Effects of exogenous growth hormone administration on dexamethasone-induced growth impairment in adolescent male rats.

Growth impairment (GI) is one of the adverse effects of dexamethasone (DXM), and growth hormone (GH) has been used clinically to improve GI. The present study aimed to evaluate the manner in which DXM disturbs the growth rate of longitudinal bones, and the recovery effects of GH on DXM-induced GI in the longitudinal bones of adolescent male rats. In the first experiment, DXM (0, 0.5, 1, 2 and 5 mg/kg) was administered subcutaneously to identify a potential dose-dependent activity and calculate the median effective dose (ED50) of DXM-induced GI. The ED50 was identified to be 1.15 mg/kg. In the second experiment, GH (0, 2.5, 5 and 10 mg/kg) with 1.15 mg/kg DXM was injected subcutaneously to assess the recovery effects of GH on DXM-induced GI. The growth rates of the longitudinal bones, total height of the growth plate, local mRNA expressions of insulin-like growth factor 1 (IGF-1), GH receptor (GHR) and IGF-1 receptor (IGF-1R), and local protein expression of IGF-1 were measured to evaluate the recovery effects of GH on DXM-induced GI. The local expressions of IGF-1, GHR and IGF-1R mRNA, and IGF-1 protein were measured using quantitative polymerase chain reaction following laser microdissection and antigen-specific immunohistochemistry, respectively. GH administration partially recovered DXM-induced GI in the longitudinal bones and growth plate. GH significantly increased the levels of IGF-1, GHR and IGF-1R mRNA in the proliferative zone of the control group (P<0.05), whereas it failed to increase them in the proliferative zone of the DXM-treated group. Furthermore, GH increased the levels of IGF-1, GHR and IGF-1R mRNA in the hypertrophic zone of both the vehicle and DXM-treated groups (P<0.05). Immunohistochemical analysis of IGF-1 protein expression revealed a similar pattern to that of IGF-1 mRNA. These results suggest that increased GH insensitivity in the proliferative zone of the growth plate, induced by DXM, leads to GI in longitudinal bones. Thus, combined administration of GH with GH insensitivity-alleviating medications may be more effective in the treatment of DXM-induced GI.

Hypoglycemic Effect of Opuntia ficus-indica var. saboten Is Due to Enhanced Peripheral Glucose Uptake through Activation of AMPK/p38 MAPK Pathway.

Opuntia ficus-indica var. saboten (OFS) has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, detailed mechanisms underlying hypoglycemic effects remain unclear. In this study, the mechanism underlying the hypoglycemic activity of OFS was evaluated using in vitro and in vivo systems. OFS treatment inhibited α-glucosidase activity and intestinal glucose absorption assessed by Na⁺-dependent glucose uptake using brush border membrane vesicles. AMP-activated protein kinase (AMPK) is widely recognized as an important regulator of glucose transport in skeletal muscle, and p38 mitogen-activated protein kinase (MAPK) has been proposed to be a component of AMPK-mediated signaling. In the present study, OFS dose-dependently increased glucose uptake in L6 muscle cells. The AMPK and p38 MAPK phosphorylations were stimulated by OFS, and inhibitors of AMPK (compound C) and p38 MAPK (SB203580) abolished the effects of OFS. Furthermore, OFS increased glucose transporter 4 (GLUT4) translocation to the plasma membrane. OFS administration (1 g/kg and 2 g/kg body weight) in db/db mice dose-dependently ameliorated hyperglycemia, hyperinsulinemia, and glucose tolerance. Insulin resistance assessed by homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were also dose-dependently improved with OFS treatment. OFS administration improved pancreatic function through increased ß-cell mass in db/db mice. These findings suggest that OFS acts by inhibiting glucose absorption from the intestine and enhancing glucose uptake from insulin-sensitive muscle cells through the AMPK/p38 MAPK signaling pathway.

Extrusion process of Acanthopanax senticosus leaves enhances the gastroprotective effect of compound 48/80 on acute gastric mucosal lesion in rats.

OBJECTIVE: To investigate the gastroprotective effects of Acanthopanax senticosus leaves (ASLs) extrusion on acute gastric mucosal lesion in rats induced by compound 48/80 (C48/80). METHODS: Rats were divided into six groups: normal; C48/80-induced gastric lesion control; gastric lesion positive control (famotidine 4 mg/kg); gastric lesion administered with two levels of extruded ASLs (ASLE, 40 and 200 mg/kg); and gastric lesion treated with ASLs (ASL 200 mg/kg). Mucus secretion/damage was determined by immunohistological staining. Immunofluorescence and western blotting were performed to determine gastric mucosal Bax and Bcl-2 expression. Gastric mucosal oxidative-stress-related enzymes and malondialdehvde were determined. RESULTS: C48/80-induced mucus depletion and inflammation in the gastric mucosa were significantly attenuated by ASLs. The increased serum serotonin and histamine concentrations in C48/80-treated rats were also attenuated by ASLs. Gastric mucosal Bax protein expression was increased and Bcl-2 expression was decreased after C48/80 treatment, and ASLs ameliorated Bax and Bcl-2 expression. The extrusion process significantly augmented the effects of ASLs in a dose-dependent manner. ASLEs at 200 mg/kg normalized mucus damage/secretion, C48/80-induced increases of mucosal myeloperoxidase activity (index of inflammation), xanthine oxidase, and malondialdehyde content (index of lipid peroxidation). The effects of ASLs on Bax and Bcl-2 expression were also enhanced by extrusion. Furthermore, these effects of ASLEs at 200 mg/kg were similar to those of famotidine, a histamine H2-receptor antagonist commonly used to treat gastric ulcers. CONCLUSION: ASLEs prevented acute gastric mucosal lesion progression induced by C48/80, possibly by inducing mucus production, and reduced inflammation and oxidative stress in gastric mucosa through an anti-apoptotic mechanism.

Comparison of the Effect of Velvet Antler from Different Sections on Longitudinal Bone Growth of Adolescent Rats.

The aim of this study was to compare the effectiveness of velvet antler (VA) from different sections for promoting longitudinal bone growth in growing rats. VA was divided into upper (VAU), middle (VAM), and basal sections (VAB). An in vivo study was performed to examine the effect on longitudinal bone growth in adolescent rats. In addition, in vitro osteogenic activities were examined using osteoblastic MG-63 cells. VA promoted longitudinal bone growth and height of the growth plate in adolescent rats. Bone morphogenetic protein-2 (BMP-2) in growth plate of VA group was highly expressed compared with control. The anabolic effect of VA on bone was further supported by in vitro study. VA enhanced the proliferation, differentiation, and mineralization of MG-63 cells. The mRNA expressions of osteogenic genes such as collagen, alkaline phosphatase, and osteocalcin were increased by VA treatment. These effects of in vivo and in vitro study were decreased from upper to basal sections of VA. In conclusion, VA treatment promotes longitudinal bone growth in growing rats through enhanced BMP-2 expression, osteogenic activities, and bone matrix gene expressions. In addition, present study provides evidence for the regional differences in the effectiveness of velvet antler for longitudinal bone growth.

Effects of egg yolk-derived peptide on osteogenic gene expression and MAPK activation.

The present study investigated the effects of egg yolk-derived peptide (YPEP) on osteogenic activities and MAPK-regulation of osteogenic gene expressions. The effects of YPEP on cell proliferation, alkaline phosphatase activity, collagen synthesis, and mineralization were measured in human osteoblastic MG-63 cells. Activation of MAPKs and downstream transcription factors such as extracellular-signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK1/2), p38, ELK1, and cJUN were examined using western blot analysis. YPEP dose-dependently increased MG-63 cell proliferation, ALP activity, collagen synthesis, and calcium deposition. YPEP activated ERK1/2, p38, and ELK1 phosphorylation whereas JNK and cJUN were not affected by YPEP. The COL1A1 (collagen, type I, alpha 1), ALPL (alkaline phosphatase), and SPP1 (secreted phosphoprotein 1, osteopontin) gene expressions were increased while BGLAP (osteocalcin) was not affected by YPEP. The ERK1/2 inhibitor (PD98509) blocked the YPEP-induced COL1A1 and ALPL gene expressions as well as ELK1 phosphorylation. The p38 inhibitor (SB203580) blocked YPEP-induced COL1A1 and ALPL gene expressions. SPP1 gene expression was not affected by these MAPK inhibitors. In conclusion, YPEP treatment stimulates the osteogenic differentiation via the MAPK/ELK1 signaling pathway. These results could provide a mechanistic explanation for the bone-strengthening effects of YPEP.

Protective effect of ginsenoside Re on acute gastric mucosal lesion induced by compound 48/80.

The protective effect of ginsenoside Re, isolated from ginseng berry, against acute gastric mucosal lesions was examined in rats with a single intraperitoneal injection of compound 48/80 (C48/80). Ginsenoside Re (20 mg/kg or 100 mg/kg) was orally administered 0.5 h prior to C48/80 treatment. Ginsenoside Re dose-dependently prevented gastric mucosal lesion development 3 h after C48/80 treatment. Increases in the activities of myeloperoxidase (MPO; an index of neutrophil infiltration) and xanthine oxidase (XO) and the content of thiobarbituric acid reactive substances (TBARS; an index of lipid peroxidation) and decreases in the contents of hexosamine (a marker of gastric mucus) and adherent mucus, which occurred in gastric mucosal tissues after C48/80 treatment, were significantly attenuated by ginsenoside Re. The elevation of Bax expression and the decrease in Bcl2 expression after C48/80 treatment were also attenuated by ginsenoside Re. Ginsenoside Re significantly attenuated all these changes 3 h after C48/80 treatment. These results indicate that orally administered ginsenoside Re protects against C48/80-induced acute gastric mucosal lesions in rats, possibly through its stimulatory action on gastric mucus synthesis and secretion, its inhibitory action on neutrophil infiltration, and enhanced lipid peroxidation in the gastric mucosal tissue.

Collagen hydrolysates increased osteogenic gene expressions via a MAPK signaling pathway in MG-63 human osteoblasts.

The present study investigated the effects of CHs on osteogenic activities and MAPK-regulation on bone matrix gene expressions. The effects of CHs on cell proliferation, alkaline phosphatase (ALP) activity, collagen synthesis, and mineralization were measured in human osteoblastic MG-63 cells. Activation of MAPKs and downstream transcription factors such as extracellular-signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK1/2), p38, ELK1, and cJUN was examined using Western blot analysis. The expressions of osteogenic genes were measured by quantitative real-time PCR. CHs dose-dependently increased MG-63 cell proliferation, ALP activity, collagen synthesis, and calcium deposition. CHs activated ERK1/2, JNK1/2, p38, and ELK1 phosphorylation except cJUN. The COL1A1 (collagen, type I, alpha 1), ALPL (alkaline phosphatase), BGLAP (osteocalcin), and SPP1 (secreted phosphoprotein 1, osteopontin) gene expressions were increased by CH treatment. The ERK1/2 inhibitor (PD98509) blocked the CH-induced COL1A1 and ALPL gene expression, as well as ELK1 phosphorylation. The JNK1/2 inhibitor (SP600125) abolished CH-induced COL1A1 expression. The p38 inhibitor (SB203580) blocked CH-induced COL1A1 and SPP1 gene expression. In conclusion, CH treatment stimulates the osteogenic activities and increases bone matrix gene expressions via the MAPK/ELK1 signaling pathway. These results could provide a mechanistic explanation for the bone-strengthening effects of CHs.

Involvement of MAPK signaling pathway in the osteogenic gene expressions of Cervi Pantotrichum Cornu in MG-63 human osteoblast-like cells.

AIMS: The purposes of this study were to determine whether Cervi Pantotrichum Cornu (CPC) has osteogenic activities in human osteoblastic MG-63 cells and to investigate the underlying molecular mechanism. MAIN METHODS: The effects of CPC on alkaline phosphatase activity, collagen synthesis, and calcium deposits were measured. The COL1A1, ALPL, BGLAP, and SPP1 expressions were measured by real-time PCR. Phosphorylated MAP kinases (ERK1/2, JNK1/2, p38, ELK1, and cJUN) were studied by western blot analysis. The involvement of MAPK pathway in osteogenic gene expressions was determined by using each selective MAPK inhibitor (PD98059, SP600125, and SB203580). KEY FINDINGS: CPC increased alkaline phosphatase activity, collagen synthesis, and calcium deposits. CPC activated ERK1/2, JNK1/2, p38, and ELK1 phosphorylation except cJUN. CPC increased the COL1A1, ALPL, BGLAP, and SPP1 gene expressions. The elevated COL1A1 and BGLAP expressions were inhibited by PD98059, SP600125 or SB203580. The elevated ALPL expression was blocked by SB203580. The elevated SPP1 expression was inhibited by SP600125 or SB203580. CPC increased COL1A1 and BGLAP expressions via ERK1/2, JNK1/2, and p38 MAPKs pathways and SPP1 expression via JNK1/2 and p38 pathways. p38 pathway is needed for ALPL expression. SIGNIFICANCE: These results imply that MAPK signaling pathway is an indispensable factor for bone matrix genes expression of CPC in MG-63 human osteoblast-like cells.

Osteogenic activity of collagen peptide via ERK/MAPK pathway mediated boosting of collagen synthesis and its therapeutic efficacy in osteoporotic bone by back-scattered electron imaging and microarchitecture analysis.

Collagen hydrolysate (CH) has been reported to exhibit a positive effect on bone. In the present study, the in vitro effects of CH (<3 kDa) were examined and the in vivo experiments confirmed the positive effects of CH in ovariectomized (OVX) rats. Bone mineral density (BMD) was examined by DXA analysis. Scanning electron microscopic analysis and quantitative 3D-color backscattered electrons imaging analysis were performed on the lumbar vertebrae. CH increased osteoblastic cell proliferation and alkaline phosphatase activity in a dose-dependent manner. Collagen synthesis and collagen, type1, alpha1 (COL1A1) gene expression were also increased by CH treatment. Furthermore, CH-induced COL1A1 gene expression was completely abolished by extracellular signal-regulated kinase (ERK) inhibitor, suggesting the involvement of ERK/MAPK signaling for transcriptional effects on COL1A1 expression. OVX rats supplemented with CH showed osteoprotective effects as the BMD levels were increased compared with control. Moreover, CH prevented the trabecular bone loss induced by OVX and improved the microarchitecture of lumbar vertebrae. CH administration dose-dependently reduced the serum procollagen type I N-terminal propeptide level, which was elevated by OVX. The present study suggests that CH isolated in this study is a promising alternative to current therapeutic agents for the management of osteoporosis.

Inhibitory effects of ginsenoside re isolated from ginseng berry on histamine and cytokine release in human mast cells and human alveolar epithelial cells.

The berry of Panax ginseng significantly inhibited the histamine releases at the concentration of 30 µg/mL (p<0.05) and 10 µg/mL (p<0.01). The ginsenoside Re from ginseng berry was found out to have a potent effect in the experiment of histamin and cytokine release.

Inhibitory effects of egg yolk soluble protein on bone resorption.

We determined the effects of yolk water-soluble protein (YSP) on bone resorption. YSP potently suppressed osteoclastogenesis from bone marrow-derived precursor cells driven by tumor necrosis factor-alpha (TNF-alpha). YSP (200 microg/ml) abolished the formation of tartarate-resistant acid phosphatase (TRAP)-positive osteoclasts. Furthermore, TNF-alpha induced TRAP activity was greatly inhibited by YSP (100 microg/ml) treatment. Our results suggest that YSP has therapeutic potential for bone-erosive diseases.

Inhibitory effects of Angelicae Gigantis Radix on osteoclast formation.

Angelicae Gigantis Radix (AGR) is one of the most widely used herbal medications. AGR is the dried root of Angelica gigas Nakai (Umbelliferae), which is known as Korean angelica. This study investigated the effects of AGR on osteoclast formation using primary bone marrow cells. TNF-alpha treatment increased tartrate-resistant acid phosphatase (Trap) positive cells and Trap activity in bone marrow cells. However, AGR significantly decreased both TNF-alpha-induced Trap positive cells and Trap activity. RT-PCR analyses revealed that AGR decreased mRNA levels of Trap and matrix metalloproteinase-9 in TNF-alpha-treated bone marrow cells. In addition, AGR decreased TNF-alpha-induced activation of NF-kappaB. These results suggest that AGR has an inhibitory effect on the formation of osteoclasts and its effect is partially related to the NF-kappaB pathway.

Protective effects of a novel herbal decoction on focal cerebral ischemia in a rodent model.

BACKGROUND: Herbs have been used to treat stroke and coma patient in traditional Korean medicine (TKM). The novel decoction, Guhpoongchungsimhwan (GCH), was developed on the basis of clinical data and TKM theory. METHODS: We examined the neuroprotective effect of GCH on cerebral ischemia. The middle cerebral artery occlusion (MCAO) model was used to produce cerebral ischemia in Sprague-Dawley rats. Subjects were treated with GCH (50 or 200 mg/kg) or vehicle alone (controls) 0 and 2 hours after MCAO. The functional status was tested 24 hours after MCAO by neurological examination (clinical score) and by series of motor function tasks (foot placement and parallel bar crossing). RESULTS: The infarct volume was determined by 2,3,5-triphenyltetrazolium chloride staining 24 hours after surgery, and the expression of cyclooxygenase-2 was determined by immunohistochemistry. The clinical score of the GCH-treated group (200 mg/kg) was significantly lower than that of the control group (p<0.05), indicating fewer neurological deficits. The impairment of motor functions induced by MCAO was significantly reduced by the administration of GCH (p<0.05). The infarct volume was significantly smaller in the GCH-treated group (203.1 +/- 40.2 mm(3), p<0.05), as compared to the control group (377.8 +/- 32.6 mm(3)). The level of motor function in the GCH-treated group was associated with reduced infarct volume. In the analysis of immunohistochemistry, GCH treatment markedly inhibited the ischemia-induced expression of PTGS2 (prostaglandin-endoperoxidase synthase 2) or cyclooxygenase 2 (COX2), which plays an important role in ischemic neuronal cell death. CONCLUSION: The results showed that GCH reduced the infarct size and the functional deficits in MCAO rats.

Effects of Platycodon grandiflorum on lipopolysaccharide-stimulated production of prostaglandin E2, nitric oxide, and interleukin-8 in mouse microglial BV2 cells.

The roots of Platycodon grandiflorum, which belongs to the Campanulaceae family, have been used as a food material and as a traditional Oriental medicine. The effect of P. grandiflorum against lipopolysaccharide (LPS)-stimulated inflammation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, reverse transcription-polymerase chain reaction, prostaglandin E(2 )(PGE(2)) immunoassay, nitric oxide (NO) detection assay, and interleurkin-8 (IL- 8) immunoassay on BV2 microglial cells. The aqueous extract of P. grandiflorum was shown to suppress PGE(2 )synthesis and NO production by inhibiting LPS-stimulated cyclooxygenase (COX)-2 activity and expression of inducible NO synthase (iNOS) mRNAs. In addition, the treatment with P. grandiflorum reduced the LPS-induced IL-8 release. These results suggest that P. grandiflorum inhibits PGE(2) and NO production through its suppression of LPS-induced COX-2 and iNOS expression, and also reduces IL-8 secretion by microglial cells.

Effects of ephedrae herba on melanogenesis and gene expression profiles using cDNA microarray in B16 melanocytes.

Ephedrae Herba (EH) is obtained by drying the stems of Ephedra sinica Stapf (family Ephedraceae). EH has been used clinically to treat colds and to reduce edema in skin. The effects of EH on melanogenesis were studied in B16 murine melanocytes. The tyrosinase activity and melanin content were measured after incubation with EH. Both reverse transcription-polymerase chain reaction and cDNA microarray analysis were used to study the mechanism of EH action. EH decreased tyrosinase activity and melanin content in a dose-dependent manner. EH decreased microphthalmia-associated transcription factor (MITF) and tyrosinase gene expression. These effects were controlled by MITF-mediated regulation of tyrosinase gene expression. EH also altered the expression of about 100 other genes. These results suggest that EH may be used clinically to treat freckles and liver spots.

Effects of egg yolk proteins on the longitudinal bone growth of adolescent male rats.

Hen egg is a nutritional store for a new life. We examined the effect of egg yolk proteins on longitudinal bone growth in the rat. Protein fractions from egg yolk were tested. Milk protein, casein, was used as a control. The bone growth rate was significantly increased by yolk water-soluble protein (YSP, 100 mg/kg) administration for 5 d. The bone morphogenetic protein-2 immunostaining of growth plate was also increased. Considering the results, YSP can be used as a growth-promoting factor.