genes

In previous studies, we confirmed that the ethanol extract of Polygonatum sibiricum (ID1216) has anti-obesity effects on high-fat diet-fed mice. To identify the obesity-related genes affected by ID1216, we studied its effects both in vivo and in vitro. In mice, single administration of ID1216 increased the expression of obesity-related genes including sirtuin1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and peroxisome proliferator-activated receptor α (PPARα) compared to that in mice administered the vehicle; their downstream genes (uncoupling proteins, acylCoA oxidase, adipocyte protein 2, and hormone-sensitive lipase) were also increased by ID1216. In fully differentiated 3T3-L1 adipocytes, ID1216 showed the same effects on anti-obesity genes as those in the animal model. Based on these results, we propose that ID1216 has anti-obesity effects by regulating the SIRT1-PGC1α-PPARα pathway and their downstream genes, thereby controlling energy and lipid metabolisms.

Identification of Novel Bacillus subtilis IDCC 9204 Producing a High-Level Fibrinolytic Enzyme and Properties of NK-IL9204

A Bacillus sp. that produces fibrinolytic enzyme was isolated from Cheonggukjang, a traditional Korean soybean-fermented food. According to 16S rRNA gene base sequencing, the bacillus was identified as a variety of Bacillus subtilis, and named Bacillus subtilis IDCC 9204. Fibrinolytic enzyme NK-IL9204 was stable up to and within pH range of 5-10. Purified NK-IL9204 was detected through fibrin zymography. The molecular weight and isoelectric point of the enzyme were estimated to be 27.7 kDa and 6.7 by SDS-PAGE and 2D electrophoresis, respectively. Its amino acid sequence was similar to that of nattokinase (identities 99.5%) and different from that of nattokinase BPN (identities 86.4%). The plasma fibrinolytic activity of NK-IL9204 was measured by euglobulin clot lysis times (ECLT). The NK-IL9204 was orally administered to SD rats for 3 weeks (1,000 FU/rat/day). The ECLT was significantly shortened by supplementation of NK-IL9204.

Effects of Polygonatum sibiricum rhizome extract on lipid and energy metabolism in high-fat diet-induced obese mice

In this study, factors involved in lipid and energy metabolism following treatment with ethanolic extract of the Polygonatum sibiricum rhizome (ID1216) were evaluated in high-fat diet-induced obese mice. ID1216-treated mice showed a significant reduction in weight gain compared to non-treated mice. ID1216 treatment increased the protein levels of AMP-dependent protein kinase, sirtuin1, peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), peroxisome proliferator-activated receptor α (PPARα) and uncoupling proteins in the adipose tissue, liver and muscle compared to vehicle treatment. Analysis of downstream signals of the sirtuin1 PGC1α-PPARα pathway showed that ID1216 regulates the expression of β-oxidation related genes such as acyl-CoA oxidase, carnitine palmitoyltransferase1, acyl-CoA dehydrogenase and adipocyte protein 2. In addition, ID1216 increased the expression of adipose triglyceride lipase. These results suggest that ID1216 has anti-obesity effects by regulating the genes involved thermogenesis, β-oxidation and lipolysis in a diet-induced obesity model.

Quantification of IDP-73152, a novel antibiotic, in plasma from mice, rats and humans using an ultra-high performance liquid chromatography/tandem mass spectrometry method for use in pharmacokinetic studies

HighlightsUPLC–MS/MS assay for IDP‐73152 was developed in plasma samples from mice/rats/humans.The assay was applicable to the pharmacokinetic studies of IDP‐73152 in mice and rats.The assay can be applied to routine pharmacokinetic studies in humans. Abstract IDP‐73152, a novel inhibitor of a bacterial peptide deformylase, was recently approved as a new, investigational drug in Korea for the clinical management of infections caused by Gram positive bacteria. The objective of this study was to develop/validate a simple and robust analytical method for the determination of IDP‐73152 in plasma samples from rodents and humans, and to assess the feasibility of the assay for use in pharmacokinetic studies using animal models. Plasma samples were processed using a standard method for protein precipitation and an aliquot of the extract then injected onto an UHPLC–MS/MS system. The drug and IDP‐117293, an internal standard, were analyzed in the positive ion‐mode by electrospray ionization and quantified by monitoring the transition at m/z 555.2 → 245.2 for IDP‐73152 and 563.3 → 253.1 for the internal standard, respectively. The lower and upper limit of the assay was determined to be 5 and 10000 ng/ml, respectively, with an acceptable linearity (R > 0.999) in the response‐concentration relationship. Validation parameters, including accuracy, precision, dilution, recovery, matrix effect and stability were found to be within the acceptable ranges recommended by the assay validation guidelines of the United States FDA. The method was successfully applied to the quantification of IDP‐73152 in plasma from mice/rats that had received a single oral administration of 80 mg/kg IDP‐73152, in the form of the mesylate salt. These findings suggest that the validated assay can be used in preclinical and clinical pharmacokinetic studies of IDP‐73152.

ID1201, the ethanolic extract of the fruit of Melia toosendan ameliorates impairments in spatial learning and reduces levels of amyloid beta in 5XFAD mice.

A previous study has demonstrated the anti-amyloidogenic effects of the ethanolic extract of Meliae Fructus (ID1201) using cell lines with stably expressed human Swedish mutant APP695 and β-secretase 1, and 5Xfamilial AD (FAD) mice carrying five mutations. Here, we investigated the effects of ID1201 on cognitive impairment in 5XFAD mice. Daily administration of ID1201 was commenced at 3 months of age and continued for 3 months. Mice were serially trained in cued/response and place/spatial training tasks in the Morris water maze. After this training, testing for strategy preference was conducted. Non-transgenic control mice with vehicle treatment, vehicle-treated 5XFAD, and ID1201-treated 5XFAD mice showed equivalent performance in cued/response training. However, as training progressed to the subsequent place/spatial learning, vehicle-treated control and ID1201-treated 5XFAD mice differed significantly from vehicle-treated 5XFAD mice in measures of spatial learning (search error and adaptive spatial learning strategy). In the strategy preference test that followed, control mice preferred a place/spatial strategy relative to vehicle-treated 5XFAD mice, but differences between ID1201-treated 5XFAD mice and vehicle-treated 5XFAD mice were not significant. Additionally, ID1201 treatment reduced hippocampal levels of insoluble Aβ42 and increased cortical levels of soluble amyloid precursor protein α. These results indicate that ID1201 may possess potential as a therapeutic agent for Alzheimers disease by decreasing Aβ deposits.