Ji-Eun Kim

In vitro and in vivo study of effects of fermented soybean product (chungkookjang) on NGF secretion ability and NGF receptor signaling pathway

In order to investigate the effects of a fermented soybean product (Chungkookjang, CKJ) on nerve growth factor (NGF) metabolism, NGF secretion ability and its related signaling pathway were analyzed in B35 neuronal cells and the Tg2576 mouse model of Alzheimers disease (AD). In B35 cells, the concentration of NGF significantly increased upon treatment with Taegwang (TG)-CKJ and Shinhwa (SH)-CKJ extracts compared with vehicle. Further, a significant increase in PC12 cell length as well as the phsophorylation levels of TrkA and Akt, which are members of a high affinity NGF receptor signaling pathway, were observed after treatment with TG-CKJ and SH-CKJ conditional medium (CM). On the other hand, there was no difference in activation of the NGF receptor p75NTR signaling pathway between vehicle and all CKJ treated groups. In Tg2576 mice showing early stage of AD, the concentrations of NGF in the serum and brain were reduced compared with those in Non-Tg mice. Treatment of Tg2576 mice with SH-CKJ, which contains high concentrations of total flavonoids and phenolic compounds, for 8 weeks dramatically recovered the NGF level to that of Non-Tg mice. Furthermore, the low phosphorylation levels of TrkA and Erk in the NGF receptor TrkA signaling pathway were rapidly recovered to those of Non-Tg mice after SH-CKJ treatment in vehicle treated Tg2576 mice, whereas the phosphorylation level of Akt was maintained at a constant level. These results suggest that CKJ may stimulate NGF secretion ability as well as the NGF receptor TrkA signaling pathway in PC12 cells and Tg2576 mice.

Transdermal treatment of the surgical and burned wound skin via phytochemical-capped gold nanoparticles

The biological activities and therapeutic potential of phytochemical-decorated Au nanoparticles (Phyto-AuNPs) were investigated through the treatment of Phyto-AuNPs on the dorsal skin of rats via transdermal drug delivery process in order to regenerate surgical wounded and burned skin. Two different Phyto-AuNPs were applied to the dorsal skin: gallic acid-isoflavone--covered AuNPs (GI-AuNPs) and protocatechuic acid-isoflavone--covered AuNPs (PI-AuNPs). From the biological activity monitoring, it has been resulted that 5-fold thicker epidermis (ER), 50% reduction of metalloproteinase-1 (MMP-1) level, 3-fold higher superoxide dismutase (SOD) activity were obtained in the Phyto-AuNP-treated group, compared with a vehicle group (deionized water (DI-water) treatment). Moreover, the Phyto-AuNPs treatment on the surgical and burn damaged Sprague-Dawley (SD) rats induced higher expression of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2). It would be plausible that antioxidant property of Phyto-AuNPs assist the acceleration and activation of biomolecules in the healing mechanism, where Phyto-AuNPs can be potential candidates for skin regeneration and wound healing.

The adverse effect of 4-tert-octylphenol on fat metabolism in pregnant rats via regulation of lipogenic proteins

Alkylphenols such as 4-tert-octylphenol (OP), nonylphenol, and bisphenol A are classified as endocrine-disrupting chemicals (EDCs). Digestion and metabolism of food are controlled by many endocrine factors, including insulin, glucagon, and estrogen. These factors are differentially regulated during pregnancy. The alteration of nutritional intake and fat metabolism may affect the maintenance of pregnancy and supplementation of nutrients to the fetus, and therefore can cause severe metabolic diseases such as ketosis, marasmus and diabetes mellitus in pregnant individuals. In this study, we examined the effects of OP on fat metabolism in pregnant rats. Ethinyl estradiol (EE) was also administered as an estrogenic positive control. In our results, rats treated with OP showed significantly reduced body weights compared to the control group. In addition, histological analysis showed that the amount of fat deposited in adipocytes was reduced by OP treatment. To study the mechanism of action of OP in fat metabolism, we examined the expression levels of fat metabolism-associated genes in rat adipose tissue and liver by real-time PCR. OP and EE negatively regulated the expression of lipogenic enzymes, including FAS (fatty acid synthase), ACC-1 (acetyl-CoA carboxylase-1), and SCD-1 (stearoyl-CoA desaturase-1). The levels of lipogenic enzyme-associated transcription factors such as C/EBP-α (CAAT enhancer binding protein alpha) and SREBP-1c (sterol regulatory element binding protein-1c) were also reduced in both liver and adipose tissue. In summary, these findings suggest that OP has adverse effects on fat metabolism in pregnant rats and inhibits fat deposition via regulating lipogenic genes in the liver and adipose tissue. The altered fat metabolism by OP may affect the nutrition balance during pregnancy and can cause metabolism-related diseases.

Metabolomics approach to serum biomarker for loperamide-induced constipation in SD rats

Loperamide has long been known as an opioid-receptor agonist useful as a drug for treatment of diarrhea resulting from gastroenteritis or inflammatory bowel disease as well as to induce constipation. To determine and characterize putative biomarkers that can predict constipation induced by loperamide treatment, alteration of endogenous metabolites was measured in the serum of Sprague Dawley (SD) rats treated with loperamide for 3 days using 1H nuclear magnetic resonance (1H NMR) spectral data. The amounts and weights of stool and urine excretion were significantly lower in the loperamide-treated group than the No-treated group, while the thickness of the villus, crypt layer, and muscle layer was decreased in the transverse colon of the same group. The concentrations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatinine (Cr) were also slightly changed in the loperamide-treated group, although most of the serum components were maintained at a constant level. Furthermore, pattern recognition of endogenous metabolites showed completely separate clustering of the serum analysis parameters between the No-treated group and loperamide-treated group. Among 35 endogenous metabolites, four amino acids (alanine, glutamate, glutamine and glycine) and six endogenous metabolites (acetate, glucose, glycerol, lactate, succinate and taurine) were dramatically decreased in loperamide-treated SD rats. These results provide the first data pertaining to metabolic changes in SD rats with loperamide-induced constipation. Additionally, these findings correlate the changes in 10 metabolites with constipation.

Effects of Red Liriope platyphylla on NGF secretion ability, NGF receptor signaling pathway and γ-secretase components in NSE/hAPPsw transgenic mice expressing Alzheimer’s Disease

Liriope platyphylla (LP) has long been regarded as a curative herb for the treatment of diabetes, asthma, and neurodegenerative disorders. To examine the therapeutic effects of Red LP (RLP) manufactured by steaming process on neurodegenerative disorders, significant alteration of the key factors influencing Alzheimers Disease (AD) was detected in NSE/hAPPsw transgenic (Tg) mice after RLP treatment. The concentration of nerve growth factor (NGF) in serum increased in RLP-treated NSE/hAPPsw Tg mice compared with vehicle-treated Tg mice. However, downstream effectors of the NGF receptor signaling pathway, including TrkA and p75NTR proteins, were suppressed in RLP-treated NSE/hAPPsw Tg mice. Especially, Tg mice showed decreased levels of TrkA, p75NTR, and RhoA expression. Production of Aβ-42 peptides was lower in RLP-treated NSE/hAPPsw Tg mice than in vehicle-treated Tg mice. Further, analysis of γ-secretase components showed that Aβ-42 peptide expression was downregulated. Of the four components, the expression of APH-1 and Nicastrin (NCT) decreased in RLP-treated NSE/hAPPsw Tg mice, whereas expression of PS-2 and Pen-2 was maintained or increased within the same group. Overall, these results suggest that RLP can help relieve neurodegenerative diseases, especially AD, through upregulation of NGF secretion ability, activation of NGF signaling pathway, downregulation of Aβ-42 peptide deposition, and alteration of γ-secretase components.

Aqueous extract of Liriope platyphylla, a traditional Chinese medicine, significantly inhibits abdominal fat accumulation and improves glucose regulation in OLETF type II diabetes model rats

Liriope platyphylla is a medical herb that has long been used in Korea and China to treat cough, sputum, neurodegenerative disorders, obesity, and diabetes. The aims of this study were to determine the antidiabetic and antiobesity effects of aqueous extract of L. platyphylla (AEtLP) through glucose and lipid regulation in both pre-diabetes and obesity stage of type II diabetes model. Two concentrations of AEtLP were orally administrated to OLETF (Otsuka Long-Evans Tokushima Fatty) rats once a day for 2 weeks, after which changes in glucose metabolism and fat accumulation were measured. Abdominal fat mass dramatically decreased in AEtLP-treated OLETF rats, whereas glucose concentration slightly decreased in all AEtLP-treated rats. However, compared to vehicle-treated OLETF rats, only AEtLP10 (10% concentration)-treated OLETF rats displayed significant induction of insulin production, whereas AEtLP5 (5% concentration)-treated OLETF rats showed a lower level of insulin. Although serum adiponectin level increased in only AEtLP5-treated rats, significant alteration of lipid concentration was detected in AEtLP5-treated OLETF rats. Expression of Glut-1 decreased in all AEtLP-treated rats, whereas Akt phosphorylation increased only in AEtLP10-treated OLETF rats. Furthermore, the pattern of Glut-3 expression was very similar with that of Glut-1 expression, which roughly corresponded with the phosphorylation of c-Jun N-teminal kinase (JNK) and p38 in the mitogen-activated protein kinase pathway. Therefore, these findings suggest that AEtLP should be considered as a therapeutic candidate during pre-diabetes and obesity stage capable of inducing insulin secretion from pancreatic β-cells, glucose uptake in liver cells, as well as a decrease in fat and lipid accumulation.

Beneficial effects of ethanol extracts of Red Liriope platyphylla on vascular dysfunction in the aorta of spontaneously hypertensive rats

Some biological effects of Red Liriope platyphylla (RLP) on various chronic diseases including Alzheimers disease, diabetes and obesity were suggested after a report of the production from Liriope platyphylla (L. platyphylla, LP) roots using a steaming process. To examine the beneficial effects of ethanol extracts RLP (EEtRLP) on the vascular dysfunction of hypertension, alterations in key factors related to vascular regulation and antioxidant conditions were investigated in spontaneously hypertensive rats (SHR) after EEtRLP treatment for 2 weeks. High levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were detected in 500 or 1,000 mg/mL EEtRLP. Although no significant improvement of systolic blood pressure or aortic wall thickness were observed in the EEtRLP treated group, the expression level of angiotensin converting enzyme (ACE) and ACE2 increased significantly after EEtRLP treatment. Moreover, the concentration of aldosterone and K ion in serum rapidly recovered in the EEtRLP treated group relative to the vehicle treated group. Furthermore, the endothelial nitric oxide synthase (eNOS) expression and superoxide dismutase (SOD) activity were significantly increased in the EEtRLP treated group relative to the vehicle treated group, while the level of malondialdehyde (MDA) and NOx in the serum of the same group were recovered to the level of Wistar Kyoto (WKY) rats. Overall, the results presented herein provide novel evidence that EEtRLP treatment may improve vascular dysfunction in the aorta of the SHR through up regulation of the antioxidant state and down regulation of aldosterone and K ion concentration. These results also suggest that EEtRLP may be a potential candidate for treatment of various chronic diseases showing vascular dysfunction.

Toxicity of fermented soybean product (cheonggukjang) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on liver and kidney of ICR mice.

To investigate the toxic effects of cheonggukjang (CKJ) manufactured using mixed cultures of Bacillus subtilis MC31 and Lactobacillus sakei 383 on the liver and kidney of ICR mice, an alteration on the related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed after oral administration at dosage of 25, 50 and 100 mg/kg body weight/day of CKJ for 14 days. Any significant toxicity was not observed on the body and organ weight, clinical phenotypes, urine parameters and mortality in the CKJ-treated group compared with the vehicle-treated group. Also, liver toxicity analysis revealed no significant increase in alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) or lactate dehydrogenase (LDH) in response to CKJ. Additionally, the specific pathological features induced by most toxic compounds were not observed upon liver histological analysis. Furthermore, kidney toxicological analysis revealed that blood urea nitrogen (BUN) and the serum creatinine (Cr) levels and pathological features on histological sections did not differ significantly between the vehicle- and CKJ-treated groups. Overall, these results suggest that CKJ does not induce any specific toxicity in liver and kidney organs of ICR at dose of 100 mg/kg body weight/day as no observed adverse effect level (NOAEL).

Altered expression of γ-secretase components in animal model of major depressive disorder induced by reserpine administration

Altered expression of neurotrophic factors as well as neuroinflammation is commonly associated with Major depressive disorder (MDD) and Alzheimers disease (AD). To investigate whether or not reserpine-induced MDD affects the expression of AD-related proteins, the expression of γ-secretase components and substrate were measured in brains of ICR mice following reserpine treatment for 15 days. In active avoidance test, total response time and peak slightly increased in the 2 mg/kg reserpine (RSP2)-treated group compared to vehicle-treated group (P<0.05). Expression and phosphorylation of MKP-1, which is a key factor in MDD pathology, were both higher in the RSP2-treated group than the vehicle- and 1 mg/kg reserpine (RSP1)-treated groups (P<0.02). Furthermore, full-length expression of amyloid precursor protein (APP) was enhanced in the RSP1 and RSP2-treated groups compared to the vehicle-treated group, whereas expression of γ-secretase components decreased (P<0.03). Among the three components of the γ-secretase complex, nicastrin protein underwent the largest decrease in expression, as detected by Western blotting (P<0.03). Therefore, the data presented here provide additional evidence about the pathological correlation between MDD and AD.

Red Liriope platyphylla stimulated the insulin secretion through the regulation of calcium concentration in rat insulinoma cells and animal models

The aim of this study was to investigate the effects of Red L. platyphylla (RLP) on calcium and glucose levels during insulin secretion. To achieve this, alteration of insulin and calcium concentrations was measured in rat insulinoma-1 (INS-1) cells and animal models in response to RLP treatment. In INS-1 cells, maximum secretion of insulin was detected upon treatment with 200 µg/mL of RLP for 20 min. Nifedipine, an L-type calcium channel blocker, effectively inhibited insulin secretion from INS-1 cells. Regarding calcium levels, the maximum concentration of intracellular calcium in INS-1 cells was obtained by treatment with 100 µg/mL of RLP, whereas this level was reduced under conditions of 200 µg/mL of RLP. Further, RLP-treated INS-1 cells showed a higher level of intracellular calcium than that of L. platyphylla (LP), Korea White Ginseng (KWG), or Korea Red Ginseng (KRG)-treated cells. This RLP-induced increase in intracellular calcium was abrogated but not completely abolished upon treatment with 40 µM nifedipine in a dose-dependent manner. Furthermore, the insulin level was dramatically elevated upon co-treatment with high concentrations of glucose and RLP, whereas it was maintained at a low level in response to glucose and RLP co-treatment at low concentrations. In an animal experiment, the serum concentration of calcium increased or decreased upon RLP treatment according to glucose level compared to vehicle treatment. Therefore, these results suggest that insulin secretion induced by RLP treatment may be tightly correlated with calcium regulation, which suggests RLP is an excellent candidate for diabetes treatment.