We monitored the serum concentration of ceftriaxone (CTRX) in order to clarify its pharmacokinetics in pediatric patients. Subjects were 21 patients undergoing CTRX therapy (50 mg/kg/d) for pneumonia from January to September 2007. To determine the serum concentration of CTRX and to obtain other laboratory data, blood samples were drawn just before and after drug administration. To clarify the relationship between protein concentration and the protein binding ratio of CTRX in vitro and in vivo, the effect of human albumin on the binding ratio was investigated. Thereafter, the relationship between the protein binding ratio and the concentration of CTRX in pediatric patients was analyzed. There was no significant correlation between age and the elimination half-life of CTRX. Moreover, no significant differences were observed in the distribution volume and the clearance between pediatric patients and adults. The binding ratios increased with increased CTRX and albumin concentrations in both in vitro and in vivo studies. It was suggested that the CTRX concentration just before administration (i.e., Ctrough) was sufficiently maintained above the mean inhibitory concentration against Streptococcus pneumoniae and Haemophilus influenzae. Therefore, CTRX administration once daily to pediatric patients with pneumonia was shown to be bacteriologically and pharmacokinetically superior in terms of efficacy.
Paeonol (2′-hydroxy-4′-methoxyacetophenone) is known to possess anti-inflammatory and anti-proliferative activities. Recently there is evidence that anti-inflammatory agents may be useful in the setting of angiogenesis-related diseases. Thus in the present study the anti-angiogenic activity of paeonol and its mechanism were investigated in vitro and in vivo. Paeonol significantly inhibited proliferation of basic fibroblast growth factor (bFGF)-stimulated human umbilical vein endothelial cells (HUVECs). Paeonol also significantly inhibited migration and tube formation of bFGF-stimulated HUVECs in vitro. In addition, paeonol significantly suppressed neovessel formation on bFGF-treated chick chorioallantoic membrane (CAM) and disrupted bFGF-induced neovascularization in Matrigel plug assay in vivo. Furthermore, paeonol downregluated Akt phosphorylation in bFGF-stimulated HUVECs and reduced expression of matrix metalloproteinases-2 and -9 in HT1080 human fibrosarcoma cells. The Akt inhibitor LY294002 synergistically potentiated paeonol-induced inactivation of Akt and vascular endothelial growth factor in bFGF-treated HUVECs. Taken together, these findings suggest that paeonol can be a potent suppressor of angiogenesis and metastasis partially through inhibition of Akt signaling pathway and matrix metalloproteinase activity.
FXYD3, also known as Mat-8 (Mammary tumor 8 kDa), is one of mRNAs highly expressed in mouse and human breast cancers. Here, we newly found that FXYD3 protein was also overexpressed in human breast cancer specimens; invasive ductal carcinomas and intra-ductal carcinomas, whereas its expression was low in benign lesion specimens; mastopathy, fibroadenoma and phyllodes tumors. Although human FXYD3 has two isoforms (shorter FXYD3a and longer FXYD3b), there have been no reports in which these two mRNAs were separately quantified. Here, we found that FXYD3a mRNA is a major transcript product expressed in human normal tissues as well as in breast, colon, stomach and pancreas cancer cell lines. In addition, expression level of FXYD3b was much lower than that of FXYD3a in these cancer cell lines. Cell proliferation rate of MCF-7 breast cancer cell line was drastically decreased when FXYD3a and 3b mRNAs were suppressed by the small interfering RNA. These results suggest that FXYD3a protein is highly expressed in breast cancers, and responsible for cancer cell proliferation.
Proanthocyanidins (PAs) are polymer chains of flavonoids known to have a high free radical scavenging capacity. However, their efficacy for use in dermatological health has not been fully explored. In the present study, we investigated the inhibitory property of PAs on melanogenesis and oxidative stress of cultured B16F10 melanoma cells (B16 cells) utilizing both oligomer and polymer PAs that were isolated from freshly crushed persimmon peel. To assess the suppressive effects of PAs against oxidative insults, lipid peroxidation, total reactive species (RS), peroxynitrite (ONOO−), superoxide (˙O2), and nitric oxide (NO˙) were quantitated. In addition, the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio was measured to evaluate the cellular oxidative status. Results showed that the PAs studied had a strong inhibitory effect on the murine tyrosinase and melanin synthesis that was correlated with the modulation of oxidative stress. Thus, our present work produced evidence that in B16 cells, the anti-melanogenic capacity of PAs as shown by the inhibition of tyrosinase and melanin synthesis likely occurs through the suppression of oxidative stress by the ability of PAs to modulate total RS, ˙O2, NO˙, ONOO−, lipid peroxidation, and redox balance.
In our previous report, clofibric acid increased both the enzyme activities of peroxisomes (catalase and fatty acyl-CoA oxidase) and the secretion of progesterone in immortalized human extravillous trophoblast cells (TCL-1) (F. Hashimoto et al., Biochem. Pharm., 68, 313 (2004)). WY-14643 is reported to be stronger inducer of peroxisomes in rodents than clofibric acid. Therefore, the effects of WY-14643 on the activities of peroxisomal enzymes and hormone secretion in TCL-1 were studied. After incubation for 3 d with WY-14643, WY-14643 (≧0.15 mM) suppressed the rate of increase in DNA and protein. The specific activities of catalase were increased by 0.1 mM WY-14643. The specific activities of fatty acyl-CoA oxidase were hardly changed by WY-14643. The concentration of progesterone in the medium was increased by 0.1 mM WY-14643, but human chorionic gonadotropin was decreased by 0.2 mM WY-14643. After a discontinuous Nycodenz-density gradient centrifugation of the light mitochondrial fraction of the cells, catalase activity was distributed in lower density fractions than cytochrome-c oxidase (a mitochondria marker enzyme) activity, but the distribution was not changed by WY-14643. These results suggest that WY-14643 inhibits the proliferation of trophoblast cells. The density of peroxisomes in human trophoblast cells is lower than that of mitochondria, and it is not affected by WY-14643. WY-14643 may increase the progesterone secretion. Effects of WY-14643 on metabolism of human trophoblast cells are different from those of clofibric acid.
Biguanides are known to have a serious side effect, lactic acidosis. We previously reported that buformin suppressed the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPD) and suggested that this decrease was one of the causes of lactic acidosis. In this study, we examined the signaling pathway and regulatory factors for the expression of the GAPD gene triggered by metformin in HepG2 cells. The mRNA and protein expression of GAPD, detected by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively, decreased upon treatment of the cells with 10 mM metformin for 24 h. Under the conditions, metformin induced phosphorylation of AMP-activated protein kinase (AMPK). The expression of GAPD mRNA decreased on treatment with an activator for AMPK, 5-amino-imidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR). Inhibitors for signal transducers, Compound C, H-89, and MDL-12,330A, restored the level of GAPD mRNA. A luciferase reporter plasmid containing bp −1795 to +57 of the 5′-flanking region of the GAPD gene was constructed for a reporter gene assay. The luciferase activity in transfectants decreased on incubation with metformin. A mutant reporter plasmid with an altered cAMP-response element (CRE) counteracted the metformin-mediated repression of GAPD transcription. These results suggest that signal transducers, adenylate cyclase (AC), protein kinase A (PKA), and AMPK, are involved in the signaling pathway triggered by metformin and CRE-binding protein is one of the transcription factors for the GAPD gene down-regulated by metformin.
Hypoxia-inducible factor (HIF) is a heterodimer composed of HIF-α and -β, and to date, three HIF-α subunits, HIF-1α, -2α, and -3α, have been identified. Among these HIF-α subunits, HIF-1α represses peroxisome proliferator activator γ2 gene expression and then inhibits adipogenesis, and HIF-2α is induced during adipose differentiation and functions as a positive regulator of adipogenesis. We here found that like HIF-2α, HIF-3α was induced during 3T3-L1 adipose differentiation. Reporter gene analysis revealed that HIF-2α enhanced the promoter activity of the 5′-flanking region of the mouse HIF-3α gene (nucleotides −2710 to +56), while HIF-1α had no substantial effects on the promoter activity. These results suggested that HIF-2α, which was induced during adipogenesis, might regulate the HIF-3α gene expression. Furthermore, the 5′-deletion analysis revealed that the sequence between −251 and −228 in mouse HIF-3α promoter was essential in response to HIF-2α. We further examined the effect of ectopic expression of HIF-3α in 3T3-L1 cells on adipose differentiation and found that ectopic expression of HIF-3α at the early stage of differentiation induced the expression of several kinds of adipocytes-related genes and enhanced adipogenic potential. HIF-3α, which is induced by HIF-2α, might function as an accelerator of adipogenesis.
Proteinase-activated receptor-2 (PAR2) may be an important regulator of skin mast cell function during cutaneous inflammation and hypersensitivity. However, little is known of the role of PAR2 in allergic pruritus, because mast cells, which are thought to be responsible for this symptom, can release a number of different pruritogens. In the present study, we investigated the effects of several agents on passive cutaneous anaphylaxis-induced scratching behavior in ICR mice. As a result, cetirizine and ketanserin produced dose-dependent inhibition of scratching behavior induced by passive cutaneous anaphylaxis. Combined cetirizine with ketanserin exhibited significant inhibitory effects for the number of passive cutaneous anaphylaxis-induced scratching behavior. Pretreatment of the experimental animals with PAR2-neutralizing antibody and protease inhibitor leupeptin significantly inhibited passive cutaneous anaphylaxis-induced scratching behavior. Furthermore, we found that topical application of tacrolimus significantly reduced the number of scratching behavior induced by passive cutaneous anaphylaxis in a dose-dependent manner. Combined cetirizine with tacrolimus also exhibited significant inhibitory effects for the number of passive cutaneous anaphylaxis-induced scratching behavior. Tacrolimus in doses of 3% and 10% significantly inhibited tryptase-induced scratching behavior. These results suggest that PAR2 may be involved in passive cutaneous anaphylaxis-induced scratching behavior and tacrolimus produces an anti-allergic pruritus effect in ICR mice.
Adipose differentiation-related protein (ADRP) is associated with intracellular lipid droplets that accumulate neutral lipids. Here we report that ADRP expression in a human choriocarcinoma cell line, BeWo, is regulated through activation of retinoid X receptor (RXR) and peroxisome proliferator-activated receptor-γ (PPARγ). Incubation with docosahexaenoic acid (DHA) or oleic acid (OA) induced accumulation of triacylglycerol (TG) and ADRP in BeWo cells. DHA-induced ADRP expression was suppressed by RXR-antagonists, PA452 and HX531. However, oleic acid-induced ADRP expression was not blocked by the RXR-antagonists but by a PPARγ-antagonist. Treatment of the cells with RXR-agonists, HX630 and PA024, increased Adrp transcripts, however, they alone did not change the levels of ADRP protein and TG in BeWo cells. Induction of ADRP protein was observed in the presence of a proteasome inhibitor, suggesting that ADRP is degraded under lipid-poor conditions. These results suggest that expression of ADRP is in part regulated by RXR and PPARγ transcription factors, and DHA induces ADRP by acting as an endogenous agonist of RXR.
In the vertebrate circadian feedback loop, CLOCK:BMAL heterodimers induce the expression of Cry genes. The CRY proteins in turn inhibit CLOCK:BMAL-mediated transcription closing the negative feedback loop. Four CRYs, which all inhibit CLOCK:BMAL-mediated transcription, exist in zebrafish. Although these zebrafish Crys (zCry1a, 1b, 2a, and 2b) show a circadian pattern of expression, previous studies have indicated that the circadian oscillation of zCry1a could be CLOCK:BMAL-independent. Here we show that abrogation of CLOCK:BMAL-dependent transcription in zebrafish cells by the dominant negative zCLOCK3-DeltaC does not affect the circadian oscillation of zCry1a. Moreover, we provide several lines of evidence indicating that the extracellular signal-regulated kinase (ERK) signaling cascade modulates the circadian expression of zCry1a gene in constant darkness. Taken together, our data strongly support the notion that circadian oscillation of zCry1a is CLOCK:BMAL-independent and further indicate that mechanisms involving non-canonical clock genes could contribute to the circadian expression of zCry1a gene in a cell autonomous manner.
The Epstein–Barr virus (EBV)-encoded latency protein Epstein–Barr nuclear antigen 2 (EBNA2) is a nuclear transcriptional activator that is essential for EBV-induced cellular transformation. In a previous study, we demonstrated that EBNA2 interacts with signal transducer and activator of transcription 3 (STAT3), a signal transducer for an interleukin (IL)-6 family cytokine, and enhances its transcriptional activity. Here, we show that overexpression of a corepressor, silencing mediator of retinoic acid and thyroid hormone receptor (SMRT), decreases the EBNA2-mediated enhanced STAT3 activation. Furthermore, small-interfering RNA-mediated reduction of endogenous SMRT expression augments the EBNA2-mediated enhanced STAT3 activation. Importantly, EBNA2 reduces interactions between STAT3 and SMRT. These data demonstrate that EBNA2 acts as a transcriptional coactivator of STAT3 by influencing the SMRT corepressor complex.
Hesperidin, a flavonoid obtained from citrus fruits, is known to have multiple biological activities and antimicrobial activities for human viruses; however, hesperidin has very low solubility in water and the target molecule of hesperidin for influenza virus remains unknown. A water-soluble derivative of hesperidin, glucosyl hesperidin (GH), which was synthesized by regioselective transglycosylation with cyclodextrin glucanotransferase, has been reported to have biological activities that are as or stronger than those of hesperidin. To determine the inhibitory effect of GH on influenza A virus (IAV) infection, Madin–Darby canine kidney (MDCK) cells were treated with GH before, at the same time as, and after IAV inoculation. GH treatment before IAV inoculation had no effect on virus replication, whereas, treatment with GH at the same time as or after IAV inoculation induced distinct reduction in IAV replication. Inhibition analysis of GH against two surface glycoprotein spikes of IAV revealed that GH prevents IAV replication by inhibition of viral sialidase activity that is involved in the entry and release stages on IAV infection but not by receptor binding inhibition. GH had no cytotoxic effects on MDCK cells in a dose range of 0—25 mM. Our results provide useful information for the development of novel sialidase inhibitors for influenza prevention.
Risedronate, a nitrogen-containing bisphosphonate, is widely used in the clinical field for the treatment of osteoporosis. Risedronate is known to exert its effects through binding to hydroxyapatite in bone tissue, inhibiting osteoclastic activity, and inducing apoptosis of osteoclasts. The purpose of this study was to determine the effects of risedronate on osteoclast differentiation in vitro and on an inflammatory bone loss model in vivo. Risedronate inhibited osteoclast differentiation in co-culture of bone marrow cells (BMCs) and osteoblasts, and suppressed receptor activator of nuclear factor (NF)-κB ligand (RANKL)-mediated osteoclast differentiation from bone marrow-derived macrophages (BMMs) in a dose-dependent manner without toxicity. Risedronate significantly inhibited expression of c-Fos and nuclear factor of activated T cells (NFAT) c1 induced by RANKL. To examine the effect of risedronate on bone loss in vivo, we used a mouse model of lipopolysaccharide (LPS)-mediated bone loss. Micro-CT analysis of the femurs showed that LPS treatment caused bone loss. However, bone loss was significantly attenuated in mice administered with risedronate. Taken together, we conclude that risedronate exerts beneficial effects on osteoporosis by inhibiting osteoclast differentiation both directly and indirectly. In infectious conditions, the inhibitory effect of risedronate on bone erosion was excellent. Thus risedronate could be a treatment option for osteoporosis caused by inflammatory and infectious conditions.
Estrogen-related receptors alpha (ERRα) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) function coordinately to regulate mitochondrial biogenesis and oxidative phosphorylation particularly in muscle tissue. In this study, we addressed the consequences of suppressing the activity of ERRα in L6 myotubes using an ERRα inverse agonist XCT-790. We found that treating differentiated L6 myotubes with XCT-790 reduced the expression of PGC-1α and suppressed mitochondrial biogenesis. Additionally, XCT-790 increased the production of reactive oxygen species (ROS) which in turn induced the expressions of glucose transporters 1, 2, and 5 leading to an increase in glucose uptake and uncoupling protein 3 leading to a reduction of mitochondrial membrane potential. Thus, suppressing the activity of ERRα which is primarily responsible for controlling β-oxidation would nonetheless indirectly affect glucose uptake in a ROS-dependent manner.
The concentration of NZ-419 (5-hydroxy-1-methylimidazolidine-2,4-dione), an intrinsic antioxidant, has been shown to increase in the sera of animals and patients with chronic renal failure (CRF). This is the first report that orally administered exogenous NZ-419 prevents the initiation and/or progression of CRF in rats using an adenine-loaded model. After 24 d of adenine loading, there was a ca. 90% decrease in creatinine clearance (CCr) in the control rats. Treatment with NZ-419 from the beginning significantly inhibited the decrease in CCr and also the increase in serum creatinine (sCr). Bio-markers for in vivo hydroxyl radicals, the serum methylguanidine (sMG) level, and sMG/sCr molar ratio, not only in serum but also in the urine, kidney, liver, and muscle indicated that NZ-419 inhibited the increase in oxidative stress induced by CRF in rats. An increase of guanidinosuccinic acid, an another bio-marker of oxidative stress, was also inhibited with NZ-419.
Magnolol was previously shown to inhibit genotoxicity induced by environmental mutagens both in vitro and in vivo. Here, we investigate the effects of the magnolol-containing kampo (traditional) medicines Hange-koboku-to, Dai-joki-to, and Goshaku-san, as well as Magnoliae Cortex, on the clastogenesis induced by benzo(a)pyrene (B(a)P) using the mouse micronucleus test. The mice were first treated with a single intraperitoneal injection of B(a)P, followed by a single oral dose of Hange-koboku-to, Dai-joki-to, Goshaku-san, or Magnoliae Cortex. Peripheral blood specimens were prepared 48 h after B(a)P administration and analyzed using the acridine orange (AO) technique. The anti-clastogenic mechanisms employed by the kampo medicines and Magnoliae Cortex were also investigated by evaluating in vivo CYP1A1 activity using the zoxazolamine paralysis test. Results show that Hange-koboku-to, Dai-joki-to, and Magnoliae Cortex, which contain high levels of magnolol, significantly inhibited the clastogenesis induced by B(a)P and sufficiently inhibited in vivo CYP1A1 activity. In contrast, Goshaku-san, which contains low levels of magnolol, had little inhibitory effect on clastogenicity and in vivo CYP1A1 activity. These findings suggest that magnolol is a major contributor to the inhibition of B(a)P-induced clastogenesis, and that kampo medicines exert significant anti-clastogenic effects.
The edible mushroom Lentinula edodes (shiitake) contains many bioactive compounds. In the present study, we cultivated L. edodes mycelia in solid medium and examined the hot-water extract (L.E.M.) for its suppressive effect on concanavalin A (ConA)-induced liver injury in mice. ConA injection into the tail vein caused a great increase in the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. The intraperitoneal administration of L.E.M. significantly decreased the levels of the transaminases. L.E.M. contains many bioactive substances, including polysaccharides and glucan, which could be immunomodulators. Since ConA-induced liver injury is caused by the activation of T cells, immunomodulating substances might be responsible for the suppressive effect of L.E.M. L.E.M. also contains phenolic compounds that are produced from lignocellulose by mycelia-derived enzymes. The major phenolics in L.E.M., syringic acid and vanillic acid, were intraperitoneally injected into mice shortly before the ConA treatment. Similar to L.E.M., the administration of syringic acid or vanillic acid significantly decreased the transaminase activity and suppressed the disorganization of the hepatic sinusoids. In addition, the inflammatory cytokines tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6 in the serum increased rapidly, within 3 h of the ConA administration, but the administration of syringic acid or vanillic acid significantly suppressed the cytokine levels. Together, these findings indicate that the phenolic compounds in L.E.M. are hepatoprotective through their suppression of immune-mediated liver inflammation.
Accumulation of unfolding or misfolded proteins within the lumen of the endoplasmic reticulum (ER) triggers ER stress, and sustained ER stress ultimately leads to cell death. Both of these events are involved in the activation of glucose-regulated protein of 78 kDa (GRP78, also known as Bip), CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP, also known as growth arrest and DNA damage-inducible gene 153 (GADD153)), and caspase-12. ER stress has been shown to be involved in neurodegenerative disorders, such as Alzheimer, Parkinson, and polyglutamine diseases. We previously showed that genipin, a natural iridoid compound, has a protective effect against amyloid-β (Aβ)-induced cytotoxicity. Here, we studied the protective effects of genipin on cytotoxicity induced in Neuro2a cells by the specific ER stress inducer tunicamycin (TM). TM treatment significantly reduced cell viability in a dose-dependent manner. Genipin dramatically rescued the cells against TM-induced cell death. In addition, genipin suppressed ER stress-induced upregulation of CHOP and GRP78. These data suggest that genipin is effective at protecting against neurodegenerative disorders.
Many lines of evidences have shown that Panax ginseng exhibits beneficial effects on cardiovascular systems. We previously demonstrated that ginsenoside Rg3 (Rg3), one of active ingredients of Panax ginseng, inhibits Ca2+ channel currents in a stereospecific manner and affects the steady-state activation but not inactivation. This points a possibility that Rg3 regulates Ca2+ channels through specific interaction site(s) for Ca2+ influx inhibition through Ca2+ channels. However, it was not known how Rg3 interacts with Ca2+ channel proteins. In the current study, we sought to identify these site(s) in Xenopus oocytes expressing cardiac wild-type and mutant L(α1C)-type Ca2+ channels using the two-microelectrode voltage-clamp technique. To this end, we assessed how various point mutations of the L-type Ca2+ channel affected the Rg3 action. Mutations of L427R, N428R and L431K in transmembrane domain-I-segment 6 (IS6) of the channel significantly attenuated the Rg3 action and caused rightward shifts in dose–response curves. Rg3 treatment produced a negative shift in the inactivation voltage but did not alter the steady-state activation voltage, and none of the mutant channels affected the Rg3-induced negative shift of inactivation voltage. Rg3 had no effects on inactivation time constant in wild-type and mutant channels. These results indicate that Rg3 inhibition of L-type Ca2+ channel currents is attenuated by mutations of Leu427, Asn428 and Leu431 in transmembrane IS6 residues. Leu427, Asn428 and Leu431 residues of the L-type Ca2+ channel play important roles in the Rg3 effect on channel properties.
Because chronic vincristine (VCR) treatment causes neuropathic pain, as demonstrated by mechanical allodynia, effective therapeutic strategy is required. In this study, we investigated a suppressive effect of imipramine (IMI) on VCR-induced mechanical allodynia in mice. VCR (0.1 mg/kg, intraperitoneally (i.p.)) was administered once per day for 7 d in ICR male mice. Mechanical allodynia was evaluated by withdrawal response using von Frey filaments. In VCR-treated mice, mechanical allodynia was observed on day 3, 7, and 14. On day 14, morphine (3 mg/kg, subcutaneously) slightly but significantly suppressed VCR-induced mechanical allodynia. The percent inhibition by morphine of VCR-induced mechanical allodynia was less than that of the λ-carrageenan-induced inflammatory pain and was similar to that of nerve injury-induced neuropathic pain. Although single administration of IMI (30 mg/kg, i.p.) had no effect on VCR-induced mechanical allodynia, repeated administration of IMI (30 mg/kg, i.p.) for 7 d significantly suppressed VCR-induced mechanical allodynia. Suppressive effects by repeated IMI administration were observed in both early phase (day 0—6) and late phase (day 7—13) of VCR-induced mechanical allodynia. These results suggest that chronic VCR administration induces opioid analgesics-resistant mechanical allodynia, and repeated IMI administration may be an effective therapeutic approach for the treatment of VCR-induced mechanical allodynia.
Adult T-cell leukemia (ATL) is a severe chemotherapy-resistant malignancy associated with prolonged infection by the human T cell-lymphotropic virus 1 (HTLV-1). One approach to prevent the onset of ATL is to inhibit the growth/transmission of HTLV-1 infected cells using arsenic trioxide (As2O3). However, there are no reports on the transmission inhibitory effect of As2O3. In this study, we reveal that As2O3 exerts an inhibitory effect on syncytium formation between HTLV-1 infected MT-2 and HeLa cells. In addition, Western blot analysis revealed that the HTLV-1 derived envelope protein gp46 was down regulated by As2O3 treatment, suggesting that As2O3 may inhibit HTLV-1 virus transmission via down-regulation of gp46. These results suggest that As2O3 may be a promising drug to treat refractory HTLV-1-related diseases.
Ephedrae herba has been used in traditional Chinese and Japanese (Kampo) medicine from ancient times, with the primary resource being in China. In the present study, a field survey as well as molecular and chemical assessments were conducted on Ephedra plants in Mongolia to clarify whether they could be an alternative resource of the Ephedrae herba used in Japanese Kampo medicine. Ephedra sinica, E. equisetina, E. przewalskii, E. regeliana, E. monosperma and an unknown taxon (ESP) collected in Mongolia were divided into 9 genotypes on the basis of nucleotide sequences of 18S ribosomal RNA (rRNA) gene and trnK gene. E. sinica, E. equisetina, and E. monosperma presented completely identical sequences to the corresponding species from China. The sequences of trnK gene and 18S rRNA gene provide a useful index for identification and taxonomic classification of Mongolian Ephedra plants. Quantitative analysis of 5 ephedrine alkaloids revealed that almost all Mongolian Ephedra plants contained high amounts of total ephedrine alkaloids (TAs, 1.86—4.90%) and a high percentage of pseudoephedrine in TAs differed obviously from the Chinese. E. sinica and E. equisetina found in eastern and central Mongolia, showing total contents of ephedrine and pseudoephedrine higher than 1.43%, were potential new resources of Japanese Pharmacopoeia grade Ephedrae herba.
Propolis, a honeybee product, has become popular as a food and alternative medicine. Its constituents have been shown to exert pharmacological effects, such as anticancer, antimicrobial, and anti-inflammatory effects. The present study was performed to investigate whether Brazilian green propolis exerts antihypertensive effects in spontaneously hypertensive rats (SHR) and which constituents are involved in its effects. Brazilian green propolis was extracted with ethanol and subjected to LH-20 column chromatography eluted with ethanol. The ethanol-eluted fractions at 10 mg/kg were administered orally to SHR for 14 d. Significant decreases in blood pressure were observed in fractions 6 and 7. The active constituents were purified and identified to be four flavonoids: dihydrokaempferide and isosakuranetin in fraction 6 and betuletol and kaempferide in fraction 7. These flavonoids at 10 mg/kg were administered orally to SHR for 28 d, and as a result, isosakuranetin, dihydrokaempferide and betuletol produced significant decrease in blood pressure, especially marked were the effects observed in the group that received isosakuranetin. Brazilian green propolis, fractions 6 and 7, and the 4 active constituents relaxed isolated SHR aorta in a concentration-dependent manner. Therefore, these finding suggest that the vasodilating action may be partly involved in the mechanism of antihypertensive effect. Hence, the ethanol extract of Brazilian green propolis and its main constituents may be useful for prevention of hypertension.
Rhinacanthone, a main bioactive naphthoquinone, isolated from roots of Rhinacanthus nasutus KURZ, (family Acanthaceae), a Thai traditional medicine, has been reported to possess anticancer effects, although the anticancer mechanism is still unclear. Therefore, we investigated the effects of rhinacanthone on cell proliferation, cell cycle progression and apoptosis induction in human cervical carcinoma (HeLa) cells. β-Lapachone, an anticancer drug having a chemical structure related to rhinacanthone, was used as a positive control. The results demonstrated that rhinacanthone inhibited proliferation of HeLa cells in a dose-dependent manner and had greater efficacy than that of β-lapachone: IC50 values of the compound ranged from 1.2±0.1 to 5.5±0.86 μM for 2—24 h time periods. Rhinacanthone-treated HeLa cells displayed several apoptotic features as evidenced by the appearance of chromatin condensation, internucleosomal DNA fragmentation, increase in the proportion of sub G1 apoptotic cells, and externalization of annexin-V. The apoptotic processes by the treatment with rhinacanthone involved in a marked increase in the level of pro-apoptotic protein Bax and decrease in the levels of anti-apoptotic proteins Bcl-2 and survivin as well as subsequent activation of caspase-9 and caspase-3. Moreover, rhinacanthone increased the expression of apoptosis-inducing factor (AIF) which would translocate from mitochondria to nucleus through cytosol, and induce apoptosis through caspase independent signaling pathway. Taken together, our findings for the first time demonstrate that rhinacanthone-induced apoptosis in HeLa cells is mediated primarily through the mitochondria-dependent signaling pathway, suggesting that it may be a promising agent for the treatment of human cervical cancer.
In the course of our search for anti-angiogenic substances, pyripyropenes A (1), B (2), and D (3) were re-discovered as selective anti-proliferative substances against human umbilical vein endothelial cells (HUVECs) from a marine-derived fungus of Aspergillus sp. Pyripyropenes showed potent anti-proliferative activity against HUVECs with IC50 values of the range of 0.1—1.8 μM, which were cytostatic at 0.05 to 20 μM. The selective index was more than 55-fold in comparison with those of several tumor cell lines. Compound 1 inhibited vascular endothelial growth factor (VEGF)-induced migration and tubular formation of HUVECs, while 1 showed no effect on the VEGF-induced phosphorylations of extracellular signal-regulated kinase (ERK)1/2, p38, and Akt. Pyripyropenes were originally isolated as an inhibitor of acyl-CoA: cholesterol acyltransferase (ACAT-2). While, the expression level of ACATs between HUVECs and other tumor cell lines did not correspond to the selective index of the anti-proliferative activity of compound 1. Moreover, ACATs inhibitor, 2,2-dimethyl-N-(2,4,6-trimethoxyphenyl)dodecanamide (CI-976), showed growth inhibitory activity with only poor selectivity (2.4-fold) between HUVECs and human epidermoid carcinoma KB3-1 cells.
Scavenger receptor class B type I (SR-BI), as well as its human homologue CLA-1, plays an important role in reverse cholesterol transport (RCT) as high density lipoprotein (HDL) receptor. Using a previously developed cell-based screening model for CLA-1 up-regulators, pratensein, was shown to present activity in elevating CLA-1 transcriptional level. In this study, three other isoflavones including formononetin, genistein and daidzein were also shown to up-regulate CLA-1 transcriptional activity in the cell-based reporter assay. The effects of pratensein on up-regulating CLA-1 expression were demonstrated at both mRNA and protein levels, and validated by its increasing of 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate-labeled (DiI)-HDL uptake in HepG2 cells. Furthermore, the cis-elements responsible for the pratensein up-regulatory effects were mapped to the −1055/−182 bp fragment of CLA-1 promoter in HepG2 cells. These findings might provide a new molecular mechanism by which isoflavones potentially prevent atherosclerosis.
To evaluate the residence of chitosan-coated emulsion (CE) containing indomethacin in tears, the drug retention of CE in tear fluid was compared with non-coated emulsion (NE) after instillation in rabbit eyes. CE had mean concentrations 3.6-fold and 3.8-fold higher than NE at 0.5 h and 0.75 h after instillation, respectively. Mean residence time and half-life of CE were lengthened to 1.5-fold and 1.8-fold those of NE, respectively. Volume of distribution of CE in tear fluid was also 1.6-fold greater than that of NE. These findings indicated that retention of the drug in tears was appreciably prolonged by chitosan-coated emulsion, and that CE had higher distribution on the ocular surface than NE. The drug levels in cornea, conjunctiva, and aqueous humor at 1 h after instillation were clearly higher than those of NE. In a generalized ocular pharmacokinetic model, the ratio of CE to NE for peak concentration values (Cmax) and the area under the concentration/time curve (AUC) nearly corresponded to aqueous humor levels in vivo. Additionally, tensile testing showed that the force of detachment between CE and mucin was significantly larger than that of emulsion containing hydroxypropylmethyl cellulose (HPMCE) with a viscosity similar to CE; the forces of detachment of CE and HPMCE measured using phosphate-buffered saline (PBS) were almost the same since these formulations have similar viscosity. Mucoadhesive strength of CE was confirmed by measurements of force of detachment between formulations and mucin. The residence time of the emulsion in tear fluid was prolonged by chitosan coating because of its mucoadhesive properties.
The mechanism of the nonlinear concentration dependence of intestinal absorption of (1→3)-β-D-glucan was studied using in situ rat intestinal perfusion, as well as the in vitro Ussing-type chamber method mounted with rat intestinal tissue. The intestinal absorption rate constant of a (1→3)-β-D-glucan, laminaran, evaluated by the loop method increased significantly with increasing concentration of laminaran up to 0.5 μM in a nonlinear fashion and tended to decrease at higher concentrations. Mucosal-to-serosal directed permeation of the laminaran across rat ileal sheets evaluated by the in vitro Ussing-type chamber method also decreased in a dose-dependent fashion. Serosal-to-mucosal directed permeation decreased in a concentration-dependent manner. In addition, the serosal-to-mucosal flux was reduced in the presence of metabolic inhibitor, 2,4-di-nitrophenol. These results suggest that laminaran is secreted into the intestinal lumen predominantly by the efflux transporting system. We conclude that intestinal transport of (1→3)-β-D-glucan involves specialized transporter or something similar in both absorptive and secretory directions, and complex nonlinear intestinal absorption characteristics can be ascribed to the participation of multiple transport mechanism.
Development of technology to deliver foreign gene(s) to a specific organ/tissue is one of the major challenges in gene therapy. Here, we show liver- and lobe-specific gene transfer following the continuous microinstillation of plasmid DNA (pDNA) onto the liver surface in mice. Naked pDNA was continuously instilled onto the right medial liver lobe using syringe pump in male ddY mice. Our previous studies showed liver- and lobe-selective gene expression after instillation of 30 μl of pDNA solution onto the liver surface, but gene expression was also found in the other liver lobe, kidney and spleen. To improve target site selectivity of gene expression, the instillation volume was decreased; however, non-specific gene expression in the other liver lobe and diaphragm was still detected. To prevent immediate diffusion of the pDNA solution, we performed continuous microinstillation of pDNA using a syringe pump; as a result, target site selectivity was greatly improved. As for instillation speed, 5 min infusion was enough to prevent diffusion of pDNA solution. Furthermore, transfection efficiency in the target site was maintained when instillation speed was slowed. Wiping off residual pDNA solution from the applied liver lobe resulted in a further improvement in selectivity, suggesting not only immediate diffusion, but also gradual diffusion, are important factors for successful target site-specific gene transfer. Information in this study will be useful for further development of an effective gene delivery system targeted to a specific organ/tissue by use of other non-viral or viral vectors.
The nuclear delivery process is a crucial barrier to successful gene delivery, especially in non-dividing cells. We previously proposed a novel strategy for the nuclear delivery of plasmid DNA (pDNA), in which the pDNA is encapsulated in lipid bilayers that had been modified with nucleus-targeting signals, including nuclear localizing signals derived from SV40 (NLS) or sugar units. In the present study, we report on an investigation of the effect of the topology of the liposome-modified NLS on its ability to bind to the isolated nucleus. NLS was directly attached to a liposome (NLS-Lip) by incorporating stearylated NLS (STR-NSL), or by modification with a polyethyleneglycol (PEG) spacer (NLS-PEG-Lip). NLS-unmodified liposomes (PEG-Lip) were used as a control. The liposomes, after labeling with 7-nitrobenz-2-oxa-1,3-diazole (NBD), were incubated with a cell homogenate derived from JAWS II cells, followed by isolation of the nuclear fraction by centrifugation. The PEG-Lip preparation showed negligible binding to the nucleus. In contrast, the binding of NLS-Lips to the nucleus gradually increased in a STR-NLS density-dependent manner. Interestingly, the binding of NLS-PEG-Lips to the nucleus is highly effective even at low density, suggesting that the presence of the PEG spacer is an important factor in improving the binding activity of NLS-modified liposomes to the nucleus. This information will be useful for the design of nucleus-targeting carriers.
Membrane type-1 matrix metalloproteinase (MT1-MMP) expressed on the tumor cell surface activates pro-MMP-2 and pro-MMP-13 to exacerbate the malignancy, suggesting its suitability as a target molecule for diagnosis by in vivo molecular imaging. Thus, we prepared radiolabeled anti-MT1-MMP monoclonal antibody (mAb) as a novel radiolabeled probe for detecting MT1-MMP in vivo and evaluated its usefulness in breast tumor-bearing rodents. 99mTc-anti-MT1-MMP mAb was prepared using HYNIC as a bifunctional chelating agent and immunoreactivity was evaluated by flow cytometry. MT1-MMP expression in breast carcinoma cells (rat: Walker-256 and MRMT-1, mouse: FM3A) was measured by Western blotting. In vivo biodistribution was examined for 48 h using tumor-implanted rodents followed by estimation of radiation absorbed by a standard quantitation platform Organ Level Internal Dose Assessment (OLINDA). 99mTc-anti-MT1-MMP mAb was obtained with 84% immunoreactivity to MT1-MMP and more than 92% radiochemical purity. MT1-MMP was highly expressed in all malignant cells. Tumor radioactivity increased with time after administration and reached 3 to 5 times higher values at 24 h post-injection than those at 1 h. Other organs, including the stomach, showed decreasing values over time. Tumor to blood ratios increased with time and reached more than 1.3 at 48 h. The effective dose was <5.0 μSv/MBq. The results suggest that 99mTc-anti-MT1-MMP mAb is a promising probe for future diagnosis of breast tumors by in vivo nuclear medical imaging.
The purpose of this study is to investigate whether a synthetic retinoid Am80 (tamibarotene) exhibits any improving effects on amyloid precursor protein (APP)23 mice, a model of Alzheimer's disease. Am80 was orally administered in feed to 20-week (5-month)-old APP23 mice at a dose of 0 (control) or 0.5 mg/kg/d for 14 weeks. The Am80 treatment reduced significantly the insoluble Aβ levels in brain, in particular Aβ42, while it gave no apparent effects on the soluble Aβ levels. The results suggest that oral administration of Am80 may have potency to reduce the extracellular Aβ42 of insoluble and possibly oligomeric or protofibril forms, which are related to the cause and/or progression of Alzheimer's disease. The Am80 treatment showed no significant effect on spatial learning and memory of APP23 mice by Morris water maze analysis. The main reason for the absence of significance seems based on the large deviation and some mice both in the treated and the non-treated groups would neither swim nor make efforts to reach the platform.