The gastric H+,K+-ATPase is a proton pump that is responsible for gastric acid secretion and that actively transports protons and K+ ions in opposite directions to generate in excess of a million-fold proton gradient across the membrane under physiological conditions. This pump is also a target molecule of proton pump inhibitors which are used for the clinical treatment of hyperacidity. In this review, we wish to summarize the molecular regulation of this pump based on mutational studies, particularly those used for the identification of binding sites for cations and specific inhibitors. Recent reports by Toyoshima et al. (2000, 2002) presented precise three-dimensional (3-D) structures of the sarcoplasmic reticulum (SR) Ca2+-ATPase, which belongs to the same family as the gastric H+,K+-ATPase. We have studied the structure–function relationships for the gastric H+,K+-ATPase using 3-D structures constructed by homology modeling of the related SR Ca2+-ATPase, which was used as a template molecule. We also discuss in this review, the regulation of cell surface expression and synthesis control of the gastric proton pump.
More than half of differentiating spermatogenic cells undergo apoptosis before maturing into spermatozoa during mammalian spermatogenesis. These cells are selectively and rapidly eliminated through phagocytosis by Sertoli cells, a testicular somatic cell type possessing phagocytic activity. We have investigated the mechanism by which Sertoli cells specifically recognize and phagocytose apoptotic spermatogenic cells and the consequences of phagocytosis. We showed by in vitro as well as in vivo analyses that Sertoli cells recognize apoptotic spermatogenic cells through the binding of their surface receptor, class B scavenger receptor type I, to phosphatidylserine that is expressed on the surface of spermatogenic cells during apoptosis. The inhibition of phagocytosis in live animals resulted in a decrease in the number of epididymal sperm. These results suggest that phosphatidylserine-mediated phagocytosis of apoptotic spermatogenic cells by Sertoli cells is required for the efficient production of sperm.
We have established an enzyme-linked immunosorbent assay suitable for routine monitoring of serum levels of sotalol. Anti-sotalol antibody was obtained by immunizing rabbits with sotalol conjugated with bovine serum albumin using the N-succinimidyl ester method. An enzyme marker was similarly prepared by coupling sotalol with β-D-galactosidase. The detection limit of sotalol by the enzyme-linked immunosorbent assay was approximately 32 ng/ml with 50-μl samples. This assay was specific for sotalol because of very slight cross-reactivity with 4-(methanesulfonylamino)benzonitrile (1.6%), but none with D,L-isoproterenol. Using this assay, drug levels were easily measured in the serum of rabbits after oral administration of sotalol at a single dose of 3 mg/kg. The enzyme-linked immunosorbent assay should be a valuable tool in therapeutic drug monitoring and pharmacokinetic studies of sotalol.
This paper describes the O2-dependent control of the reactivity of nitrogen oxide species for the production of biologically important nitrated and nitrosated compounds. In this study, the effects of O2 on the reactivity of NO, NO2, and ONOO−/ONOOH for nitration of tyrosine (Tyr) and nitrosation of glutathione (GSH) and morpholine (MOR) were examined. NO produced S-nitrosoglutathione (GSNO) and N-nitrosomorpholine (NMOR) through the formation of N2O3 under aerobic conditions, and NO2 produced 3-nitrotyrosine (3-NO2Tyr), GSNO, and NMOR. Transnitrosation from GSNO to MOR was observed only in the presence of O2. Although preformed ONOO−/ONOOH produced all the products under aerobic conditions, the formation of 3-NO2Tyr and GSNO was markedly reduced and the formation of NMOR was enhanced under anaerobic conditions. The reactivity of the CO2 adduct of ONOO− was similarly dependent on O2. 3-NO2Tyr was produced effectively by reaction with ONOO−/ONOOH at the O2 concentration of 270 μM and by reaction with its CO2 adduct at O2 concentrations greater than 5 μM. Generation of ·OH from ONOO−/ONOOH was suppressed under anaerobic conditions. The reactivity of ONOO−/ONOOH and ·OH generation from ONOO− were reversibly controlled by the O2 concentration.
In our attempt to investigate the mechanism of the release of platelet-activating factor (PAF) from cells, the erythroleukemic cell line K562 was preloaded with a radiolabeled PAF analogue having an ethylcarbamyl residue, 1-O-octadecyl-2-O-ethylcarbamyl-sn-glycero-3-phosphocholine (ethylcarbamyl-PAF), that is resistant to the hydrolytic action of PAF acetylhydrolase. Its extracellular release was monitored using an albumin back-extraction method, and its metabolic degradation was analyzed by TLC. Phorbol myristate acetate (PMA) was found to stimulate the release of two radioactive lipids, ethylcarbamyl-PAF itself and its metabolite, 1-O-octadecyl-2-ethylcarbamyl-sn-glycerol, whereas only ethylcarbamyl-PAF was released from the resting cells. The increased release of radioactive lipids in PMA-stimulated cells was suggested to be due to stimulated degradation of intracellular ethylcarbamyl-PAF into the cell-permeable metabolite. Thus K562 cells have much less capacity to release intact PAF-like lipid in comparison with its high ability to uptake exogenously added PAF analogues previously described by us and others.
The effects of two kinds of oral cephalosporins, cefixime and cefdinir, on cytochrome P450 (CYP) activities in human hepatic microsomes were investigated. Both cefixime and cefdinir at 2 mM concentration neither inhibited nor stimulated CYP1A1/2-mediated 7-ethoxyresorufin O-deethylation, CYP2A6-mediated coumarin 7-hydroxylation, CYP2B6-mediated 7-benzyloxyresorufin O-debenzylation, CYP2C8/9-mediated tolbutamide methylhydroxylation, CYP2C19-mediated S-mephenytoin 4′-hydroxylation, CYP2D6-mediated bufuralol 1′-hydroxylation, CYP2E1-mediated chlorzoxazone 6-hydroxylation, CYP3A4-mediated nifedipine oxidation, or CYP3A4-mediated testosterone 6β-hydroxylation. The free fractions of cefixime and cefdinir in the incubation mixture, which were measured by ultracentrifugation, were 86.1—93.8% and 94.1—97.8%, respectively. These results suggest that both cefixime and cefdinir would not cause clinically significant interactions with other drugs, which are metabolized by CYPs, via the inhibition of metabolism.
Transporter associated with antigen processing (TAP)-like (TAPL) is a half-type ATP-binding cassette (ABC) transporter with sequence similarity to TAP1 and TAP2 and is highly conserved in mammals. Tissue distribution of the TAP family (TAP1, TAP2, TAPL) in rat was investigated using the semi quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). In young male rat, greater amounts of TAPL mRNA were detected in the brain and testis than in the thymus and intestine. On the other hand, both TAP1 and TAP2 mRNAs had higher expression in the thymus. Furthermore, the expression level of TAP1 in the intestine and that of TAP2 in the brain and testis were also high. Analysis of rat TAPL cDNAs demonstrated that the carboxyl terminal sequence of the ATP-binding region was heterogeneous. At least four different isoforms (C-I, -II, -III, -IV) could be produced by alternative splicing of mRNA, as was confirmed by a genomic data search. Both C-III and C-IV types had shorter carboxyl-terminal sequences, and the C-III had the shortest sequence. The functional heterogeneity of the carboxyl-terminal splicing variants of TAPL is discussed.
Susceptibility to oxidative stress by X-ray irradiation was examined in splenic cells of BDF1 mouse and fetal human lung fibroblasts, TIG-7. Survival rates of splenic cells irradiated with X-rays were lower than those of TIG-7 cells irradiated similarly. The content of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) immediately after X-ray irradiation in the DNA of splenic cells increased until 2 Gy irradiation, but remained constant above 2 Gy. The 8-oxodG contents rose in proportion to the dose of X-rays in TIG-7 cells. Although the survival rate of splenic cells exposed to 1 Gy irradiation decreased with time, the survival rate of TIG-7 cells remained unchanged. The 8-oxodG content in splenic cells irradiated with X-rays did not decrease even 48 h after irradiation, while that in TIG-7 cells decreased with time, and recovered to the pre-irradiation level after 48 h. A DNA ladder was observed in splenic cells 2 h after X-ray irradiation, but the ladder was not found in fibroblasts. Furthermore, caspase-3 activity increased after X-ray irradiation of splenic cells. These results indicate that splenic cells are sensitive to oxidative stress induced by X-ray irradiation and that splenic cells damaged by even low doses of X-rays are removed through apoptosis rather than by a repair pathway.
The physiological correlation between casein kinase I (CK-I) and an isoform η of protein kinase C (C-kinase η) was investigated in vitro, since it has been reported that (i) cholesterol-3-sulfate (CH-3S) effectively activates C-kinase η rather than the other isoforms (C-kinase ε and C-kinase δ) in vitro; and (ii) CK-I efficiently phosphorylates CH-3S-binding proteins, such as high mobility group protein 1 (HMG1), in the presence of CH-3S in vitro. We found that (i) CK-I phosphorylated Thr in preference to Ser on recombinant human C-kinase isoform η (rhC-kinase η) in the presence of CH-3S; (ii) this phosphorylation was selectively inhibited by CK-I-7 (a CK-I inhibitor); and (iii) the activity (phosphorylation of protamine sulfate) of rhC-kinase η was approx. 3.2-fold stimulated by its full phosphorylation by CK-I in the presence of 3 μM CH-3S. These results suggest that CK-I is a protein kinase responsible for the activation of rhC-kinase η in the presence of CH-3S in vitro.
Pyroglutamyl aminopeptidase I (PAP-I) is known for specifically removing the L-pyroglutamate (L-pGlu) residue from the amino terminus of L-pGlu proteins and peptides. In general, substrate recognition of PAP-I as to L-pGlu moiety is tightly regulated. However, we recently identified PAP-I as a metabolic enzyme of an organic nitrate compound, RS-7897, which contains L-2-oxothiazolidine-4-carboxylic acid (L-OTCA). L-OTCA is a latent sulfhydryl group, which has moiety structurally related to L-pGlu. In this study, we investigated the substrate specificity of PAP-I toward modified L-pGlu-containing substrates using recombinant rat, mouse and human PAP-Is. PAP-I was tolerant of replacement of a carbon atom at the 4-position of the L-pGlu moiety by a sulfur atom (L-OTCA), an oxygen atom (L-2-oxooxazolidine-4-carboxylic acid, L-OOCA) and an NH group (L-2-oxoimidazolidine-4-carboxylic acid, L-OICA). The Km values for rat PAP-I in hydrolyzing L-pGlu–L-Ala, L-OTCA–L-Ala, L-OOCA–L-Ala and L-OICA–L-Ala were 0.057, 0.43, 0.71 and 0.42 mM, respectively. Similar results were observed in mouse and human PAP-Is as well. Moreover, the hydrolysis of RS-7897 in rat and mouse liver cytosols were both completely inhibited by an antibody against rat PAP-I, strongly suggesting that PAP-I is solely involved in the hydrolysis of L-OTCA-containing compounds in rat and mouse liver cytosols.
The herbal formulation Bouum-Myunyuk-Dan (BMD) has long been used for various diseases. It has been shown to have antimicrobial and anti viral activity clinically. However, it is still unclear how BMD exerts these effects in experimental models. In this study, we investigated the effect of BMD on the production of cytokines in a human T cell line, MOLT-4 cells, and in mouse peritoneal macrophages. As a result, BMD significantly increased the viability and proliferation of splenocytes (p<0.05) and also significantly increased interleukin (IL)-2 and IL-4 production compared with media control (about 2.7-fold for IL-2 and 6.7-fold for IL-4, p<0.05) after 24 h. BMD increased the interferon (IFN)-γ production by 3.7-fold but there were no significant differences compared with controls. Maximal effective concentrations of BMD were 1 mg/ml for IL-2 and IL-4 and 0.1 mg/ml for IFN-γ. In addition, BMD (0.01 mg/ml) increased the production of tumor necrosis factor (TNF)-α and IL-12 in mouse peritoneal macrophages (by 2.7-fold for TNF-α and 42.5-fold for IL-12, p<0.05). In conclusion, these data indicate that BMD may have an immune-enhancing effect through the production of various cytokines.
Plant medications have been applied to treat pains from various types of arthritis in Korea. Rheumatoid arthritis (RA) is well known to be a chronic autoimmune/inflammatory disease that leads to progressive joint damage and cartilage destruction. Accumulation and activation of mast cells have been demonstrated in rheumatoid synovial tissue. Because infiltrated mast cells and their mediators may contribute to the initiation and progression of the inflammatory process and matrix degradation of RA, we tested the inhibitory effects of ‘Cool-Cool’ (CC, Cool-X-A), an Oriental medication, on the production and migration of major inflammatory cytokines in mast cells. CC was treated in vitro before activation of human mast cell line (HMC-1) with phorbol 12-myristate 13-acetate, and the cytotoxicity of CC was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide assay. CC had no cytotoxic effects on HMC-1 cell viability. The inhibitory effects on cytokine production were monitored by enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction (RT-PCR). CC inhibited not only the secretion but also the expression of TNF-α and IL-8 in HMC-1 cells. CC also suppressed migration of mast cells induced by stem cell factor. These findings may help in understanding the mechanism of action of this herbal medication, leading to the control of mast cells in inflammatory conditions like RA.
The antioxidant properties of Choto-san and its related constituents such as Chotoko and Choto-san without Chotoko, and phenolic compounds contained in Chotoko such as epicatechin, caffeic, acid and quercetin were evaluated. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay, the scavenging activity of Chotoko (IC50 14.3 μg/ml) was found to be higher than that of Choto-san (IC50 206.2 μg/ml) and Choto-san without Chotoko (IC50 244.3 μg/ml). Epicatechin (IC50 10.4 μM), caffeic acid (IC50 13.8 μM), and quercetin (IC50 7.1 μM) also revealed scavenging activity against DPPH radicals. Choto-san (IC50 67.7 μg/ml) exhibited stronger inhibitory activity against superoxide anion formation than Choto-san without Chotoko (IC50 92.4 μg/ml) but weaker activity than Chotoko (IC50 18.3 μg/ml). The generation of superoxide anion was also inhibited by epicatechin (IC50 175.2 μM), caffeic acid (IC50 141.7 μM), and quercetin (IC50 18.7 μM). In a hydroxyl radical-scavenging experiment, Choto-san (IC50 2.4 mg/ml), Chotoko (IC50 2.2 mg/ml), Choto-san without Chotoko (IC50 2.8 mg/ml), epicatechin (IC50 3.9 mM), caffeic acid (IC50 3.6 mM), and quercetin (IC50 1.9 mM) exhibited activity. In NG108-15 cells, when added simultaneously with H2O2 (500 μM), Choto-san (250 μg/ml), Chotoko (250 μg/ml), Choto-san without Chotoko (500 μg/ml), epicatechin (200 μM), caffeic acid (200 μM), and quercetin (200 μM) effectively protected cells from oxidative damage. In conclusion, the present results provide evidence that Choto-san acts as an antioxidant and cytoprotective agent against oxidative damage, which is due at least partly to the phenolic compounds contained in Chotoko.
In order to evaluate the improvement in the treatment of chronic arthritis, we investigated chondroitin sulfate depolymerization product (low molecular weight chondroitin sulfate, LMWCS) and intact chondroitin sulfate (CS) in vitro and in vivo. LMWCS was prepared by a chemical depolymerization process induced by hydrogen peroxide in the presence of copper salts. LMWCS (300 mg/kg) and CS (1200 mg/kg) were orally administered to DBA/1J mice once daily for 14 d prior to initial immunization with type II collagen. Their elastase activities and the production of cytokines in sera were examined on type II collagen-induced arthritis in DBA/1J mice. We also compared the paracellular transport of LMWCS and CS across Caco-2 cell monolayers and examined the inhibitory effects on elastase activities. LMWCS inhibited elastase activity slightly, but CS did not show inhibition. Hind paw edema was significantly decreased by LMWCS treatment. Levels of anti-type II collagen antibody and tumor necrosis factor-alpha (TNF-α) in sera were also reduced by LMWCS treatment but not in case of CS, although no significant difference was observed between LMWCS and CS on interleukin-6 (IL-6) induction. The LMWCS preparation showed preventive effects on the type II collagen-induced arthritis in DBA/1J mice and better permeability through Caco-2 cells.
The effect of sodium diclofenac on serum and tissue amoxicillin concentration as well as their effect against staphylococcal infection was observed. Four polyurethane sponges were placed in the back of thirty rats. After 14 d, two granulomatous tissues received 0.5 ml of 108 cfu/ml (Staphylococcus aureus). Two days later, the rats were divided into five groups: group 1 received amoxicillin 50 mg/kg/p.o., group 2 received amoxicillin 25 mg/kg/p.o., group 3 received sodium diclofenac 2.5 mg/kg/i.m. and amoxicillin 50 mg/kg/p.o., group 4 received sodium diclofenac 2.5 mg/kg/i.m., and group 5 (control group) received NaCl 1 ml/p.o. After six hours of drug administration, blood serum (10 μl) and noninfected granulomatous tissues were placed on Mueller–Hinton agar inoculated with 108 cfu/ml (S. aureus). Infected tissues were dispersed in a sonic system and were spread (10 μl) on salt mannitol agar. Microorganisms were counted and the inhibition zones were measured after 18 h of incubation at 37 °C. Amoxicillin tissue concentration was 6.27 μg/g for group 1, 2.18 μg/g for group 2, and 0.72 μg/g for group 3. The serum concentrations were 11.56 μg/ml for group 1, 5.36 μg/ml for group 2, and 1.34 μg/ml for group 3. No differences were observed among group 1, 2, and 3 regarding staphylococci counts (Kruskall–Wallis test p>0.05). Group 4 reduced (p<0.05) staphylococci counts comparing to group 5. It was concluded that sodium diclofenac reduced serum and tissue amoxicillin concentration and, even in large doses, amoxicillin was not effective in eradicating the staphylococcal infection after 6 h of administration.
Herbkines has been used for the purpose of development of physical strength. In the present study, we investigated the effect of Herbkines on performance of the forced swimming test (FST) and on blood biochemical parameters related to fatigue: blood urea nitrogen (BUN), creatine kinase (CK), lactic dehydrogenase (LDH), glucose (Glc), and total protein (TP). Herbkines were orally administered to mice, 10 ml/kg, continuously once per day for 2 weeks using a feeding atraumatic needle. After 2 d, on FST, the immobility time was decreased in the Herbkines-fed group (178±8.2 s) in comparison with the control group (189±22 s); however, the statistical difference was very weak (p=0.596). After 2 weeks, the immobility time was significantly decreased in the Herbkines-fed group (196±4.5 s) in comparison with the control group (221±6.2 s). In addition, the content of BUN in the blood serum was significantly decreased. However, the levels of CK, LDH, Glc, and TP did not show a significant change. The results predict a potential benefit of Herbkines as an anti-fatigue treatment and for improving physical stamina.
Flavonoids and monophenolic compounds have been well described in recent years as antioxidants and scavengers of reactive oxygen and nitrogen species. In the present study, we aimed to characterize the effects of long-term administration of ferulic acid on the centrally administered β-amyloid peptide (Aβ)1—42-induced activation of microglial cells in mice. Aβ1—42 increased the immunoreactivity of OX-42, a microglial marker, and interferon-γ in the hippocampus at 8 h after the intracerebroventricular injection. The effects were suppressed by long-term (4-week) pretreatment with ferulic acid. This inhibition of microglial cell activation may underlie the beneficial effects of long-term administration of ferulic acid on Aβ1—42-induced toxicity in vivo.
The modulatory effects of behavioral stress on [3H]flunitrazepam, an agonist for the central-type benzodiazepine receptor binding to the GABAA-benzodiazepine receptor complex, in borderline hypertensive rats (BHR) were examined. In repeatedly immobilized (for 2 weeks, for 2 h/d) BHR, enhancement of [3H]flunitrazepam binding to the receptor was observed to be potentiated. The percent enhancement of [3H]flunitrazepam binding in BHR was higher than that in normotensive control Wistar-Kyoto rats. Pregnanolone, a neuroactive steroid that has been reported to be a putative endogenous modulator in the stress response, concentration dependently enhanced [3H]flunitrazepam binding to the receptor. Enhancement of [3H]flunitrazepam binding was observed to be potentiated by the same immobilized stress, and the EC50 values of pregnanolone in BHR was significantly lower than those in controls and Emax values were higher. From the above results, it can be concluded that neural modulation to behavioral stress, especially in GABAergic neurotransmission, is exaggerated in BHR. We propose strain-specific differences of stress reactivity as an important pathogenetic factor in psychosomatic disorders including stress-induced hypertension. This is supported by reports showing exaggerated cardiovascular and symathoadrenal responses to stress in BHR.
The antidiabetic activity of aqueous, ethanolic and hexanic extracts of Bauhinia forficata was investigated in a model of alloxan-induced diabetes in rats. The biochemical parameters studied were: plasma glucose, serum triglycerides, cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL). Extracts were administered daily for 7 d at doses of 200 and 400 mg/kg, p.o., 48 h after alloxan injection (60 mg/kg, i.v.). The alloxan-diabetic rats showed significant reductions in plasma glucose, triglycerides, total cholesterol and HDL-cholesterol after treatment with the extracts and glibenclamide (used as standard) as compared to the diabetic controls. Levels of LDL were not altered. In conclusion, our results showed that the plant extracts when administered by gavage may reduce glucose, triglycerides, total cholesterol and HDL-cholesterol levels. These results suggest the validity of the clinical use of B. forficata in the treatment of diabetes mellitus type II.
The drug–drug interactions between antiarrhythmic drugs were studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. Procainamide or flecainide with and without propranolol was injected into the air sac of a fertilized egg. Electrocardiograms (ECGs) were recorded 0 to 60 min after the injection. After each drug injection alone, the heart rate was not different compared with the control. However, the heart rate was significantly decreased by combinations of procainamide and propranolol or flecainide and propranolol. In addition, arrhythmia was produced in combination with propranolol. These findings indicate that the drug–drug interactions between antiarrhythmic drugs have a marked influence on the heart rate in chick embryos.
The effects of terfenadine, an antiallergic drug also known for its QT-prolonging and arrhythmogenic activities, on the action potential of isolated myocardial tissue preparations from rabbits were examined with microelectrode techniques. In the Purkinje fibers and atrium, terfenadine concentration dependently decreased the maximum rate of rise (+V̇max) without affecting other action potential parameters. In the ventricle, terfenadine had little effect on action potential configuration. In the sinoatrial node, terfenadine 20 μM prolonged cycle length mainly through inhibition of +V̇max. Terfenadine 1 μM completely inhibited the human ether a go-go-related gene (HERG) channel current expressed in HEK293 cells in the same experimental solution as in microelectrode experiments. The lack of terfenadine effect on the action potential duration suggests that there are drugs for which the HERG channel inhibitory action underlying in vivo QT prolongation cannot be evaluated based on their action potential-prolonging activity in isolated myocardial tissue preparations.
The effects of cytochrome P450 (P450, CYP) ligands and permeabilization of microsomes on 3-hydroxybenzo(a)pyrene [3-OH-B(a)P] glucuronidation mediated by rat hepatic microsomes were studied. While the UDP-glucuronosyltransferase (UGT) activity with non-permeabilized microsomes from 3-methylcholanthrene (MC)-treated rats was markedly reduced by α-naphthoflavone (NF), this inhibitor had hardly any effect when permeabilized microsomes were used in which the inhibitor was expected to have easy access to UGT. Kinetic analysis indicated that the inhibitory effect of α-NF is competitive. These results suggest that a UGT isoform(s) involved in 3-OH-B(a)P glucuronidation is interfered by a CYP1A inhibitor via a mechanism dependent on the intact nature of microsomal membranes in MC-treated rats. It is likely that P450 functions as a substrate transporter for some isoforms of UGT via possible interactions between UGT and P450.
The fundamental role that receptor tyrosine kinases play in cancer and other proliferative diseases has provided the impetus for an extensive effort on the part of both academic and pharmaceutical laboratories to develop highly specific inhibitors. In this study, inhibitory activity of previously synthesized arylacetic and arylcarboxylic acid derivatives were examined against substrate of tyrosine kinase. It can be assumed that the activity of compounds becomes higher when the –CH2 linkage exist between aromatic ring and the amide group of the side chain. In addition, when the R1 and R2 substitutents are methyl group in both series, the higher activity observed. The data obtained from docking study (DOCK4.0) indicated that compounds 2, 4, 7, 8, 11 render satisfactory interaction with the active site of enzyme, Lys295 of p60c-Src tyrosine kinase. Comparison of this interaction and the evaluation of biological data showed that compound 4 is the most active among the entire derivatives.
For immunization, saikosaponin a (SSa) was conjugated with bovine serum albumin (BSA). The hapten number in an antigen conjugate was determined to be eleven by matrix-assisted laser adsorption/ionization time-of-flight mass spectrometry (MALDI-TOF Mass). Hybridomas secreting monoclonal antibodies (MAb) against SSa were produced by fusing splenocytes immunized with SSa-BSA conjugate and a hypoxanthine-aminopterin-thymidine-sensitive (HAT) mouse myeloma cell line, P3-X63-Ag8-653. A high specific MAb against SSa was selected from hybridomas using enzyme-linked immunosorbent assay (ELISA) analysis. Weak cross-reactivities occurred with saikosaponin c, b2 and d, which are stereochemical and/or functional isomers of SSa, but no cross-reactivities were observed with other related steroidal glycosides. The full range of the assay extends 26 ng/ml to 1.5 μg/ml of SSa. Good correlation of SSa concentrations in a crude extract of Bupleuri radix between ELISA and HPLC methods was obtained after hydrolysis of acyl saikosaponins by treatment with a mild alkaline solution. The newly established ELISA has been applied for the quantitative assay of SSa in the Bupleuri radix and the Kampo medicines (TCM) prescribed with Bupleuri radix.
Naringenin, a phytoalexin found in grapefruits and tomatoes, has been reported to exhibit a wide range of pharmacological properties. In this study, we investigated the protective effect of naringenin on hepatic injury induced by dimethylnitrosamine (DMN) in rats. Oral administration of naringenin (20 and 50 mg/kg daily for 4 weeks) remarkably prevented the DMN-induced loss in body and liver weights and inhibited the elevation of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and bilirubin levels. Naringenin also restored serum albumin and total protein levels, and reduced the hepatic level of malondialdehyde. Furthermore, DMN-induced collagen accumulation, as estimated by histological analysis of liver tissue stained with Sirius red, was reduced in the naringenin-treated rats. A reduction in hepatic stellate cell activation, as assessed by α-smooth muscle actin staining, was associated with naringenin treatment. In conclusion, these results demonstrate that naringenin exhibited in vivo hepatoprotective and anti-fibrogenic effects against DMN-induced liver injury. It suggests that naringenin may be useful in preventing the development of hepatic fibrosis.
To investigate the effectiveness of benzyl β-D-glucopyranoside (BG) and chlorogenic acid (CA), the constituents of the fruit of Prunus mume, for relieving tension in experimental menopausal model rats (M-rats) caused by ether stress, the effects of BG and CA on adrenocorticotropic hormone (ACTH) and catecholamine (adrenaline, noradrenaline, and dopamine) levels were examined in the plasma of M-rats. Caffeic acid, quinic acid, and rosmarinic acid, which are compounds structurally related to CA, were also examined. BG obviously recovered catecholamine levels decreased by ether stress and increased dopamine to high levels. On the other hand, CA significantly decreased the ACTH level increased by ether stress and showed the greatest effect of all compounds. These results suggest that BG and CA may contribute to relieving the tension in M-rats caused by ether stress.
A pancreatic lipase inhibitor, 5-hydroxy-7-(4′-hydroxy-3′-methoxyphenyl)-1-phenyl-3-heptanone (HPH), from the rhizome of Alpinia officinarum (AO) was isolated and its antihyperlipidemic activity was measured. HPH inhibited a pancreatic lipase with an IC50 value of 1.5 mg/ml (triolein as a substrate). HPH significantly lowered the serum TG level in corn oil feeding-induced triglyceridemic mice, and reduced serum triglyceride (TG) and cholesterol in Triton WR-1339-induced hyperlipidemic mice. However, HPH did not show hypolipidemic activity in high cholesterol diet-induced hyperlipidemic mice. Based on these findings, we propose that PL inhibitors may be effective as hypolipidemic agents.
The constituents of the leaves of Garcinia intermedia and heartwood of Calophyllum brasiliense were investigated based on their trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent of Chagas' disease. As the active components, the polyisoprenylated benzophenone derivative guttiferone A and the xanthone 8-desoxygartanin were isolated along with the biflavonoids podocarpusflavone A and amentoflavone, and friedelin from the former. Three xanthones, jacareubin, 6-deoxyjacareubin, and 1,3,5,6-tetrahydroxy-2-(3-methyl-2-butenyl)xanthone from the latter showed activity. The trypanocidal activity of these compounds against trypomastigotes, an infectious form of T. cruzi, was examined as well as gossypol, berberine chloride, and harmine for comparison.
The aim of this study was to investigate whether the concomitant administration of the substrates or inhibitors of PEPT1, OCTN1, OCTN2, and P-glycoprotein affects the intestinal absorption of sulpiride in rats. The absorption of sulpiride from rat intestine was decreased by the substrates or inhibitors of PEPT1, OCTN1, and OCTN2. On the other hand, the absorption was increased by the substrates of P-glycoprotein. The effects of these concomitantly administered drugs on the pharmacokinetic behavior of sulpiride after oral administration in rats were investigated. Peak concentration (Cmax) and area under the plasma concentration–time curve (AUC0—8 h) of sulpiride were decreased by the concomitant administration of the substrates or inhibitors of PEPT1, OCTN1, and OCTN2. However, the same parameters were significantly increased by the concomitant administration of the substrates of P-glycoprotein. The present results suggest the possibility of drug–drug interaction during the absorption process in the small intestine due to the coadministration of sulpiride and these agents. These findings provide important information for preventing adverse effects and for ensuring the effectiveness of sulpiride and concomitantly administered drugs.
In this study, the effects of combination therapy consisting of X-ray irradiation and Z-100 on the survival time of C57BL/6 mice inoculated with B16F10 melanoma were investigated. Survival time was significantly prolonged in B16F10 melanoma-bearing mice treated with the X-ray irradiation (5 Gy) and Z-100 (10 mg/kg s.c.) combination therapy compared with mice irradiated with X-rays alone. The weight of primary tumors and number of metastatic colonies were also significantly suppressed by the combination therapy compared with that in the X-ray irradiation group. These results indicated that Z-100 could enhance the anti-tumor effects of radiotherapy against B16F10 melanoma. On the other hand, the survival time of CD4 knockout mice bearing the same tumors was not prolonged by the combination therapy compared with mice irradiated with X-rays alone, suggesting that CD4+ cells are partly involved in augmentation of the anti-tumor effect of radiotherapy by Z-100. In addition, type 1 cytokine (IL-2, IFN-γ) production was significantly increased and type 2 cytokine (IL-4, IL-10) production was significantly suppressed in the tumor-bearing mice treated with the combination therapy compared with the X-ray irradiation group. Moreover, interleukin-12 production by CD11c+ cells was also significantly increased in mice treated with the combination therapy compared with the X-ray irradiation group. These results indicate that Z-100 augmented the anti-tumor effects of X-ray irradiation. Moreover, we demonstrated that the effects of Z-100 were expressed at least in part, by the improvement of the T cell responses from type 2-dominant to type 1-dominant via up-regulation of IL-12 production.
We have developed a novel method of extracting proteins from human hair in the absence of detergent called the ‘Shindai Method’. Using the protein solution consisting of hard α-keratins and matrix proteins prepared by this method, we developed two procedures for preparing hair protein films. The protein solution was mixed with trichloroacetic acid (TCA), perchloric acid (PCA) or guanidine–HCl (GHA), and then exposed in distilled water. Light brown aggregates immediately formed (Pre-cast method). The other method is based on the same characteristics of the hair proteins to form protein aggregates. The protein was directly exposed to the solution containing TCA, PCA, GHA, HCl, H2SO4 or acetate buffer (Post-cast method). The maximum yield was greater than 70%. These protein films were water-insoluble and mainly made up of α-keratins. Scanning electron micrographs showed that the fine surface of the protein films was composed of particles, filaments, and porous structures and the constitution was dependent on the preparation procedure used. When porcine intestine alkaline phosphatase (ALP) was mixed with the hair protein solution in a Post-cast method using acetate buffer (pH 5), ALP was incorporated into the α-keratin films. The activity retained in the protein film was approximately 8% of the original level. The biochemical properties of the ALP activity in the film were similar to those of the native enzyme.
We previously found that Curcuma plants and drugs derived from Curcuma longa, C. phaeocaulis, C. zedoaria, and C. aromatica could be identified by the nucleotide differences at two sites and the existence of a 4-base indel on trnK gene. In this paper, based on species-specific nucleotide sequences, the application of a new method, single-nucleotide polymorphism (SNP) analysis was investigated to identify Curcuma plants more conveniently. First, three types of reverse primer were synthesized in different lengths, 34 mer, 26 mer, and 30 mer, to anneal the template DNAs from each species at sites immediately upstream from substitution positions 177 and 645, and at the site including the 4-base insertion from 728 to 731, respectively. After single-base extension reaction of these primers using fluorescent-labeled ddNTPs and PCR products of the trnK gene region as template, the resulting products were detected using an ABI PRISM 310 Genetic Analyzer. The electrophoretogram showed three or two peaks at different positions depending on the 27 mer, 31 mer, and 35 mer product lengths. Each peak was derived from the incorporated fluorescent-labeled ddNMPs complementary to template nucleotides at positions 645, 724, and 177, respectively. C. phaeocaulis showed three peaks of ddCMP, ddAMP, and ddAMP. The other three species showed two peaks derived from 27 mer and 35 mer products: peaks of ddCMP and ddAMP in C. longa, those of ddCMP and ddTMP in C. zedoaria, and those of ddTMP and ddAMP in C. aromatica. Thus SNP analysis to identify four Curcuma plants was newly developed.