Drug-induced gingival overgrowth is a side effect associated with 3 types of drugs: anticonvulsants (phenytoin), immunosuppressive agents (cyclosporine A), and various calcium channel blockers for cardiovascular diseases. Gingival overgrowth is characterized by the accumulation of extracellular matrix in gingival connective tissues, particularly collagenous components with various degrees of inflammation. Although the mechanisms of these disorders have not been elucidated, recent studies suggest that these disorders seem to be induced by the disruption of homeostasis of collagen synthesis and degradation in gingival connective tissue, predominantly through the inhibition of collagen phagocytosis of gingival fibroblasts. The integrins are a large family of heterodimeric transmembrane receptors for extracellular matrix molecules. α2β1 integrin serves as a specific receptor for type I collagen on fibroblasts, and α2 integrin has been shown to play a crucial role in collagen phagocytosis. Actin filaments, which are assembled from monomers and oligomers, are involved in collagen internalization after binding to integrins. Furthermore, the implication of intracellular calcium in the regulation of integrin-mediated binding activity and gelsolin activity, known as a calcium-dependent actin-severing protein, is also described. In this review, we focus on collagen metabolism in drug-induced gingival overgrowth, focusing on the regulation of collagen phagocytosis in fibroblasts.
Communication between nerves and mast cells is a prototypic demonstration of neuro-immune interaction. Numerous studies have shown that the stimulation of nerves (or addition of neurotransmitters) can evoke activation of mast cells, and that mast cell-derived mediators can influence neuronal activity. However, it is still unknown whether high affinity IgE receptors (FcεRI) themselves are involved directly in the communication between nerves and mast cells. In the present experiments, we used an in vitro co-culture approach comprising interaction between immune (bone marrow-derived mast cells, BMMCs) and nerve cells (superior cervical ganglia, SCG) to solve the above problem. We found that the intracellular calcium ion concentration ([Ca2+]i) increased much more in BMMCs after antigen (DNP7-BSA) stimulation when they were associated with SCG neurites in the co-culture system. But the [Ca2+]i in BMMCs was less increased when they were not associated with the neurites. Further, the in vitro co-culture approach of BMMCs with SCG neurites for 3 d showed the increases of FcεRI expression occurred on the plasma membranes of BMMCs which were attached to the neurites. On the contrary, N-cadherin molecules which localized on the interface between on the plasma membrane of BMMCs and SCG neurites did not increase with the co-culture for 3 d. All of these results indicated that co-culturing BMMCs with SCG neurites for 3 d promoted not only the calcium response but also the FcεRI expression in BMMCs.
The tuberculostatic drug rifampicin has been described as a scavenger of reactive species. Additionally, the recent demonstration that oral therapy with a complex of rifampicin and horseradish peroxidase (HRP) was more effective than rifampicin alone, in an animal model of experimental leprosy, suggested the importance of redox reactions involving rifampicin and their relevance to the mechanism of action. Hence, we studied the oxidation of rifampicin catalyzed by HRP, since this enzyme may represent the prototype of peroxidation-mediated reactions. We found that the antibiotic is efficiently oxidized and that rifampicin-quinone is the product, in a reaction dependent on both HRP and hydrogen peroxide. The steady-state kinetic constants Kmapp (101±23 μmol/l), Vmaxapp (0.78±0.09 μmol/l·s−1) and kcat (5.1±0.6 s−1) were measured (n=4). The reaction rate was increased by the addition of co-substrates such as tetramethylbenzidine, salicylic acid, 5-aminosalicylic acid and paracetamol. This effect was explained by invoking an electron-transfer mechanism by which these drugs acted as mediators of rifampicin oxidation. We suggested that this drug interaction might be important at the inflammatory site.
Arsenicals are known to be toxic and carcinogenic in humans. Inorganic arsenicals are enzymatically methylated to monomethylarsonic acid (MMAsV) and dimethylarsinic acid (DMAsV), which are the major pentavalent methyl arsenic metabolites. Recent reports indicate that trivalent methyl arsenicals are produced through methylation of inorganic arsenicals and participate in arsenic poisoning. Trivalent methyl arsenicals may be generated as arsenical–glutathione conjugates, such as monomethylarsonous diglutathione (MMAsIIIDG) and dimethylarsinous glutathione (DMAsIIIG), during the methylation process. It has been well known that reduced glutathione (GSH) reduces MMAsV and DMAsVin vitro, and produces MMAsIIIDG and DMAsIIIG. Some studies have shown that exogenous GSH increased cytolethality of MMAsV and DMAsVin vitro, while other studies have suggested that exogenous GSH decreased them. In this study, we examined the true effects of exogenous GSH on the cytolethality of MMAsV and DMAsV by investigating reactions between various concentrations of MMAsV or DMAsV and GSH. GSH significantly increased the cytolethality and cellular uptake of pentavalent methyl arsenicals when GSH over 25 mM was pre-incubated with mM levels of arsenicals, and this cytolethality might have been caused by arsenical–GSH conjugate generation. However, GSH at less than 25 mM did not affect the cytolethality and cellular uptake of pentavalent methyl arsenicals. These findings suggest that high concentrations of arsenicals and GSH are needed to form arsenical–GSH conjugates and to show significant cytolethality. Furthermore, we speculated that MMAsIIIDG and DMAsIIIG may separate into trivalent methyl arsenicals and glutathione, which are then transported into cells where they show significant cytolethality.
The epidermal growth factor tyrosine kinase inhibitor gefitinib is a novel, molecularly targeted agent that has been approved for the treatment of advanced non-small cell lung cancer. This paper reports a specific and sensitive enzyme-linked immunosorbent assay (ELISA) for pharmacokinetic studies of gefitinib. Anti-gefitinib antibody was obtained by immunizing rabbits with an antigen conjugated with bovine serum albumin using diazotized 4-amino-2-methoxy-1-[3-(morpholin-4-yl)propoxy]benzene. Enzyme labeling of gefitinib with β-D-galactosidase was similarly performed using a diazotized 4-amino-2-methoxy-1-[3-(morpholin-4-yl)propoxy]benzene. A simple ELISA for gefitinib was developed using the principle of direct competition between gefitinib and the enzyme marker for anti-gefitinib antibody which had been adsorbed to the plastic surface of a microtiter plate. Gefitinib concentrations in serum lower than 800 pg/ml were measurable reproducibly using the ELISA. Cross-reactivity data showed that the antibody well recognizes both the 3-morpholinopropoxy and methoxy moieties well, and thus is sufficiently specific for the structure of gefitinib. Using this assay, drug levels were easily measured in the serum of rabbits after oral administration of gefitinib at a single dose of 5 mg/kg. The specificity and sensitivity of the ELISA for gefitinib should provide a valuable new tool for use in pharmacokinetic and toxicity studies of gefitinib.
In order to investigate the effects of mutation of Ser93, a component of base recognition site (B2 site) of a base non-specific RNase from Rhizopus niveus, we prepared 10 mutant enzymes at this position, S93A, S93V, S93F, S93T, S93G, S93D, S93N, S93E, S93Q and S93R, and their enzymatic activities towards RNA and 16 dinucleoside phosphates were measured. Enzymatic activities of the mutant enzymes towards RNA were between 3.5—75% of the native enzyme. From the rates of hydrolysis of 16 dinucleoside phosphates by the mutant enzymes, we estimated the base preference of B1 and B2 base recognition sites. The results indicated that mutation of Ser93 to Phe, Thr, Glu. Gln and Arg caused the B2 site of the enzymes to more cytosine base preference and Asp and Asn substitution caused more uracil base preference. The results suggested that we are able to construct an enzyme that preferentially cleaves internucleotidic linkage at the 5′-side of cytidine or uridine. The results seem able to convert a base non-specific RNase to a base specific one.
Histone deacetylases (HDACs) are generally thought to play important roles in human disease. However, little information is available concerning the specific functions of individual HDACs. We previously reported on transgenic mice that expressed human HDAC1 and experienced steatosis and nuclear pleomorphism in their hepatic tissues. To find out if the over-expression of HDAC1 contributes to the expression of genes related to the cell cycle, apoptosis, and lipid metabolism that eventually contribute to the pathological changes in the livers of the transgenic mice, the expression profiles of the related genes in liver tissues were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. The activated human HDAC1 significantly induced the expression levels of mRNA for p53, PPAR-gamma and Bak and reduced the p21 expression level compared with the levels in control littermates. However, the protein levels of p53 and PPAR-gamma were significantly decreased. In conclusion, our results indicate that HDAC1 can regulate gene expression at the mRNA and protein levels independently and that this may be a potential cytopathic factor for hepatic tissue in transgenic mice that over-express HDAC1.
Methanolic extract of Opuntia dillenii cladodes and its pure compound α-pyrone glycoside, opuntioside-I showed potent hypotensive activity in normotensive rats. Both the extract and opuntioside-I showed comparable effect of 44—54% fall in Mean Arterial Blood Pressure (MABP) at the dose of 10 mg/kg. No mortality was observed in rats even at the doses of 1000 mg/kg/d and 900 mg/kg/d per oral of extract and opuntioside-I respectively. However, histopathology revealed adverse effects of high doses on liver and spleen of the experimental animals.
We investigated the effects of hot-water extract from the root bark of Morus alba (HEMA) on anaphylactic reactions. Using in vitro and in vivo experiments, we examined whether HEMA could inhibit compound 48/80-induced systemic anaphylactic shock and anti-chicken gamma globulin (CGG) IgE-mediated rat peritoneal mast cell activation. HEMA significantly inhibited systemic anaphylaxis induced by the compound 48/80 in mice. HEMA also significantly inhibited the passive cutaneous anaphylaxis activated by anti-CGG IgE. HEMA had no cytotoxicity on rat peritoneal mast cells (RPMC). Moreover, HEMA dose-dependently inhibited mast cell degranulation, histamine release and calcium uptake into RPMC induced by the compound 48/80 or anti-CGG IgE. When HEMA was added, the level of intracellular cAMP in RPMC showed a transient and significant increase (5-fold) compared with that of control cells. HEMA also inhibited significantly the compound 48/80-induced cAMP reduction in RPMC. These results suggested that HEMA inhibits the compound 48/80- or anti-CGG IgE-induced mast cell activation and its inhibitory effects on mast cell activations were favorably comparable to disodium cromoglycate. And HEMA is a candidate for effective therapeutic tools of allergic diseases.
Metallothionein (MT) is a small sulfydryl-rich protein that binds to and is inducible by heavy metals such as mercury, cadmium, zinc, and copper. However, little is known about the induction of MT by trivalent metals except for bismuth. In this study, we examined the induction of MT synthesis by cerium, a trivalent lanthanoid metal. Administration of cerium chloride (CeCl3) to mice resulted in accumulation of cerium and induction of MT in the liver in a dose-dependent manner. Distribution profiles of metals in the soluble fraction of the liver of CeCl3-treated mice analyzed by high performance liquid chromatography/inductively coupled argon plasma-mass spectrometry (HPLC/ICP-MS) demonstrated that the metal bound to MT-I and MT-II was zinc, but not cerium. Administration of CeCl3 caused increases in the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of serum amyloid A (SAA), an acute phase protein. Among inflammatory cytokines examined, interleukin 6 (IL-6) exhibited a marked increase in the serum at 3 h after the CeCl3 administration. In order to evaluate the involvement of IL-6 in the induction of MT by cerium, we examined MT induction by CeCl3 in IL-6 null mice. Both the induction of hepatic MT and the increases in SAA levels were markedly suppressed in IL-6 null mice. These results suggest that IL-6 plays an important role in the induction of hepatic MT by cerium.
The present study was investigated the effect of Houttuynia cordata THUNB water extract (HCWE) on mast cell-mediated anaphylactic reactions. The mast cell-mediated anaphylactic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. HCWE has been used as a traditional medicine in Korea and is known to have an antioxidant and anti-cancer activities. However, its specific effect of mast cell-mediated anaphylactic reactions is still unknown. We examined whether HCWE could inhibit compound 48/80-induced systemic anaphylaxis, IgE-mediated passive cutaneous anaphylaxis (PCA), and mast cell activation. The oral administration of HCWE inhibited compound 48/80-induced systemic anaphylaxis in mice. HCWE also inhibited the local allergic reaction, PCA, activated by anti-dinitrophenyl (DNP) IgE antibody in rats. HCWE reduced the compound 48/80-induced mast cell degranulation and colchicine-induced deformation of rat peritoneal mast cells (RPMC). Moreover, HCWE dose-dependently inhibited histamine release and calcium uptake of RPMC induced by compound 48/80 or anti-DNP IgE. HCWE increased the level of intracellular cAMP and inhibited significantly the compound 48/80-induced cAMP reduction in RPMC. These results suggest that HCWE may be beneficial in the treatment of mast cell-mediated anaphylactic responses.
A newly devised formulation for self-medication in Toyama, PanaWang, is a new herbal medicine (so called Toyama original brand formulation) developed based on traditional philosophy and scientific evidence. We here tried to examine the effect of oral administration of PanaWang on the balance of type I helper T cells (Th1) and Th2 cells. Splenic lymphocytes from normal mice were stimulated with Concanavalin A (Con A) in vitro and the secretion of Th1- and Th2-type cytokines, interferon-γ (IFN-γ) and interleukin-4 (IL-4) respectively, was investigated. Con A-induced production of IFN-γ from spleen cells, but not IL-4, was enhanced by the administration of PanaWang. Increased production of IFN-γ was also detected in splenic lymphocytes from Th2-predominant BALB/c mice after DNP-immunization, without a change in antigen-specific IgE levels in vivo. Antigen-specific proliferative responses were also increased in lymphocytes from PanaWang-treated mice. These findings raise the possibility that PanaWang has Th1-stimulating activity and induces Th1-predominant immunity.
We have previously shown using a water maze task that transient 2 vessel occlusion (T2VO) induced learning deficit in mice and that the deficit was prevented by pre-treatment of mice with chotosan, a Kampo prescription. In this study, we investigated the mechanism underlying the preventive effect of chotosan on T2VO-induced learning deficit. Chotosan administration 1 h before T2VO operation prevented learning impairment. The extract of Uncaria, a major constituent of chotosan, also had a protective effect on learning impairment in T2VO mice, whereas Uncaria-free chotosan had no beneficial effect on maze performance of T2VO mice. The ameliorative effect of chotosan was blocked by pirenzepine, a muscarinic M1 antagonist, but not by mecamylamine, a nicotinic receptor antagonist. Acetylcholine (ACh) content in the hippocampus of T2VO mice was significantly lower than that in the hippocampus of sham-operated control mice. Chotosan and Uncaria administration attenuated T2VO-induced reduction of ACh levels in the brain. These results suggest that the preventive effect of chotosan on transient ischemia-induced learning impairment is mainly attributable to the effect of Uncaria and that the ameliorative effect is mediated by stimulation of muscarinic M1 receptor.
Herbal Sambucus williamsii HANCE (SWH) is a folk medicine with a long history of safe use for treatment of bone fractures and joint diseases in China. The present study was designed to investigate if SWH extract could be used for treatment of postmenopausal osteoporosis. SWH extracts (30 or 60 mg/100 g body weight/d) were orally administrated to four-months-old ovariectomized (OVX) rats for 3 months. SWH extracts did not alter weight gain and uterus weight in OVX rats. SWH extracts significantly increased serum Ca levels (p<0.05, vs. OVX control group) as well as decreased urinary Ca excretion (p<0.01, vs. OVX control group) in OVX rats. The upregulation of serum alkaline phosphatase, serum osteocalcin as well as urinary deoxypyridinoline levels by OVX was suppressed by treatment with SWH extracts in rats (p<0.05, vs. OVX control group). SWH extract increased the stiffness of femur at both dosage (p<0.05, vs. OVX control group) and increased tibial bone mineral density at 60 mg/100 g body weight/d (p<0.05, vs. OVX control group) in OVX rats. Our results indicate that orally administrated SWH extracts can decrease urinary calcium excretion and bone turnover rate in OVX rats, resulting in positive effects on biomechanical strength of bone and bone mineral density. This study is the first to report that SWH could be considered as a potential candidate for management of postmenopausal osteoporosis. Then in vitro experiments were performed to determine the potential molecular mechanism of the anti-osteoporotic effect of SWH. Results suggested that chloroform fraction and ethyl acetate fraction of SWH can inhibit osteoclastogenesis osteoclast by modulating the expression of osteoprotegrin (OPG) and receptor activator of NF-κB ligand (RANKL) mRNA in osteoblastic UMR 106 cells. Both of them increased OPG mRNA and decreased RANKL mRNA expression, resulting in a dose-dependent increase in OPG/RANKL mRNA ratio (p<0.01, vs. vehicle-treated). Taken together, SWH treatment can effectively suppress the OVX-induced increase in bone turnover and its effects might be mediated by a decrease in osteoclastogenesis.
The effects of a liquid nutritive and tonic drug (NTD) selected from a modification of the “Kai-xin-shou-yu-shen-qi-wan” prescription, on scopolamine-induced amnesia in mice were investigated using the passive avoidance and water-maze tasks. A popular NTD in Japan that contains 17 crude (natural) drug extracts together with synthetic drugs such as taurine, caffeine, various vitamins and ethanol, and the natural drug extracts is based on a prescription of “Kampo” origin in Chinese medicine. Scopolamine (0.4 mg/kg, i.p.) reduces the step-through latency of the passive avoidance test and fear reaction behavior at 24 and 48 h after treatment. A single oral administration of the NTD (10 ml/kg) increased the step-through latency and the fear reaction behavior score in scopolamine-treated mice. Administration of the natural drug extracts found in the NTD tended to extend the step-through latency in the retention test at 48 h, but not 24 h after the initial scopolamine trial. However, administration of the synthetic drugs found in the NTD did not improve either the step-through latency or the behavioral score. The NTD and the natural drug extracts also improved the scopolamine-induced spatial memory impairment as assessed using the Morris water-maze test. In contrast, the synthetic drugs did not affect the escape latencies. Both NTD and the synthetic drugs increased the locomotor activity in scopolamine-treated mice, whereas the natural drug extracts did not. These results suggest that NTD improves scopolamine-induced amnesia, and that this action is attributable to the natural drug extracts in the NTD.
The purpose of the present study was to examine whether chitobiose and chitotriose can protect rats from CCl4-induced hepatic toxicity when given orally. We studied the effects of the 2 chitooligosaccharides given orally to rats on the acute hepatotoxicity induced by CCl4-dependent lipid peroxidation. The increase in the sum of malondialdehyde and 4-hydroxy-2-alkenals, a marker of lipid peroxidation, in both plasma and liver of CCl4-treated rats was suppressed by oral administration of chitobiose or chitotriose. The elevation in the levels of plasma aspartate transaminase and alanine transaminase activities, markers of hepatic injury, induced by CCl4 intoxication was also counteracted by oral administration of either chitooligosaccharide. The results indicate that chitobiose and chitotriose have the ability to exert a protective action against CCl4-induced acute hepatoxicity, probably by their antioxidant activity.
The overexpression of P-glycoprotein (P-gp) is associated with multidrug resistance (MDR) of tumor cells to a number of chemotherapeutic drugs. P-gp inhibitors have been shown to effectively reverse P-gp-mediated MDR in both in vitro and in vivo. Our previous studies demonstrated that E6, a novel synthetic calmodulin inhibitor, exhibited potent inhibitory effect on P-gp in rat brain microvessel endothelial cells (RBMECs). In the present study, the effect of E6 on MDR in a K562 MDR cell line (K562/DOX) highly expressing P-gp was studied and compared with that of a conventional P-gp inhibitor, verapamil (VER). E6 at concentrations of 1, 3, 10, 30 μM reduced the IC50 value of doxorubicin in K562/DOX cells from 79.19 μM to 35.18, 21.86, 6.31 and 1.97 μM, respectively. However, the IC50 value of doxorubicin in K562 sensitive subline was not significantly changed by E6. Using a DNA content analysis and an annexin V binding assay, the effects of E6 on doxorubicin-induced apoptosis were also examined. The results indicated that E6 effectively reversed the resistance to doxorubicin-induced apoptosis in K562/DOX cells. In addition, co-treatment of E6 and doxorubicin resulted in a remarkably G2/M blocking effect in K562/DOX cells. Furthermore, the treatment of K562/DOX cells with 10 μM E6 led to increased intracellular accumulation and decreased efflux of doxorubicin. Overall, the pharmacological effects of E6 on P-gp-mediated MDR is much stronger than that of positive control drug VER. These results suggested that E6 is a novel and potent MDR reversal agent and may be a potential adjunctive agent for tumor chemotherapy.
We examined the ability of partially synthesized new compounds from fangchinoline and tetrandrine to reverse P-glycoprotein (P-gp)-dependent multidrug resistance (MDR) in vitro and in vivo. All compound enhanced the in vitro cyctotoxic effect of vinblastin (VBL) at 0.1 μM as potent as 10 μM verapamil against the resistant cell line P388/ADR. The combination effect tended to be strong by substitution of bulky group, resulting 5,14-dibromotetrandrine (compound #9) showed the strongest effect. Compound #9 increased intracellular VBL accumulation in P388/ADR cells, much stronger than verapamil, as well as cytotoxic combined effect. This mechanism seems to inhibit the function of P-gp, but not the expression of P-gp. In combination with VBL, this compound also synergistically prolonged the life-span of P388/ADR-bearing mice. Bisbenzylisoquinoline alkaloids and their derivatives are possible to be good candidates as modifier of MDR in cancer chemotherapy.
The effect of the hypothyroidism induced by thiamazole on toxic interactions between propranolol and disopyramide were studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. 1.2 mg/0.2 ml/egg of thiamazole was injected into the albumen of fertilized eggs on the 9th day of incubation. The control group was given 0.2 ml/egg of physiological saline in the same manner. Propranolol at 0.1 mg/egg and disopyramide at 0.3 mg/egg were injected into the air sac of fertilized eggs on the 16th day of incubation. Electrocardiograms were recorded 0 to 60 min after the injection. After the injection of propranolol and disopyramide into the thiamazole treated eggs, the heart rate was significantly decreased compared with the thiamazole untreated eggs. These findings indicate that hypothyroidism induced by thiamazole has a marked influence on the toxic interaction between propranolol and disopyramide in chick embryos.
The aim of the present study was to investigate whether diabetes model can be made by treatment of streptozotocin (STZ) in chick embryos and this model can be used to predict the effect of drug. When STZ (0.3 mg/egg) was injected into the albumen of fertile eggs on the 14th day of incubation, level of blood glucose significantly increased than that of the control on the 17th day of incubation, and level of serum insulin significantly decreased. In addition, the enhanced level of blood glucose in STZ-treated embryos reduced by injection of human insulin. In conclusion, STZ-treated embryos may be applicable to evaluate human insulin and anti-diabetes drugs as an experimental diabetes model.
The chemical composition of the essential oil obtained from the aerial parts of Z. clinopodioides subsp. rigida (BOISS.) RECH. f. was analysed by GC and GC-MS. Thirty-one constituents accounting to 99.5% of the total oil were identified. Oxygenated monoterpenes (93.3%) were the predominant portion of the oil with pulegone (45.8%), piperitenone (17.4%), p-menth-3-en-8-ol (12.5%) and thymol (8.0%) as the main constituents. Antibacterial activity of the oil and its two main compounds and various extracts of plant were tested against seven Gram-(+) or Gram-(−) bacteria. It was found that the oil and MeOH extract (M) exhibited interesting antibacterial activity. The samples were also subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrazylhydrazyl (DPPH) assay. The free radical scavenging activity of MeOH extract (M) was superior to all other extracts (IC50=30.7 μg/ml), while the oil was less effective.
In the course of our clinical studies of Kampo medicine (traditional Japanese medicines), we observed the pharmacokinetic interactions between two herbs. When Onpito (TJ-8117, Kampo medicine) containing licorice and rhubarb was administered orally to human subjects, we observed that the AUC(0—lim) and Cmax of glycyrrhetic acid (GA) in plasma were lower than those treated with other Kampo medicines containing licorice. In this study, we demonstrate the pharmacokinetic interactions of GA derived from glycyrrhizinic acid (GL) in licorice and anthraquinones derived from rhubarb. To our knowledge, this is the first report to investigate the pharmacokinetic interactions between two herbs. When GL was orally co-administrated to rats with a non-effective dose of sennoside A having purgative activity, the AUC(0—lim) and Cmax of GA decreased. In addition, sennoside A did not affect the metabolism of GL by the intestinal bacteria in vitro. In the examination using an in situ loop of rat colon, the remaining ratio of GA rose drastically by the co-administration of sennoside A, sennidin A and rhein. Observed inhibition activity of these anthraquinones on GA absorption depended on the concentration of the components added. The maximum inhibition ratio was approximately 75% by rhein, 60% by sennoside A and 25% by sennidin A. We conclude that the decrease of the pharmacokinetic parameters of GA in human plasma observed in the clinical study of TJ-8117 is attributable to an interactive action of absorption from the intestinal tract by anthraquinones contained in or derived from rhubarb.
To understand the relationship between the metabolism and biological activity of ginsenoside Re, a main protopanaxatriol saponin in Panax ginseng C. A. MEYER, its metabolic pathway and estrogenic effect by human intestinal microflora were investigated. All human fecal specimens metabolized ginsenoside Re, mainly to ginsenoside Rh1 and ginsenoside F1, via ginsenoside Rg1, with protopanaxadiol as a minor component. Almost all isolated ginsenoside Re-metabolizing intestinal bacteria (GHIB) also metabolized ginsenoside Re, mainly to ginsenosides Rh1 and F1, via ginsenoside Rg1. α-Rhamnosidase and β-glucosidase, partially purified from the most potent GHIB, Bacteroides JY-6, hydrolyzed ginsenoside Re and ginsenoside Rg1, respectively; however, they did not hydrolyze ginsenosides Rh1 and F1. These findings suggest that the ginsenosides Rh1 and/or F1 may not be suitable substrates of intestinal bacteria, particularly Bacteroides JY-6. The estrogenic effects of ginsenoside Re and its main metabolites, ginsenosides Rg1 and Rh1, were also investigated. Ginsenoside Rh1 showed the greatest estrogenic effect in human breast carcinoma MCF-7 cells. Based on these findings, the estrogenic effect of ginsenoside Re may be expressed by intestinal microflora.
Brazilian propolis was extracted with water or various concentrations of ethanol and were administered orally to spontaneously hypertensive rats (SHR) and the effects on blood pressure and heart rate were determined. Single oral administration of 100 mg/kg of propolis extracts decreased the blood pressure in SHR. Significant decrease in blood pressure was observed with propolis extracted with 25 and 70% ethanol. SHR were given orally 5 mg/kg of propolis extracted with 25 or 70% ethanol, twice a day for 28 d and the effects on blood pressure and heart rate were compared with control rats. While the blood pressure in the control group increased day by day, the increase was slower in rats treated with 25 and 70% ethanol extracts of propolis. The hypotensive activity of propolis extracted with 25% ethanol was more significant compared with control group than with 70% ethanol. Di- and tri-caffeoylquinic acids (CQAs) were found to be characteristic components of propolis extracted with 25% ethanol. A single oral administration of 3,4-diCQA, 3,5-diCQA, and 3,4,5-triCQA each at a dose of 10 mg/kg were conducted in SHR. These three components were found to have antihypertensive effects and therefore contribute to the antihypertensive effects of propolis extract. These results suggest that 25% ethanol extract of propolis is useful for prevention and treatment of hypertension.
The root of Morinda officinalis (Rubiaceae) is used to treat rheumatoid arthritis and impotence in the traditional Oriental medicine. To identify the antinociceptive anti-inflammatory components of this crude drug, we adopted an activity-directed fractionation approach. The active fraction of the BuOH extract of M. officinalis root was subjected to silica gel and ODS column chromatography to yield two diterpenes, compounds 1 and 2 and these were identified as monotropein and deacetylasperulosidic acid, respectively. The iridoid glycoside, monotropein, was tested for its anti-inflammatory antinociceptive effects using hot plate- and writhing antinociceptive assays and by using carrageenan-induced anti-inflammatory assays in mice and rats. Pretreatment with monotropein (at 20, 30 mg/kg/d, p.o.) significantly reduced stretching episodes and prolonged action time in mice. It also significantly reduced acute paw edema by carrageenan in rats. These results indicate that monotropein contributes to the antinociceptive and anti-inflammatory action of Morinda officinalis root.
In the present study, the effects of several triterpenes isolated from the leaves of Acanthopanax chiisanensis (Araliaceae), namely, chiisanoside, isochiisanoside, 22-hydroxychiisanoside and chiisanogenin (the aglycone of chiisanoside) were evaluated on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by the RAW 264.7 macrophage cell line. Of the triterpenes tested, chiisanoside was found to most potently inhibit NO and PGE2 production. In addition, chiisanoside significantly reduced the release of inflammatory cytokines like TNF-α and IL-1β. Consistent with these observations, the protein and mRNA expression levels of iNOS and COX-2 enzyme were found to be inhibited by chiisanoside in a concentration-dependent manner. Furthermore, chiisanoside inhibited the nuclear factor-κB (NF-κB) activation induced by LPS and this was associated with a reduction in p65 protein in the nucleus and with the phosphorylations of ERK1/2 and JNK MAP kinases. Taken together, our data indicate that the anti-inflammatory properties of chiisanoside might be the result from the inhibition of iNOS, COX-2, TNF-α and IL-1β expression through the down-regulation of NF-κB binding activity.
Four triterpenoids 1—4 isolated from the fruit body of Torametes orientaris were found to inhibit lipid droplet accumulation in macrophages. From the biochemical analysis, compounds 2 and 3 inhibited selectively cholesteryl ester synthesis in macrophages, while compounds 1 and 4 showed inhibition of both cholesteryl ester and triacylglycerol syntheses.
To determine the antinociceptive mechanism of incarvillateine (INCA), the opiate antagonists nor-binaltorphimine (nor-BNI), β-funaltrexamine (β-FNA) and naltrindole (NTI) were pretreated prior to its injection in a formalin test. The antinociceptive effect of INCA was antagonized by nor-BNI (κ-receptor antagonist) and β-FNA (μ-receptor antagonist), while NTI (δ-receptor antagonist) did not influence its effect. Furthermore, the antinociceptive effect of INCA was blocked by theophylline (THEO), an adenosine-receptor antagonist. These results suggested that the antinociceptive effect arose from the activation of μ-, κ-receptors and adenosine-receptor.
To evaluate the hepatoprotective effect of Red Ginseng (RG), we isolated a main constituent 20(S)-ginsenoside Rg3 from RG, and its metabolite 20(S)-ginsenoside Rh2 by human intestinal microflora, and investigated their hepatoprotective activities in tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity of HepG2 cells and mice. When HepG2 cells were treated with t-BHP, its cytotoxicity was significantly increased. 20(S)-Ginsenoside Rh2 potently protected its cytotoxicity, but 20(S)-ginsenoside Rg3 weakly protected it. Intraperitoneally and orally administered 20(S)-ginsenoside Rh2 to t-BHP-injured mice significantly inhibited the increase of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Orally administered 20(S)-ginsenoside Rg3 also showed the inhibition against the increase of ALT and AST of t-BHP-induced mice. However, intraperitoneally administered 20(S)-ginsenoside Rg3 could not inhibit the elevation of serum ALT and AST activities. These results suggest that 20(S)-ginsenoside Rg3 a main component of RG may be a prodrug for hepatotoxicity.
Sixteen triterpene acids, viz., five of the oleanane-type (1—5), nine of the ursane-type (6—14), and two of the lupane-type (15, 16), were isolated and identified from the ethyl acetate-soluble fraction of the methanol extract of the leaves of loquat, Eriobotrya japonica LINDL. (Rosaceae). Twelve of these compounds, 1—4, 6, 8—13, and 15, were evaluated for their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 μg/ear) in mice. All the compounds tested showed a marked anti-inflammatory effect, with a 50% inhibitory dose (ID50) of 0.03—0.43 mg per ear. In addition, an evaluation against the Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA for all of the compounds, 12 and 13 showed potent inhibitory effects on EBV-EA induction. Furthermore, euscaphic acid (12) exhibited marked antitumor-promoting activity in an in vivo two-stage carcinogenesis test of mouse tumor by using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.
The extract of licorice (Glycyrrhiza uralensis FISHER, Leguminosae) showed CYP3A4 inhibitory activity with the IC50 value of 0.022 mg/ml. Bioassay-guided purification afforded nine compounds, 3-(p-hydroxyphenyl)propionic acid (1), isoliquiritigenin (2), (3R)-vestitol (3), licopyranocoumarin (4), 4-hydroxyguaiacol apioglucoside (5), liquiritin (6), liquiritigenin 7,4′-diglucoside (7), liquiritin apioside (8), and glucoliquiritin apioside (9). Among these compounds, 3, 7, and 5 showed potent CYP3A4 inhibitory activities with IC50 values of 3.6, 17, and 20 μM, respectively. Glycyrrhizin (10), a main constituent of licorice, however, was inactive for CYP3A4 inhibition.
Long term and repeated exposure of ultraviolet light on the skin often induces chronic skin diseases such as skin cancer as well as photoaging, and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinase's (MMPs) activities. The methylene chloride soluble fraction of methanol extract from the stems of Styrax japonica. (Styracaceae) showed significant MMP-1 inhibition in primary human skin fibroblasts cause by ultraviolet irradiation. Four triterpenoids were isolated by column chromatography. Among them, Erythrodiol-3-acetate reduced of MMP-1 and induced of type 1 procollagen at the protein levels in a dose-dependent manner.
Many dietary constituents are chemopreventive in animal models, and experiments with cultured cells are revealing various potential mechanisms of action. Compounds classified as blocking agents can prevent, or greatly reduce, initiation of carcinogenesis, or suppressing agents can act on cell proliferation. Caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), members of the polyphenolic compounds, are present in high concentrations in medicinal plants and propolis, a natural beehive product. A water-soluble extract of propolis (WSDP) and two components of propolis, CA and CAPE were investigated for direct antitumor activity in vivo and in vitro. The local presence of CA and CAPE in the tissue caused a significant delay in tumor formation and increased life span 29.30 to 51.73%, respectively. CA and CAPE, but not WSDP, significantly suppressed human HeLa cervical carcinoma cell proliferation in vitro. Based on these results, we postulate that the antitumor activity of polyphenolic compounds includes direct cytotoxic effects on tumor cells.
To evaluate the pharmacokinetic properties and an optimum dose schedule of amiodarone in long-term oral therapy, serum concentrations of amiodarone and its metabolite, desethylamiodarone, were monitored from 345 Japanese inpatients who received amiodarone therapy for a variety of cardiac arrhythmias. Serum amiodarone and desethylamiodarone concentrations were determined by high performance liquid chromatography system. It was observed that the amiodarone and desethylamiodarone concentrations gradually increased with time. The frequency distribution in the amiodarone clearance of 245 subjects, who received fixed maintenance amiodarone therapy for at least 6 months, was nearly a unimodal one. The variation in the ratio of desetylamiodarone to amiodarone concentration in serum was very small. Although no differences in age, dose, dose duration, amiodarone or desethyamiodarone concentration or ratio were observed between men and women: however, the mean amiodarone clearance of women was significantly higer than that of men. The laboratory data were mostly within normal values and no significant relations were observed between serum amiodarone concentration and clinical laboratory data. These results suggest that the individual variation in pharmacokinetics of amiodarone is comparatively small, which might be sufficient to decide that the maintenance dose was the same one (200 mg/d) in long-term oral amiodarone therapy.
An efficient delivery system is required if antisense oligodeoxynucleotides (ODN) are to be utilized for gene therapy. We report herein on the development of a novel ODN delivery system, ODN-encapsulated nano particles (ODN-ENP) using an efficient and simple packaging method. The ODN-ENP consists of a condensed ODN particle and a lipid envelope, which can be equipped with various functional devices for the efficient delivery of ODN with a small diameter (150 nm). The encapsulation efficiency and ODN recovery of ODN-ENP were significantly higher than those of other packaging methods, such as a stabilized antisense-lipid particles method or a freeze-thaw method. Furthermore, the time required for the preparation of the ODN-ENP was shorter than the other methods. The method developed in this study is a simple and efficient packaging method for ODN with a condensed nano particle in lipid-envelope structure.
The relationship between in vivo biodistribution of 6-deoxy-6-[18F]fluoro-L-ascorbic acid (18F-DFA) and the content of tissue glutathione (GSH) was investigated in Wistar male rats. Following intravenous administration of 18F-DFA, the accumulation of radioactivity in most tissues, including the adrenal glands, liver and brain, was significantly reduced together with a decrease in the content of GSH by preloading of diethyl maleate (DEM) which depletes cellular GSH. Similar decreased uptake was also observed in the distribution of L-[1-14C]ascorbic acid (14C-AA) after DEM treatment. The possible biological mechanisms, including competition with endogenous AA and ascorbate recycling, that modulate the uptake and accumulation into tissues of 18F-DFA and 14C-AA in GSH-deficient rats are discussed.
Phytoestrogens are plant chemicals that are structurally analogous to estrogen and are known to affect estrogenic activity. Biochanin A, a naturally occurring isoflavone, has been identified and detected in various diets and plant species. We examined the effects of biochanin A on the differentiation of osteoblastic MC3T3-E1 cells and the production of local factors in osteoblasts. Biochanin A (1—50 μM) caused a significant elevation of cell growth, alkaline phosphatase (ALP) activity, collagen content, and osteocalcin secretion in osteoblastic MC3T3-E1 cells (p<0.05). The effect of biochanin A (10 μM) in increasing ALP activity and collagen content was completely prevented by the presence of 10−6 M cycloheximide and 10−6 M tamoxifen, suggesting that biochanin A's effect results from a newly synthesized protein component and might be partly involved in estrogen action. We then examined the effect of biochanin A on the H2O2-induced production of inflammatory mediators in osteoblasts. Biochanin A (1—10 μM) decreased the 0.2 mM H2O2-induced production of TNF-α, IL-6 and NO in osteoblasts. These results suggest that biochanin A may be useful as potential phytoestrogens, which play important physiological roles in the prevention of postmenopausal osteoporosis.
Renal interstitial fibrosis is the common pathway of chronic renal disease, while it causes end-stage renal failure. A lot of cytokines and biologically active substances are well recognized to be the candidates of primary mediators to induce accumulation of extracelluar matrix (ECM) in the interstitial fibrotic area. Interstitial fibroblasts are played a crucial role in the accumulation of excess ECM during renal interstitial fibrogenesis. Therefore, the targeting of therapeutic drugs and genes to interstitial renal fibroblasts is effective in suppressing the progress of interstitial renal failure. However, despite various approaches and techniques, few successful results have been reported on the in vivo targeting for interstitial fibroblasts. The objective of this study is to deliver an enhanced green fluorescent protein (EGFP) plasmid DNA, as a model plasmid DNA, into renal interstitial space by a cationized gelatin. After the plasmid DNA with or without complexation of the cationized gelatin was injected to the left kidney of mice via the ureter, unilateral ureteral obstruction (UUO) was performed for the mice injected to induce the renal interstitial fibrosis. When the EGFP plasmid DNA complexed with the cationized gelatin was injected, EGFP expression was observed in the fibroblasts in the interstitial area of renal cortex. It is concluded that the retrograde injection of EGFP plasmid DNA complexed with the cationized gelatin is available to target the interstitial renal fibroblasts which are currently considered as the cell source responsible for excessive ECM synthesis.
An implant tablet of ketoprofen (KP) was developed in order to achieve its sustained supply for approximately one week, and its release was evaluated in vitro and in vivo. Implant tablets (30 mg) containing 1 and 5 mg of ketoprofen, prepared using poly(DL-lactic acid-co-glycolic acid) copolymer (PLGA; MW 10000; lactic acid : glycolic acid=1 : 1 (mol/mol)) as a matrix, exhibited similar week-long sustained release in vitro. Plasma concentration was monitored after the implant tablet (5 mg of KP) and a KP solution (0.5 mg of KP) were administered subcutaneously to rats, and in vivo release rate was analyzed by deconvolution. The release rate from the implant tablet was faster in vivo than in vitro in the initial phase, but much lower in vivo than in vitro in the later phase. The plasma level decreased to the level less than the minimal effective concentration at 96 h after administration. However, the calculated plasma concentration given by convolution based on in vitro release rate was more than 7 times greater than the minimal effective concentration even at 96 h after administration. As the implant displayed the discrepancy between in vitro and in vivo release rates, the improvement of the in vivo release rate is required.
While histamine H4 receptor (H4R) has been implicated in immune system disturbances in different organ tissues, the presence and possible roles of H4R in synovial cells (SC) of rheumatoid arthritis (RA) patients has not previously been documented. This study conclusively evidences H4R expression in SC of RA patients by use of RT-PCR method. As RA consists mainly of immunological disturbances in SC of RA patients, this study's findings document a novel histamine action site, and opens potential new avenues to investigate mechanisms and to develop pharmacotherapeutic agents for the disease.
Cationic lipid-mediated transfer of DNA is promising in gene therapy. However, one disadvantage with this approach is the induction of an inflammatory response, which may decrease transgene expression. Recently, we found that plasmid DNA containing N6-methyladenine (N6-MeA), a bacterium-specific modified base, induced cytokine twice as efficiently as plasmid DNA without N6-MeA, when complexed with cationic lipids. Thus, plasmid DNA without N6-MeA might express a transgene more efficiently than that containing N6-MeA in vivo. To evaluate the effects of adenine methylation on transgene expression in vivo, we injected luciferase-encoding plasmid DNA, complexed with cationic lipids or a cationic polymer, intravenously into mice. When the plasmid DNA-cationic lipid complexes were injected, the luciferase expression from the methylated and unmethylated plasmids was similar, although cytokine was more efficiently elicited by the methylated DNA than the unmethylated DNA. Hydrodynamics-based injections of plasmid DNA–cationic polymer complexes did not induce cytokine, and the luciferase expression from the unmethylated plasmid was slightly lower than that from the methylated plasmid DNA. These results suggest that the presence of N6-MeA did not reduce transgene expression in vivo.
A high concentration of cisplatin induces apoptosis in many tumor cell lines. Whether cisplatin induces apoptosis even in a controlled release formulation has not been determined. We therefore studied the relationship between the dosing regimen of cisplatin and the induction of apoptosis in rat hepatoma AH-109A cells. A colorimetric assay was used to quantify cell proliferation and viability, and caspase activity was determined using an exogenous fluorogenic peptide substrate. When delivered as a single dose, cisplatin caused a dose-dependent inhibition of AH-109A growth and enhancement of caspase-3 activity. Also, DNA laddering was detected in cells that had elevated caspase-3 activity. However, caspase-3 activity was low and DNA laddering and a sub-G1 population were not detected when cells were treated with a combination of cisplatin and the caspase inhibitor Z-VAD-FMK. These results suggest that cisplatin is cytotoxic in AH-109A cells because it induces apoptosis. We next examined intermittent exposure to cisplatin to estimate the effects of continuous exposure by a controlled release formulation. Cisplatin was divided into equal parts and was added intermittently into the medium resulting in the same final concentration as the single dose. The individual additions alone were not cytotoxic, but all of the doses together had a similar cytotoxic effect as a single exposure of cisplatin. The intermittent exposure resulted caspase-3 activity even higher than a single dose. These findings indicate that cisplatin induces apoptosis in AH-109A cells when delivered continuously even at the concentration that alone have no activity.
We recently found that a heat-denatured, double-stranded DNA fragment, prepared from plasmid DNA (dsHES), and a sense single-stranded DNA fragment, prepared from single-stranded phagemid DNA (fSense), corrected an inactivated hygromycin-resistance and enhanced green fluorescence protein fusion (Hyg-EGFP) gene containing a base substitution (G:C to C:G) mutation 2-fold and more than 10-fold, respectively, more efficiently than the conventional PCR fragment (pcrHES), in the small fragment homologous replacement method. In this study, we tested the abilities of these new DNA fragments to correct Hyg-EGFP genes inactivated by one base insertion (+G) and deletion (−C) mutations. In contrast to its activity with the substitution mutation, the fSense fragment showed similar efficiencies to those of the dsHES fragment in the correction of frameshift mutations. For the correction of the insertion mutation, the efficiencies were in the order of dsHES (0.21%)≥fSense (0.18%)>pcrHES (0.08%). In the case of the correction of the deletion mutation, the efficiencies were in the order of fSense (0.27%)≥dsHES (0.19%)>pcrHES (0.12%). These results suggest that sense single- and double-stranded DNA fragments prepared from phagemid and plasmid DNAs, respectively, have the potential to correct frameshift mutations.
Total and unbound concentrations of six teicoplanin components in human plasma were determined by high-performance liquid chromatography with a coextractive cleanup technique. Unbound concentrations of teicoplanin components were estimated after ultrafiltration of plasma. For determination of each component in plasma, plasma was deproteinized with acetonitrile and the supernatant was shaken for 60 s with chloroform under acidic conditions. The recoveries of A3-1, A2-1, A2-2, A2-3, A2-4 and A2-5 were greater than 88%. The within-day and between-day coefficients of variation were 1.3—8.8% and 2.8—11.9%, respectively. The limits of detection in ultrafiltered plasma for each component were 0.82, 2.87, 4.23, 3.36, 7.33 and 4.93 nM, respectively. A good correlation was observed between the FPIA and HPLC methods when total concentrations of each teicoplanin component in patient plasma were determined. The analytical methods established in this study are suitable for determining the total and unbound concentrations of six components of teicoplanin in human plasma and for studying the pharmacokinetics of teicoplanin components in patients.
Effects of cytochrome P450 isoforms, CYP1A2, CYP2C9 and CYP3A4, on the catalytic activity of UDP-glucuronosyltransferase 2B7 (UGT2B7) expressed in COS cell microsomal membranes were investigated using morphine as a substrate. When detergent-untreated COS cell microsomes were used as the enzyme source, the activity of morphine-3-glucuronide formation by UGT2B7 was reduced by addition of purified CYP1A2 and CYP2C9 in a concentration-dependent manner. The effect of CYP1A2 was greater than that of CYP2C9. In contrast, exogenous CYP3A4 had little effect on morphine glucuronidation activity. These results suggest that CYP1A2 and CYP2C9 have ability to modify UGT2B7 function. However, the mechanism(s) underlying the modulation of UGT2B7 function by these P450s seems to differ from that by CYP3A4.